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  • I am not able to delete a corrupt NTFS partition on my pen drive. How can I force its deletion?

    - by yesuraj
    I formatted my 16GB pen drive with the NTFS file system in windows vista. After that I started copying some files. However, only a few files were copied to the pen drive before the copy operation hung. So I cancelled the copy operation. Now I am unable to use the pen drive. I DON'T REALLY NEED ANY FILES THAT I COPIED TO THE PENDRIVE. I JUST WANT TO USE THE PENDRIVE AGAIN. I have tried using Ubuntu to format the pen drive. But when i use fdisk to delete the partition, it looks like it is working fine but in fact it does not delete the partition. Also I am unable to format it with any other file system. When I tried to use gparted, it throws the following error: Error mounting: mount exited with exit code 14: The disk contains an unclean file system(0,0). The file system wasn't safely closed on window. Fixing ntfs_attr_pread_i:ntfs_pread failed: Input/output error Failed to read NTFS$Bitmap:Input/output error NTFS is either inconsistent, or there is a hardware fault, or it's a softRAID/FakeRAID hardware. In the first case run chkdsk /f on Windows then reboot into windows twice. The usage of the /f parameter is very important!. If the device is a SoftRAID/FakeRAID then first activate it and mount a different device under the /dev/mapper directory, (e.g. /dev/mapper/nvidia_eahaabcc1). Please see the dmraid documentation for more details When I searched the Internet I found help on how to recover. But I don’t want to recover, I want to format it again. When I pressed w after deleting the partition, it took more time than previously. After that i removed the pen drive and re-inserted, but the partition I had deleted was still present. If I simply type the command fdisk /dev/sdb without removing the pen drive after the partition is deleted, then it returns the error message Unable to open /dev/sdb. Here are the steps that I followed: root@yesuraj-ubuntu:~# fdisk /dev/sdb Command (m for help): d Selected partition 1 Command (m for help): w The partition table has been altered! Calling ioctl() to re-read partition table. Syncing disks THE DEMESG PRINTS ARE AS FOLLOWS, [ 6139.774753] usb 2-1.3: reset high speed USB device number 4 using ehci_hcd [ 6154.816941] usb 2-1.3: device descriptor read/64, error -110 [ 6169.968908] usb 2-1.3: device descriptor read/64, error -110 [ 6170.158427] usb 2-1.3: reset high speed USB device number 4 using ehci_hcd [ 6185.200638] usb 2-1.3: device descriptor read/64, error -110 [ 6200.352572] usb 2-1.3: device descriptor read/64, error -110 [ 6200.542093] usb 2-1.3: reset high speed USB device number 4 using ehci_hcd [ 6205.559460] usb 2-1.3: device descriptor read/8, error -110 I used the dd command and it erased the partition table. But now when I connect the pen drive, dmesg contains this error message: [88143.437001] sdb: unknown partition table. I am not able to create a partion using fdisk /dev/sdb. The error message says that it is unable to find the node. Other messages from dmesg follow below. [87100.531596] usb 2-1.3: new high speed USB device number 39 using ehci_hcd [87130.915257] usb 2-1.3: new high speed USB device number 40 using ehci_hcd [87135.932647] usb 2-1.3: device descriptor read/8, error -110

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  • Type of computer for a developer on the road

    - by nabucosound
    Hi developers: I am planning to be traveling through eurasia and asia (russia, china, korea, japan, south east asia...) for a while and, although there are plenty of marvelous things to see and to do, I must keep on working :(. I am a python developer, dedicated mainly to web projects. I use django, sqlite3, browsers, and ocassionaly (only if I have no choice) I install postgres, mysql, apache or any other servers commonly used in the internets. I do my coding on vim, use ssh to connect, lftp to transfer files, IRC, grep/ack... So I spend most of my time in the terminal shells. But I also use IM or Skype to communicate with my clients and peers, as well as some other software (that after all is not mandatory for my day-to-day work). I currently work with a Macbook Pro (3 years old now) and so far I am very happy with the performance. But I don't want to carry it if I am going to be "on transit" for long time, it is simply huge and heavy for what I am planning to load in my rather small backpack (while traveling, less is more, you know). So here I am reading all kind of opinions about netbooks, because at first sight this is the kind of computer I thought I had to choose. I am going to use Linux for it, Microsoft is not my cup of tea and Mac is not available for them, unless I were to buy a Macbook air, something that I won't do because if I am robbed or rain/dust/truck loaders break it I would burst in tears. I am concerned about wifi performance and connectivity, I am going to use one of those linux distros/tools to hack/test on "open" networks (if you know what I mean) in case I am not in a place with real free wifi access and I find myself in an emergency. CPU speed should be acceptable, but since I don't plan to run Photoshop or expensive IDEs, I guess most of the time I won't be overloading the machine. Apart from this, maybe (surely) I am missing other features to consider. With that said (sorry about the length) here it comes my question, raised from a deep ignorance regarding the wars betweeb betbooks vs notebooks (I assume tablet PCs are not for programming yet): If I buy a netbook will I have to throw it away after 1 month on the road and buy a notebook? Or will I be OK? Thanks! Hector Update I have received great feedback so far! I would like to insist on the fact that I will be traveling through many different countries and scenarios. I am sure that while in Japan I will be more than fine with anything related to technology, connectivity, etc. But consider that I will be, for example, on a train through Russia (transsiberian) and will cross Mongolia as well. I will stay in friends' places sometimes, but most of the time I will have to work from hostel rooms, trains, buses, beaches (hey this last one doesn't sound too bad hehe!). I think some of your answers guys seem to focus on the geek part but loose the point of this "on the road" fact. I am very aware and agree that netbooks suck compared to notebooks, but what I am trying to do here is to find a balance and discover your experiences with netbooks to see first hand if a netbook will be a fail in the mid-long term of the trip for my purposes. So I have resumed the main concepts expressed here on this small list, in no particular order: keyboard/touchpad feel: I use vim so no need of moving mouse pointers that much, unless I am browsing the web, but intensive use of keyboard screen real state: again, terminal work for most of the time battery life: I think something very important weight/size: also very important looks not worth stealing it, don't give a shit if it is lost/stolen/broken: this may depend on kind of person, your economy, etc. Also to prevent losing work, I will upload EVERYTHING to the cloud whenever I'll have a chance. wifi: don't want to discover my wifi is one of those that cannot deal with half the routers on this planet or has poor connectivity. Thanks again for your answers and comments!

