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  • what is the problem in ATM machine program

    - by Have alook
    in this prigramm when the account number is uncorrect it should display a message to write a gain but when i wrote a gain by corrrect account number always it diplay the result of first account also there is aproblem in PIN number ,the use have only three time to try if he enter wrong numbe and if enter three times wrong it should stop the program but it complete to the last part I dont know why pleas help me this is my proram import java.util.*; class assignment2_70307{ public static void main(String args[]){ Scanner m=new Scanner(System.in); int i; i=0; int [] accountNo =new int[7] ;//declear the Accont number array accountNo [0] =1111; accountNo [1] =2222; accountNo [2] =3333; accountNo [3] =4444; accountNo [4] =5555; accountNo [5] =6666; accountNo [6] =7777; int [] PINno =new int[7]; //declear the PIN number array PINno [0] =1234; PINno [1] =5678; PINno [2] =9874; PINno [3] =6523; PINno [4] =1236; PINno [5] =4569; PINno [6] =8521; String [] CusomerNm =new String[7]; //dclear the customer name CusomerNm [0] ="Ali"; CusomerNm [1] ="Ahmed"; CusomerNm [2] ="Amal"; CusomerNm [3] ="Said"; CusomerNm [4] ="Rashid"; CusomerNm [5] ="Fatema"; CusomerNm [6] ="Mariam"; double [] Balance =new double[7]; //declear the Balane array Balance [0] =100.50; Balance [1] =5123.00; Balance [2] =12.00; Balance [3] =4569.00; Balance [4] =1020.25; Balance [5] =0.00; Balance [6] =44.10; System.out.println("Wellcome to mini ATM Machine"); int accountno,pino; accountno=0; pino=0; System.out.println("Please Enter your account number: or -1 to stop" ); accountno=m.nextInt(); if (accountno==accountNo[0]) System.out.print("Customer Name: "+CusomerNm [0]+ "\n" ); else if (accountno==accountNo[1]) System.out.print("Customer Name: "+CusomerNm [1]+ "\n" ); else if (accountno==accountNo[2]) System.out.print("Customer Name: "+CusomerNm [2]+ "\n" ); else if (accountno==accountNo[3]) System.out.print("Customer Name: "+CusomerNm [3]+ "\n" ); else if (accountno==accountNo[4]) System.out.print("Customer Name: "+CusomerNm [4]+ "\n" ); else if (accountno==accountNo[5]) System.out.print("Customer Name: "+CusomerNm [5]+ "\n" ); else if (accountno==accountNo[6]) System.out.print("Customer Name: "+CusomerNm [6]+ "\n" ); // else if (accountNo[0]==-1) //break; else { System.out.println("The account dose not exist,please try again"); //accountNo[i]=m.nextInt(); accountno=m.nextInt(); if(accountNo[i]==accountno) System.out.println("Customer Name: "+CusomerNm[i] ); else System.out.println("The account dose not exist,please try again"); accountno=m.nextInt(); System.out.println("Customer Name: "+CusomerNm[i] ); } System.out.print("Enter your PIN number:"); PINno[i]=m.nextInt(); if(PINno[i]==1234) { System.out.println(PINno[i]); System.out.println("Balance:"+Balance [0]+ "Rial"); //return 0; } else if(PINno[i]==5678) { System.out.println(PINno[i]); System.out.println("Balance:"+Balance [1]+ "Rial"); // return 1; } else if(PINno[i]==9874) { System.out.println(PINno[i]); System.out.println("Balance:"+Balance [2]+ "Rial"); // return 2; } else if(PINno[i]==6523) { System.out.println(PINno[i]); System.out.println("Balance:"+Balance [3]+ "Rial"); // return 3; } else if(PINno[i]==1236) { System.out.println(PINno[i]); System.out.println("Balance:"+Balance [4]+ "Rial"); // return 4; } else if(PINno[i]==4569) { System.out.println(PINno[i]); System.out.println("Balance:"+Balance [5]+ "Rial"); // return 5; } else if(PINno[i]==8521) { System.out.println(PINno[i]); System.out.println("Balance:"+Balance [6]+ "Rial"); // return 6; } else {System.out.println("try again"); //return 7; //if its wrong u can enter PIN number three times only for( i=0;i<2;i++) { System.out.println("enter pin again"); PINno[i]=m.nextInt(); String ss; //ss = "MAnal"; // goto ss ; } } //ss = "m"; int x; x=0; System.out.println("Enter the option from the list /n 1.Deposit /n 2.Withdraw /n 3.Balance"); x=m.nextInt(); double balance,amount; balance=0; amount=0; double deposit ,Withdraw; deposit=0; Withdraw=0; if (x==1){ System.out.println("Enter the amont you want to deposit:"+amount); amount=m.nextDouble(); Balance [i]=Balance [i]+amount; System.out.println("your balance ="+Balance [i]); } else if (x==2) { System.out.println("Enter the amont to withdraw:"); amount=m.nextDouble(); System.out.print(amount); if(Withdraw<=Balance [i]) { Balance [i]=Balance [i]-amount; System.out.println("your balance ="+Balance [i]); } else { System.out.println("sorry,please enter the amont less or equal your balance"); System.out.println(Balance [i]); } } else { if(x==1) { Balance [i]=Balance [i]+deposit; System.out.println("your current balance is :" +Balance [i]); } else { Balance [i]=Balance [i]-Withdraw; System.out.println("your current balance is :"+Balance [i]); } System.out.println("Thank you"); // err() } } }

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  • Upgrading Team Foundation Server 2008 to 2010

    - by Martin Hinshelwood
    I am sure you will have seen my posts on upgrading our internal Team Foundation Server from TFS2008 to TFS2010 Beta 2, RC and RTM, but what about a fresh upgrade of TFS2008 to TFS2010 using the RTM version of TFS. One of our clients is taking the plunge with TFS2010, so I have the job of doing the upgrade. It is sometimes very useful to have a team member that starts work when most of the Sydney workers are heading home as I can do the upgrade without impacting them. The down side is that if you have any blockers then you can be pretty sure that everyone that can deal with your problem is asleep I am starting with an existing blank installation of TFS 2010, but Adam Cogan let slip that he was the one that did the install so I thought it prudent to make sure that it was OK. Verifying Team Foundation Server 2010 We need to check that TFS 2010 has been installed correctly. First, check the Admin console and have a root about for any errors. Figure: Even the SQL Setup looks good. I don’t know how Adam did it! Backing up the Team Foundation Server 2008 Databases As we are moving from one server to another (recommended method) we will be taking a backup of our TFS2008 databases and resorting them to the SQL Server for the new TFS2010 Server. Do not just detach and reattach. This will cause problems with the version of the database. If you are running a test migration you just need to create a backup of the TFS 2008 databases, but if you are doing the live migration then you should stop IIS on the TFS 2008 server before you backup the databases. This will stop any inadvertent check-ins or changes to TFS 2008. Figure: Stop IIS before you take a backup to prevent any TFS 2008 changes being written to the database. It is good to leave a little time between taking the TFS 2008 server offline and commencing the upgrade as there is always one developer who has not finished and starts screaming. This time it was John Liu that needed 10 more minutes to make his changes and check-in, so I always give it 30 minutes and see if anyone screams. John Liu [SSW] said:   are you doing something to TFS :-O MrHinsh [SSW UK][VS ALM MVP] said:   I have stopped TFS 2008 as per my emails John Liu [SSW] said:   haven't finish check in @_@   can we have it for 10mins? :) MrHinsh [SSW UK][VS ALM MVP] said:   TFS 2008 has been started John Liu [SSW] said:   I love you! -IM conversation at TFS Upgrade +25 minutes After John confirmed that he had everything done I turned IIS off again and made a cup of tea. There were no more screams so the upgrade can continue. Figure: Backup all of the databases for TFS and include the Reporting Services, just in case.   Figure: Check that all the backups have been taken Once you have your backups, you need to copy them to your new TFS2010 server and restore them. This is a good way to proceed as if we have any problems, or just plain run out of time, then you just turn the TFS 2008 server back on and all you have lost is one upgrade day, and not 10 developer days. As per the rules, you should record the number of files and the total number of areas and iterations before the upgrade so you have something to compare to: TFS2008 File count: Type Count 1 1845 2 15770 Areas & Iterations: 139 You can use this to verify that the upgrade was successful. it should however be noted that the numbers in TFS 2010 will be bigger. This is due to some of the sorting out that TFS does during the upgrade process. Restore Team Foundation Server 2008 Databases Restoring the databases is much more time consuming than just attaching them as you need to do them one at a time. But you may be taking a backup of an operational database and need to restore all your databases to a particular point in time instead of to the latest. I am doing latest unless I encounter any problems. Figure: Restore each of the databases to either a latest or specific point in time.     Figure: Restore all of the required databases Now that all of your databases are restored you now need to upgrade them to Team Foundation Server 2010. Upgrade Team Foundation Server 2008 Databases This is probably the easiest part of the process. You need to call a fire and forget command that will go off to the database specified, find the TFS 2008 databases and upgrade them to 2010. During this process all of the 6 main TFS 2008 databases are merged into the TfsVersionControl database, upgraded and then the database is renamed to TFS_[CollectionName]. The rename is only the database and not the physical files, so it is worth going back and renaming the physical file as well. This keeps everything neat and tidy. If you plan to keep the old TFS 2008 server around, for example if you are doing a test migration first, then you will need to change the TFS GUID. This GUID is unique to each TFS instance and is preserved when you upgrade. This GUID is used by the clients and they can get a little confused if there are two servers with the same one. To kick of the upgrade you need to open a command prompt and change the path to “C:\Program Files\Microsoft Team Foundation Server 2010\Tools” and run the “import” command in  “tfsconfig”. TfsConfig import /sqlinstance:<Previous TFS Data Tier>                  /collectionName:<Collection Name>                  /confirmed Imports a TFS 2005 or 2008 data tier as a new project collection. Important: This command should only be executed after adequate backups have been performed. After you import, you will need to configure portal and reporting settings via the administration console. EXAMPLES -------- TfsConfig import /sqlinstance:tfs2008sql /collectionName:imported /confirmed TfsConfig import /sqlinstance:tfs2008sql\Instance /collectionName:imported /confirmed OPTIONS: -------- sqlinstance         The sql instance of the TFS 2005 or 2008 data tier. The TFS databases at that location will be modified directly and will no longer be usable as previous version databases.  Ensure you have back-ups. collectionName      The name of the new Team Project Collection. confirmed           Confirm that you have backed-up databases before importing. This command will automatically look for the TfsIntegration database and verify that all the other required databases exist. In this case it took around 5 minutes to complete the upgrade as the total database size was under 700MB. This was unlike the upgrade of SSW’s production database with over 17GB of data which took a few hours. At the end of the process you should get no errors and no warnings. The Upgrade operation on the ApplicationTier feature has completed. There were 0 errors and 0 warnings. As this is a new server and not a pure upgrade there should not be a problem with the GUID. If you think at any point you will be doing this more than once, for example doing a test migration, or merging many TFS 2008 instances into a single one, then you should go back and rename the physical TfsVersionControl.mdf file to the same as the new collection. This will avoid confusion later down the line. To do this, detach the new collection from the server and rename the physical files. Then reattach and change the physical file locations to match the new name. You can follow http://www.mssqltips.com/tip.asp?tip=1122 for a more detailed explanation of how to do this. Figure: Stop the collection so TFS does not take a wobbly when we detach the database. When you try to start the new collection again you will get a conflict with project names and will require to remove the Test Upgrade collection. This is fine and it just needs detached. Figure: Detaching the test upgrade from the new Team Foundation Server 2010 so we can start the new Collection again. You will now be able to start the new upgraded collection and you are ready for testing. Do you remember the stats we took off the TFS 2008 server? TFS2008 File count: Type Count 1 1845 2 15770 Areas & Iterations: 139 Well, now we need to compare them to the TFS 2010 stats, remembering that there will probably be more files under source control. TFS2010 File count: Type Count 1 19288 Areas & Iterations: 139 Lovely, the number of iterations are the same, and the number of files is bigger. Just what we were looking for. Testing the upgraded Team Foundation Server 2010 Project Collection Can we connect to the new collection and project? Figure: We can connect to the new collection and project.   Figure: make sure you can connect to The upgraded projects and that you can see all of the files. Figure: Team Web Access is there and working. Note that for Team Web Access you now use the same port and URL as for TFS 2010. So in this case as I am running on the local box you need to use http://localhost:8080/tfs which will redirect you to http://localhost:8080/tfs/web for the web access. If you need to connect with a Visual Studio 2008 client you will need to use the full path of the new collection, http://[servername]/tfs/[collectionname] and this will work with all of your collections. With Visual Studio 2005 you will only be able to connect to the Default collection and in both VS2008 and VS2005 you will need to install the forward compatibility updates. Visual Studio Team System 2005 Service Pack 1 Forward Compatibility Update for Team Foundation Server 2010 Visual Studio Team System 2008 Service Pack 1 Forward Compatibility Update for Team Foundation Server 2010 To make sure that you have everything up to date, make sure that you run SSW Diagnostics and get all green ticks. Upgrade Done! At this point you can send out a notice to everyone that the upgrade is complete and and give them the connection details. You need to remember that at this stage we have 2008 project upgraded to run under TFS 2010 but it is still running under that same process template that it was running before. You can only “enable” 2010 features in a process template you can’t upgrade. So what to do? Well, you need to create a new project and migrate things you want to keep across. Souse code is easy, you can move or Branch, but Work Items are more difficult as you can’t move them between projects. This instance is complicated more as the old project uses the Conchango/EMC Scrum for Team System template and I will need to write a script/application to get the work items across with their attachments in tact. That is my next task! Technorati Tags: TFS 2010,TFS 2008,VS ALM

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  • Fix Problems Upgrading Office 2010 Beta to RTM (Final) Release

    - by Mysticgeek
    There are several scenarios where you may run into trouble uninstalling the 2010 Beta and trying to install the RTM (final) release. Today we’ll cover the problems we ran into, and how to fix them. You would think upgrading from the Office 2010 Beta to the final release would be an easy process. Unfortunately, it’s not always that simple. In fact, we ran into three different scenarios where the install wasn’t smooth whatsoever. If you currently have the 2010 Beta installed, you have to remove it before you can install the RTM.  Here we’ll take a look at three different troublesome install scenarios we ran into, and how we fixed each one. Important Note: Before proceeding with any of these steps, make sure and backup your Outlook .pst files! Scenario 1 – Uninstall Office 2010 Beta & Fix Install Errors In this first scenario we have Office Professional Plus 2010 Beta 32-bit installed on a Windows 7 Home Premium 32-bit system. First try to uninstall the Office 2010 Beta by going into Control Panel and selecting Programs and Features. Scroll down to Microsoft Office Professional Plus 2010, right-click it and select Uninstall. Click Yes when the confirmation dialog box comes up. Wait while Office 2010 Beta uninstalls…the amount of time it takes will vary from system to system. To complete the uninstall process, a reboot is required. Fixing Setup Errors The problem is when you start the installation of the 2010 RTM… You get the following setup error even though you uninstalled the 2010 Beta. The problem is there are leftover Office apps or stand alone Office products. So, we need a utility that will clean them up for us.   Windows Installer Clean Up Utility Download and install the Clean Up Utility (link Below) following the defaults. After it’s installed you’ll find it in Start \ All Programs \ Windows Install Clean Up …go ahead and launch the utility. Now go through and remove all Office Programs or addins that you find in the list. Make sure you are just deleting Office apps and not something you need like Java for example. If you’re not sure what something is, doing a quick Google search should help you out. For instance we had the Office labs Ribbon Hero installed… just highlight and click Remove. Remove anything that has something to do with Office…then reboot your machine. Now, you should be able to begin the installation of Office 2010 RTM (Final) Release without any errors. If you do get an error during the install process, like this one telling us we have old version of Groove Server… Navigate to C:\Users\username\AppData\Local\Microsoft (where username is the computer name) and delete any existing MS Office folders. Then try the install again, this solved the problem in our first scenario. Scenario 2 – Not Being Able to Uninstall 2010 Beta from Programs and Features In this next scenario we have Office Professional Plus 2010 Beta 32-bit installed on a Windows 7 Home Premium 32-bit system. Another problem we ran into is not being able to uninstall the 2010 Beta from Programs and Features. When you go in to uninstall it, nothing happens. If you run into this problem, we again need to download and install the Windows Installer Clean Up Utility (link below) and manually uninstall the Beta. When you launch it, scroll down to Microsoft Office Professional Plus 2010 (Beta), highlight it and click Remove.   Click OK to the Warning Dialog box… If you see any other Office 2010, 2007, or 2003 entries you can hold the “Shift” key and highlight them all…then click Remove and click OK to the warning dialog. Now we need to delete some Registry settings. Click on Start and type regedit into the Search box and hit Enter. Navigate to HKEY_CURRENT_USER \ Software \ Microsoft \ Office and delete the folder. Then navigate to HKEY_LOCAL_MACHINE \ Software \ Microsoft \ Office and delete those keys as well. Now go into C:\Program Files and find any of these three folders…Microsoft Office, OfficeUpdate, or OfficeUpdate14…you might find one, two or all three. Either way just rename the folders with “_OLD” (without quotes) at the end. Then go into C:\Users\username\AppData\Local\Microsoft and delete any existing MS Office folders. Where in this example we have office, Office Labs, One Note…etc. Now we want to delete the contents of the Temp folder. Click on Start and type %temp% into the Search box and hit Enter. Use the key combination “Ctrl+A” to select all the files in this folder, then right-click and click Delete, or simply hit the Delete key. If you have some files that won’t delete, just skip them as they shouldn’t affect the Office install. Then empty the Recycle Bin and restart your machine. When you get back from the restart launch the Office 2010 RTM installer and you should be good to go with installation. Because we uninstalled the Office 2010 Beta manually, you may have some lingering blank icons that you’ll need to clean up. Scenario –3 Uninstall 2007 and Install 2010 32-Bit on x64 Windows 7 For this final scenario we are uninstalling Office Professional 2007 and installing Office Professional Plus 2010 32-Bit edition on a Windows Ultimate 64-bit computer. This machine actually had Office 2010 Beta 64-bit installed at one point also, it’s since been removed, and 2007 was reinstalled.  Go into Programs and Settings and uninstall Microsoft Office Professional 2007. Click Yes to the dialog box asking if you’re sure you want to uninstall it… Then wait while Office 2007 is uninstalled. The amount of time it takes will vary between systems. A restart is required to complete the process… Again we need to call upon the Windows Installer Clean Up Utility. Go through and delete any left over Office 2007 and 2010 entries. Click OK to the warning dialog that comes up. After that’s complete, navigate to HKEY_CURRENT_USER \ Software \ Microsoft \ Office and delete the folder. Then navigate to HKEY_LOCAL_MACHINE \ Software \ Microsoft \ Office and delete those keys as well. We still need to go into C:\Users\ username\AppData\ Local\ Microsoft (where username is the computer name) and delete any Office folders. In this example we have Outlook Connector, Office, and Outlook to delete. Now let’s delete the contents of the Temp folder by typing %temp% into the Search box in the Start Menu. Then delete all of the files and folders in the Temp directory. If you have some files that won’t delete, just skip them as they shouldn’t affect the Office install. Then empty the Recycle Bin and restart your machine. If you try to install the 2010 RTM at this point you might be able to begin the install, but may get the following Error 1402 message. To solve this issue, we opened the command prompt and ran the following: secedit /configure /cfg %windir%\inf\defltbase.inf /db defltbase.sdb /verbose After the command completes, kick off the Office 2010 (Final) RTM 32-bit edition. This solved the issue and Office 2010 installed successfully.   Conclusion Except for the final scenario, we found using the Windows Installer Clean Up Utility to come in very handy. Using that along with deleting a couple folders and registry settings did the trick. In the last one, we had to get a bit more geeky and use some command line magic, but it got the job done. After some extensive testing in our labs, the only time the upgrade to the RTM went smoothly was when we had a clean Vista or Windows 7 system with a fresh install of the 2010 beta only. However, chances are you went from 2003 or 2007 to the free 2010 Beta. You might also have addins or other Office products installed, so there are going to be a lot of different office files scattered throughout your PC. If that’s the case, you may run into the issues we covered here. These are a few scenarios where we got errors and were not able to install Office 2010 after removing the beta. There could be other problems, and if any of you have experienced different issues or have more good suggestions, leave a comment and let us know! Link Download Windows Installer Clean Up Utility Similar Articles Productive Geek Tips Remove Office 2010 Beta and Reinstall Office 2007How to Upgrade the Windows 7 RC to RTM (Final Release)Upgrading Ubuntu from Dapper to Edgy with Update ManagerDisable Office 2010 Beta Send-a-Smile from StartupAdd or Remove Apps from the Microsoft Office 2007 or 2010 Suite TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 Case Study – How to Optimize Popular Wordpress Sites Restore Hidden Updates in Windows 7 & Vista Iceland an Insurance Job? Find Downloads and Add-ins for Outlook Recycle ! Find That Elusive Icon with FindIcons

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  • top tweets WebLogic Partner Community – October 2012