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  • Drawing texture does not work anymore with a small amount of triangles

    - by Paul
    When i draw lines, the vertices are well connected. But when i draw the texture inside the triangles, it only works with i<4 in the for loop, otherwise with i<5 for example, there is a EXC_BAD_ACCESS message, at @synthesize textureImage = _textureImage. I don't understand why. (The generatePolygons method seems to work fine as i tried to draw lines with many vertices as in the second image below. And textureImage remains the same for i<4 or i<5 : it's a 512px square image). Here are the images : What i want to achieve is to put the red points and connect them to the y-axis (the green points) and color the area (the green triangles) : If i only draw lines, it works fine : Then with a texture color, it works for i<4 in the loop (the red points in my first image, plus the fifth one to connect the last y) : But then, if i set i<5, the debug tool says EXC_BAD_ACCESS at the synthesize of _textureImage. Here is my code : I set a texture color in HelloWordLayer.mm with : CCSprite *textureImage = [self spriteWithColor:color3 textureSize:512]; _terrain.textureImage = textureImage; Then in the class Terrain, i create the vertices and put the texture in the draw method : @implementation Terrain @synthesize textureImage = _textureImage; //EXC_BAD_ACCESS for i<5 - (void)generatePath2{ CGSize winSize = [CCDirector sharedDirector].winSize; float x = 40; float y = 0; for(int i = 0; i < kMaxKeyPoints+1; ++i) { _hillKeyPoints[i] = CGPointMake(x, y); x = 150 + (random() % (int) 30); y += 30; } } -(void)generatePolygons{ _nPolyVertices = 0; float x1 = 0; float y1 = 0; int keyPoints = 0; for (int i=0; i<4; i++){ /* HERE : 4 = OK / 5 = crash */ //V0: at (0,0) _polyVertices[_nPolyVertices] = CGPointMake(x1, y1); _polyTexCoords[_nPolyVertices++] = CGPointMake(x1, y1); //V1: to the first "point" _polyVertices[_nPolyVertices] = CGPointMake(_hillKeyPoints[keyPoints].x, _hillKeyPoints[keyPoints].y); _polyTexCoords[_nPolyVertices++] = CGPointMake(_hillKeyPoints[keyPoints].x, _hillKeyPoints[keyPoints].y); keyPoints++; //from point at index 0 to 1 //V2, same y as point n°2: _polyVertices[_nPolyVertices] = CGPointMake(0, _hillKeyPoints[keyPoints].y); _polyTexCoords[_nPolyVertices++] = CGPointMake(0, _hillKeyPoints[keyPoints].y); //V1 again _polyVertices[_nPolyVertices] = _polyVertices[_nPolyVertices-2]; _polyTexCoords[_nPolyVertices++] = _polyVertices[_nPolyVertices-2]; //V2 again _polyVertices[_nPolyVertices] = _polyVertices[_nPolyVertices-2]; _polyTexCoords[_nPolyVertices++] = _polyVertices[_nPolyVertices-2]; //V3 = same x,y as point at index 1 _polyVertices[_nPolyVertices] = CGPointMake(_hillKeyPoints[keyPoints].x, _hillKeyPoints[keyPoints].y); _polyTexCoords[_nPolyVertices] = CGPointMake(_hillKeyPoints[keyPoints].x, _hillKeyPoints[keyPoints].y); y1 = _polyVertices[_nPolyVertices].y; _nPolyVertices++; } } - (id)init { if ((self = [super init])) { [self generatePath2]; [self generatePolygons]; } return self; } - (void) draw { //glDisable(GL_TEXTURE_2D); glDisableClientState(GL_COLOR_ARRAY); glDisableClientState(GL_TEXTURE_COORD_ARRAY); glBindTexture(GL_TEXTURE_2D, _textureImage.texture.name); glColor4f(1, 1, 1, 1); glVertexPointer(2, GL_FLOAT, 0, _polyVertices); glTexCoordPointer(2, GL_FLOAT, 0, _polyTexCoords); glDrawArrays(GL_TRIANGLE_STRIP, 0, (GLsizei)_nPolyVertices); glColor4f(1, 1, 1, 1); for(int i = 1; i < 40; ++i) { ccDrawLine(_polyVertices[i-1], _polyVertices[i]); } // restore default GL states glEnable(GL_TEXTURE_2D); glEnableClientState(GL_COLOR_ARRAY); glEnableClientState(GL_TEXTURE_COORD_ARRAY); } Do you see anything wrong in this code? Thanks for your help

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  • Call For Papers Tips and Tricks