    - by JuergenKress
    Send your tweets @wlscommunity #WebLogicCommunity and follow us at http://twitter.com/wlscommunity WebLogic Community?@wlscommunity Real World Java EE Patterns by Adam Bien http://wp.me/p1LMIb-mp Markus Eisele?@myfear #JavaOne Content Available for Free https://blogs.oracle.com/java/entry/javaone_content_available_for_free … /via @java Adam Bien?@AdamBien Thought that 1h screencast is way too long to be popular. I was wrong. Lightweight Java EE is doing very well: http://www.adam-bien.com/roller/abien/entry/lightweight_java_ee_screencast … OracleBlogs?@OracleBlogs COLLABORATE 13 Call for Papers http://ow.ly/2szPuZ Oracle WebLogic?@OracleWebLogic New Blog Post: Data Source Security Part 1 http://ow.ly/2szFbv Markus Eisele?@myfear My Three Days at #JavaOne 2012 http://yakovfain.com/2012/10/04/my-three-days-at-javaone-2012/ … < nice writeup ;) Adam Bien?@AdamBien JavaOne 2012 Announcements And Surprises: NetBeans 7.3+ comes with HTML 5, JavaScript, CSS 3 support. JavaScript... http://bit.ly/Uy14eD Andrejus Baranovskis?@andrejusb OOW'12: Oracle ADF Implementations Around the Globe: Best Practices http://fb.me/1IVg6gzU0 gschmutz?@gschmutz Just published a blog with a wrap-up of my presentations at OOW 2012. https://guidoschmutz.wordpress.com/2012/10/07/my-presentations-at-oracle-open-world-2012/ … #oow2012 #trivadis Andrejus Baranovskis?@andrejusb OOW'12: Oracle Business Process Management/Oracle ADF Integration Best Practices http://fb.me/1GY3nz1lb WebLogic Community?@wlscommunity ExaLogic 2.01 ppt & training & Installation check-list & tips & Web tier roadmap http://wp.me/p1LMIb-mh Adam Bien?@AdamBien JavaOne 2012, First Feedback and The Strange Thing: NetBeans day was surprising well attended. A big room was fu... http://bit.ly/PwWwx8 OracleSupport_WLS?@weblogicsupport Free registration for our next webcast on setting up and using a #weblogic #cluster http://pub.vitrue.com/xWV8 WebLogic Community?@wlscommunity UKOUG Application Server & Middleware SIG Meeting http://wp.me/p1LMIb-mC Ronald Luttikhuizen?@rluttikhuizen Discussing future plans for Oracle Middleware Infrastructure Group with @simon_haslam @Jphjulstad and Rene van Wijk #oow @wlscommunity JAX London?@jaxlondon Be part of #JAXLondon- only 11 days to go! Still need a ticket? http://buff.ly/TUPKmL WebLogic Community?@wlscommunity ExaLogic X3-2 launched at OOW 2012 http://wp.me/p1LMIb-mM WebLogic Community?@wlscommunity @OracleEvents Dear Oracle Team thanks for promoting the WebLogic bootcamp, new schedules are online https://blogs.oracle.com/emeapartnerweblogic/resource/weblogic12c.htm … #weblogiccommunity OracleBlogs?@OracleBlogs Partner Webcast Introducing Oracle Business Activity Monitoring - 18 October 2012 http://ow.ly/2svzyz AMIS, Oracle & Java?@AMIS_Services Grant posted a nice little video on youtube about the #ADF EMG activities during Oracle Open World. http://youtu.be/qZhtBqnK-Zc GlassFish?@glassfish ADF Essentials - Available for free and certified on GlassFish!: If you are an Oracle customer, you are probably... http://bit.ly/UCtVwY OracleBlogs?@OracleBlogs WebLogic 12 hands-on bootcamps for partnersnew dates & locations http://ow.ly/2smOfs Pieter Kranenburg?@pskranenburg I'm EXA and I know IT! How about you? Go to http://bit.ly/OnSlDd and find out! (you might win an #iphone5 ;-) #OOW please RT Andrejus Baranovskis?@andrejusb Enabling WebLogic Administrator Group Inside Custom ADF Application http://fb.me/2d5SCeJ2g Michel Schildmeijer?@MNEMONIC01 I'm EXA and I know IT! How about you? Go to http://bit.ly/OnSlDd (you might win an #iphone5 ;-) #oow OracleSupport_WLS?@weblogicsupport Step-by-step instructions on how to configure mail Alerts in #OEM 11g for #WebLogic Servers up/down status http://pub.vitrue.com/KpZq Jeff West?@jeffreyawest Answer: Deliver JMS message to a single node in a Weblogic Cluster with a Distributed Topic http://stackoverflow.com/a/12396492/697114?stw=2 … Java?@java Bucharest Java User Group: Launched and Growing! #JUG http://ow.ly/dDnbN OracleSupport_WLS?@weblogicsupport Don't shoot the messenger! #Java source code analyzer @ http://pub.vitrue.com/Cy2J JAX London?@jaxlondon .@BrianGoetz gives in depth session on the details of how #Lambda expressions are implemented in the #Java language at #JAXLondon" ADF Community DE?@ADFCommunityDE Webcast ADFNewsSession: ADF as a basis of Fusion Apps - the biggest ADF project ever. Sep 14, 8:30 AM CET. Dial in https://blogs.oracle.com/jdevotnharvest/entry/adf_partner_community_news_session … OracleBlogs?@OracleBlogs WebLogic & Coherence & Cloud presentations for customer meetings http://ow.ly/1mqwrC Pieter Kranenburg?@pskranenburg Seminar: Oracle WebLogic 12c at Qualogy. You are invited! http://bit.ly/Ps9LDF Oracle WebLogic?@OracleWebLogic New Blog Post: Oracle OpenWorld Update -- General Session: Oracle Fusion Middleware Strategies Driving Business Inno... http://ow.ly/2stylf Oracle Cloud Zone?@OracleCloudZone New partner programs for Oracle Cloud Solutions http://bit.ly/PrVq5O #cloud #oow Lucas Jellema?@lucasjellema The strategy on Java - JEE, SE, ME, FX: http://technology.amis.nl/2012/10/02/javaone-2012-strategy-and-technical-keynote/ … #javaone #oow_amis WebLogic Community?@wlscommunity Send your #WebLogicCommunity #oow pictures and blog posts @wlscommunity or http://www.facebook.com/weblogiccommunity … Enjoy OOW ;-) WebLogic Community?@wlscommunity Become an WebLogic 12c expert, attend our partner bootcampshttps://blogs.oracle.com/emeapartnerweblogic/resource/weblogic12c.htm … #WebLogicCommunity #opn AMIS, Oracle & Java?@AMIS_Services Volgende #oracle #ADF training bij @AMIS_SERVICES is van 12 tot 16 november. Meer info of aanmelden? http://www.amis.nl/Trainingen/oracle-adf-11g-applicatieontwikkeling/ … Devoxx?@Devoxx ALL the Devoxx 2011 talks are now freely available on Parleys @ http://www.parleys.com/#st=4&id=102998 Pls RT! Adam Bien?@AdamBien Use the coupon code "PLUMA" and you will get 20% off for "Real World Java EE Patterns": http://realworldpatterns.com Lucas Jellema?@lucasjellema Very good summary of the #JavaOne Technical Keynote last night: http://java.dzone.com/articles/javaone-2012-javaone-technical … Arun Gupta?@arungupta Blogged: JavaOne 2012 Keynote and GlassFish Party Pictures: Some pictures from the keynote ... And som... http://bit.ly/ViH0ue Lucas Jellema?@lucasjellema Most recent promoted build for GassFish 4.0 (EE7) has WebSocket support: to play with: http://dlc.sun.com.edgesuite.net/glassfish/4.0/promoted/ … #javaone michael palmeter?@michaelpalmeter If you haven't seen the 5-minute Exalogic demo, you need to (do it now!) - http://lnkd.in/GRqy3x Lonneke Dikmans?@lonnekedikmans VENNSTER BLOG: Running EclipseLink DBWS 2.4.0 on GlassFish 3.1.2 http://blog.vennster.nl/2012/09/running-eclipselink-dbws-240-on.html?spref=tw … WebLogic Community?@wlscommunity WebLogic Partner Community Newsletter September 2012 http://wp.me/p1LMIb-mf WebLogic Community?@wlscommunity again again again&hellip;. it is Oracle Open World 2012 http://wp.me/p1LMIb-m6 Markus Eisele?@myfear #WebLogic and #JavaEE Roadmap and Strategy Session at OOW http://ow.ly/2slZEY /via @OracleWebLogic Adam Bien?@AdamBien An Article About Java EE Connector Architectures 1.6 (JCA 1.6): The free Java Magazine article: Java EE Connect... http://bit.ly/St6sxq Lucas Jellema?@lucasjellema ADF Essentials - free to develop and to deploy (I said: free!) - http://www.oracle.com/technetwork/developer-tools/adf/overview/adfessentials-1719844.html … AMIS, Oracle & Java?@AMIS_Services Blog by Lucas Jellema: "Develop and Deploy ADF applications – free of charge using the new ADF Essentials" http://bit.ly/StAhxY Andrejus Baranovskis?@andrejusb ADF Essentials - Quick Technical Review http://fb.me/2hKCXyF43 OracleBlogs?@OracleBlogs GlassFish Extension for Oracle JDeveloper http://ow.ly/2slIO8 Retweetet von WebLogic Community Oracle Eclipse?@OEPE New Tutorial: Using ADF Faces and ADF Controller with Oracle Enterprise Pack for Eclipse. #OEPE http://pub.vitrue.com/QoUg Simon Haslam?@simon_haslam As of the last day or two there's a new Java Products Media Pack on http://edelivery.oracle.com (rather than it being in FMW pack) WebLogic Community?@wlscommunity top tweets WebLogic Partner Community &ndash; September 2012 http://wp.me/p1LMIb-m2 Adam Bien?@AdamBien I was interviewed by OTN: http://www.oracle.com/technetwork/articles/java/jaxawards-1843595.html …See you at JavaOne! Oracle WebLogic?@OracleWebLogic DevOps Basics for #WebLogic: Track Down High CPU Thread with ps, top and the new JDK7 jcmd tool. Great blog @frankmuz. http://ow.ly/dOBM4 Simon Haslam?@simon_haslam Looking for "oak style"(!) advanced content but you're a middleware specialist? See #ukoug2012 #middlewaresunday http://2012.ukoug.org/default.asp?p=9355 … Julien Ponge ?@jponge Just finished Java EE 6 + AngularJS samples for my upcoming middleware lectures. Code at https://github.com/jponge/todoapp-javaee6-angularjs … and https://github.com/jponge/todoapp-bosswatch … Markus Eisele?@myfear #Oracle #WebLogic is now totally #FREE for #Developer - more than just OTN license to develop the 1st prototype! http://bit.ly/SWltsR Markus Eisele?@myfear #WebSockets on #WebLogic Server http://ow.ly/1mv4QP by @wlsteve < need to give this a testdrive ;) OracleEnterpriseMgr?@oracle_em EM Blog : Oracle Enterprise Manager Cloud Control 12c Release 2 (12.1.0.2) is Available Now ! #em12c http://pub.vitrue.com/mk7o OracleBlogs?@OracleBlogs ADF training material now on the iPad http://ow.ly/1mqz1Q GlassFish?@glassfish GlassFish grows by 50% in Software Stack Market Share Report for August 2012 by @Jelastic http://awe.sm/o4ZAp WebLogic Partner Community For regular information become a member in the WebLogic Partner Community please visit: http://www.oracle.com/partners/goto/wls-emea ( OPN account required). If you need support with your account please contact the Oracle Partner Business Center. Blog Twitter LinkedIn Mix Forum Wiki Technorati Tags: twitter,WebLogic,WebLogic Community,Oracle,OPN,Jürgen Kress

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  • Quick guide to Oracle IRM 11g: Server installation

    - by Simon Thorpe
    Quick guide to Oracle IRM 11g index This is the first of a set of articles designed to assist with the successful installation, configuration and deployment of a document security solution using Oracle IRM. This article goes through a set of simple instructions which detail how to download, install and configure the IRM server, the starting point for building a document security solution. This article contains a subset of information from the official documentation and is focused on installing the server on Oracle Enterprise Linux. If you are planning to deploy on a non-Linux platform, you will need to reference the documentation for platform specific information. Contents Introduction Downloading the software Preparing a database Creating the schema WebLogic Server installation Installing Oracle IRM Introduction Because we are using Oracle Enterprise Linux in this guide, and before we get into the detail of IRM, i'd like to share some tips with Linux to make life a bit easier.Use a 64bit platform, IRM 11g runs just fine on a 32bit server but with 64bit you will build a more future proof service. Download and install the latest Java JDK package. Make sure you get the 64bit version if you are on a 64bit server. Configure Linux to use a good Yum server to simplify installing packages. For Oracle Enterprise Linux we maintain a great public Yum here. Have at least 20GB of free disk space on the partition you intend to install the IRM server. The downloads are big, then you extract them and then install. This quickly consumes disk space which you can easily recover by deleting the downloaded and extracted files after wards. But it's nice to have the disk space spare to keep these around in case you need to restart any part of the installation process again. Downloading the software OK, so before you can do anything, you need the software install kits. Luckily Oracle allows you to freely download every technology we create. You'll need to get the following; Oracle WebLogic Server Oracle Database Oracle Repository Creation Utility (rcu) Oracle IRM server You can use Microsoft SQL server 2005 or 2008, in this guide i've used Oracle RDBMS 11gR2 for Linux. Preparing the database I'm not going to go through the finer points of installing the database. There are many very good guides on installing the Oracle Database. However one thing I would suggest you think about is enabling TDE, network encryption and using Database Vault. These Oracle database security technologies are excellent for creating a complete end to end security solution. No point in going to all the effort to secure document access with IRM when someone can go directly to the database and assign themselves rights to documents. To understand this further, you can see a video of the IRM service using these database security technologies here. With a database up and running we need to create a schema to hold the IRM data. This schema contains the rights model, cryptographic keys, user account id's and associated rights etc. Creating the IRM database schema Oracle uses the Repository Creation Tool which builds your schema, extract the files from the rcu zip. Then in a terminal window; cd /oracle/install/rcu/bin ./rcu This will launch the Repository Creation Tool and you will be presented with the image to the right. Hit next and continue onto the next dialog. You are asked if you are going to be creating a new schema or wish to drop an existing one, you obviously just need to click next at this point to create a new schema. The RCU next needs to know where your database is so you'll need the following details of your database instance. Below, for reference, is the information for my installation. Hostname: irm.oracle.demo Port: 1521 (This is the default TCP port for the Oracle Database) Service Name: irm.oracle.demo. Note this is not the SID, but the service name. Username: sys Password: ******** Role: SYSDBA And then select next. Because the RCU contains schemas for many of the Oracle Technologies, you now need to select to just deploy the Oracle IRM schema. Open the section under "Enterprise Content Management" and tick the "Oracle Information Rights Management" component. Note that you also get the chance to select a prefix which defaults to "DEV" (for development). I usually change this to something that reflects my own install. PROD for a production system, INT for internal only etc. The next step asks for the passwords for the schema users. We are only creating one schema here so you just enter one password. Some brave souls store this password in an Excel spreadsheet which is then secure against the IRM server you're about to install in this guide. Nearing the end of the schema creation is the mapping of the tablespaces to the schema. Note I had setup a table space already that was encrypted using TDE and at this point I was able to select that tablespace by clicking in the "Default Tablespace" column. The next dialog confirms your actions and clicking on next causes it to create the schema and default data. After this you are presented with the completion summary. WebLogic Server installation The database is now ready and the next step is to install the application server. Oracle IRM 11g is a JEE application and currently only supported in Oracle WebLogic Server. So the next step is get WebLogic Server installed, which is pretty easy. Depending on the version you download, you either run the binary or for a 64 bit platform (like mine) run the following command. java -d64 -jar wls1033_generic.jar And in the resulting dialog hit next to start walking through the install. Next choose a directory into which you will install WebLogic Server. I like to change from the default and install into /oracle/. Then all my software goes into this one folder, all owned by the "oracle" user. The next dialog asks for your Oracle support information to ensure you are kept up to date. If you have an Oracle support account, enter your details but for most evaluation systems I leave these fields blank. Again, for evaluation or development systems, I usually stick with the "Typical" install type which you are next asked for. Next you are asked for the JDK which will be used for the server. When installing from the generic jar on a 64bit platform like in this guide, no JDK is bundled with the installer. But as you can see in the image on the right, that it does a good job of detecting the one you've got installed. Defaults for the install directories are usually taken, no changes here, just click next. And finally we are ready to install, hit next, sit back and relax. Typically this takes about 10 minutes. After the install, do not run the quick start, we need to deploy the IRM install itself from which we will create a new WebLogic domain. For now just hit done and lets move to the final step of the installation process. Installing Oracle IRM The last piece of the puzzle to getting your environment ready is to deploy the IRM files themselves. Unzip the Oracle Enterprise Content Management 11g zip file and it will create a Disk1 directory. Switch to this folder and in the console run ./runInstaller. This will launch the installer which will also ask for the location of the JDK. Look at the image on the right for the detail. You should now see the first stage of the IRM installation. The dialog warns you need to have a WebLogic server installed and have created the schema's, but you've just done all that above (I hope) so we are ready to go. The installer now checks that you have all the required libraries installed and other system parameters are correct. Because nearly all of my development and evaluation installations have the database server on the same system, the installer passes these checks without issue... Next... Now chose where to install the IRM files, you must install into the same Middleware Home as the WebLogic Server installation you just performed. Usually the installer already defaults to this location anyway. I also tend to change the Oracle Home Directory to Oracle_IRM so it's clear this is just an IRM install. The summary page tells you about space needed to deploy the files. Unfortunately the IRM install comes with all of the other Oracle ECM software, you can't just select the IRM files, everything gets deployed to disk and uses 1.6GB of space! Not fun, but Oracle has to package up similar technologies otherwise we would have a very large number of installers to QA and manage, again, not fun. Hit Install, time for another drink, maybe a piece of cake or a donut... on a half decent system this part of the install took under 10 minutes. Finally the installation of your IRM server is complete, click on finish and the next phase is to create the WebLogic domain and start configuring your server. Now move onto the next article in this guide... configuring your IRM server ready to seal your first document.

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  • Begin the Clone Wars Have!

    - by Antony Reynolds
    Creating a New Virtual Machine from an Existing Virtual Disk In previous posts I described how I set up an OEL6 machine under VirtualBox that can run an 11gR2 database and FMW 11.1.1.5.  That is great if you want the DB and FMW running in the same virtual image and it has served me well for some proof of concepts and also for some testing of different JVMs.  However I also wanted to run some testing of FMW with the database running on a separate physical machine.  So in this post I will show how to take a VirtualBox image and create a new image based on the disks from that original image. What are my Options? There is more than one way to skin a cat, or in this case to create two separate VMs that can run on different hardware.  Some of the options include: Create new virtual disk images for each new VM. Clone the existing disk images and point the new VM at the cloned images. Point the new VM at the existing snapshots. #1 is too much like hard work, install OEL twice, install a database again, install FMW again, run RCU again!  Life is too short! #2 is probably the safest way of doing things.  VirtualBox allows you to clone a disk image for use in a separate machine.  However this of course duplicates the disk and means that it is now occupying 3 times the space, once for the original disk and twice more for the two clones I would need. #3 is the most space efficient way of doing things.  It does mean however that I can only run the new “cloned” images if I have access to the original image because that is where the base snapshots reside.  However this is not a problem for me as long as I remember to keep all threee images together.  So this is the approach we will follow. Snapshot, What Snapshot? As we are going to create new virtual machines based on existing snapshots we need to figure out which snapshot to use.  We do this by opening the “Media Manager” from within VirtualBox and moving the mouse over the snapshot images until we find the snapshots we want – the snapshot name is identified in the “Attached to:” comment.  In my case I wanted the FMW installed snapshot because that had a database configured for FMW alongside the FMW software.  I made a note of the filename of that snapshot (actually I just noted the first 5 characters as that was all that was needed to uniquely identify the snapshot file). When we create the new machines we will point them at the snapshot filename we have just checked. Network or NotWork? Because we want the two new machines to communicate with each other when hosted in different physical machines we can’t use the default NAT networking mode without a lot of hassle.  But at the same time we need them to have fixed IP addresses relative to each other so that they can see each other whilst also being able to see the outside world. To achieve all these requirements I created two network adapters for each machine.  Adapter 1 was a standard NAT mapping.  This will allow each machine to get a dynamic IP address (10.0.2.15 by default) that can be used to access the external world through the VBox provided NAT gateway.  This is the same as the existing configuration. The second adapter I created as a bridged adapter.  This gives the virtual machine direct access to the host network card and by using fixed IP addresses each machine can see the other.  It is important to choose fixed IP addresses that are not routable across your internal network so you don’t get any clashes with other machines on your network.  Of course you could always get proper fixed IP addresses from your network people, but I have serveral people using my images and as long as I don’t have two instances of the same VM on the same network segment this is easier and avoids reconfiguring the network every time someone wants a copy of my VM.  If it is available I would suggest using the 10.0.3.* network as 10.0.2.* is the default NAT network.  You can check availability by pinging 10.0.3.1 and 10.0.3.2 from your host machine.  If it times out then you are probably safe to use that. Creating the New VMs Now that I had collected the data that I needed I went ahead and created the new VMs. When asked for a “Boot Hard Disk” I used the “Choose a virtual hard disk file…” link to find the snapshot I had previously selected and set that to be the existing hard disk.  I chose the previously existing SOA 11.1.1.5 install for both the new DB and FMW machines because that snapshot had the database with the RCU completed that I wanted for my DB machine and it had the SOA software installed which I wanted for my FMW machine. After the initial creation of the virtual machine go into the network setting section and enable a second adapter which will be bridged.  Make a note of the MAC addresses (the last four digits should be sufficient) of the two adapters so that you can later set the bridged adapter to use fixed IP and the NAT adapter to use DHCP. We are now ready to start the VMs and reconfigure Linux. Reconfiguring Linux Because I now have two new machines I need to change their network configuration.  In particular I need to change the hostname, update the hosts file and change the network settings. Changing the Hostname I renamed both hosts by running the hostname command as root: hostname vboxfmw.oracle.com I also edited the /etc/sysconfig file and set the correct hostname in there. HOSTNAME=vboxfmw.oracle.com Changing the Network Settings I needed to change the network configuration to give the bridged network a fixed IP address.  I first explicitly set the MAC addresses of the two adapters, because the order of the virtual adapters in the VirtualBox Manager is not necessarily the same as the order of the adapters in the guest OS.  So I went in to the System->Preferences->Network Connections screen and explicitly set the “Device MAC address” for the two adapters. Having correctly mapped the Linux adapters to the VirtualBox adapters I then set the Bridged adapter to use fixed IP addressing rather than DHCP.  There is no need for additional routing or default gateways because we expect the two machine to be on the same LAN segment. Updating the Hosts File Having renamed the machines and reconfigured the network I then updated the /etc/hosts file to refer to the new machine name add a new line to the hosts file to provide an additional IP address for my server (the new fixed IP address) add a new line for the fixed IP address of the other virtual machine 10.0.3.101      vboxdb.oracle.com       vboxdb  # Added by NetworkManager 10.0.2.15       vboxdb.oracle.com       vboxdb  # Added by NetworkManager 10.0.3.102      vboxfmw.oracle.com      vboxfmw # Added by NetworkManager 127.0.0.1       localhost.localdomain   localhost ::1     vboxdb.oracle.com       vboxdb  localhost6.localdomain6 localhost6 To make sure everything takes effect I restarted the server. Reconfiguring the Database on the DB Machine Because we changed the hostname the listener and the EM console no longer start so I need to modify the listener.ora to use the new hostname and I also need to rebuild the EM configuration because it also relies on the hostname. I edited the $ORACLE_HOME/network/admin/listener.ora and changed the listening address to the new hostname:       (ADDRESS = (PROTOCOL = TCP)(HOST = vboxdb.oracle.com)(PORT = 1521)) After changing the listener.ora I was able to start the listener using: lsnrctl start I also had to reconfigure the EM database control.  I first deconfigured it using the command: emca -deconfig dbcontrol db -repos drop This drops the repository and removes any existing registered dbcontrols. I then re-configured it using the following command: emca -config dbcontrol db -repos create This creates the EM repository and then configures and starts dbcontrol. Now my database machine is ready so I can close it down and take a snapshot. Disabling the Database on the FMW Machine I set up the database to start automatically by creating a service called “dbora”.  On the FMW machine I do not need the database running so I can prevent it auto-starting by running the following command: chkconfig –del dbora Note that because I am using a snapshot it is not a waste of disk space to have the DB installed but not used.  As long as I don’t run it, it won’t cost me anything. I can now close the FMW machine down and take a snapshot. Creating a New Domain The FMW machine is now ready to create a new domain.  When creating the domain I can point it at the second machine which is running the database.  I can potentially run these machines on two separate physical machines as long as I have the original virtual machine available to both of the physical machines. Gotchas in Snapshotting VirtualBox does not support the concept of linked machines in a network like some virtualization technologies so when creating a snapshot it is a good idea to shut both VMs down and then take a snapshot on both of them.  This is because we want to keep the database in sync with the middleware.  One way to make sure that this happens would be to place all the domain configuration files on the database server via an NFS share, this would mean that all we would need to snapshot would be the database machine because that would hold all the state and configuration. The Sky’s the Limit We have covered a simple case of having just two machines.  I have a more complicated configuration in which two machine run a RAC database off the same base OS image, and two more machines run a SOA cluster based on the same OS image.  Just remember what machine holds state and what are the consequences of taking a snapshot.