    - by speakjava
    This year's JavaOne session review has just been completed and by now everyone who submitted papers should know whether they were successful or not.  I had the pleasure again this year of leading the review of the 'JavaFX and Rich User Experiences' track.  I thought it would be useful to write up a few comments to help people in future when submitting session proposals, not just for JavaOne, but for any of the many developer conferences that run around the world throughout the year.  This also draws on conversations I recently had with various Java User Group leaders at the Oracle User Group summit in Riga.  Many of these leaders run some of the biggest and most successful Java conferences in Europe. Try to think of a title which will sound interesting.  For example, "Experiences of performance tuning embedded Java for an ARM architecture based single board computer" probably isn't going to get as much attention as "Do you like coffee with your dessert? Java on the Raspberry Pi".  When thinking of the subject and title for your talk try to steer clear of sessions that might be too generic (and so get lost in a group of similar sessions).  Introductory talks are great when the audience is new to a subject, but beware of providing sessions that are too basic when the technology has been around for a while and there are lots of tutorials already available on the web. JavaOne, like many other conferences has a number of fields that need to be filled in when submitting a paper.  Many of these are selected from pull-down lists (like which track the session is applicable to).  Check these lists carefully.  A number of sessions we had needed to be shuffled between tracks when it was thought that the one selected was not appropriate.  We didn't count this against any sessions, but it's always a good idea to try and get the right one from the start, just in case. JavaOne, again like many other conferences, has two fields that describe the session being submitted: abstract and summary.  These are the most critical to a successful submission.  The two fields have different names and that is significant; a frequent mistake people make is to write an abstract for a session and then duplicate it for the summary.  The abstract (at least in the case of JavaOne) is what gets printed in the show guide and is typically what will be used by attendees when deciding what sessions to attend.  This is where you need to sell your session, not just to the reviewers, but also the people who you want in your audience.  Submitting a one line abstract (unless it's a really good one line) is not usually enough to decide whether this is worth investing an hour of conference time.  The abstract typically has a limit of a few hundred characters.  Try to use as many of them as possible to get as much information about your session across.  The summary should be different from the abstract (and don't leave it blank as some people do).  This field is where you can give the reviewers more detail about things like the structure of the talk, possible demonstrations and so on.  As a reviewer I look to this section to help me decide whether the hard-sell of the title and abstract will actually be reflected in the final content.  Try to make this comprehensive, but don't make it excessively long.  When you have to review possibly hundreds of sessions a certain level of conciseness can make life easier for reviewers and help the cause of your session. If you've not made many submissions for talks in the past, or if this is your first, try to give reviewers places to find background on you as a presenter.  Having an active blog and Twitter handle can also help reviewers if they're not sure what your level of expertise is.  Many call-for-papers have places for you to include this type of information.  It's always good to have new and original presenters and presentations for conferences.  Hopefully these tips will help you be successful when you answer the next call-for-papers.

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  • Make your TSQL easier to read during a presentation

    - by Jonathan Allen
    SQL Server Management Studio 2012 has some neat settings that you can use to help your presentations at a SQL event better for the attendees if you are willing to spend a few minutes making some settings changes. Historically, I have been reluctant to make changes to my SSMS settings as it is such a tedious process and it’s not 100% clear that what you think you are changing is actually what gets changed. With SSMS 2012 this has become a lot easier and a lot less risky. In any session that involves TSQL there is a trade off between the speaker having all the code on screen and the attendees being able to read any of what is on screen. You (the speaker) might be able to read this when you are working on the code but plenty of your audience wont be able to make head or tail of it. SSMS 2012 has a zoom facility that can help: but don’t go nuts … Having the font too big means you will be scrolling a lot and the code will again be rendered unreadable. There is more though but you need to take a deep breath and open the Tools menu and delve into the SSMS options. In previous versions of SSMS this is a deep, dark and scary place where changing values can be obscure and sometimes catastrophic to the UI when you get back to the code editor. First things first, we set out as a good DBA and save our current (and presumably acceptable) SSMS configuration. From the import and Export Settings you can set up a file to hold all of the settings that you currently have. The wizard will open and ask you to pick an option. This time around choose to export settings. hit next and next again and then name your settings profile in the final step of the wizard and then click Finish. Once this is done then you can change whatever you like and always get back to this configuration in a couple of clicks. So what can you change to make for a good experience? Well there are plenty of things that can be altered but don’t go too mad and change too many things without taking a look at the results for every item on the list above you can change font, size, weight, colour, background colour etc. etc. but consider what you are trying to achieve and take it slowly. I have seen presenters with their settings set to have a yellow highlight and black font rather than the default pale blue background and slightly darker font so to achieve that select Text Editor and then select “Selected Text” in the Display Items listbox. As you change things the Sample area give you an idea of what effect you are going to have. Black and yellow is the colour combination with the highest contrast – that’s why bees and wasps# are that colour. What next? how about increasing the default font for your demo scripts? This means that any script you open and any new ones that you start will take on this font. No more zooming (or forgetting to) in the middle of sessions. now don’t forget to save this profile – follow the same steps as above but give the profile a different name, something like PresentationBigFontHighContrast might be appropriate. Once you are done making changes, export the settings once more and then go into the Import Export wizard and import settings from the first profile you created. Everything will be back to normal. Now making changes to suit your environment can be done very easily and with confidence. * – and warning tape and safety signs and so forth – Health and Safety officers simply copy nature!

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  • Customer owes me half my payment. Should I take ownership of his AWS account for charging? How?

    - by Cawas
    Background They paid me my first half (back in April 15th) before even we could get into an agreement. Very nice of him! Then I've finished the 2 weeks job of setting up the servers, using his AWS credentials he had just bought. I waited for another 2 weeks for everything settling up, and it was all running fine. He did what he needed with his sftp account, everyone were happy. Now, it has been almost 2 months since I've finished the job and I still didn't get the 2nd half. I must assume, it's not much money (about U$400, converted), but it would help me pay the bills at least. Heck, the Amazon bills they are paying are little less than that (for now). Measures I'm wondering how I can go to charge him now. First thought, of course, would be taking everything down and say "pay now, or be doomed". If that's not good enough, then I lost it. I have no contracts and I doubt I could get a law suit in this country for such a low value based only on emails. And I don't really want to get too agressive here - there might be a business chance in the future and I don't want to ruin it. Second though would be just changing the password. But then he probably could gain access again by some recovery means. That's where my question may mainly relay. How can I do it and not leaving any room for recovery from his side? I even got the first AWS "your account was created" mail from himself, showing me I could begin my job, back then. Lastly, do you have any other idea on what I can and what I should do in this case? Responding to Answers Please, consider reading the current answers and comments. This is not a very simple case. I've considered many, many options (including all lawful ones) before considering this ones I've listed here, and I am willing to take the loss and all that. That's not the point. The point is being practical here. I will call him again and talk about it. I will do terrorism on getting lawyers and getting contract. I am ready to go all forth while I have time and energy for it. But, in practice, there is this extra thing I can do to assure myself of the work I've done. I can basically take it back and delete everything! I'd only take his password because I can find no other way to do it within Amazon. Maybe, contacting Amazon and explaining the situation? I don't know. Give me ideas on this technical side! And thank everyone for the attention and helping me clarifying the issue so far! :)