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  • Looking Back at MIX10

    - by WeigeltRo
    It’s the sad truth of my life that even though I’m fascinated by airplanes and flight in general since my childhood days, my body doesn’t like flying. Even the ridiculously short flights inside Germany are taking their toll on me each time. Now combine this with sitting in the cramped space of economy class for many hours on a transatlantic flight from Germany to Las Vegas and back, and factor in some heavy dose of jet lag (especially on my way eastwards), and you get an idea why after coming back home I had this question on my mind: Was it really worth it to attend MIX10? This of course is a question that will also be asked by my boss at Comma Soft (for other reasons, obviously), who decided to send me and my colleague Jens Schaller, to the MIX10 conference. (A note to my German readers: An dieser Stelle der Hinweis, dass Comma Soft noch Silverlight-Entwickler und/oder UI-Designer für den Standort Bonn sucht – aussagekräftige Bewerbungen bitte an [email protected]) Too keep things short: My answer is yes. Before I’ll go into detail, let me ask the heretical questions whether tech conferences in general still make sense. There was a time, where actually being at a tech conference gave you a head-start in regard to learning about new technologies. Nowadays this is no longer true, where every bit of information and every detail is immediately twittered, blogged and whatevered to death. In the case of MIX10 you even can download the video-taped sessions shortly after. So: Does visiting a conference still make sense? It depends on what you expect from a conference. It should be clear to everybody that you’ll neither get exclusive information, nor receive training in a small group. What a conference does offer that sitting in front of your computer does not can be summarized as follows: Focus Being away from work and home will help you to focus on the presented information. Of course there are always the poor guys who are haunted by their work (with mails and short text messages reporting the latest showstopper problem), but in general being out of your office makes a huge difference. Inspiration With the focus comes the emotional involvement. I find it much easier to absorb information if I feel that certain vibe when sitting in a session. This still means that I have put work into reviewing the information later, but it’s a better starting point. And all the impressions collected at a (good) conference combined lead to a higher motivation – be it by the buzz (“this is gonna be sooo cool!”) or by the fear to fall behind (“man, we’ll have work on this, or else…”). People At a conference it’s pretty easy to get into contact with other people during breakfast, lunch and other breaks. This is a good opportunity to get a feel for what other development teams are doing (on a very general level of course, nobody will tell you about their secret formula) and what they are thinking about specific technologies. So MIX10 did offer focus, inspiration and people, but that would have meant nothing without valuable content. When I (being a frontend developer with a strong interest in UI/UX) planned my visit to MIX10, I made the decision to focus on the "soft" topics of design, interaction and user experience. I figured that I would be bombarded with all the technical details about Silverlight 4 anyway in the weeks and months to come. Actually, I would have liked to catch a few technical sessions, but the agenda wasn’t exactly in favor of people interested in any kind of Silverlight and UI/UX/Design topics. That’s one of my few complaints about the conference – I would have liked one more day and/or more sessions per day. Overall, the quality of the workshops and sessions was pretty high. In fact, looking back at my collection of conferences I’ve visited in the past I’d say that MIX10 ranks somewhere near the top spot. Here’s an overview of the workshops/sessions I attended (I’ll leave out the keynotes): Day 0 (Workshops on Sunday) Design Fundamentals for Developers Robby Ingebretsen is the man! Great workshop in three parts with the perfect mix of examples, well-structured definition of terminology and the right dose of humor. Robby was part of the WPF team before founding his own company so he not only has a strong interest in design (and the skillz!) but also the technical background.   Design Tools and Techniques Originally announced to be held by Arturo Toledo, the Rosso brothers from ArcheType filled in for the first two parts, and Corrina Black had a pretty general part about the Windows Phone UI. The first two thirds were a mixed bag; the two guys definitely knew what they were talking about, and the demos were great, but the talk lacked the preparation and polish of a truly great presentation. Corrina was not allowed to go into too much detail before the keynote on Monday, but the session was still very interesting as it showed how much thought went into the Windows Phone UI (and there’s always a lot to learn when people talk about their thought process). Day 1 (Monday) Designing Rich Experiences for Data-Centric Applications I wonder whether there was ever a test-run for this session, but what Ken Azuma and Yoshihiro Saito delivered in the first 15 minutes of a 30-minutes-session made me walk out. A commercial for a product (just great: a video showing a SharePoint plug-in in an all-Japanese UI) combined with the most generic blah blah one could imagine. EPIC FAIL.   Great User Experiences: Seamlessly Blending Technology & Design I switched to this session from the one above but I guess I missed the interesting part – what I did catch was what looked like a “look at the cool stuff we did” without being helpful. Or maybe I was just in a bad mood after the other session.   The Art, Technology and Science of Reading This talk by Kevin Larson was very interesting, but was more a presentation of what Microsoft is doing in research (pretty impressive) and in the end lacked a bit the helpful advice one could have hoped for.   10 Ways to Attack a Design Problem and Come Out Winning Robby Ingebretsen again, and again a great mix of theory and practice. The clean and simple, yet effective, UI of the reader app resulted in a simultaneous “wow” of Jens and me. If you’d watch only one session video, this should be it. Microsoft has to bring Robby back next year! Day 2 (Tuesday) Touch in Public: Multi-touch Interaction Design for Kiosks & Architectural Experiences Very interesting session by Jason Brush, a great inspiration with many details to look out for in the examples. Exactly what I was hoping for – and then some!   Designing Bing: Heart and Science How hard can it be to design the UI for a search engine? An input field and a list of results, that should be it, right? Well, not so fast! The talk by Paul Ray showed the many iterations to finally get it right (up to the choice of a specific blue for the links). And yes, I want an eye-tracking device to play around with!   The Elephant in the Room When Nishant Kothary presented a long list of what his session was not about, I told to myself (not having the description text present) “Am I in the wrong talk? Should I leave?”. Boy, was I wrong. A great talk about human factors in the process of designing stuff.   An Hour with Bill Buxton Having seen Bill Buxton’s presentation in the keynote, I just had to see this man again – even though I didn’t know what to expect. Being more or less unplanned and intended to be more of a conversation, the session didn’t provide a wealth of immediately useful information. Nevertheless Bill Buxton was impressive with his huge knowledge of seemingly everything. But this could/should have been a session some when in the evening and not in parallel to at least two other interesting talks. Day 3 (Wednesday) Design the Ordinary, Like the Fixie This session by DL Byron and Kevin Tamura started really well and brought across the message to keep things simple. But towards the end the talk lost some of its steam. And, as a member of the audience pointed out, they kind of ignored their own advice when they used a fancy presentation software other then PowerPoint that sometimes got in the way of showing things.   Developing Natural User Interfaces Speaking of alternative presentation software, Joshua Blake definitely had the most remarkable alternative to PowerPoint, a self-written program called NaturalShow that was controlled using multi-touch on a touch screen. Not a PowerPoint-killer, but impressive nevertheless. The (excellent) talk itself was kind of eye-opening in regard to what “multi-touch support” on various platforms (WPF, Silverlight, Windows Phone) actually means.   Treat your Content Right The talk by Tiffani Jones Brown wasn’t even on my planned schedule, but somehow I ended up in that session – and it was great. And even for people who don’t necessarily have to write content for websites, some points made by Tiffani are valid in many places, notably wherever you put texts with more than a single word into your UI. Creating Effective Info Viz in Microsoft Silverlight The last session of MIX10 I attended was kind of disappointing. At first things were very promising, with Matthias Shapiro giving a brief but well-structured introduction to info graphics and interactive visualizations. Then the live-coding began and while the result was interesting, too much time was spend on wrestling to get the code working. Ending earlier than planned, the talk was a bit light on actual content, but at least it included a nice list of resources. Conclusion It could be felt all across MIX10, UIs will take a huge leap forward; in fact, there are enough examples that have already. People who both have the technical know-how and at least a basic understanding of design (“literacy” as Bill Buxton called it) are in high demand. The concept of the MIX conference and initiatives like design.toolbox shows that Microsoft understands very well that frontend developers have to acquire new knowledge besides knowing how to hack code and putting buttons on a form. There are extremely exciting times before us, with lots of opportunity for those who are eager to develop their skills, that is for sure.

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  • This is the End of Business as Usual...

    - by Michael Snow
    This week, we'll be hosting our last Social Business Thought Leader Series Webcast for 2012. Our featured guest this week will be Brian Solis of Altimeter Group. As we've been going through the preparations for Brian's webcast, it became very clear that an hour's time is barely scraping the surface of the depth of Brian's insights and analysis. Accordingly, in the spirit of sharing Brian's perspective for all of our readers, we'll be featuring guest posts all this week pulled from Brian's larger collection of blog postings on his own website. If you like what you've read here this week, we highly recommend digging deeper into his tome of wisdom. Guest Post by Brian Solis, Analyst, Altimeter Group as originally featured on his site with the minor change of the video addition at the beginning of the post. This is the End of Business as Usual and the Beginning of a New Era of Relevance - Brian Solis, Principal Analyst, Altimeter Group The Times They Are A-Changin’ Come gather ’round people Wherever you roam And admit that the waters Around you have grown And accept it that soon You’ll be drenched to the bone If your time to you Is worth savin’ Then you better start swimmin’ Or you’ll sink like a stone For the times they are a-changin’. - Bob Dylan I’m sure you are wondering why I chose lyrics to open this article. If you skimmed through them, stop here for a moment. Go back through the Dylan’s words and take your time. Carefully read, and feel, what it is he’s saying and savor the moment to connect the meaning of his words to the challenges you face today. His message is as important and true today as it was when they were first written in 1964. The tide is indeed once again turning. And even though the 60s now live in the history books, right here, right now, Dylan is telling us once again that this is our time to not only sink or swim, but to do something amazing. This is your time. This is our time. But, these times are different and what comes next is difficult to grasp. How people communicate. How people learn and share. How people make decisions. Everything is different now. Think about this…you’re reading this article because it was sent to you via email. Yet more people spend their online time in social networks than they do in email. Duh. According to Nielsen, of the total time spent online 22.5% are connecting and communicating in social networks. To put that in perspective, the time spent in the likes of Facebook, Twitter, and Youtube is greater than online gaming at 9.8%, email at 7.6% and search at 4%. Imagine for a moment if you and I were connected to one another in Facebook, which just so happens to be the largest social network in the world. How big? Well, Facebook is the size today of the entire Internet in 2004. There are over 1 billion people friending, Liking, commenting, sharing, and engaging in Facebook…that’s roughly 12% of the world’s population. Twitter has over 200 million users. Ever hear of tumblr? More time is spent on this popular microblogging community than Twitter. The point is that the landscape for communication and all that’s affected by human interaction is profoundly different than how you and I learned, shared or talked to one another yesterday. This transformation is only becoming more pervasive and, it’s not going back. Survival of the Fitting But social media is just one of the channels we can use to reach people. I must be honest. I’m as much a part of tomorrow as I am of yesteryear. It’s why I spend all of my time researching the evolution of media and its impact on business and culture. Because of you, I share everything I learn in newsletters, emails, blogs, Youtube videos, and also traditional books. I’m dedicated to helping everyone not only understand, but grasp the change that’s before you. Technologies such as social, mobile, virtual, augmented, et al compel us adapt our story and value proposition and extend our reach to be part of communities we don’t realize exist. The people who will keep you in business or running tomorrow are the very people you’re not reaching today. Before you continue to read on, allow me to clarify my point of view. My inspiration for writing this is to help you augment, not necessarily replace, the programs you’re running today. We must still reach those whom matter to us in the ways they prefer to be engaged. To reach what I call the connected consumer of Geneeration-C we must too reach them in the ways they wish to be engaged. And in all of my work, how they connect, talk to one another, influence others, and make decisions are not at all like the traditional consumers of the past. Nor are they merely the kids…the Millennial. Connected consumers are representative across every age group and demographic. As you can see, use of social networks, media sharing sites, microblogs, blogs, etc. equally span across Gen Y, Gen X, and Baby Boomers. The DNA of connected customers is indiscriminant of age or any other demographic for that matter. This is more about psychographics, the linkage of people through common interests (than it is their age, gender, education, nationality or level of income. Once someone is introduced to the marvels of connectedness, the sensation becomes a contagion. It touches and affects everyone. And, that’s why this isn’t going anywhere but normalcy. Social networking isn’t just about telling people what you’re doing. Nor is it just about generic, meaningless conversation. Today’s connected consumer is incredibly influential. They’re connected to hundreds and even thousands of other like-minded people. What they experiences, what they support, it’s shared throughout these networks and as information travels, it shapes and steers impressions, decisions, and experiences of others. For example, if we revisit the Nielsen research, we get an idea of just how big this is becoming. 75% spend heavily on music. How does that translate to the arts? I’d imagine the number is equally impressive. If 53% follow their favorite brand or organization, imagine what’s possible. Just like this email list that connects us, connections in social networks are powerful. The difference is however, that people spend more time in social networks than they do in email. Everything begins with an understanding of the “5 W’s and H.E.” – Who, What, When, Where, How, and to What Extent? The data that comes back tells you which networks are important to the people you’re trying to reach, how they connect, what they share, what they value, and how to connect with them. From there, your next steps are to create a community strategy that extends your mission, vision, and value and it align it with the interests, behavior, and values of those you wish to reach and galvanize. To help, I’ve prepared an action list for you, otherwise known as the 10 Steps Toward New Relevance: 1. Answer why you should engage in social networks and why anyone would want to engage with you 2. Observe what brings them together and define how you can add value to the conversation 3. Identify the influential voices that matter to your world, recognize what’s important to them, and find a way to start a dialogue that can foster a meaningful and mutually beneficial relationship 4. Study the best practices of not just organizations like yours, but also those who are successfully reaching the type of people you’re trying to reach – it’s benching marking against competitors and benchmarking against undefined opportunities 5. Translate all you’ve learned into a convincing presentation written to demonstrate tangible opportunity to your executive board, make the case through numbers, trends, data, insights – understanding they have no idea what’s going on out there and you are both the scout and the navigator (start with a recommended pilot so everyone can learn together) 6. Listen to what they’re saying and develop a process to learn from activity and adapt to interests and steer engagement based on insights 7. Recognize how they use social media and innovate based on what you observe to captivate their attention 8. Align your objectives with their objectives. If you’re unsure of what they’re looking for…ask 9. Invest in the development of content, engagement 10. Build a community, invest in values, spark meaningful dialogue, and offer tangible value…the kind of value they can’t get anywhere else. Take advantage of the medium and the opportunity! The reality is that we live and compete in a perpetual era of Digital Darwinism, the evolution of consumer behavior when society and technology evolve faster than our ability to adapt. This is why it’s our time to alter our course. We must connect with those who are defining the future of engagement, commerce, business, and how the arts are appreciated and supported. Even though it is the end of business as usual, it is the beginning of a new age of opportunity. The consumer revolution is already underway, and the question is: How do you better understand the role you play in this production as a connected or social consumer as well as business professional? Again, this is your time to define a new era of engagement and relevance. Originally written for The National Arts Marketing Project Connect with Brian via: Twitter | LinkedIn | Facebook | Google+ --- Note from Michael: If you really like this post above - check out Brian's TEDTalk and his thought process for preparing it in this post: 12.00 Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-family:"Calibri","sans-serif"; mso-bidi-font-family:"Times New Roman";} http://www.briansolis.com/2012/10/tedtalk-reinventing-consumer-capitalism-screw-business-as-usual/

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  • Understanding Windows 8 Recovery options

    - by stuffe
    Background: I am preparing a PC that I am sending to a relative abroad, who has little or no internet access, and next to no sensible options for getting IT support should anything go wrong. As such I am trying to provide a full set of recovery options such that they are able to reinstall the OS with minimum fuss or assistance if required. The PC is a brand new Acer laptop that came with Windows 7 pre-installed (and an associated recovery partition) and a free upgrade to Windows 8. I have installed Windows 8 from scratch performing a format and clean install from media I burned from the official download. The existing Windows 7 recovery partition is still there, and I can still boot from it. I have created recovery DVDs of that in case it is ever lost. Here are my recovery options so far. I can perform a factory reset of Win 7 via the recovery partition I can perform a factory reset of Win 7 via burned recovery DVDs I can re-install Windows 8 cleanly from a DVD All of these are useful, but not what I want, because the first 2 methods use Win 7, and still fill the machine with crapware, and the latter doesn't provide for any post-install customisation and software installation. So, I am looking to see what other options are available to perform a Windows 8 recovery that will be more than a simple install. I am aware that Win8 comes with some useful refresh tools: Refresh your PC - Re-install Win 8 over the top of your existing installation, recovering from any Windows corruption etc. I can run this from my current install, although it says some files are missing that will be provided by me install or recovery media, which seems to be code for stick your install DVD in, and it starts after I do that - unfortunately for this particular laptop you need to specify a particular WIFI driver or the install bombs out part way through with IRQL errors, and this refresh method skips the part where you can load a driver, so it's no use to me. I think I can fix this by creating a custom recovery image using the recimg.exe command but it takes hours to complete so I haven't tried it yet. Reset your PC - Perform a full install and lose all your files. Again it needs my Install media inserting before it will do anything, but then it provides an error (will include later when I recreate it...) Now, these recovery options look useful (in principal, although both are fail for me) but they rely on having a working system to access the tools, which leads me to the last option, of making a Recovery USB drive. I have made a recovery drive, and it should perform loads of useful things, including copying my WIN7 recovery partition to the drive, providing the above refresh and reset options, providing other troubleshooting options and also the ability to restore from a custom image, only none of them seem to work for me. Creating the Recovery Drive - the option to include my recovery partition is greyed out. The partition exists and works fine, why will it not copy it? Refresh - I imagine this would have the same issues as I described before, but this is moot because when I try it says that the "drive where Windows is installed is locked, please unlock the drive and try again" with no info on what that means and how to do it. Restore - Again, probably pointless as I can just use the DVD, but it also errors: "unable to reset your PC. A required drive partition is missing" System Restore - should let me roll back a bad driver etc as per normal in Windows, only it simply says "To use system restore you must specify which windows installation to restore. Restart this computer, select an operating system, and select system restore" ?!?! System Image Recovery - this seems to be offering to restore from a Windows system image, but this is deprecated in Windows 8, although you can still make one if you use the Windows 7 Backup tools, however the resultant file is too large to put on the USB stick as it's FAT formatted, and would be a massive stack of DVDs anyway. So useless. It would be nice it it would work with the custom recovery image you can use with the refresh command, but there seems no option to do this. Automatic Repair - some diagnostics, which seem useless as it happily tells me it can't fix my problem, even though I have none. Command Prompt - yay, this works! What on earth do I want to use it for... Had any of the above worked, it might be useful, but as any form of install still requires you to have the DVD, and any form of custom recovery image also requires you to have either a massive stack of DVDs or an NTFS formatted backup device in addition to the recovery drive, it sort of ruins the point. It doesn't seem rocket science. I want to create a bootable USB drive that I can refresh Windows over an existing install with, perform a clean reinstall to a bare system, or recovery a customised image with existing apps installed. If anyone can point me in a direction that allows me to make a single recovery drive do these all these things, I would appreciate it. I have a 32Gb USB3 thumb drive that I bought for this very purpose, but it's seems to be fighting to let me do anything useful. At this rate I will be making a DriveImageXML recovery stick and dumping the OS with that, which I know works, but isn't so elegant as using the proper tools..

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  • Load and Web Performance Testing using Visual Studio Ultimate 2010-Part 2

    - by Tarun Arora
    Welcome back, in part 1 of Load and Web Performance Testing using Visual Studio 2010 I talked about why Performance Testing the application is important, the test tools available in Visual Studio Ultimate 2010 and various test rig topologies. In this blog post I’ll get into the details of web performance & load tests as well as why it’s important to follow a goal based pattern while performance testing your application. Tools => Options => Test Tools Have you visited the treasures of Visual Studio Menu bar tools => Options => Test Tools lately? The options to enable disable prompts on creating, editing, deleting or running manual/automated tests can be controller from here. The default test project language and default test types created on a new test project creation could be selected/unselected from here. Ever wondered how you can change the default limit of 25 test results, this can again be changed from here. If you record a lot of Web Tests and wish for the web test recorder to start with “that” URL populated, well this again can be specified from here. If you haven’t so far, I would urge you to spend 2 minutes in the test tools options.   Test Menu => Ready Steady Test Action! The Test tools are under the Test Menu in Visual Studio, apart from being able to create a new Test and Test List you can also load an existing vsmdi file. You can also manage your test controllers from here. A solution can have one or more test setting files, but there can only be one active test settings file at any time. Again, this selection can be done from here.  You can open the various test windows from under the windows option from the test menu. If you open the Test view window you will see that you have the option to group the tests by work items, project, test type, etc. You can set these properties by right clicking a test in the test list and choosing properties from the context menu.    So, what is a vsmdi file? vsmdi stands for Visual Studio Test Metadata File. Placed under the Solution Items this file keeps track of the list of unit tests in your solution. If you open the vsmdi file as an xml file you will see a series of Test Links nested with in the list Test List tags along with the Run Configuration tag. When in visual studio you run tests, the IDE looks at the vsmdi file to see what tests need to be run. You also have the option of using the vsmdi file in your team builds to specify which tests need to run as part of the build. Refer here for a walkthrough from a fellow blogger on how to use the vsmdi file in the team builds. Web Performance Test – The Truth! In Visual Studio 2010 “Web Tests” have been renamed to “Web Performance Tests”. Apart from renaming this test type there have been several improvements to this test type in visual studio 2010. I am very active on the MSDN Visual Studio And Load Testing forum and a frequent question from many users is “Do Web Tests support Pages that run JavaScript?” I will start with a little bit of background before answering this question. Web Performance Tests operate at the HTTP Layer, but why? To enable you to generate high loads with a relatively low amount of hardware, Web performance tests are driven at the protocol layer rather than instantiating a browser.The most common source of confusion is that users do not realize Web Performance Tests work at the HTTP layer. The tool adds to that misconception. After all, you record in IE, and when running a Web test you can select which browser to use, and then the result viewer shows the results in a browser window. So that means the tests run through the browser, right? NO! The Web test engine works at the HTTP layer, and does not instantiate a browser. What does that mean? In the diagram below, you can see there are no browsers running when the engine is sending and receiving requests. Does that mean I can’t test pages that use Java script? The best example for java script generating HTTP traffic is AJAX calls. The most common example of browser plugins are Silverlight or Flash. The Web test recorder will record HTTP traffic from AJAX calls and from most (but not all) browser plugins. This means you will still be able to web performance test pages that use java script or plugin and play back the results but the playback engine will not show the java script or plug in results in the ‘browser control’. If you want to test the page behaviour as a result of the java script or plug in consider using Coded UI Tests. This page looks like it failed, when in fact it succeeded! Looking closely at the response, and subsequent requests, it is clear the operation succeeded. As stated above, the reason why the browser control is pasting this message is because java script has been disabled in this control. So, to reiterate, the web performance test recorder: - Sends and receives data at the HTTP layer. - Does NOT run a browser. - Does NOT run java script. - Does NOT host ActiveX controls or plugins. There is a great series of blog posts from Ed Glas, i would highly recommend his blog to any one performing Load/Performance testing through Visual Studio. Demo – Web Performance Test [Demo] - Visual Studio Ultimate 2010: Test Settings and Configuration   [Demo]–Visual Studio Ultimate 2010: Web Performance Test   In this short video I try and answer the following questions, Why is performance Testing important? How does Visual Studio Help you performance Test your applications? How do i record a web performance test? How do make a web performance test data driven, transaction driven, loop driven, convert to code, add validations? Best practices for recording Web Performance Tests. I have a web performance test, what next? Creating the Web Performance Test was the first step towards load testing your application. Now that we have the base test we can test the page behaviour when N-users access the page. Have you ever had the head of business call you and mention that the marketing team has done a fantastic job and are expecting increased traffic on the web site, can the website survive the weekend with that additional load? This is the perfect opportunity to capacity test your application to see how your website holds up under various levels of load, you can work the results backwards to see how much hardware you may need to scale up your application to survive the weekend. Apart from that it is always a good idea to have some benchmarks around how the application performs under light loads for short duration, under heavy load for long duration and soak test the application run a constant load for a very week or two to record the effects of constant load for really long durations, this is a great way of identifying how your application handles the default IIS application pool reset which by default is configured to once every 25 hours. These bench marks will act as the perfect yard stick to measure performance gains when you start making improvements. BUT there are some best practices! => Goal Based Load Testing Approach Since the subject is vast and there are a lot of things to measure and analyse, … it is very easy to get distracted from the real goal!  You can optimize your application once you know where the pain points are. There is no point performing a load test of 5000 users if your intranet application will only have a 100 simultaneous users, it is important to keep focussed on the real goals of the project. So the idea is to have a user story around your load testing scenarios and test realistically. So it is recommended that you follow the below outline, It is an Iterative process, refine your objectives, identify the key scenarios, what is the expected workload, key metrics you want to report, record the web performance tests, simulate load and analyse results. Is your application already deployed in Production? This is great! You can analyse the IIS Logs to understand the user behaviour… But what are IIS LOGS? The IIS logs allow you to record events for each application and Web site on the Web server. You can create separate logs for each of your applications and Web sites. Logging information in IIS goes beyond the scope of the event logging or performance monitoring features provided by Windows. The IIS logs can include information, such as who has visited your site, what the visitor viewed, and when the information was last viewed. You can use the IIS logs to identify any attempts to gain unauthorized access to your Web server. How to configure IIS LOGS? For those Ninjas who already have IIS Logs configured (by the way its on by default) and need a way to analyse the IIS Logs, can use the Windows IIS Utility – Log Parser. Log Parser is a very powerful tool that provides a generic SQL-like language on top of many types of data like IIS Logs, Event Viewer entries, XML files, CSV files, File System and others; and it allows you to export the result of the queries to many output formats such as CSV, XML, SQL Server, Charts and others; and it works well with IIS 5, 6, 7 and 7.5. Frequently used Log Parser queries. Demo – Load Test [Demo]–Visual Studio Ultimate 2010: Load Testing   In this short video I try and answer the following questions, - Types of Performance Testing? - Perform Goal driven Load Testing, analyse Test Run Result and Generate a report? Recap A quick recap of what we have covered so far,     Thank you for taking the time out and reading this blog post, in part III of this blog series I’ll be getting into the details of Test Result Analysis, Test Result Drill through, Test Report Generation, Test Run Comparison, and the Asp.net Profiler. If you enjoyed the post, remember to subscribe to http://feeds.feedburner.com/TarunArora. Questions/Feedback/Suggestions, etc please leave a comment. See you on in Part III   Share this post : CodeProject

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  • Refactor This (Ugly Code)!

    - by Alois Kraus
    Ayende has put on his blog some ugly code to refactor. First and foremost it is nearly impossible to reason about other peoples code without knowing the driving forces behind the current code. It is certainly possible to make it much cleaner when potential sources of errors cannot happen in the first place due to good design. I can see what the intention of the code is but I do not know about every brittle detail if I am allowed to reorder things here and there to simplify things. So I decided to make it much simpler by identifying the different responsibilities of the methods and encapsulate it in different classes. The code we need to refactor seems to deal with a handler after a message has been sent to a message queue. The handler does complete the current transaction if there is any and does handle any errors happening there. If during the the completion of the transaction errors occur the transaction is at least disposed. We can enter the handler already in a faulty state where we try to deliver the complete event in any case and signal a failure event and try to resend the message again to the queue if it was not inside a transaction. All is decorated with many try/catch blocks, duplicated code and some state variables to route the program flow. It is hard to understand and difficult to reason about. In other words: This code is a mess and could be written by me if I was under pressure. Here comes to code we want to refactor:         private void HandleMessageCompletion(                                      Message message,                                      TransactionScope tx,                                      OpenedQueue messageQueue,                                      Exception exception,                                      Action<CurrentMessageInformation, Exception> messageCompleted,                                      Action<CurrentMessageInformation> beforeTransactionCommit)         {             var txDisposed = false;             if (exception == null)             {                 try                 {                     if (tx != null)                     {                         if (beforeTransactionCommit != null)                             beforeTransactionCommit(currentMessageInformation);                         tx.Complete();                         tx.Dispose();                         txDisposed = true;                     }                     try                     {                         if (messageCompleted != null)                             messageCompleted(currentMessageInformation, exception);                     }                     catch (Exception e)                     {                         Trace.TraceError("An error occured when raising the MessageCompleted event, the error will NOT affect the message processing"+ e);                     }                     return;                 }                 catch (Exception e)                 {                     Trace.TraceWarning("Failed to complete transaction, moving to error mode"+ e);                     exception = e;                 }             }             try             {                 if (txDisposed == false && tx != null)                 {                     Trace.TraceWarning("Disposing transaction in error mode");                     tx.Dispose();                 }             }             catch (Exception e)             {                 Trace.TraceWarning("Failed to dispose of transaction in error mode."+ e);             }             if (message == null)                 return;                 try             {                 if (messageCompleted != null)                     messageCompleted(currentMessageInformation, exception);             }             catch (Exception e)             {                 Trace.TraceError("An error occured when raising the MessageCompleted event, the error will NOT affect the message processing"+ e);             }               try             {                 var copy = MessageProcessingFailure;                 if (copy != null)                     copy(currentMessageInformation, exception);             }             catch (Exception moduleException)             {                 Trace.TraceError("Module failed to process message failure: " + exception.Message+                                              moduleException);             }               if (messageQueue.IsTransactional == false)// put the item back in the queue             {                 messageQueue.Send(message);             }         }     You can see quite some processing and handling going on there. Yes this looks like real world code one did put together to make things work and he does not trust his callbacks. I guess these are event handlers which are optional and the delegates were extracted from an event to call them back later when necessary.  Lets see what the author of this code did intend:          private void HandleMessageCompletion(             TransactionHandler transactionHandler,             MessageCompletionHandler handler,             CurrentMessageInformation messageInfo,             ErrorCollector errors             )         {               // commit current pending transaction             transactionHandler.CallHandlerAndCommit(messageInfo, errors);               // We have an error for a null message do not send completion event             if (messageInfo.CurrentMessage == null)                 return;               // Send completion event in any case regardless of errors             handler.OnMessageCompleted(messageInfo, errors);               // put message back if queue is not transactional             transactionHandler.ResendMessageOnError(messageInfo.CurrentMessage, errors);         }   I did not bother to write the intention here again since the code should be pretty self explaining by now. I have used comments to explain the still nontrivial procedure step by step revealing the real intention about all this complex program flow. The original complexity of the problem domain does not go away but by applying the techniques of SRP (Single Responsibility Principle) and some functional style but we can abstract the necessary complexity away in useful abstractions which make it much easier to reason about it. Since most of the method seems to deal with errors I thought it was a good idea to encapsulate the error state of our current message in an ErrorCollector object which stores all exceptions in a list along with a description what the error all was about in the exception itself. We can log it later or not depending on the log level or whatever. It is really just a simple list that encapsulates the current error state.          class ErrorCollector          {              List<Exception> _Errors = new List<Exception>();                public void Add(Exception ex, string description)              {                  ex.Data["Description"] = description;                  _Errors.Add(ex);              }                public Exception Last              {                  get                  {                      return _Errors.LastOrDefault();                  }              }                public bool HasError              {                  get                  {                      return _Errors.Count > 0;                  }              }          }   Since the error state is global we have two choices to store a reference in the other helper objects (TransactionHandler and MessageCompletionHandler)or pass it to the method calls when necessary. I did chose the latter one because a second argument does not hurt and makes it easier to reason about the overall state while the helper objects remain stateless and immutable which makes the helper objects much easier to understand and as a bonus thread safe as well. This does not mean that the stored member variables are stateless or thread safe as well but at least our helper classes are it. Most of the complexity is located the transaction handling I consider as a separate responsibility that I delegate to the TransactionHandler which does nothing if there is no transaction or Call the Before Commit Handler Commit Transaction Dispose Transaction if commit did throw In fact it has a second responsibility to resend the message if the transaction did fail. I did see a good fit there since it deals with transaction failures.          class TransactionHandler          {              TransactionScope _Tx;              Action<CurrentMessageInformation> _BeforeCommit;              OpenedQueue _MessageQueue;                public TransactionHandler(TransactionScope tx, Action<CurrentMessageInformation> beforeCommit, OpenedQueue messageQueue)              {                  _Tx = tx;                  _BeforeCommit = beforeCommit;                  _MessageQueue = messageQueue;              }                public void CallHandlerAndCommit(CurrentMessageInformation currentMessageInfo, ErrorCollector errors)              {                  if (_Tx != null && !errors.HasError)                  {                      try                      {                          if (_BeforeCommit != null)                          {                              _BeforeCommit(currentMessageInfo);                          }                            _Tx.Complete();                          _Tx.Dispose();                      }                      catch (Exception ex)                      {                          errors.Add(ex, "Failed to complete transaction, moving to error mode");                          Trace.TraceWarning("Disposing transaction in error mode");                          try                          {                              _Tx.Dispose();                          }                          catch (Exception ex2)                          {                              errors.Add(ex2, "Failed to dispose of transaction in error mode.");                          }                      }                  }              }                public void ResendMessageOnError(Message message, ErrorCollector errors)              {                  if (errors.HasError && !_MessageQueue.IsTransactional)                  {                      _MessageQueue.Send(message);                  }              }          } If we need to change the handling in the future we have a much easier time to reason about our application flow than before. After we did complete our transaction and called our callback we can call the completion handler which is the main purpose of the HandleMessageCompletion method after all. The responsiblity o the MessageCompletionHandler is to call the completion callback and the failure callback when some error has occurred.            class MessageCompletionHandler          {              Action<CurrentMessageInformation, Exception> _MessageCompletedHandler;              Action<CurrentMessageInformation, Exception> _MessageProcessingFailure;                public MessageCompletionHandler(Action<CurrentMessageInformation, Exception> messageCompletedHandler,                                              Action<CurrentMessageInformation, Exception> messageProcessingFailure)              {                  _MessageCompletedHandler = messageCompletedHandler;                  _MessageProcessingFailure = messageProcessingFailure;              }                  public void OnMessageCompleted(CurrentMessageInformation currentMessageInfo, ErrorCollector errors)              {                  try                  {                      if (_MessageCompletedHandler != null)                      {                          _MessageCompletedHandler(currentMessageInfo, errors.Last);                      }                  }                  catch (Exception ex)                  {                      errors.Add(ex, "An error occured when raising the MessageCompleted event, the error will NOT affect the message processing");                  }                    if (errors.HasError)                  {                      SignalFailedMessage(currentMessageInfo, errors);                  }              }                void SignalFailedMessage(CurrentMessageInformation currentMessageInfo, ErrorCollector errors)              {                  try                  {                      if (_MessageProcessingFailure != null)                          _MessageProcessingFailure(currentMessageInfo, errors.Last);                  }                  catch (Exception moduleException)                  {                      errors.Add(moduleException, "Module failed to process message failure");                  }              }            }   If for some reason I did screw up the logic and we need to call the completion handler from our Transaction handler we can simple add to the CallHandlerAndCommit method a third argument to the MessageCompletionHandler and we are fine again. If the logic becomes even more complex and we need to ensure that the completed event is triggered only once we have now one place the completion handler to capture the state. During this refactoring I simple put things together that belong together and came up with useful abstractions. If you look at the original argument list of the HandleMessageCompletion method I have put many things together:   Original Arguments New Arguments Encapsulate Message message CurrentMessageInformation messageInfo         Message message TransactionScope tx Action<CurrentMessageInformation> beforeTransactionCommit OpenedQueue messageQueue TransactionHandler transactionHandler        TransactionScope tx        OpenedQueue messageQueue        Action<CurrentMessageInformation> beforeTransactionCommit Exception exception,             ErrorCollector errors Action<CurrentMessageInformation, Exception> messageCompleted MessageCompletionHandler handler          Action<CurrentMessageInformation, Exception> messageCompleted          Action<CurrentMessageInformation, Exception> messageProcessingFailure The reason is simple: Put the things that have relationships together and you will find nearly automatically useful abstractions. I hope this makes sense to you. If you see a way to make it even more simple you can show Ayende your improved version as well.

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  • C#/.NET Little Wonders: Fun With Enum Methods