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  • Find Knowledge Quickly

    - by Get Proactive Customer Adoption Team
    Untitled Document Get to relevant knowledge on the Oracle products you use in a few quick steps! Customers tell us that the volume of search results returned can make it difficult to find the information they need, especially when similar Oracle products exist. These simple tips show you how to filter, browse, search, and refine your results to get relevant answers faster. Filter first: PowerView is your best friend Powerview is an often ignored feature of My Oracle Support that enables you to control the information displayed on the Dashboard, the Knowledge tab and regions, and the Service Request tab based on one or more parameters. You can define a PowerView to limit information based on product, product line, support ID, platform, hostname, system name and others. Using PowerView allows you to restrict: Your search results to the filters you have set The product list when selecting your products in Search & Browse and when creating service requests   The PowerView menu is at the top of My Oracle Support, near the title You turn PowerView on by clicking PowerView is Off, which is a button. When PowerView is On, and filters are active, clicking the button again will toggle Powerview off. Click the arrow to the right to create new filters, edit filters, remove a filter, or choose from the list of previously created filters. You can create a PowerView in 3 simple steps! Turn PowerView on and select New from the PowerView menu. Select your filter from the Select Filter Type dropdown list and make selections from the other two menus. Hint: While there are many filter options, selecting your product line or your list of products will provide you with an effective filter. Click the plus sign (+) to add more filters. Click the minus sign (-) to remove a filter. Click Create to save and activated the filter(s) You’ll notice that PowerView is On displays along with the active filters. For more information about the PowerView capabilities, click the Learn more about PowerView… menu item or view a short video. Browse & Refine: Access the Best Match Fast For Your Product and Task In the Knowledge Browse region of the Knowledge or Dashboard tabs, pick your product, pick your task, select a version, if applicable. A best match document – a collection of knowledge articles and resources specific to your selections - may display, offering you a one-stop shop. The best match document, called an “information center,” is an aggregate of dynamically updated links to information pertinent to the product, task, and version (if applicable) you chose. These documents are refreshed every 24 hours to ensure that you have the most current information at your fingertips. Note: Not all products have “information centers.” If no information center appears as a best match, click Search to see a list of search results. From the information center, you can access topics from a product overview to security information, as shown in the left menu. Just want to search? That’s easy too! Again, pick your product, pick your task, select a version, if applicable, enter a keyword term, and click Search. Hint: In this example, you’ll notice that PowerView is on and set to PeopleSoft Enterprise. When PowerView is on and you select a product from the Knowledge Base product list, the listed products are limited to the active PowerView filter. (Products you’ve previously picked are also listed at the top of the dropdown list.) Your search results are displayed based on the parameters you entered. It’s that simple! Related Information: My Oracle Support - User Resource Center [ID 873313.1] My Oracle Support Community For more tips on using My Oracle Support, check out these short video training modules. My Oracle Support Speed Video Training [ID 603505.1]

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  • How can I best implement 'cache until further notice' with memcache in multiple tiers?

    - by ajreal
    the term "client" used here is not referring to client's browser, but client server Before cache workflow 1. client make a HTTP request --> 2. server process --> 3. store parsed results into memcache for next use (cache indefinitely) --> 4. return results to client --> 5. client get the result, store into client's local memcache with TTL After cache workflow 1. another client make a HTTP request --> 2. memcache found return memcache results to client --> 3. client get the result, store into client's local memcache with TTL TTL = time to live Is possible for me to know when the data was updated, and to expire relevant memcache(s) accordingly. However, the pitfalls on client site cache TTL Any data update before the TTL is not pick-up by client memcache. In reverse manner, where there is no update, client memcache still expire after the TTL First request (or concurrent requests) after cache TTL will get throttle as it need to repeat the "Before cache workflow" In the event where client require several HTTP requests on a single web page, it could be very bad in performance. Ideal solution should be client to cache indefinitely until further notice. Here are the three proposals about futher notice Proposal 1 : Make use on HTTP header (current implementation) 1. client sent HTTP request last modified time header 2. server check if last data modified time=last cache time return status 304 3. client based on header to decide further processing GOOD? ---- - save some parsing for client - lesser data transfer BAD? ---- - fire a HTTP request is still slow - server end still need to process lots of requests Proposal 2 : Consistently issue a HTTP request to check all data group last modified time 1. client fire a HTTP request 2. server to return last modified time for all data group 3. client compare local last cache time with the result 4. if data group last cache time < server last modified time then request again for that data group only GOOD? ---- - only fetch what is no up-to-date - less requests for server BAD? ---- - every web page require a HTTP request Proposal 3 : Tell client when new data is available (Push) 1. when server end notice there is a change on a data group 2. notify clients on the changes 3. help clients to fetch again data 4. then reset client local memcache after data is parsed GOOD? ---- - let the cache act/behave like a true cache BAD? ---- - encourage race condition My preference is on proposal 3, and something like Gearman could be ideal Where there is a change, Gearman server to sent the task to multiple clients (workers). Am I crazy? (I know my first question is a bit crazy)

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  • Inside Red Gate - Exercising Externally

    - by simonc
    Over the next few weeks, we'll be performing experiments on SmartAssembly to confirm or refute various hypotheses we have about how people use the product, what is stopping them from using it to its full extent, and what we can change to make it more useful and easier to use. Some of these experiments can be done within the team, some within Red Gate, and some need to be done on external users. External testing Some external testing can be done by standard usability tests and surveys, however, there are some hypotheses that can only be tested by building a version of SmartAssembly with some things in the UI or implementation changed. We'll then be able to look at how the experimental build is used compared to the 'mainline' build, which forms our baseline or control group, and use this data to confirm or refute the relevant hypotheses. However, there are several issues we need to consider before running experiments using separate builds: Ideally, the user wouldn't know they're running an experimental SmartAssembly. We don't want users to use the experimental build like it's an experimental build, we want them to use it like it's the real mainline build. Only then will we get valid, useful, and informative data concerning our hypotheses. There's no point running the experiments if we can't find out what happens after the download. To confirm or refute some of our hypotheses, we need to find out how the tool is used once it is installed. Fortunately, we've applied feature usage reporting to the SmartAssembly codebase itself to provide us with that information. Of course, this then makes the experimental data conditional on the user agreeing to send that data back to us in the first place. Unfortunately, even though this does limit the amount of useful data we'll be getting back, and possibly skew the data, there's not much we can do about this; we don't collect feature usage data without the user's consent. Looks like we'll simply have to live with this. What if the user tries to buy the experiment? This is something that isn't really covered by the Lean Startup book; how do you support users who give you money for an experiment? If the experiment is a new feature, and the user buys a license for SmartAssembly based on that feature, then what do we do if we later decide to pivot & scrap that feature? We've either got to spend time and money bringing that feature up to production quality and into the mainline anyway, or we've got disgruntled customers. Either way is bad. Again, there's not really any good solution to this. Similarly, what if we've removed some features for an experiment and a potential new user downloads the experimental build? (As I said above, there's no indication the build is an experimental build, as we want to see what users really do with it). The crucial feature they need is missing, causing a bad trial experience, a lost potential customer, and a lost chance to help the customer with their problem. Again, this is something not really covered by the Lean Startup book, and something that doesn't have a good solution. So, some tricky issues there, not all of them with nice easy answers. Turns out the practicalities of running Lean Startup experiments are more complicated than they first seem! Cross posted from Simple Talk.

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  • Patterns for a tree of persistent data with multiple storage options?

    - by Robin Winslow
    I have a real-world problem which I'll try to abstract into an illustrative example. So imagine I have data objects in a tree, where parent objects can access children, and children can access parents: // Interfaces interface IParent<TChild> { List<TChild> Children; } interface IChild<TParent> { TParent Parent; } // Classes class Top : IParent<Middle> {} class Middle : IParent<Bottom>, IChild<Top> {} class Bottom : IChild<Middle> {} // Usage var top = new Top(); var middles = top.Children; // List<Middle> foreach (var middle in middles) { var bottoms = middle.Children; // List<Bottom> foreach (var bottom in bottoms) { var middle = bottom.Parent; // Access the parent var top = middle.Parent; // Access the grandparent } } All three data objects have properties that are persisted in two data stores (e.g. a database and a web service), and they need to reflect and synchronise with the stores. Some objects only request from the web service, some only write to it. Data Mapper My favourite pattern for data access is Data Mapper, because it completely separates the data objects themselves from the communication with the data store: class TopMapper { public Top FetchById(int id) { var top = new Top(DataStore.TopDataById(id)); top.Children = MiddleMapper.FetchForTop(Top); return Top; } } class MiddleMapper { public Middle FetchById(int id) { var middle = new Middle(DataStore.MiddleDataById(id)); middle.Parent = TopMapper.FetchForMiddle(middle); middle.Children = BottomMapper.FetchForMiddle(bottom); return middle; } } This way I can have one mapper per data store, and build the object from the mapper I want, and then save it back using the mapper I want. There is a circular reference here, but I guess that's not a problem because most languages can just store memory references to the objects, so there won't actually be infinite data. The problem with this is that every time I want to construct a new Top, Middle or Bottom, it needs to build the entire object tree within that object's Parent or Children property, with all the data store requests and memory usage that that entails. And in real life my tree is much bigger than the one represented here, so that's a problem. Requests in the object In this the objects request their Parents and Children themselves: class Middle { private List<Bottom> _children = null; // cache public List<Bottom> Children { get { _children = _children ?? BottomMapper.FetchForMiddle(this); return _children; } set { BottomMapper.UpdateForMiddle(this, value); _children = value; } } } I think this is an example of the repository pattern. Is that correct? This solution seems neat - the data only gets requested from the data store when you need it, and thereafter it's stored in the object if you want to request it again, avoiding a further request. However, I have two different data sources. There's a database, but there's also a web service, and I need to be able to create an object from the web service and save it back to the database and then request it again from the database and update the web service. This also makes me uneasy because the data objects themselves are no longer ignorant of the data source. We've introduced a new dependency, not to mention a circular dependency, making it harder to test. And the objects now mask their communication with the database. Other solutions Are there any other solutions which could take care of the multiple stores problem but also mean that I don't need to build / request all the data every time?