    - by James Michael Hare
    Once again lets dive into the Little Wonders of .NET, those small things in the .NET languages and BCL classes that make development easier by increasing readability, maintainability, and/or performance. So probably every one of us has used an enumerated type at one time or another in a C# program.  The enumerated types we create are a great way to represent that a value can be one of a set of discrete values (or a combination of those values in the case of bit flags). But the power of enum types go far beyond simple assignment and comparison, there are many methods in the Enum class (that all enum types “inherit” from) that can give you even more power when dealing with them. IsDefined() – check if a given value exists in the enum Are you reading a value for an enum from a data source, but are unsure if it is actually a valid value or not?  Casting won’t tell you this, and Parse() isn’t guaranteed to balk either if you give it an int or a combination of flags.  So what can we do? Let’s assume we have a small enum like this for result codes we want to return back from our business logic layer: 1: public enum ResultCode 2: { 3: Success, 4: Warning, 5: Error 6: } In this enum, Success will be zero (unless given another value explicitly), Warning will be one, and Error will be two. So what happens if we have code like this where perhaps we’re getting the result code from another data source (could be database, could be web service, etc)? 1: public ResultCode PerformAction() 2: { 3: // set up and call some method that returns an int. 4: int result = ResultCodeFromDataSource(); 5:  6: // this will suceed even if result is < 0 or > 2. 7: return (ResultCode) result; 8: } So what happens if result is –1 or 4?  Well, the cast does not fail, so what we end up with would be an instance of a ResultCode that would have a value that’s outside of the bounds of the enum constants we defined. This means if you had a block of code like: 1: switch (result) 2: { 3: case ResultType.Success: 4: // do success stuff 5: break; 6:  7: case ResultType.Warning: 8: // do warning stuff 9: break; 10:  11: case ResultType.Error: 12: // do error stuff 13: break; 14: } That you would hit none of these blocks (which is a good argument for always having a default in a switch by the way). So what can you do?  Well, there is a handy static method called IsDefined() on the Enum class which will tell you if an enum value is defined.  1: public ResultCode PerformAction() 2: { 3: int result = ResultCodeFromDataSource(); 4:  5: if (!Enum.IsDefined(typeof(ResultCode), result)) 6: { 7: throw new InvalidOperationException("Enum out of range."); 8: } 9:  10: return (ResultCode) result; 11: } In fact, this is often recommended after you Parse() or cast a value to an enum as there are ways for values to get past these methods that may not be defined. If you don’t like the syntax of passing in the type of the enum, you could clean it up a bit by creating an extension method instead that would allow you to call IsDefined() off any isntance of the enum: 1: public static class EnumExtensions 2: { 3: // helper method that tells you if an enum value is defined for it's enumeration 4: public static bool IsDefined(this Enum value) 5: { 6: return Enum.IsDefined(value.GetType(), value); 7: } 8: }   HasFlag() – an easier way to see if a bit (or bits) are set Most of us who came from the land of C programming have had to deal extensively with bit flags many times in our lives.  As such, using bit flags may be almost second nature (for a quick refresher on bit flags in enum types see one of my old posts here). However, in higher-level languages like C#, the need to manipulate individual bit flags is somewhat diminished, and the code to check for bit flag enum values may be obvious to an advanced developer but cryptic to a novice developer. For example, let’s say you have an enum for a messaging platform that contains bit flags: 1: // usually, we pluralize flags enum type names 2: [Flags] 3: public enum MessagingOptions 4: { 5: None = 0, 6: Buffered = 0x01, 7: Persistent = 0x02, 8: Durable = 0x04, 9: Broadcast = 0x08 10: } We can combine these bit flags using the bitwise OR operator (the ‘|’ pipe character): 1: // combine bit flags using 2: var myMessenger = new Messenger(MessagingOptions.Buffered | MessagingOptions.Broadcast); Now, if we wanted to check the flags, we’d have to test then using the bit-wise AND operator (the ‘&’ character): 1: if ((options & MessagingOptions.Buffered) == MessagingOptions.Buffered) 2: { 3: // do code to set up buffering... 4: // ... 5: } While the ‘|’ for combining flags is easy enough to read for advanced developers, the ‘&’ test tends to be easy for novice developers to get wrong.  First of all you have to AND the flag combination with the value, and then typically you should test against the flag combination itself (and not just for a non-zero)!  This is because the flag combination you are testing with may combine multiple bits, in which case if only one bit is set, the result will be non-zero but not necessarily all desired bits! Thanks goodness in .NET 4.0 they gave us the HasFlag() method.  This method can be called from an enum instance to test to see if a flag is set, and best of all you can avoid writing the bit wise logic yourself.  Not to mention it will be more readable to a novice developer as well: 1: if (options.HasFlag(MessagingOptions.Buffered)) 2: { 3: // do code to set up buffering... 4: // ... 5: } It is much more concise and unambiguous, thus increasing your maintainability and readability. It would be nice to have a corresponding SetFlag() method, but unfortunately generic types don’t allow you to specialize on Enum, which makes it a bit more difficult.  It can be done but you have to do some conversions to numeric and then back to the enum which makes it less of a payoff than having the HasFlag() method.  But if you want to create it for symmetry, it would look something like this: 1: public static T SetFlag<T>(this Enum value, T flags) 2: { 3: if (!value.GetType().IsEquivalentTo(typeof(T))) 4: { 5: throw new ArgumentException("Enum value and flags types don't match."); 6: } 7:  8: // yes this is ugly, but unfortunately we need to use an intermediate boxing cast 9: return (T)Enum.ToObject(typeof (T), Convert.ToUInt64(value) | Convert.ToUInt64(flags)); 10: } Note that since the enum types are value types, we need to assign the result to something (much like string.Trim()).  Also, you could chain several SetFlag() operations together or create one that takes a variable arg list if desired. Parse() and ToString() – transitioning from string to enum and back Sometimes, you may want to be able to parse an enum from a string or convert it to a string - Enum has methods built in to let you do this.  Now, many may already know this, but may not appreciate how much power are in these two methods. For example, if you want to parse a string as an enum, it’s easy and works just like you’d expect from the numeric types: 1: string optionsString = "Persistent"; 2:  3: // can use Enum.Parse, which throws if finds something it doesn't like... 4: var result = (MessagingOptions)Enum.Parse(typeof (MessagingOptions), optionsString); 5:  6: if (result == MessagingOptions.Persistent) 7: { 8: Console.WriteLine("It worked!"); 9: } Note that Enum.Parse() will throw if it finds a value it doesn’t like.  But the values it likes are fairly flexible!  You can pass in a single value, or a comma separated list of values for flags and it will parse them all and set all bits: 1: // for string values, can have one, or comma separated. 2: string optionsString = "Persistent, Buffered"; 3:  4: var result = (MessagingOptions)Enum.Parse(typeof (MessagingOptions), optionsString); 5:  6: if (result.HasFlag(MessagingOptions.Persistent) && result.HasFlag(MessagingOptions.Buffered)) 7: { 8: Console.WriteLine("It worked!"); 9: } Or you can parse in a string containing a number that represents a single value or combination of values to set: 1: // 3 is the combination of Buffered (0x01) and Persistent (0x02) 2: var optionsString = "3"; 3:  4: var result = (MessagingOptions) Enum.Parse(typeof (MessagingOptions), optionsString); 5:  6: if (result.HasFlag(MessagingOptions.Persistent) && result.HasFlag(MessagingOptions.Buffered)) 7: { 8: Console.WriteLine("It worked again!"); 9: } And, if you really aren’t sure if the parse will work, and don’t want to handle an exception, you can use TryParse() instead: 1: string optionsString = "Persistent, Buffered"; 2: MessagingOptions result; 3:  4: // try parse returns true if successful, and takes an out parm for the result 5: if (Enum.TryParse(optionsString, out result)) 6: { 7: if (result.HasFlag(MessagingOptions.Persistent) && result.HasFlag(MessagingOptions.Buffered)) 8: { 9: Console.WriteLine("It worked!"); 10: } 11: } So we covered parsing a string to an enum, what about reversing that and converting an enum to a string?  The ToString() method is the obvious and most basic choice for most of us, but did you know you can pass a format string for enum types that dictate how they are written as a string?: 1: MessagingOptions value = MessagingOptions.Buffered | MessagingOptions.Persistent; 2:  3: // general format, which is the default, 4: Console.WriteLine("Default : " + value); 5: Console.WriteLine("G (default): " + value.ToString("G")); 6:  7: // Flags format, even if type does not have Flags attribute. 8: Console.WriteLine("F (flags) : " + value.ToString("F")); 9:  10: // integer format, value as number. 11: Console.WriteLine("D (num) : " + value.ToString("D")); 12:  13: // hex format, value as hex 14: Console.WriteLine("X (hex) : " + value.ToString("X")); Which displays: 1: Default : Buffered, Persistent 2: G (default): Buffered, Persistent 3: F (flags) : Buffered, Persistent 4: D (num) : 3 5: X (hex) : 00000003 Now, you may not really see a difference here between G and F because I used a [Flags] enum, the difference is that the “F” option treats the enum as if it were flags even if the [Flags] attribute is not present.  Let’s take a non-flags enum like the ResultCode used earlier: 1: // yes, we can do this even if it is not [Flags] enum. 2: ResultCode value = ResultCode.Warning | ResultCode.Error; And if we run that through the same formats again we get: 1: Default : 3 2: G (default): 3 3: F (flags) : Warning, Error 4: D (num) : 3 5: X (hex) : 00000003 Notice that since we had multiple values combined, but it was not a [Flags] marked enum, the G and default format gave us a number instead of a value name.  This is because the value was not a valid single-value constant of the enum.  However, using the F flags format string, it broke out the value into its component flags even though it wasn’t marked [Flags]. So, if you want to get an enum to display appropriately for whether or not it has the [Flags] attribute, use G which is the default.  If you always want it to attempt to break down the flags, use F.  For numeric output, obviously D or  X are the best choice depending on whether you want decimal or hex. Summary Hopefully, you learned a couple of new tricks with using the Enum class today!  I’ll add more little wonders as I think of them and thanks for all the invaluable input!   Technorati Tags: C#,.NET,Little Wonders,Enum,BlackRabbitCoder

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  • C#/.NET Little Wonders: The Predicate, Comparison, and Converter Generic Delegates

    - by James Michael Hare
    Once again, in this series of posts I look at the parts of the .NET Framework that may seem trivial, but can help improve your code by making it easier to write and maintain. The index of all my past little wonders posts can be found here. In the last three weeks, we examined the Action family of delegates (and delegates in general), the Func family of delegates, and the EventHandler family of delegates and how they can be used to support generic, reusable algorithms and classes. This week I will be completing my series on the generic delegates in the .NET Framework with a discussion of three more, somewhat less used, generic delegates: Predicate<T>, Comparison<T>, and Converter<TInput, TOutput>. These are older generic delegates that were introduced in .NET 2.0, mostly for use in the Array and List<T> classes.  Though older, it’s good to have an understanding of them and their intended purpose.  In addition, you can feel free to use them yourself, though obviously you can also use the equivalents from the Func family of delegates instead. Predicate<T> – delegate for determining matches The Predicate<T> delegate was a very early delegate developed in the .NET 2.0 Framework to determine if an item was a match for some condition in a List<T> or T[].  The methods that tend to use the Predicate<T> include: Find(), FindAll(), FindLast() Uses the Predicate<T> delegate to finds items, in a list/array of type T, that matches the given predicate. FindIndex(), FindLastIndex() Uses the Predicate<T> delegate to find the index of an item, of in a list/array of type T, that matches the given predicate. The signature of the Predicate<T> delegate (ignoring variance for the moment) is: 1: public delegate bool Predicate<T>(T obj); So, this is a delegate type that supports any method taking an item of type T and returning bool.  In addition, there is a semantic understanding that this predicate is supposed to be examining the item supplied to see if it matches a given criteria. 1: // finds first even number (2) 2: var firstEven = Array.Find(numbers, n => (n % 2) == 0); 3:  4: // finds all odd numbers (1, 3, 5, 7, 9) 5: var allEvens = Array.FindAll(numbers, n => (n % 2) == 1); 6:  7: // find index of first multiple of 5 (4) 8: var firstFiveMultiplePos = Array.FindIndex(numbers, n => (n % 5) == 0); This delegate has typically been succeeded in LINQ by the more general Func family, so that Predicate<T> and Func<T, bool> are logically identical.  Strictly speaking, though, they are different types, so a delegate reference of type Predicate<T> cannot be directly assigned to a delegate reference of type Func<T, bool>, though the same method can be assigned to both. 1: // SUCCESS: the same lambda can be assigned to either 2: Predicate<DateTime> isSameDayPred = dt => dt.Date == DateTime.Today; 3: Func<DateTime, bool> isSameDayFunc = dt => dt.Date == DateTime.Today; 4:  5: // ERROR: once they are assigned to a delegate type, they are strongly 6: // typed and cannot be directly assigned to other delegate types. 7: isSameDayPred = isSameDayFunc; When you assign a method to a delegate, all that is required is that the signature matches.  This is why the same method can be assigned to either delegate type since their signatures are the same.  However, once the method has been assigned to a delegate type, it is now a strongly-typed reference to that delegate type, and it cannot be assigned to a different delegate type (beyond the bounds of variance depending on Framework version, of course). Comparison<T> – delegate for determining order Just as the Predicate<T> generic delegate was birthed to give Array and List<T> the ability to perform type-safe matching, the Comparison<T> was birthed to give them the ability to perform type-safe ordering. The Comparison<T> is used in Array and List<T> for: Sort() A form of the Sort() method that takes a comparison delegate; this is an alternate way to custom sort a list/array from having to define custom IComparer<T> classes. The signature for the Comparison<T> delegate looks like (without variance): 1: public delegate int Comparison<T>(T lhs, T rhs); The goal of this delegate is to compare the left-hand-side to the right-hand-side and return a negative number if the lhs < rhs, zero if they are equal, and a positive number if the lhs > rhs.  Generally speaking, null is considered to be the smallest value of any reference type, so null should always be less than non-null, and two null values should be considered equal. In most sort/ordering methods, you must specify an IComparer<T> if you want to do custom sorting/ordering.  The Array and List<T> types, however, also allow for an alternative Comparison<T> delegate to be used instead, essentially, this lets you perform the custom sort without having to have the custom IComparer<T> class defined. It should be noted, however, that the LINQ OrderBy(), and ThenBy() family of methods do not support the Comparison<T> delegate (though one could easily add their own extension methods to create one, or create an IComparer() factory class that generates one from a Comparison<T>). So, given this delegate, we could use it to perform easy sorts on an Array or List<T> based on custom fields.  Say for example we have a data class called Employee with some basic employee information: 1: public sealed class Employee 2: { 3: public string Name { get; set; } 4: public int Id { get; set; } 5: public double Salary { get; set; } 6: } And say we had a List<Employee> that contained data, such as: 1: var employees = new List<Employee> 2: { 3: new Employee { Name = "John Smith", Id = 2, Salary = 37000.0 }, 4: new Employee { Name = "Jane Doe", Id = 1, Salary = 57000.0 }, 5: new Employee { Name = "John Doe", Id = 5, Salary = 60000.0 }, 6: new Employee { Name = "Jane Smith", Id = 3, Salary = 59000.0 } 7: }; Now, using the Comparison<T> delegate form of Sort() on the List<Employee>, we can sort our list many ways: 1: // sort based on employee ID 2: employees.Sort((lhs, rhs) => Comparer<int>.Default.Compare(lhs.Id, rhs.Id)); 3:  4: // sort based on employee name 5: employees.Sort((lhs, rhs) => string.Compare(lhs.Name, rhs.Name)); 6:  7: // sort based on salary, descending (note switched lhs/rhs order for descending) 8: employees.Sort((lhs, rhs) => Comparer<double>.Default.Compare(rhs.Salary, lhs.Salary)); So again, you could use this older delegate, which has a lot of logical meaning to it’s name, or use a generic delegate such as Func<T, T, int> to implement the same sort of behavior.  All this said, one of the reasons, in my opinion, that Comparison<T> isn’t used too often is that it tends to need complex lambdas, and the LINQ ability to order based on projections is much easier to use, though the Array and List<T> sorts tend to be more efficient if you want to perform in-place ordering. Converter<TInput, TOutput> – delegate to convert elements The Converter<TInput, TOutput> delegate is used by the Array and List<T> delegate to specify how to convert elements from an array/list of one type (TInput) to another type (TOutput).  It is used in an array/list for: ConvertAll() Converts all elements from a List<TInput> / TInput[] to a new List<TOutput> / TOutput[]. The delegate signature for Converter<TInput, TOutput> is very straightforward (ignoring variance): 1: public delegate TOutput Converter<TInput, TOutput>(TInput input); So, this delegate’s job is to taken an input item (of type TInput) and convert it to a return result (of type TOutput).  Again, this is logically equivalent to a newer Func delegate with a signature of Func<TInput, TOutput>.  In fact, the latter is how the LINQ conversion methods are defined. So, we could use the ConvertAll() syntax to convert a List<T> or T[] to different types, such as: 1: // get a list of just employee IDs 2: var empIds = employees.ConvertAll(emp => emp.Id); 3:  4: // get a list of all emp salaries, as int instead of double: 5: var empSalaries = employees.ConvertAll(emp => (int)emp.Salary); Note that the expressions above are logically equivalent to using LINQ’s Select() method, which gives you a lot more power: 1: // get a list of just employee IDs 2: var empIds = employees.Select(emp => emp.Id).ToList(); 3:  4: // get a list of all emp salaries, as int instead of double: 5: var empSalaries = employees.Select(emp => (int)emp.Salary).ToList(); The only difference with using LINQ is that many of the methods (including Select()) are deferred execution, which means that often times they will not perform the conversion for an item until it is requested.  This has both pros and cons in that you gain the benefit of not performing work until it is actually needed, but on the flip side if you want the results now, there is overhead in the behind-the-scenes work that support deferred execution (it’s supported by the yield return / yield break keywords in C# which define iterators that maintain current state information). In general, the new LINQ syntax is preferred, but the older Array and List<T> ConvertAll() methods are still around, as is the Converter<TInput, TOutput> delegate. Sidebar: Variance support update in .NET 4.0 Just like our descriptions of Func and Action, these three early generic delegates also support more variance in assignment as of .NET 4.0.  Their new signatures are: 1: // comparison is contravariant on type being compared 2: public delegate int Comparison<in T>(T lhs, T rhs); 3:  4: // converter is contravariant on input and covariant on output 5: public delegate TOutput Contravariant<in TInput, out TOutput>(TInput input); 6:  7: // predicate is contravariant on input 8: public delegate bool Predicate<in T>(T obj); Thus these delegates can now be assigned to delegates allowing for contravariance (going to a more derived type) or covariance (going to a less derived type) based on whether the parameters are input or output, respectively. Summary Today, we wrapped up our generic delegates discussion by looking at three lesser-used delegates: Predicate<T>, Comparison<T>, and Converter<TInput, TOutput>.  All three of these tend to be replaced by their more generic Func equivalents in LINQ, but that doesn’t mean you shouldn’t understand what they do or can’t use them for your own code, as they do contain semantic meanings in their names that sometimes get lost in the more generic Func name.   Tweet Technorati Tags: C#,CSharp,.NET,Little Wonders,delegates,generics,Predicate,Converter,Comparison

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  • So&hellip; What is a SharePoint Developer?

    - by Mark Rackley
    A few days ago Stacy Draper and I were chatting about what it means to be a SharePoint Developer. That actually turns about to be a conversation with lots of shades of grey. Stacy thought it would make a good blog post… well, I can’t promise this to be a GOOD blog post… So, anyway, I decided to let off a little bomb this morning by posting the following tweet on Twitter: @mrackley: Can someone be considered a SharePoint Developer if all they know how to do is work in SPD? Now, I knew this is a debate that has been going on since the first SharePoint Designer User put SharePoint Developer on their resume. There are probably several blogs out there on the subject, but with the wildfire that is jQuery and a few other new features out there I believe it is an important subject to tackle again. I got a lot of great feedback as well on Twitter. The entire twitter conversation is at the end of this blog posting. Thanks everyone for their opinions. Who cares? Why does it matter? Can’t we all just get along? Yes it matters… everything must be labeled and put in it’s proper place. Pigeon holing is the only way to go!  Just kidding.. I’m not near that anal, but yes! It is important to be able to properly identify the skill set of those people on your team and correctly identify the role you are wanting to hire. Saying you are a “SharePoint Developer” is just too vague and just barely begins to answer the question. Also, knowing who’s on your team and what they can do will ensure you give your clients the best people for the job. A Developer writes code right? So, a Developer uses Visual Studio! Whoa, hold on there Sparky. Even if I concede that to be a developer you have to write code then you still can’t say a SharePoint Developer has to use Visual Studio.  So, you can spell C#, how well can you write XSLT? How’s your jQuery? Sorry bud, that’s code whether you like it or not. There are many ways to write code in SharePoint that have nothing to do with cracking open Visual Studio. So, what are the different ways to develop in SharePoint then? How many different ways can you “develop” in SharePoint?? A lot… Out of the box features In SharePoint you can create a site, create a custom list on that site, do basic calculations in a calculated column, set up alerts, and add all sorts of web parts to a page. Let’s face it.. that IS development! javaScript/jQuery Perhaps you’ve heard by now about this thing called jQuery? It’s all over the place and the answer to a lot of people’s prayers. However be careful, with great power comes great responsibility. Remember, javaScript is executed on the client side and if you abuse it your performance could be affected. Also, Marc Anderson (@sympmarc) wrote a pretty awesome javaScript library called SPServices.  This allows you to access SharePoint’s Web Services using jQuery. How freakin cool is that? With these tools at your disposal the number of things you CAN’T do without Visual Studio grows smaller and smaller. This is definitely development no matter what anyone else says and there is no Visual Studio involved. SharePoint Designer Ahhh.. The cause of and the answer to all of your SharePoint development problems. With SharePoint Designer you can use DataView Web Parts, develop (there’s that word again) your branding, and even connect to external datasources.  There’s a lot you can do in SharePoint Designer. It’s got it’s shortcomings, but it is an invaluable tool in the SharePoint developers toolbox. InfoPath So, can InfoPath development really be considered SharePoint development? I would say yes. You can connect to SharePoint lists, populate fields in a SharePoint list, and even write code in InfoPath. Sounds like SharePoint development to me. Visual Studio – Web Services/WCF So, get this. You can write code for SharePoint and not have a clue what the 12 hive is, what “site actions” means, or know how to do ANYTHING in SharePoint? Poppycock! You say? SharePoint Web Services I say… With SharePoint Web Services you can totally interact with SharePoint without knowing anything about SharePoint. I don’t recommend it of course, but it’s possible. What can you write using SharePoint Web Services? How about a little application called SharePoint Designer? Visual Studio – Object Model And here we are finally:  the SharePoint Object Model.  When you hear “SharePoint Developer” most people think of someone opening Visual Studio and creating a custom web part, workflow, event receiver, etc.. etc.. but I hope that by now I have made the point that this is NOT the only form of SharePoint Development! Again… Who cares? Just crack open Visual Studio for everything! Problem solved! Let’s ponder for a moment, shall we? The business comes to you with a requirement that involves some pretty fancy business calculations, and a complicated view that they do NOT want to look like SharePoint. “No Problem” you proclaim you mighty SharePoint Developer. You go back to your cube, chuckle at the latest Dilbert comic, and crack open Visual Studio. Then you build your custom web part… fight with all the deployment, migration, and UAT that you must go through and proclaim victory two weeks later!!!! Well done my good sir/ma’am! Oh wait… it turns out Sally who is not a “developer” did the exact same thing with a Dataview web part and some jQuery and it’s been in production for two weeks? #CockinessFail I know there are many ASP.NET developers out there that can create a custom control and wrap it to be a SharePoint Web Part.  That does NOT mean they are SharePoint Developers though as far as I’m concerned and I personally would much rather have someone on my team that can manipulate the heck (yes, I said ‘heck’) out of SharePoint using Dataview Web Parts, jQuery, and a roll of duct tape. Just because you know how to write code in Visual Studio does not mean you are a SharePoint Developer. What’s the conclusion here? How do we define ‘it’ and what ‘it’ is called? Fortunately, this is MY blog. I don’t have to give answers, I can stir the pot, laugh and leave you to ponder what it means! There is obviously no right or wrong answer here (unless you disagree with me,then you are flat out wrong). Anyway, there are many opinions.  Here’s mine.  If you put SharePoint Developer on your resume make sure to clearly specify HOW you develop in SharePoint and what tools you use. If we must label these gurus of jQuery and SPD, how about “SharePoint Client Developer” or “SharePoint Front End Developer”? Just throwing out an idea. Whatever we call them, to say they are not developers is short-sighted, arrogant, and unfair. Of course, then we need to figure out what to call all those other SharePoint development types.  Twitter Conversation @next_connect: RT @mrackley: Can someone be considered a SharePoint Developer if all they know how to do is work in SPD? | I say no.... @mikegil:  @mrackley re: yr Developer question: SPD expert <> SP Developer. Can be "sous-developer," though. #SharePoint #SPD @WonderLaura:  Rt @mrackley Can someone be considered a SharePoint Dev if all they know how to do is work in SPD? -- My opinion is that devs write code. @exnav29:  Rt @mrackley Can someone be considered a SharePoint Dev if all they know how to do is work in SPD? => I think devs would use VS as well @ssKevin:  @WonderLaura @mrackley does that mean strictly vb and c# when it comes to #SharePoint ? @jimmywim:  @exnav29 @mrackley nah, I'd say they were a power user. Devs know their way around the 12 hive ;) @sympmarc:  RT @mrackley: Can someone be considered a SharePoint Developer if all they know how to do is work in SPD? -> Fighting words. @sympmarc:  @next_connect @mrackley Besides, we prefer to be called "hacks". ;+) @next_connect:  @sympmarc The important thing is that you don't have to develop code to solve problems and create solutions. @mrackley @mrackley:  @sympmarc @next_connect not tryin to pick fight.. just try and find consensus on definition @usher:  @mrackley I'd still argue that you have a DevLite title that's out there for the collaboration engineers (@sympmarc @next_connect) @next_connect: @usher I agree. I've called it Light Dev/ Configuration before. @sympmarc @mrackley @usher:  @next_connect I like DevLite, low calorie but still same great taste :) @mrackley @sympmarc @mrackley:  @next_connect @usher @sympmarc I don't think there's any "lite" to someone who can bend jQuery and XSLT to their will. @usher:  @mrackley okay, so would you refer to someone that writes user controls and assemblies something different (@next_connect @sympmarc) @usher:  @mrackley when looking for a developer that can write .net code, it's a bit different than an XSLT/jQuery designer. @sympmarc @next_connect @jimmywim:  @mrackley @sympmarc @next_connect I reckon a "dev" does managed code and works in the 12 hive @sympmarc:  @jimmywim @mrackley @next_connect We had a similar debate a few days ago @toddbleeker et al @sympmarc:  @sympmarc @jimmywim @mrackley @next_connect @toddbleeker @stevenmfowler More abt my Middle Tier term, but still connected. Meet bus need. @toddbleeker:  @sympmarc @jimmywim @mrackley @next_connect I used "No Assembly Required" in the past. I also suggested "Supplimenting the SharePoint DOM" @toddbleeker:  @sympmarc @jimmywim @mrackley @next_connect Others suggested Information Worker Solutions/Enhancements @toddbleeker:  @sympmarc @jimmywim @mrackley @next_connect @stevenmfowler I also like "SharePoint Scripting Solutions". All the technologies are script. @jimmywim:  @toddbleeker @sympmarc @mrackley @next_connect I like the IW solutions one... @toddbleeker:  @sympmarc @jimmywim @mrackley @next_connect @stevenmfowler This is like the debate that never ends: it is definitely not called Middle Tier. @jimmywim:  @toddbleeker @sympmarc @mrackley @next_connect @stevenmfowler "Scripting" these days makes me think PowerShell... @sympmarc:  @toddbleeker @jimmywim @mrackley @next_connect @stevenmfowler If it forces a debate on h2 best solve bus probs, I'll keep sayin Middle Tier. @usher:  @sympmarc so we know what we're looking for, we just can't define a name? @toddbleeker @jimmywim @mrackley @next_connect @stevemfowler @sympmarc:  @usher @sympmarc @toddbleeker @jimmywim @mrackley @next_connect @stevemfowler The naming seems to matter more than the substance. :-( @jimmywim:  @sympmarc @usher @toddbleeker @mrackley @next_connect @stevemfowler work brkdn defines tasks, defines tools needed, can then b grp'd by user @WonderLaura:  @mrackley @toddbleeker @jimmywim @sympmarc @usher @next_connect Funny you're asking. @johnrossjr and I spent hours this week on the subject. @stevenmfowler:  RT @toddbleeker: @sympmarc @jimmywim @mrackley @next_connect @stevenmfowler it is definitely not called Middle Tier. < I'm with Todd