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  • Obfuscation is not a panacea

    - by simonc
    So, you want to obfuscate your .NET application. My question to you is: Why? What are your aims when your obfuscate your application? To protect your IP & algorithms? Prevent crackers from breaking your licensing? Your boss says you need to? To give you a warm fuzzy feeling inside? Obfuscating code correctly can be tricky, it can break your app if applied incorrectly, it can cause problems down the line. Let me be clear - there are some very good reasons why you would want to obfuscate your .NET application. However, you shouldn't be obfuscating for the sake of obfuscating. Security through Obfuscation? Once your application has been installed on a user’s computer, you no longer control it. If they do not want to pay for your application, then nothing can stop them from cracking it, even if the time cost to them is much greater than the cost of actually paying for it. Some people will not pay for software, even if it takes them a month to crack a $30 app. And once it is cracked, there is nothing stopping them from putting the result up on the internet. There should be nothing suprising about this; there is no software protection available for general-purpose computers that cannot be cracked by a sufficiently determined attacker. Only by completely controlling the entire stack – software, hardware, and the internet connection, can you have even a chance to be uncrackable. And even then, someone somewhere will still have a go, and probably succeed. Even high-end cryptoprocessors have known vulnerabilities that can be exploited by someone with a scanning electron microscope and lots of free time. So, then, why use obfuscation? Well, the primary reason is to protect your IP. What obfuscation is very good at is hiding the overall structure of your program, so that it’s very hard to figure out what exactly the code is doing at any one time, what context it is running in, and how it fits in with the rest of the application; all of which you need to do to understand how the application operates. This is completely different to cracking an application, where you simply have to find a single toggle that determines whether the application is licensed or not, and flip it without the rest of the application noticing. However, again, there are limitations. An obfuscated application still has to run in the same way, and do the same thing, as the original unobfuscated application. This means that some of the protections applied to the obfuscated assembly have to be undone at runtime, else it would not run on the CLR and do the same thing. And, again, since we don’t control the environment the application is run on, there is nothing stopping a user from undoing those protections manually, and reversing some of the obfuscation. It’s a perpetual arms race, and it always will be. We have plenty of ideas lined about new protections, and the new protections added in SA 6.6 (method parent obfuscation and a new control flow obfuscation level) are specifically designed to be harder to reverse and reconstruct the original structure. So then, by all means, obfuscate your application if you want to protect the algorithms and what the application does. That’s what SmartAssembly is designed to do. But make sure you are clear what a .NET obfuscator can and cannot protect you against, and don’t expect your obfuscated application to be uncrackable. Someone, somewhere, will crack your application if they want to and they don’t have anything better to do with their time. The best we can do is dissuade the casual crackers and make it much more difficult for the serious ones. Cross posted from Simple Talk.

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  • Optimal Data Structure for our own API

    - by vermiculus
    I'm in the early stages of writing an Emacs major mode for the Stack Exchange network; if you use Emacs regularly, this will benefit you in the end. In order to minimize the number of calls made to Stack Exchange's API (capped at 10000 per IP per day) and to just be a generally responsible citizen, I want to cache the information I receive from the network and store it in memory, waiting to be accessed again. I'm really stuck as to what data structure to store this information in. Obviously, it is going to be a list. However, as with any data structure, the choice must be determined by what data is being stored and what how it will be accessed. What, I would like to be able to store all of this information in a single symbol such as stack-api/cache. So, without further ado, stack-api/cache is a list of conses keyed by last update: `(<csite> <csite> <csite>) where <csite> would be (1362501715 . <site>) At this point, all we've done is define a simple association list. Of course, we must go deeper. Each <site> is a list of the API parameter (unique) followed by a list questions: `("codereview" <cquestion> <cquestion> <cquestion>) Each <cquestion> is, you guessed it, a cons of questions with their last update time: `(1362501715 <question>) (1362501720 . <question>) <question> is a cons of a question structure and a list of answers (again, consed with their last update time): `(<question-structure> <canswer> <canswer> <canswer> and ` `(1362501715 . <answer-structure>) This data structure is likely most accurately described as a tree, but I don't know if there's a better way to do this considering the language, Emacs Lisp (which isn't all that different from the Lisp you know and love at all). The explicit conses are likely unnecessary, but it helps my brain wrap around it better. I'm pretty sure a <csite>, for example, would just turn into (<epoch-time> <api-param> <cquestion> <cquestion> ...) Concerns: Does storing data in a potentially huge structure like this have any performance trade-offs for the system? I would like to avoid storing extraneous data, but I've done what I could and I don't think the dataset is that large in the first place (for normal use) since it's all just human-readable text in reasonable proportion. (I'm planning on culling old data using the times at the head of the list; each inherits its last-update time from its children and so-on down the tree. To what extent this cull should take place: I'm not sure.) Does storing data like this have any performance trade-offs for that which must use it? That is, will set and retrieve operations suffer from the size of the list? Do you have any other suggestions as to what a better structure might look like?

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  • Entity System with C++ templates

    - by tommaisey
    I've been getting interested in the Entity/Component style of game programming, and I've come up with a design in C++ which I'd like a critique of. I decided to go with a fairly pure Entity system, where entities are simply an ID number. Components are stored in a series of vectors - one for each Component type. However, I didn't want to have to add boilerplate code for every new Component type I added to the game. Nor did I want to use macros to do this, which frankly scare me. So I've come up with a system based on templates and type hinting. But there are some potential issues I'd like to check before I spend ages writing this (I'm a slow coder!) All Components derive from a Component base class. This base class has a protected constructor, that takes a string parameter. When you write a new derived Component class, you must initialise the base with the name of your new class in a string. When you first instantiate a new DerivedComponent, it adds the string to a static hashmap inside Component mapped to a unique integer id. When you subsequently instantiate more Components of the same type, no action is taken. The result (I think) should be a static hashmap with the name of each class derived from Component that you instantiate at least once, mapped to a unique id, which can by obtained with the static method Component::getTypeId ("DerivedComponent"). Phew. The next important part is TypedComponentList<typename PropertyType>. This is basically just a wrapper to an std::vector<typename PropertyType> with some useful methods. It also contains a hashmap of entity ID numbers to slots in the array so we can find Components by their entity owner. Crucially TypedComponentList<> is derived from the non-template class ComponentList. This allows me to maintain a list of pointers to ComponentList in my main ComponentManager, which actually point to TypedComponentLists with different template parameters (sneaky). The Component manager has template functions such as: template <typename ComponentType> void addProperty (ComponentType& component, int componentTypeId, int entityId) and: template <typename ComponentType> TypedComponentList<ComponentType>* getComponentList (int componentTypeId) which deal with casting from ComponentList to the correct TypedComponentList for you. So to get a list of a particular type of Component you call: TypedComponentList<MyComponent>* list = componentManager.getComponentList<MyComponent> (Component::getTypeId("MyComponent")); Which I'll admit looks pretty ugly. Bad points of the design: If a user of the code writes a new Component class but supplies the wrong string to the base constructor, the whole system will fail. Each time a new Component is instantiated, we must check a hashed string to see if that component type has bee instantiated before. Will probably generate a lot of assembly because of the extensive use of templates. I don't know how well the compiler will be able to minimise this. You could consider the whole system a bit complex - perhaps premature optimisation? But I want to use this code again and again, so I want it to be performant. Good points of the design: Components are stored in typed vectors but they can also be found by using their entity owner id as a hash. This means we can iterate them fast, and minimise cache misses, but also skip straight to the component we need if necessary. We can freely add Components of different types to the system without having to add and manage new Component vectors by hand. What do you think? Do the good points outweigh the bad?

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  • Understanding the Value of SOA

    - by Mala Narasimharajan
    Written By: Debra Lilley, ACE Director, Fusion Applications Again I want to talk from my area of expertise of Fusion Applications and talk about their design fundamentals. If you look at the table below and start at the bottom Oracle have defined all of the business objects e.g. accounts, people, customers, invoices etc. used by Fusion Applications; each of these objects contain all of the information required and can be expanded if necessary.  That Oracle have created for each of these business objects every action that is needed for the applications e.g. all the actions to create a new customer, checking to see if it exists, credit checking with D&B (Dun & Bradstreet < http://www.dnb.co.uk/> ) , creating the record, notifying those required etc. Each of these actions is a stand-alone web service. Again you can create a new actions or subscribe to an external provided web service e.g. the D&B check. The diagram also shows that all of development of Fusion Applications is from their Fusion Middleware offerings. Then the Intelligent Business Process is the order in which you run these actions, this is Service Orientated Architecture, SOA. Not only is SOA used to orchestrate actions within Fusion Applications it is also used in the integration of Fusion Applications with the rest of the Oracle stable of applications such as EBS, PeopleSoft, JDE and Siebel. The other applications are written with propriety development tools so how do they work with SOA? It’s a very simple answer, with the introduction of the Oracle SOA platform each process within these applications was made available to be called as a web service. I won’t go into technically how that is done but what’s known as a wrapper to allow each of them to act in this way was added. Finally at the top of the diagram are the questions that each Fusion Application process must answer, and this is the ‘special’ sauce that makes them so good, the User Experience, but that is a topic for another day, or you can read about it in my blog http://debrasoracle.blogspot.co.uk/2014/04/going-on-record-about-fusion-apps-cloud.html or Oracle’s own UX blog https://blogs.oracle.com/usableapps/ The concept behind AppAdvantage is not new the idea that Oracle technology can add value to your Oracle applications investments is pretty fundamental. Nishit Rao who is in AppAdvantage team provided myself and other ACE Directors with demo kits so that we could demonstrate SOA running with the applications. The example I learnt to build was that of the EBS inventory open interface. The simple concept is that request records can be added to a table and an import run that creates these as transactions in inventory. What’s SOA allows you to do is to add to the table from any source and then run this process automatically whereas traditionally you had to run the process at regular intervals because you didn’t know if the table was empty or not. This may just sound like a different way of doing the same thing but if the process is critical for your business then the interval was very small and the process run potentially many times unnecessarily. Using SOA it only happened when necessary without any delay. So in my post today I’ve talked about how SOA is used with Fusion Applications and in the linking with more traditional applications but that is only the tip of the iceberg of potential, your applications are just part of your IT systems and SOA can orchestrate your data across all of them; the beauty of open standards.  Debra Lilley, Fusion Champion, UKOUG Board Member, Fusion User Experience Advocate and ACE Director.  Lilley has 18 years experience with Oracle Applications, with E Business Suite since 9.4.1, moving to Business Intelligence Team Lead and Oracle Alliance Director. She has spoken at over 100 conferences worldwide and posts at debrasoraclethoughts

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  • Delegates: A Practical Understanding

    - by samerpaul
    It's been a while since I have written on this blog, and I'm planning on reviving it this summer, since I have more time to do so again.I've also recently started working on the iPhone platform, so I haven't been as busy in .NET as before.In either case, today's blog post applies to both C# and Objective-C, because it's more about a practical understanding of delegates than it is about code. When I was learning coding, I felt like delegates was one of the hardest things to conceptually understand, and a lot of books don't really do a good job (in my opinion) of explaining it. So here's my stab at it.A Real Life Example of DelegatesLet's say there are three of you. You, your friend, and your brother. You're each in a different room in your house so you can't hear each other, even if you shout. 1)You are playing a computer game2) Friend is building a puzzle3) Brother is nappingNow, you three are going to stay in your room but you want to be informed if anything interesting is happening to the one of you. Let's say you (playing the computer game) want to know when your brother wakes up.You could keep walking to the room, checking to see if he's napping, and then walking back to your room. But that would waste a lot of time / resources, and what if you miss when he's awake before he goes back to sleep? That would be bad.Instead, you hand him a 2-way radio that works between your room and his room. And you inform him that when he wakes up, he should press a button on the radio and say "I'm awake". You are going to be listening to that radio, waiting for him to say he's awake. This, in essence, is how a delegate works.You're creating an "object" (the radio) that allows you to listen in on an event you specify. You don't want him to send any other messages to you right now, except when he wakes up. And you want to know immediately when he does, so you can go over to his room and say hi. (the methods that are called when a delegate event fires). You're also currently specifying that only you are listening on his radio.Let's say you want your friend to come into the room at the same time as you, and do something else entirely, like fluff your brother's pillow. You will then give him an identical radio, that also hooks into your brother's radio, and inform him to wait and listen for the "i'm awake" signal.Then, when your brother wakes up, he says "I'm awake!" and both you and your friend walk into the room. You say hi, and your friend fluffs the pillow, then you both exit.Later, if you decide you don't care to say hi anymore, you turn off your radio. Now, you have no idea when your brother is awake or not, because you aren't listening anymore.So again, you are each classes in this example, and each of you have your own methods. You're playing a computer game (PlayComputerGame()), your friend is building a puzzle (BuildPuzzle()) and your brother is napping (Napping()). You create a delegate (ImAwake) that you set your brother to do, when he wakes up. You listen in on that delegate (giving yourself a radio and turning it on), and when you receive the message, you fire a new method called SayHi()). Your friend is also wired up to the same delegate (using an identical radio) and fires the method FluffPillow().Hopefully this makes sense, and helps shed some light on how delegates operate. Let me know! Feel free to drop me a line at Twitter (preferred method of contact) here: samerabousalbi