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  • Problem installing Ubuntu 10.04 64 bit side by side with Vista by using a bootable USB drive. What n

    - by Adam Siddhi
    What happened I decided to install Ubuntu 10.04 64 bit side by side with Vista Home Premium (I guess on another partition) with a USB stick. I found instructions on how to do this here: https://help.ubuntu.com/community/Installation/FromUSBStick To create the bootable USB drive I had to download a program called Unetbootin. That process was simple enough. All I had to do was just choose the disk image option, select the ubuntu-10.04-desktop-amd64.iso image, make sure it recognizes my USB drive and then press OK. It takes only like a few minutes to create a working bootable USB drive. Then I have to restart my computer, enter the BIOS, select my USB drive as the first boot drive, save options and continue with booting up. After this Ubuntu actually loads up. I think this is known as the Live version of Ubuntu so you can try it out before fully installing it. Any ways, on the Ubuntu 10.04 desktop I saw an installer. I click it and begin the installation process. Just so you know, I tried installing it 2 times. I will explain what happened each time: The first time I tried installing Ubuntu 10.04 I got stuck at step 4 of 7. I remember selecting the last option in the window which was Specify Partitions Manually (Advanced) I made my partition for Ubuntu like 52 gigs. I clicked forward and a little pop up window appeared saying Please Wait. So the installation process stalled on this window so I closed out of it and quit the installation process. So at this point I was worried because I had already selected the partition size and assumed it started making it. Since it stalled I had to quit out though. Anyways, once again I reached step 4 of 7 a decided to select the first option which is Install them side by side choosing between them each startup. I figured this was the safe way to go. I did that and the pop up window saying Please Wait popped up again but lasted only like 10 seconds. Then I got to I guess step 6 where it asks you to enter your desired name and password. Did that and clicked forward. The Ubuntu 10.04 installation load screen appeared and the loading bar at the bottom started filling up. So I got to 83% and stalled during the Importing other profile information (I think it was called this. I had the option to do this during I think step 6) process. So at this point I decided to get stop the installation process. I was getting very nervous. I tried to restart the computer but all that happened was that Ubuntu restarted. I finally got the computer to restart. I was pretty sure I had screwed something up big time by this point. As my computer was restarting I entered BIOS again and switched back to it booting from my main hard drive containing Vista. Saved it and continued the boot process. My worst fears were confirmed as Vista would not boot up. I mean I saw the little Microsoft Windows choppy animated green loading bar at the bottom of the screen and then boom! It decided to restart. When it restarted I had the option to run a memory test check to see if there was anything that needed to be repaired. That took like 20 minutes and at the end I saw that I did indeed have to repair something. I had to go through 2 repair processes. After each I had to restart the computer. The 2nd time it went through the repair process it said that it could not fully repair the damage. I was scared and restarted but Vista did load up. I got to my desktop and saw a message saying something like Repairs have been made, Please restart for changes to take effect I noticed that some Notification icons were missing and I could not hear volume in a video. Things were a bit funky. So I did restart and here I am. Now what?! So since I got back into Vista and thankfully have a working Internet connection I am trying to find answers to my problem (that is why I am writing this post). I am scared that I have partioned my hard drive 2 times after researching Installing Ubuntu 10.04 and seeing this post http://techie-buzz.com/foss/ubuntu-10-04-lts-installation-guide.html The author shows screen shots of installing Ubuntu 10.04. He shows the image of step 4 of 7 with a caption at the bottom. I will recreate it below: Select a partitioning option. Unless you want to format all the hard drive and install Ubuntu afresh, select the last option and proceed. Questions If I have indeed partitioned my HD 2 times (which I am sure it is), how do I get to a point where I can see all my bad, unfinished Ubuntu partitions and get rid of them? How do I clean this big mess up? & How can I ensure that this mess will not happen next time I try installing Ubuntu 10.04? Thank you Adam

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  • Why does Process Explorer cause highly targeted failure of some applications / basic UI functions in a high-power EC2 Windows instance?

    - by Dan Nissenbaum
    Update: I have determined that Process Explorer itself - the program I am using to debug a performance issue - seems to be the cause of the issue. See note, with updated question, at end. I am running a high-power (cc2.8xlarge) Amazon AWS EC2 Windows instance off of a boot EBS volume, provisioned at 2500 PIOPS, which was created from a snapshot of a previous boot volume. My purpose with the instance is to use it as a development workstation with many developer tools installed, such as Visual Studio, a local XAMPP stack, etc. I have upwards of 40 programs installed on the machine. The usability of the instance as a development machine often works quite well. The RDP lag is adequately small. I have used it for hours on end without problems for some of my most intense development tasks. As a result, I have just purchased a reserved instance, and I opted to rebuild my development machine starting from scratch with a Windows Server 2012 AMI. After having installed all of my desired/required applications for development over this past week, again the machine seems to often work well and I have worked for up to an hour at a time without problems doing heavy development work. However, I continue to run into catastrophic OS usability issues that may prevent me from being able to rely on this machine as a development machine. I would like to track down the source of the problem, if there is an easily identifiable source. (Update: I have tracked down the source to be Process Explorer, the very program I was using to debug the problem. See update at end.) The issues are as follows. (These are some primary examples) Some applications, after a period of adequate responsiveness, suddenly begin to respond very, very slowly to basic user interface actions such as clicking on menus and pressing Ctrl-Tab to switch between open documents. Two examples are UltraEdit and PhpEd. It typically takes ~2 seconds for a menu to appear, and ~4 seconds to switch between open documents. Additionally, insertion point motion in the editor is lagged by upwards of ~2 seconds. Process Explorer, which I am using to help debug the problem, seems to run acceptably for a couple of minutes, but on multiple occasions Process Explorer itself hangs completely. It hangs at the same time as the problems noted above. When it hangs, it is 100% unresponsive. Clicking on its taskbar icon neither causes it to come to the top or go behind, and its viewable area is filled with nothing but a region partially containing pure white and partially containing incomplete windows widgets that are unreadable, and that never change. Waiting 10 minutes does not clear the problem. Attempting to force-quit Process Explorer by right-clicking on its taskbar icon and choosing "Close Window" takes about 5 full minutes to exit (Process Explorer itself can't be used to exit Process Explorer, and it is registered as a Task Manager substitute). Other programs work just fine during this time. For example, Chrome tabs flip very quickly back and forth, menus pop open instantly, web pages load quickly, and typing in forms/web applications inside the browser works promptly. Another example of an application that works crisply is Filemaker - its menus open instantly, and switching views in this application occurs promptly. Other applications also work without issue. Also, switching between applications occurs promptly as well. It is only a handful of applications that exhibit the problem, with some primary examples given above. At first I thought that EBS IOPS might be a problem. Therefore, I ran Performance Monitor, and watched the "Disk Transfers/sec" monitor in real time. At no point did this measure come anywhere close to hitting the 2500 PIOPS provisioned for the EBS volume. The RAM was also well under the limit (~10 GB used out of 60 GB). I did notice that one CPU core (out of 32 logical cores) was fully thrashing at 100% (i.e., ~3.1%) during the problematic periods. This seems to indicate that a single CPU core is handling the menus / flipping between open documents (for some applications only) / managing the Process Explorer user interface, and that this single core was hosed for some reason during the problematic periods. Also note that I have a desktop workstation (Windows 7) that I also use as a development machine, via a remote connection, with a nearly identical set of programs installed, and this desktop workstation does not exhibit any of the problems I've discussed above. I have been using it heavily for well over a year now. Any suggestions regarding either the source of the problem, or steps I might take to investigate the source of the problem, would be appreciated. Thanks. Note: After extensive testing & investigation, I have noticed that when I quit Process Explorer, the problem vanishes and the system performance returns to normal, and then reappears quickly when I run Process Explorer again (note: again, the performance problems only appear for a subset of applications - other applications work perfectly fine during the same period). My question is therefore (thankfully) more specific: Why does Process Explorer cause highly targeted failure of some applications (including itself) and basic UI functions, in a high-power EC2 Windows instance?

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  • Timeout Considerations for Solicit Response

    - by Michael Stephenson
    Background One of the clients I work with had been experiencing some issues for a while surrounding web service timeouts.  It's been a little challenging to work through the problems due to limitations in the diagnostic information available from one of the applications, but I learned some interesting things while troubleshooting the problem which don't seem to have been discussed much in the community so I thought I'd share my findings. In the scenario we have BizTalk trying to make calls to a .net web service which was exposed as a WSE 2 endpoint.  In the process BizTalk will try to make a large number of concurrent web service calls to the application, and the backend application has more than enough infrastructure and capability to handle the load. We have configured the <ConnectionManagement> section of the BizTalk configuration file to support up to 100 concurrent connections from each of our 2 BizTalk send servers to the web servers of the application. The problem we were facing was that the BizTalk side was reporting a significant number of timeouts when calling the web service.   One of the biggest issues was the challenge of being able to correlate a message from BizTalk to the IIS log in the .net application and the custom logs in the application especially when there was a fairly large number of servers hosting the web services.  However the key moment came when we were able to identify a specific call which had taken 40 seconds to execute on the server (yes a long time I know but that's a different story!).  Anyway we were able to identify that this had timed out on the BizTalk side.  Based on the normal 2 minute timeout we knew something unexpected was going on. From here I decided to do some experimentation and I wanted to start outside of BizTalk because my hunch was this was not a BizTalk behaviour but something which was being highlighted by BizTalk because of our large load.     Server-side - Sample Web Service To begin with I created a sample web service.  Nothing special just a vanilla asmx web service hosted in IIS6 on Windows 2003 Standard Edition.  The web service is just a hello world style web service as shown in the below picture.  The only key feature is that the server side web method has a 30 second sleep in it and will trace out some information before and after the thread is set to sleep.      In the configuration for this web service there again is nothing special it's pretty much the most plain simple web service you could build. Client-Side To begin looking at what was happening with our example I created a number of different ways to consume the web service. SoapHttpClientProtocol Example I created a small application which would use a normal proxy generated to call the web service.  It would iterate around a loop and make calls using the begin/end methods so I can do this asynchronously.  I would do a loop of 20 calls with the ConnectionManager configuration section supporting only 5 concurrent connections to the server.     <connectionManagement> <remove address="*"/> <add address = "*" maxconnection = "12" /> <add address = "http://<ServerName>" maxconnection = "5" />                         </connectionManagement> </system.net>     The below picture shows an example of the service calling code, key points are: I have configured the timeout of 40 seconds for the proxy I am using the asynchronous methods on the proxy to call the web service         The Test I would run the client and execute 21 calls to the web service.   The Results  Below is the client side trace showing what's happening on the client. In the below diagram is the web service side trace showing what's happening on the server Some observations on the results are: All of the calls were successful from the clients perspective You could see the next call starting on the server as soon as the previous one had completed Calls took significantly longer than 40 seconds from the start of our call to the return. In fact call 20 took 2 minutes and 30 seconds from the perspective of my code to execute even though I had set the timeout to 40 seconds     WSE 2 Sample In the second example I used the exact same code to call the web service again with a single exception that I modified the web service proxy to derive from WebServiceClient protocol which is part of WSE 2 (using SP3).  The below picture shows the basic code and the key points are: I have configured the timeout of 40 seconds for the proxy I am using the asynchronous methods on the proxy to call the web service        The Test This test would execute 21 calls from the client to the web service.   The Results  The below trace is from the client side: The below trace is from the server side:   Some observations on the trace results for this scenario are: With call 4 if you look at the server side trace it did not start executing on the server for a number of seconds after the other 4 initial calls which were accepted by the server. I re-ran the test and this happened a couple of times and not on most others so at this point I'm just putting this down to something unexpected happening on the development machine and we will leave this observation out of scope of this article. You can see that the client side trace statement executed almost immediately in all cases All calls after the initial few calls would timeout On the client side the calls that did timeout; timed out in a longer duration than the 40 seconds we set as the timeout You can see that as calls were completing on the server the next calls were starting to come through The calls that timed out on the client did actually connect to the server and their server side execution completed successfully     Elaboration on the findings Based on the above observations I have drawn the below sequence diagram to illustrate conceptually what is happening.  Everything except the final web service object is on the client side of the call. In the diagram below I've put two notes on the Web Service Proxy to show the two different places where the different base classes seem to start their timeout counters. From the earlier samples we can work out that the timeout counter for the WSE web service proxy starts before the one for the SoapHttpClientProtocol proxy and the WSE one includes the time to get a connection from the pool; whereas the Soap proxy timeout just covers the method execution. One interesting observation is if we rerun the above sample and increase the number of calls from 21 to 100,000 then for the WSE sample we will see a similar pattern where everything after the first few calls will timeout on the client as soon as it makes a connection to the server whereas the soap proxy will happily plug away and process all of the calls without a single timeout. I have actually set the sample running overnight and this did happen. At this point you are probably thinking the same thoughts I was at the time about the differences in behaviour and which is right and why are they different? I'm not sure there is a definitive answer to this in the documentation, or at least not that I could find! I think you just have to consider that they are different and they could have different effects depending on your messaging solution. In lots of situations this is just not an issue as your concurrent requests doesn't get to the situation where you end up throttling the web service calls on the client side, however this is definitely more common with an integration broker such as BizTalk where you often have high throughput requirements.  Some of the considerations you should make Based on this behaviour you should be aware of the following: In a .net application if you are making lots of concurrent web service calls from an application in an asynchronous manner your user may thing they are experiencing poor performance but you think your web service is working well. The problem could be that the client will have a default of 2 connections to remote servers so you should bear this in mind When you are developing a BizTalk solution or a .net solution with the WSE 2 stack you may experience timeouts under load and throttling the number of connections using the max connections element in the configuration file will not help you For an application using WSE2 or SoapHttpClientProtocol an expired timeout will not throw an error until after a connection to the server has been made so you should consider this in your transaction and durability patterns     Our Work Around In the short term for our specific scenario we know that we can handle this by just increasing our timeout value.  There is only a specific small window when we get lots of concurrent traffic that causes this scenario so we should be able to increase the timeout to take into consideration the additional client side wait, and on the odd occasion where we do get a timeout the BizTalk send port retry will handle this. What was causing our original problem was that for that short window we were getting a lot of retries which significantly increased the load on our send servers and highlighted the issue.  Longer Term Solution As a longer term solution this really gives us more ammunition to argue a migration to WCF. The application we are calling has some factors which limit the protocols we can use but with WCF we would have more control on the various timeout options because in WCF you can configure specific parts of the timeout. Summary I've had this blog post on my to do list for ages but hopefully it will be useful to some people to just understand this behaviour and to possibly help you with some performance issues you may have. I do not believe there is too much in the way of documentation particularly around WSE2 and ASMX in this area so again another bit of ammunition for migrating to WCF. I'll try to do a follow up post with the sample for WCF to show how this changes things.

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  • Remote host: can tracert, can telnet, can*not* browse: what gives?

    - by MacThePenguin
    One of my customers of the company I work for has made a change to their Internet connection, and now we can't connect to them any more from our LAN. To help me troubleshoot this issue, the network guy on the customer's site has configured their firewall so that a HTTPS connection to their public IP address is open to any IP. I should put https://<customer's IP> in my browser and get a web page. Well, it works from any network I've tried (even from my smartphone), just not from my company's LAN. I thought it may be an issue with our firewall (though I checked its rules and it allows outbound TCP port 443 to anywhere), so I just connected a PC directly to the network connection of our provider, bypassing out firewall completely, and still it didn't work (everything else worked). So I asked for help to our Internet provider's customer service, and they asked me to do a tracert to our customer's IP. The tracert is successful, as the final hop shown in the output is the host I want to reach. So they said there's no problem. :( I also tried telnet <customer's IP> 443 and that works as well: I get a blank page with the cursor blinking (I've tried using another random port and that gives me an error message, as it should). Still, from any browser of any PC in my LAN I can't open that URL. I tried checking the network traffic with Wireshark: I see the packages going through and answers coming back, thought the packets I see passing are far less than they are if I successfully connect to another HTTPS website. See the attached screenshot: I had to blur the IPs, anyway the longer string is my PC's local IP address, the shorter one is the customer's public IP. I don't know what else to try. This is the only IP doing this... Any idea what could I try to find a solution to this issue? Thanks, let me know if you need further details. Edit: when I say "it doesn't work" I mean: the page doesn't open, the browser keeps loading for a long time and eventually shows an error saying that the page cannot be opened. I'm not in my office now so I can't paste the exact message, but it's the usual message you get when the browser reaches its timeout. When I say "it works", I mean the browser loads and shows a webpage (it's the logon page for the customers' firewall admin interface: so there's the firewall brand's logo and there are fields to enter a user id and a password). Update 13/09/2012: tried again to connect to the customer's network through our Internet connection without a firewall. This is what I did: Run a Kubuntu 12.04 live distro on a spare laptop; Updated all the packages I could and installed WireShark; Attached it to my LAN and verified that I couldn't open https://<customer's IP>. Verified that the Wireshark trace for this attempt was the same as the one I've already posted; Verified that I could connect to another customer's host using rdesktop (it worked); Tried to rdesktop to <customer's IP>, here's the output: kubuntu@kubuntu:/etc$ rdesktop <customer's IP> Autoselected keyboard map en-us ERROR: recv: Connection reset by peer Disconnected the laptop from the LAN; Disconnected the firewall from the Extranet connection, connected the laptop instead. Set its network configuration so that I could access the Internet; Verified that I could connect to other websites in http and https and in RDP to other customers' hosts - it all worked as expected; Verified that I could still traceroute to <customer's IP>: I could; Verified that I still couldn't open https://<customer's IP> (same exact result as before); Checked the WireShark trace for this attempt and noticed a different behaviour: I could see packets going out to the customer's IP, but no replies at all; Tried to run rdesktop again, with a slightly different result: kubuntu@kubuntu:/etc/network$ rdesktop <customer's IP> Autoselected keyboard map en-us ERROR: <customer's IP>: unable to connect Finally gave up, put everything back as it was before, turned off the laptop and lost the WireShark traces I had saved. :( I still remember them very well though. :) Can you get anything out of it? Thank you very much. Update 12/09/2012 n.2: I followed the suggestion by MadHatter in the comments. From inside the firewall, this is what I get: user@ubuntu-mantis:~$ openssl s_client -connect <customer's IP>:443 CONNECTED(00000003) If I now type GET / the output pauses for several seconds and then I get: write:errno=104 I'm going to try the same, but bypassing the firewall, as soon as I can. Thanks. Update 12/09/2012 n.3: So, I think ISA Server is altering the results of my tests... I tried installing Wireshark directly on the firewall and monitoring the packets on the Extranet network card. When the destination is the customer's IP, whatever service I try to connect to (HTTPS, RDP or SAProuter), I can only see outbound packets and no response packets whatsoever from their side. It looks like ISA Server is "faking" the remote server's replies, that's why I get a connection using telnet or the openSSL client. This is the wireshark trace from inside our LAN: But this is the trace on the Extranet network card: This makes a bit more sense... I'll send this info to the customer's tech and see if he can make anything out of it. Thanks to all that took the time to read my question and post suggestions. I'll update this post again.

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  • VFS: file-max limit 1231582 reached

    - by Rick Koshi
    I'm running a Linux 2.6.36 kernel, and I'm seeing some random errors. Things like ls: error while loading shared libraries: libpthread.so.0: cannot open shared object file: Error 23 Yes, my system can't consistently run an 'ls' command. :( I note several errors in my dmesg output: # dmesg | tail [2808967.543203] EXT4-fs (sda3): re-mounted. Opts: (null) [2837776.220605] xv[14450] general protection ip:7f20c20c6ac6 sp:7fff3641b368 error:0 in libpng14.so.14.4.0[7f20c20a9000+29000] [4931344.685302] EXT4-fs (md16): re-mounted. Opts: (null) [4982666.631444] VFS: file-max limit 1231582 reached [4982666.764240] VFS: file-max limit 1231582 reached [4982767.360574] VFS: file-max limit 1231582 reached [4982901.904628] VFS: file-max limit 1231582 reached [4982964.930556] VFS: file-max limit 1231582 reached [4982966.352170] VFS: file-max limit 1231582 reached [4982966.649195] top[31095]: segfault at 14 ip 00007fd6ace42700 sp 00007fff20746530 error 6 in libproc-3.2.8.so[7fd6ace3b000+e000] Obviously, the file-max errors look suspicious, being clustered together and recent. # cat /proc/sys/fs/file-max 1231582 # cat /proc/sys/fs/file-nr 1231712 0 1231582 That also looks a bit odd to me, but the thing is, there's no way I have 1.2 million files open on this system. I'm the only one using it, and it's not visible to anyone outside the local network. # lsof | wc 16046 148253 1882901 # ps -ef | wc 574 6104 44260 I saw some documentation saying: file-max & file-nr: The kernel allocates file handles dynamically, but as yet it doesn't free them again. The value in file-max denotes the maximum number of file- handles that the Linux kernel will allocate. When you get lots of error messages about running out of file handles, you might want to increase this limit. Historically, the three values in file-nr denoted the number of allocated file handles, the number of allocated but unused file handles, and the maximum number of file handles. Linux 2.6 always reports 0 as the number of free file handles -- this is not an error, it just means that the number of allocated file handles exactly matches the number of used file handles. Attempts to allocate more file descriptors than file-max are reported with printk, look for "VFS: file-max limit reached". My first reading of this is that the kernel basically has a built-in file descriptor leak, but I find that very hard to believe. It would imply that any system in active use needs to be rebooted every so often to free up the file descriptors. As I said, I can't believe this would be true, since it's normal to me to have Linux systems stay up for months (even years) at a time. On the other hand, I also can't believe that my nearly-idle system is holding over a million files open. Does anyone have any ideas, either for fixes or further diagnosis? I could, of course, just reboot the system, but I don't want this to be a recurring problem every few weeks. As a stopgap measure, I've quit Firefox, which was accounting for almost 2000 lines of lsof output (!) even though I only had one window open, and now I can run 'ls' again, but I doubt that will fix the problem for long. (edit: Oops, spoke too soon. By the time I finished typing out this question, the symptom was/is back) Thanks in advance for any help. And another update: My system was basically unusable, so I decided I had no option but to reboot. But before I did, I carefully quit one process at a time, checking /proc/sys/fs/file-nr after each termination. I found that, predictably, the number of open files gradually went down as I closed things down. Unfortunately, it wasn't a large effect. Yes, I was able to clear up 5000-10000 open files, but there were still over 1.2 million left. I shut down just about everything. All interactive shells, except for the one ssh I left open to finish closing down, httpd, even nfs service. Basically everything in the process table that wasn't a kernel process, and there were still an appalling number of files apparently left open. After the reboot, I found that /proc/sys/fs/file-nr showed about 2000 files open, which is much more reasonable. Starting up 2 Xvnc sessions as usual, along with the dozen or so monitoring windows I like to keep open, brought the total up to about 4000 files. I can see nothing wrong with that, of course, but I've obviously failed to identify the root cause. I'm still looking for ideas, since I definitely expect it to happen again. And another update, the next day: I watched the system carefully, and discovered that /proc/sys/fs/file-nr showed a growth of about 900 open files per hour. I shut down the system's only NFS client for the night, and the growth stopped. Mind you, it didn't free up the resources, but it did at least stop consuming more. Is this a known bug with NFS? I'll be bringing the NFS client back online today, and I'll narrow it down further. If anyone is familiar with this behavior, feel free to jump in with "Yeah, NFS4 has this problem, go back to NFS3" or something like that.

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  • alot questings since i wanted to make a new SSB game or mario game(that use 3d models) [closed]

    - by user20465
    i have just started to study programming and i know already ppl will say why make a so big project like as a SSB game for a noob game development? cuz i always wanted a SSB engine like as Mugen is a fighter game engine but is not like as SSB´s gameplay + is not using 3d models too so i will call it SSBmugen(until i find a better title for it i got afew ideas for titles) also i wanted to make this game so it can use SSBbrawl files(models+animations mainly) the moveset+Stage coding files i wanted to redo cuz so anything can be possible like make a teleporter or a pipe teleporter(like as Super mario bros game) on a stag e or make some stuff there is impossible in SSBbrawl for moveset coding but is not in SSBmugen like make so a char. summon a Clone and the clone will do a attack and then is gone or some attacks/moves also i will make a moveset/stage Coding editor so it will be really easy to make moveset/stages coding for yours 3d models/animations moveset+stage Coding i mean: hitboxes/hurtboxes/moving Stuff/moving bones like cape or hair bones that is moving by wind effects or falling or other stuff like that/other stuff that needed to be coded i have planed to make a editor(for moveset/char. coding) or add the editor in brawlbox for my game so other ppl can easy make moveset/stages Coding to they´s models/animations so it will be easy so even kids can make a custom movesets/stages why using SSBbrawl files?: cuz ppl have made alot of models or textures/custom movesets/custom stages like goku/other anime/not brawl stuff for super smash bros brawl hacking(a.k.a modding) so ppl dont have to redo anything if they wanted to have the custom models or textures/custom movesets/custom stages from SSBbrawl to SSBmugen +there is the program named brawlbox that can open brawl files like model/animations and can edit models or animations and import models from 3ds max to be the right model format for SSBbrawl and i also wanted it so easy to add(a.k.a installer) Recolours or alt. models(like as oneslot doctor mario model over mario´s boneset) or textures/Movesets/new char. slots/new stages so easy so you only needing to download themplace them in right foldername them the right nameStart the gameRecolours or alt. models or textures/Movesets/new char. slots/new stages works an loading right so you wont needing to edit any files for add something so kids/not so smart ppl can easy use the mods other ppl is making/uploading for this game here is the file format i wanted to know if they can be readed/opened if making a game that use these files: .mld0(brawl model file) .chr0(model animation for moving/scale/rota the bones) .srt0(animations for texture like moving eyes or blinking) .vis0(Animations for get polygons to hide/show with visibilitybones on the model there is also some polygons there ) .brres(a file format where stuff like model files or textures or animations is inside) .pac(a file format where the .brres is inside to keep model+textures+model for the shadow in 1 file) .wav (for SoundFX effects or voices to char. or stages) i am sure that one is possible the .wav files is inside a other file format for brawl but that file can´t you add more .wav files inside only replace so i wanted the .wav files outside so its easy to add/replace/remove SoundFX effects or voices to char. or stages .brstm(brawl music file so the music is looped perfect so it loop in middel of the music and not start over again then the music is done) afew more file formats (mainly for the Graphics effects like fire/aura/hit effects if not needing to redo them)so only coding in the editor i will make is needed to be done for port a SSBB hack(a.k.a mod)(moveset/stage coding) to this game wanted the game to be able to load these files and load them right like if loading wait1.chr0(idle animation) it will also load at same time wait1.srt0/wait1.vis0 and all kinda of animations is inside the same .brres file i am needing since it to be able to load the file format i wanted cuz: -the animations can´t be converted to any other animation file format and i dont think ppl want to redo these animations(inc. me for Goku to SSBbrawl) -models can be converted but then they lose all the shader/materials stuff like a shine effect or lighting on the model -.brstm can be converted to .wav but then there will be no loop so i prefer it can load this file format too for the music to stage/menu -brawlbox is really easy to use for make animation for the char. and import models from 3ds max so even around "not too stupid" 10 year kids can make SSBB mods(not try to be rude but to say how easy it is) also i wanted the folder setup for characters/stages/moveset/other stuff to be like this: https://www.dropbox.com/s/2oolm5z5ri234tz/SSBmugen%20Folder%20setup.txt just uploaded a txt file since it is a wall of text and this post is already a wall of test so it easy to place stuff (if not i do a program for to that so it auto place the stuff on right place) not 100% sure what to use of game engine to make this possible but i got a dll file from that brawlbox program that can open/read/edit these file formats if that helps i also got open source of brawlbox i have kinda learned programming(since its kinda the same thing but still not 100% same) from Super smash bros modding/hacking like coding a moveset for the new animations/models + have readed alittle about it but i am soon starting for real to study it for ppl who is alittle confuse for what i am asking for here is the list: -what game engine should i use to make a SSB clone? but at same time to make all this stuff i just said possible so ppl can make they own mods and share them and use the already made mods from SSBbrawl? and easy to use aswell so noob programmors can use it? -where to learning programming on internet to be even more ready to make a game like this? and dont wanted to start in the small like making small boring 2d games that no one care about anyway ps. i am also planing a other project like as SSBmugen but it will be Super mario bros open (again tittle unsure but open means open source) i will make a Mario game engine that also use 3d models and can have 2d or 3d gameplay with any mario powerups/gameplay(from any mario platform games) there is ever made multiplayer like as in New super mario bros wii maybe multiplay over lan or online but for now over 1 PC also alittle planed for that to my SSBmugen a Level/world map editor for it too(easy to use so even kids can use it and make levels for it) so it just place the objects/enemies and options for them enemies since they are not 100% same AI in all mario game like to choose a goomba have AI from SM64 the Editor will be able to change the gameplay on a level while have a other gameplay on a other level like this: 1 level have Super mario bros 3 gameplay (then it will be a 3d model remake) a other level have super mario galaxy gameplay but in a Super mario 3d land level yet a other level have super mario 64 gameplay but with powerups from a other mario game like powerups from mario 3d land or can ride on Yoshi so you can easy remake your fav. level from a old mario game in this mario engine/editor or just make a custom one with yours fav. mario gameplay/powerups so it will be like turn off/on: walljump/triple jump/other kinda or jumps/2x punch and 1 kick+Air kick/SMG spin attack/Fludd/other stuff like that so you can make the gameplay from the first mario game to the newest or make custom gameplay on a level also the star(from 64/sunshine/galaxy) will be replaced with the flag from new super mario bros/mario 3d land since the game is not so much about getting stars its more about making/download the levels you wanted and share them to other ppl and play these level so after have killed like the boss from SM64 bomb omb field(if one have made that) you will get the flag instead of star since i wanted it to be simple to make levels in the editor to make the bosses/new enemies/new powerups/custom char. idk what to do to make that simple yet also thinking the mario game will use brawl files since it almost already got all needed animations/models for this since i dont wanted to redo animations/models and if needing more animations i can just make them easy in brawlbox since thats the program i am most used to make animations but that will be after my SSBmugen project if not this game will be easyer then SSBmugen to make since i am planing then 1 of them is done i use the that game as base to make the other (since both is kinda platfrom games and possible using same file format for both) also wanted to ask what is best to start with out of these 2 games? also will maybe make a DLC site(or ingame) for both of these games if they get done so it wont end up like as Mugen where you needing to look all over the internet to find the stuff you wanted but for my game all the mods for my game is on same place not sure about online mode for SSBmugen or super mario bros open but i can always add that then i get better at programming both games also need to have options on controls/if using joystick also that i have planed these game for a long time and got even more ideas for them but first i wanted to get them to work so i can add the other stuff later(like DLC or online mode or some other stuff later) right now i know 0,0001% to programming(in my option) maybe i know more then that since i have been study it alittle but i learning while making stuff like this that was also my plan for make these game learn while making them and get better to programming so again i say it i kinda dont want to hear dont do these projects cuz i already know it will be hard so dont wanted so much to heard stuff like: you can´t do it since you just started learning programming or this project will fail since somewhere i needing to get started with programming and this is where i want to start to make my dream games(possible other´s dream games too) and i dont think this project will fail if i work hard on it (as i possible will) and ppl will maybe help i think this was all my questing/ideas for now (sorry for it sounds more like ideas then questings) but i needing to say my ideas so you ppl can see what i needing to use for make this possible

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  • Cluster failover and strange gratuitous arp behavior

    - by lazerpld
    I am experiencing a strange Windows 2008R2 cluster related issue that is bothering me. I feel that I have come close as to what the issue is, but still don't fully understand what is happening. I have a two node exchange 2007 cluster running on two 2008R2 servers. The exchange cluster application works fine when running on the "primary" cluster node. The problem occurs when failing over the cluster ressource to the secondary node. When failing over the cluster to the "secondary" node, which for instance is on the same subnet as the "primary", the failover initially works ok and the cluster ressource continues to work for a couple of minutes on the new node. Which means that the recieving node does send out a gratuitous arp reply packet that updated the arp tables on the network. But after x amount of time (typically within 5 minutes time) something updates the arp-tables again because all of a sudden the cluster service does not answer to pings. So basically I start a ping to the exchange cluster address when its running on the "primary node". It works just great. I failover the cluster ressource group to the "secondary node" and I only have loss of one ping which is acceptable. The cluster ressource still answers for some time after being failed over and all of a sudden the ping starts timing out. This is telling me that the arp table initially is updated by the secondary node, but then something (which I haven't found out yet) wrongfully updates it again, probably with the primary node's MAC. Why does this happen - has anyone experienced the same problem? The cluster is NOT running NLB and the problem stops immidiately after failing over back to the primary node where there are no problems. Each node is using NIC teaming (intel) with ALB. Each node is on the same subnet and has gateway and so on entered correctly as far as I am concerned. Edit: I was wondering if it could be related to network binding order maybe? Because I have noticed that the only difference I can see from node to node is when showing the local arp table. On the "primary" node the arp table is generated on the cluster address as the source. While on the "secondary" its generated from the nodes own network card. Any input on this? Edit: Ok here is the connection layout. Cluster address: A.B.6.208/25 Exchange application address: A.B.6.212/25 Node A: 3 physical nics. Two teamed using intels teaming with the address A.B.6.210/25 called public The last one used for cluster traffic called private with 10.0.0.138/24 Node B: 3 physical nics. Two teamed using intels teaming with the address A.B.6.211/25 called public The last one used for cluster traffic called private with 10.0.0.139/24 Each node sits in a seperate datacenter connected together. End switches being cisco in DC1 and NEXUS 5000/2000 in DC2. Edit: I have been testing a little more. I have now created an empty application on the same cluster, and given it another ip address on the same subnet as the exchange application. After failing this empty application over, I see the exact same problem occuring. After one or two minutes clients on other subnets cannot ping the virtual ip of the application. But while clients on other subnets cannot, another server from another cluster on the same subnet has no trouble pinging. But if i then make another failover to the original state, then the situation is the opposite. So now clients on same subnet cannot, and on other they can. We have another cluster set up the same way and on the same subnet, with the same intel network cards, the same drivers and same teaming settings. Here we are not seeing this. So its somewhat confusing. Edit: OK done some more research. Removed the NIC teaming of the secondary node, since it didnt work anyway. After some standard problems following that, I finally managed to get it up and running again with the old NIC teaming settings on one single physical network card. Now I am not able to reproduce the problem described above. So it is somehow related to the teaming - maybe some kind of bug? Edit: Did some more failing over without being able to make it fail. So removing the NIC team looks like it was a workaround. Now I tried to reestablish the intel NIC teaming with ALB (as it was before) and i still cannot make it fail. This is annoying due to the fact that now i actually cannot pinpoint the root of the problem. Now it just seems to be some kind of MS/intel hick-up - which is hard to accept because what if the problem reoccurs in 14 days? There is a strange thing that happened though. After recreating the NIC team I was not able to rename the team to "PUBLIC" which the old team was called. So something has not been cleaned up in windows - although the server HAS been restarted! Edit: OK after restablishing the ALB teaming the error came back. So I am now going to do some thorough testing and i will get back with my observations. One thing is for sure. It is related to Intel 82575EB NICS, ALB and Gratuitous Arp.

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  • GNOME PPP doesn't connect

    - by Motorhead
    I am a new ubuntu user and connect to the internet using wi-fi broadband on my notebook. But I need to setup a dial-up connection through my phone which can keep me online while I travel. I have tried connecting to dial-up using pppconfig, wvdial and gnome-ppp. I do not know whether they use the same files for connecting but I have only been able to connect using Gnome-ppp. But the connection is intermittent and disconnects every five seconds or so. The exit code is 16 which I checked in man and got to know that the modem hangs itself up. I am connecting my phone to ubuntu as a usb modem. And as I am new I might have skipped a step or two. Please suggest a solution or an alternative to this. I have put down the Gnome-ppp log. Thanks. --> WvDial: Internet dialer version 1.61 --> Cannot get information for serial port. --> Initializing modem. --> Sending: ATZ ATZ OK --> Modem initialized. --> Sending: ATM1L3DT*99***1# --> Waiting for carrier. ATM1L3DT*99***1# CONNECT --> Carrier detected. Waiting for prompt. ~[7f]}#@!}!}$} }=}!}$}%\}"}&} } } } }#}%B#}%}%}&}*urW}'}"}(}"mX~ --> PPP negotiation detected. --> Starting pppd at Sat Apr 28 21:55:55 2012 --> Warning: Could not modify /etc/ppp/chap-secrets: Permission denied --> --> CHAP (Challenge Handshake) may be flaky. --> Pid of pppd: 2459 --> Using interface ppp0 --> pppd: xu! --> pppd: xu! --> pppd: xu! --> pppd: xu! --> pppd: xu! --> pppd: xu! --> pppd: xu! --> pppd: xu! --> pppd: xu! --> Disconnecting at Sat Apr 28 21:56:01 2012 --> The PPP daemon has died: A modem hung up the phone (exit code = 16) --> man pppd explains pppd error codes in more detail. --> Try again and look into /var/log/messages and the wvdial and pppd man pages for more information. --> Auto Reconnect will be attempted in 5 seconds --> Cannot get information for serial port. --> Initializing modem. --> Sending: ATZ ATZ OK --> Modem initialized. --> Cannot get information for serial port. --> Initializing modem. --> Sending: ATZ ATZ OK --> Modem initialized. --> Sending: ATM1L3DT*99***1# --> Waiting for carrier. ATM1L3DT*99***1# CONNECT --> Carrier detected. Waiting for prompt. ~[7f]}#@!}!Q} }=}!}$}%\}"}&} } } } }#}%B#}%}%}&}*u69}'}"}(}"#W~ --> PPP negotiation detected. --> Starting pppd at Sat Apr 28 21:56:07 2012 --> Warning: Could not modify /etc/ppp/chap-secrets: Permission denied --> --> CHAP (Challenge Handshake) may be flaky. --> Pid of pppd: 2470 --> Using interface ppp0 --> pppd: xu! --> pppd: xu! --> pppd: xu! --> pppd: xu! --> pppd: xu! --> pppd: xu! --> pppd: xu! --> pppd: xu! --> pppd: xu! --> Disconnecting at Sat Apr 28 21:56:09 2012 --> The PPP daemon has died: A modem hung up the phone (exit code = 16) --> man pppd explains pppd error codes in more detail. --> Try again and look into /var/log/messages and the wvdial and pppd man pages for more information. --> Auto Reconnect will be attempted in 10 seconds --> Cannot get information for serial port. --> Initializing modem. --> Sending: ATZ ATZ OK --> Modem initialized. --> Cannot get information for serial port. --> Initializing modem. --> Sending: ATZ ATZ OK --> Modem initialized. --> Sending: ATM1L3DT*99***1# --> Waiting for carrier. ATM1L3DT*99***1# CONNECT --> Carrier detected. Waiting for prompt. ~[7f]}#@!}!@} }=}!}$}%\}"}&} } } } }#}%B#}%}%}&}*uvM}'}"}(}"p}$~ --> PPP negotiation detected. --> Starting pppd at Sat Apr 28 21:56:20 2012 --> Warning: Could not modify /etc/ppp/chap-secrets: Permission denied --> --> CHAP (Challenge Handshake) may be flaky. --> Pid of pppd: 2481 --> Using interface ppp0 --> pppd: xu! --> pppd: xu! --> pppd: xu! --> pppd: xu! --> pppd: xu! --> pppd: xu! --> pppd: xu! --> pppd: xu! --> pppd: xu! --> Disconnecting at Sat Apr 28 21:56:25 2012 --> The PPP daemon has died: A modem hung up the phone (exit code = 16) --> man pppd explains pppd error codes in more detail. --> Try again and look into /var/log/messages and the wvdial and pppd man pages for more information. --> Auto Reconnect will be attempted in 20 seconds --> Cannot get information for serial port. --> Initializing modem. --> Sending: ATZ ATZ OK --> Modem initialized.

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  • Working with Timelines with LINQ to Twitter

    - by Joe Mayo
    When first working with the Twitter API, I thought that using SinceID would be an effective way to page through timelines. In practice it doesn’t work well for various reasons. To explain why, Twitter published an excellent document that is a must-read for anyone working with timelines: Twitter Documentation: Working with Timelines This post shows how to implement the recommended strategies in that document by using LINQ to Twitter. You should read the document in it’s entirety before moving on because my explanation will start at the bottom and work back up to the top in relation to the Twitter document. What follows is an explanation of SinceID, MaxID, and how they come together to help you efficiently work with Twitter timelines. The Role of SinceID Specifying SinceID says to Twitter, “Don’t return tweets earlier than this”. What you want to do is store this value after every timeline query set so that it can be reused on the next set of queries.  The next section will explain what I mean by query set, but a quick explanation is that it’s a loop that gets all new tweets. The SinceID is a backstop to avoid retrieving tweets that you already have. Here’s some initialization code that includes a variable named sinceID that will be used to populate the SinceID property in subsequent queries: // last tweet processed on previous query set ulong sinceID = 210024053698867204; ulong maxID; const int Count = 10; var statusList = new List<status>(); Here, I’ve hard-coded the sinceID variable, but this is where you would initialize sinceID from whatever storage you choose (i.e. a database). The first time you ever run this code, you won’t have a value from a previous query set. Initially setting it to 0 might sound like a good idea, but what if you’re querying a timeline with lots of tweets? Because of the number of tweets and rate limits, your query set might take a very long time to run. A caveat might be that Twitter won’t return an entire timeline back to Tweet #0, but rather only go back a certain period of time, the limits of which are documented for individual Twitter timeline API resources. So, to initialize SinceID at too low of a number can result in a lot of initial tweets, yet there is a limit to how far you can go back. What you’re trying to accomplish in your application should guide you in how to initially set SinceID. I have more to say about SinceID later in this post. The other variables initialized above include the declaration for MaxID, Count, and statusList. The statusList variable is a holder for all the timeline tweets collected during this query set. You can set Count to any value you want as the largest number of tweets to retrieve, as defined by individual Twitter timeline API resources. To effectively page results, you’ll use the maxID variable to set the MaxID property in queries, which I’ll discuss next. Initializing MaxID On your first query of a query set, MaxID will be whatever the most recent tweet is that you get back. Further, you don’t know what MaxID is until after the initial query. The technique used in this post is to do an initial query and then use the results to figure out what the next MaxID will be.  Here’s the code for the initial query: var userStatusResponse = (from tweet in twitterCtx.Status where tweet.Type == StatusType.User && tweet.ScreenName == "JoeMayo" && tweet.SinceID == sinceID && tweet.Count == Count select tweet) .ToList(); statusList.AddRange(userStatusResponse); // first tweet processed on current query maxID = userStatusResponse.Min( status => ulong.Parse(status.StatusID)) - 1; The query above sets both SinceID and Count properties. As explained earlier, Count is the largest number of tweets to return, but the number can be less. A couple reasons why the number of tweets that are returned could be less than Count include the fact that the user, specified by ScreenName, might not have tweeted Count times yet or might not have tweeted at least Count times within the maximum number of tweets that can be returned by the Twitter timeline API resource. Another reason could be because there aren’t Count tweets between now and the tweet ID specified by sinceID. Setting SinceID constrains the results to only those tweets that occurred after the specified Tweet ID, assigned via the sinceID variable in the query above. The statusList is an accumulator of all tweets receive during this query set. To simplify the code, I left out some logic to check whether there were no tweets returned. If  the query above doesn’t return any tweets, you’ll receive an exception when trying to perform operations on an empty list. Yeah, I cheated again. Besides querying initial tweets, what’s important about this code is the final line that sets maxID. It retrieves the lowest numbered status ID in the results. Since the lowest numbered status ID is for a tweet we already have, the code decrements the result by one to keep from asking for that tweet again. Remember, SinceID is not inclusive, but MaxID is. The maxID variable is now set to the highest possible tweet ID that can be returned in the next query. The next section explains how to use MaxID to help get the remaining tweets in the query set. Retrieving Remaining Tweets Earlier in this post, I defined a term that I called a query set. Essentially, this is a group of requests to Twitter that you perform to get all new tweets. A single query might not be enough to get all new tweets, so you’ll have to start at the top of the list that Twitter returns and keep making requests until you have all new tweets. The previous section showed the first query of the query set. The code below is a loop that completes the query set: do { // now add sinceID and maxID userStatusResponse = (from tweet in twitterCtx.Status where tweet.Type == StatusType.User && tweet.ScreenName == "JoeMayo" && tweet.Count == Count && tweet.SinceID == sinceID && tweet.MaxID == maxID select tweet) .ToList(); if (userStatusResponse.Count > 0) { // first tweet processed on current query maxID = userStatusResponse.Min( status => ulong.Parse(status.StatusID)) - 1; statusList.AddRange(userStatusResponse); } } while (userStatusResponse.Count != 0 && statusList.Count < 30); Here we have another query, but this time it includes the MaxID property. The SinceID property prevents reading tweets that we’ve already read and Count specifies the largest number of tweets to return. Earlier, I mentioned how it was important to check how many tweets were returned because failing to do so will result in an exception when subsequent code runs on an empty list. The code above protects against this problem by only working with the results if Twitter actually returns tweets. Reasons why there wouldn’t be results include: if the first query got all the new tweets there wouldn’t be more to get and there might not have been any new tweets between the SinceID and MaxID settings of the most recent query. The code for loading the returned tweets into statusList and getting the maxID are the same as previously explained. The important point here is that MaxID is being reset, not SinceID. As explained in the Twitter documentation, paging occurs from the newest tweets to oldest, so setting MaxID lets us move from the most recent tweets down to the oldest as specified by SinceID. The two loop conditions cause the loop to continue as long as tweets are being read or a max number of tweets have been read.  Logically, you want to stop reading when you’ve read all the tweets and that’s indicated by the fact that the most recent query did not return results. I put the check to stop after 30 tweets are reached to keep the demo from running too long – in the console the response scrolls past available buffer and I wanted you to be able to see the complete output. Yet, there’s another point to be made about constraining the number of items you return at one time. The Twitter API has rate limits and making too many queries per minute will result in an error from twitter that LINQ to Twitter raises as an exception. To use the API properly, you’ll have to ensure you don’t exceed this threshold. Looking at the statusList.Count as done above is rather primitive, but you can implement your own logic to properly manage your rate limit. Yeah, I cheated again. Summary Now you know how to use LINQ to Twitter to work with Twitter timelines. After reading this post, you have a better idea of the role of SinceID - the oldest tweet already received. You also know that MaxID is the largest tweet ID to retrieve in a query. Together, these settings allow you to page through results via one or more queries. You also understand what factors affect the number of tweets returned and considerations for potential error handling logic. The full example of the code for this post is included in the downloadable source code for LINQ to Twitter.   @JoeMayo

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  • Of transactions and Mongo

    - by Nuri Halperin
    Originally posted on: http://geekswithblogs.net/nuri/archive/2014/05/20/of-transactions-and-mongo-again.aspxWhat's the first thing you hear about NoSQL databases? That they lose your data? That there's no transactions? No joins? No hope for "real" applications? Well, you *should* be wondering whether a certain of database is the right one for your job. But if you do so, you should be wondering that about "traditional" databases as well! In the spirit of exploration let's take a look at a common challenge: You are a bank. You have customers with accounts. Customer A wants to pay B. You want to allow that only if A can cover the amount being transferred. Let's looks at the problem without any context of any database engine in mind. What would you do? How would you ensure that the amount transfer is done "properly"? Would you prevent a "transaction" from taking place unless A can cover the amount? There are several options: Prevent any change to A's account while the transfer is taking place. That boils down to locking. Apply the change, and allow A's balance to go below zero. Charge person A some interest on the negative balance. Not friendly, but certainly a choice. Don't do either. Options 1 and 2 are difficult to attain in the NoSQL world. Mongo won't save you headaches here either. Option 3 looks a bit harsh. But here's where this can go: ledger. See, and account doesn't need to be represented by a single row in a table of all accounts with only the current balance on it. More often than not, accounting systems use ledgers. And entries in ledgers - as it turns out – don't actually get updated. Once a ledger entry is written, it is not removed or altered. A transaction is represented by an entry in the ledger stating and amount withdrawn from A's account and an entry in the ledger stating an addition of said amount to B's account. For sake of space-saving, that entry in the ledger can happen using one entry. Think {Timestamp, FromAccountId, ToAccountId, Amount}. The implication of the original question – "how do you enforce non-negative balance rule" then boils down to: Insert entry in ledger Run validation of recent entries Insert reverse entry to roll back transaction if validation failed. What is validation? Sum up the transactions that A's account has (all deposits and debits), and ensure the balance is positive. For sake of efficiency, one can roll up transactions and "close the book" on transactions with a pseudo entry stating balance as of midnight or something. This lets you avoid doing math on the fly on too many transactions. You simply run from the latest "approved balance" marker to date. But that's an optimization, and premature optimizations are the root of (some? most?) evil.. Back to some nagging questions though: "But mongo is only eventually consistent!" Well, yes, kind of. It's not actually true that Mongo has not transactions. It would be more descriptive to say that Mongo's transaction scope is a single document in a single collection. A write to a Mongo document happens completely or not at all. So although it is true that you can't update more than one documents "at the same time" under a "transaction" umbrella as an atomic update, it is NOT true that there' is no isolation. So a competition between two concurrent updates is completely coherent and the writes will be serialized. They will not scribble on the same document at the same time. In our case - in choosing a ledger approach - we're not even trying to "update" a document, we're simply adding a document to a collection. So there goes the "no transaction" issue. Now let's turn our attention to consistency. What you should know about mongo is that at any given moment, only on member of a replica set is writable. This means that the writable instance in a set of replicated instances always has "the truth". There could be a replication lag such that a reader going to one of the replicas still sees "old" state of a collection or document. But in our ledger case, things fall nicely into place: Run your validation against the writable instance. It is guaranteed to have a ledger either with (after) or without (before) the ledger entry got written. No funky states. Again, the ledger writing *adds* a document, so there's no inconsistent document state to be had either way. Next, we might worry about data loss. Here, mongo offers several write-concerns. Write-concern in Mongo is a mode that marshals how uptight you want the db engine to be about actually persisting a document write to disk before it reports to the application that it is "done". The most volatile, is to say you don't care. In that case, mongo would just accept your write command and say back "thanks" with no guarantee of persistence. If the server loses power at the wrong moment, it may have said "ok" but actually no written the data to disk. That's kind of bad. Don't do that with data you care about. It may be good for votes on a pole regarding how cute a furry animal is, but not so good for business. There are several other write-concerns varying from flushing the write to the disk of the writable instance, flushing to disk on several members of the replica set, a majority of the replica set or all of the members of a replica set. The former choice is the quickest, as no network coordination is required besides the main writable instance. The others impose extra network and time cost. Depending on your tolerance for latency and read-lag, you will face a choice of what works for you. It's really important to understand that no data loss occurs once a document is flushed to an instance. The record is on disk at that point. From that point on, backup strategies and disaster recovery are your worry, not loss of power to the writable machine. This scenario is not different from a relational database at that point. Where does this leave us? Oh, yes. Eventual consistency. By now, we ensured that the "source of truth" instance has the correct data, persisted and coherent. But because of lag, the app may have gone to the writable instance, performed the update and then gone to a replica and looked at the ledger there before the transaction replicated. Here are 2 options to deal with this. Similar to write concerns, mongo support read preferences. An app may choose to read only from the writable instance. This is not an awesome choice to make for every ready, because it just burdens the one instance, and doesn't make use of the other read-only servers. But this choice can be made on a query by query basis. So for the app that our person A is using, we can have person A issue the transfer command to B, and then if that same app is going to immediately as "are we there yet?" we'll query that same writable instance. But B and anyone else in the world can just chill and read from the read-only instance. They have no basis to expect that the ledger has just been written to. So as far as they know, the transaction hasn't happened until they see it appear later. We can further relax the demand by creating application UI that reacts to a write command with "thank you, we will post it shortly" instead of "thank you, we just did everything and here's the new balance". This is a very powerful thing. UI design for highly scalable systems can't insist that the all databases be locked just to paint an "all done" on screen. People understand. They were trained by many online businesses already that your placing of an order does not mean that your product is already outside your door waiting (yes, I know, large retailers are working on it... but were' not there yet). The second thing we can do, is add some artificial delay to a transaction's visibility on the ledger. The way that works is simply adding some logic such that the query against the ledger never nets a transaction for customers newer than say 15 minutes and who's validation flag is not set. This buys us time 2 ways: Replication can catch up to all instances by then, and validation rules can run and determine if this transaction should be "negated" with a compensating transaction. In case we do need to "roll back" the transaction, the backend system can place the timestamp of the compensating transaction at the exact same time or 1ms after the original one. Effectively, once A or B visits their ledger, both transactions would be visible and the overall balance "as of now" would reflect no change.  The 2 transactions (attempted/ reverted) would be visible , since we do actually account for the attempt. Hold on a second. There's a hole in the story: what if several transfers from A to some accounts are registered, and 2 independent validators attempt to compute the balance concurrently? Is there a chance that both would conclude non-sufficient-funds even though rolling back transaction 100 would free up enough for transaction 117 (some random later transaction)? Yes. there is that chance. But the integrity of the business rule is not compromised, since the prime rule is don't dispense money you don't have. To minimize or eliminate this scenario, we can also assign a single validation process per origin account. This may seem non-scalable, but it can easily be done as a "sharded" distribution. Say we have 11 validation threads (or processing nodes etc.). We divide the account number space such that each validator is exclusively responsible for a certain range of account numbers. Sounds cunningly similar to Mongo's sharding strategy, doesn't it? Each validator then works in isolation. More capacity needed? Chop the account space into more chunks. So where  are we now with the nagging questions? "No joins": Huh? What are those for? "No transactions": You mean no cross-collection and no cross-document transactions? Granted - but don't always need them either. "No hope for real applications": well... There are more issues and edge cases to slog through, I'm sure. But hopefully this gives you some ideas of how to solve common problems without distributed locking and relational databases. But then again, you can choose relational databases if they suit your problem.

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  • Azure &ndash; Part 5 &ndash; Repository Pattern for Table Service

    - by Shaun
    In my last post I created a very simple WCF service with the user registration functionality. I created an entity for the user data and a DataContext class which provides some methods for operating the entities such as add, delete, etc. And in the service method I utilized it to add a new entity into the table service. But I didn’t have any validation before registering which is not acceptable in a real project. So in this post I would firstly add some validation before perform the data creation code and show how to use the LINQ for the table service.   LINQ to Table Service Since the table service utilizes ADO.NET Data Service to expose the data and the managed library of ADO.NET Data Service supports LINQ we can use it to deal with the data of the table service. Let me explain with my current example: I would like to ensure that when register a new user the email address should be unique. So I need to check the account entities in the table service before add. If you remembered, in my last post I mentioned that there’s a method in the TableServiceContext class – CreateQuery, which will create a IQueryable instance from a given type of entity. So here I would create a method under my AccountDataContext class to return the IQueryable<Account> which named Load. 1: public class AccountDataContext : TableServiceContext 2: { 3: private CloudStorageAccount _storageAccount; 4:  5: public AccountDataContext(CloudStorageAccount storageAccount) 6: : base(storageAccount.TableEndpoint.AbsoluteUri, storageAccount.Credentials) 7: { 8: _storageAccount = storageAccount; 9:  10: var tableStorage = new CloudTableClient(_storageAccount.TableEndpoint.AbsoluteUri, 11: _storageAccount.Credentials); 12: tableStorage.CreateTableIfNotExist("Account"); 13: } 14:  15: public void Add(Account accountToAdd) 16: { 17: AddObject("Account", accountToAdd); 18: SaveChanges(); 19: } 20:  21: public IQueryable<Account> Load() 22: { 23: return CreateQuery<Account>("Account"); 24: } 25: } The method returns the IQueryable<Account> so that I can perform the LINQ operation on it. And back to my service class, I will use it to implement my validation. 1: public bool Register(string email, string password) 2: { 3: var storageAccount = CloudStorageAccount.FromConfigurationSetting("DataConnectionString"); 4: var accountToAdd = new Account(email, password) { DateCreated = DateTime.Now }; 5: var accountContext = new AccountDataContext(storageAccount); 6:  7: // validation 8: var accountNumber = accountContext.Load() 9: .Where(a => a.Email == accountToAdd.Email) 10: .Count(); 11: if (accountNumber > 0) 12: { 13: throw new ApplicationException(string.Format("Your account {0} had been used.", accountToAdd.Email)); 14: } 15:  16: // create entity 17: try 18: { 19: accountContext.Add(accountToAdd); 20: return true; 21: } 22: catch (Exception ex) 23: { 24: Trace.TraceInformation(ex.ToString()); 25: } 26: return false; 27: } I used the Load method to retrieve the IQueryable<Account> and use Where method to find the accounts those email address are the same as the one is being registered. If it has I through an exception back to the client side. Let’s run it and test from my simple client application. Oops! Looks like we encountered an unexpected exception. It said the “Count” is not support by the ADO.NET Data Service LINQ managed library. That is because the table storage managed library (aka. TableServiceContext) is based on the ADO.NET Data Service and it supports very limit LINQ operation. Although I didn’t find a full list or documentation about which LINQ methods it supports I could even refer a page on msdn here. It gives us a roughly summary of which query operation the ADO.NET Data Service managed library supports and which doesn't. As you see the Count method is not in the supported list. Not only the query operation, there inner lambda expression in the Where method are limited when using the ADO.NET Data Service managed library as well. For example if you added (a => !a.DateDeleted.HasValue) in the Where method to exclude those deleted account it will raised an exception said "Invalid Input". Based on my experience you should always use the simple comparison (such as ==, >, <=, etc.) on the simple members (such as string, integer, etc.) and do not use any shortcut methods (such as string.Compare, string.IsNullOrEmpty etc.). 1: // validation 2: var accountNumber = accountContext.Load() 3: .Where(a => a.Email == accountToAdd.Email) 4: .ToList() 5: .Count; 6: if (accountNumber > 0) 7: { 8: throw new ApplicationException(string.Format("Your account {0} had been used.", accountToAdd.Email)); 9: } We changed the a bit and try again. Since I had created an account with my mail address so this time it gave me an exception said that the email had been used, which is correct.   Repository Pattern for Table Service The AccountDataContext takes the responsibility to save and load the account entity but only for that specific entity. Is that possible to have a dynamic or generic DataContext class which can operate any kinds of entity in my system? Of course yes. Although there's no typical database in table service we can threat the entities as the records, similar with the data entities if we used OR Mapping. As we can use some patterns for ORM architecture here we should be able to adopt the one of them - Repository Pattern in this example. We know that the base class - TableServiceContext provide 4 methods for operating the table entities which are CreateQuery, AddObject, UpdateObject and DeleteObject. And we can create a relationship between the enmity class, the table container name and entity set name. So it's really simple to have a generic base class for any kinds of entities. Let's rename the AccountDataContext to DynamicDataContext and make the type of Account as a type parameter if it. 1: public class DynamicDataContext<T> : TableServiceContext where T : TableServiceEntity 2: { 3: private CloudStorageAccount _storageAccount; 4: private string _entitySetName; 5:  6: public DynamicDataContext(CloudStorageAccount storageAccount) 7: : base(storageAccount.TableEndpoint.AbsoluteUri, storageAccount.Credentials) 8: { 9: _storageAccount = storageAccount; 10: _entitySetName = typeof(T).Name; 11:  12: var tableStorage = new CloudTableClient(_storageAccount.TableEndpoint.AbsoluteUri, 13: _storageAccount.Credentials); 14: tableStorage.CreateTableIfNotExist(_entitySetName); 15: } 16:  17: public void Add(T entityToAdd) 18: { 19: AddObject(_entitySetName, entityToAdd); 20: SaveChanges(); 21: } 22:  23: public void Update(T entityToUpdate) 24: { 25: UpdateObject(entityToUpdate); 26: SaveChanges(); 27: } 28:  29: public void Delete(T entityToDelete) 30: { 31: DeleteObject(entityToDelete); 32: SaveChanges(); 33: } 34:  35: public IQueryable<T> Load() 36: { 37: return CreateQuery<T>(_entitySetName); 38: } 39: } I saved the name of the entity type when constructed for performance matter. The table name, entity set name would be the same as the name of the entity class. The Load method returned a generic IQueryable instance which supports the lazy load feature. Then in my service class I changed the AccountDataContext to DynamicDataContext and that's all. 1: var accountContext = new DynamicDataContext<Account>(storageAccount); Run it again and register another account. The DynamicDataContext now can be used for any entities. For example, I would like the account has a list of notes which contains 3 custom properties: Account Email, Title and Content. We create the note entity class. 1: public class Note : TableServiceEntity 2: { 3: public string AccountEmail { get; set; } 4: public string Title { get; set; } 5: public string Content { get; set; } 6: public DateTime DateCreated { get; set; } 7: public DateTime? DateDeleted { get; set; } 8:  9: public Note() 10: : base() 11: { 12: } 13:  14: public Note(string email) 15: : base(email, string.Format("{0}_{1}", email, Guid.NewGuid().ToString())) 16: { 17: AccountEmail = email; 18: } 19: } And no need to tweak the DynamicDataContext we can directly go to the service class to implement the logic. Notice here I utilized two DynamicDataContext instances with the different type parameters: Note and Account. 1: public class NoteService : INoteService 2: { 3: public void Create(string email, string title, string content) 4: { 5: var storageAccount = CloudStorageAccount.FromConfigurationSetting("DataConnectionString"); 6: var accountContext = new DynamicDataContext<Account>(storageAccount); 7: var noteContext = new DynamicDataContext<Note>(storageAccount); 8:  9: // validate - email must be existed 10: var accounts = accountContext.Load() 11: .Where(a => a.Email == email) 12: .ToList() 13: .Count; 14: if (accounts <= 0) 15: throw new ApplicationException(string.Format("The account {0} does not exsit in the system please register and try again.", email)); 16:  17: // save the note 18: var noteToAdd = new Note(email) { Title = title, Content = content, DateCreated = DateTime.Now }; 19: noteContext.Add(noteToAdd); 20: } 21: } And updated our client application to test the service. I didn't implement any list service to show all notes but we can have a look on the local SQL database if we ran it at local development fabric.   Summary In this post I explained a bit about the limited LINQ support for the table service. And then I demonstrated about how to use the repository pattern in the table service data access layer and make the DataContext dynamically. The DynamicDataContext I created in this post is just a prototype. In fact we should create the relevant interface to make it testable and for better structure we'd better separate the DataContext classes for each individual kind of entity. So it should have IDataContextBase<T>, DataContextBase<T> and for each entity we would have class AccountDataContext<Account> : IDataContextBase<Account>, DataContextBase<Account> { … } class NoteDataContext<Note> : IDataContextBase<Note>, DataContextBase<Note> { … }   Besides the structured data saving and loading, another common scenario would be saving and loading some binary data such as images, files. In my next post I will show how to use the Blob Service to store the bindery data - make the account be able to upload their logo in my example.   Hope this helps, Shaun   All documents and related graphics, codes are provided "AS IS" without warranty of any kind. Copyright © Shaun Ziyan Xu. This work is licensed under the Creative Commons License.

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