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  • Is hidden content (display: none;) -indexed- by search engines? [closed]

    - by user568458
    Possible Duplicate: How bad is it to use display: none in CSS? We've established on this site before (in this question) that, since there are so many legitimate uses for hiding content with display: none; when creating interactive features, that sites aren't automatically penalised for content that is hidden this way (so long as it doesn't look algorithmically spammy). Google's Webmaster guidelines also make clear that a good practice when using content that is initially legitimately hidden for interactivity purposes is to also include the same content in a <noscript> tag, and Google recommend that if you design and code for users including users with screen readers or javascript disabled, then 9 times out of 10 good relevant search rankings will follow (though their specific advice seems more written for cases where javascript writes new content to the page). JavaScript: Place the same content from the JavaScript in a tag. If you use this method, ensure the contents are exactly the same as what’s contained in the JavaScript, and that this content is shown to visitors who do not have JavaScript enabled in their browser. So, best practice seems pretty clear. What I can't find out is, however, the simple factual matter of whether hidden content is indexed by search engines (but with potential penalties if it looks 'spammy'), or, whether it is ignored, or, whether it is indexed but with a lower weighting (like <noscript> content is, apparently). (for bonus points it would be great to know if this varies or is consistent between display: none;, visibility: hidden;, etc, but that isn't crucial). This is different to the other questions on display:none; and SEO - those are about good and bad practice and the answers are discussions of good and bad practice, I'm interested simply in the factual 'Yes or no' question of whether search engines index, or ignore, content that is in display: none; - something those other questions' answers aren't totally clear on. One other question has an answer, "Yes", supported by a link to an article that doesn't really clear things up: it establishes that search engines can spot that text is hidden, it discusses (again) whether hidden text causes sites to be marked as spam, and ultimately concludes that in mid 2011, Google's policy on hidden text was evolving, and that they hadn't at that time started automatically penalising display:none; or marking it as spam. It's clear that display: none; isn't always spam and isn't always treated as spam (many Google sites use it...): but this doesn't clear up how, or if, it is indexed. What I will do will be to follow the guidelines and make sure that all the content that is initially hidden which regular users can explore using javascript-driven interactivity is also structured in way that noscript/screenreader users can use. So I'm not interested in best practice, opinions etc because best practice seems to be really clear: accessibility best practices boosts SEO. But I'd like to know what exactly will happen: whether any display: none; content I have alongside <noscript> or otherwise accessibility-optimised content will be be ignored, or indexed again, or picked up to compare against the <noscript> content but not indexed... etc.

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  • Quick guide to Oracle IRM 11g: Configuring SSL

    - by Simon Thorpe
    Quick guide to Oracle IRM 11g index So far in this guide we have an IRM Server up and running, however I skipped over SSL configuration in the previous article because I wanted to focus in more detail now. You can, if you wish, not bother with setting up SSL, but considering this is a security technology it is worthwhile doing. Contents Setting up a one way, self signed SSL certificate in WebLogic Setting up an official SSL certificate in Apache 2.x Configuring Apache to proxy traffic to the IRM server There are two common scenarios in which an Oracle IRM server is configured. For a development or evaluation system, people usually communicate directly to the WebLogic Server running the IRM service. However in a production environment and for some proof of concept evaluations that require a setup reflecting a production system, the traffic to the IRM server travels via a web server proxy, commonly Apache. In this guide we are building an Oracle Enterprise Linux based IRM service and this article will go over the configuration of SSL in WebLogic and also in Apache. Like in the past articles, we are going to use two host names in the configuration below,irm.company.com will refer to the public Apache server irm.company.internal will refer to the internal WebLogic IRM server Setting up a one way, self signed SSL certificate in WebLogic First lets look at creating just a simple self signed SSL certificate to be used in WebLogic. This is a quick and easy way to get SSL working in your environment, however the downside is that no browsers are going to trust this certificate you create and you'll need to manually install the certificate onto any machine's communicating with the server. This is fine for development or when you have only a few users evaluating the system, but for any significant use it's usually better to have a fully trusted certificate in use and I explain that in the next section. But for now lets go through creating, installing and testing a self signed certificate. We use a library in Java to create the certificates, open a console and running the following commands. Note you should choose your own secure passwords whenever you see password below. [oracle@irm /] source /oracle/middleware/wlserver_10.3/server/bin/setWLSEnv.sh [oracle@irm /] cd /oracle/middleware/user_projects/domains/irm_domain/config/fmwconfig/ [oracle@irm /] java utils.CertGen -selfsigned -certfile MyOwnSelfCA.cer -keyfile MyOwnSelfKey.key -keyfilepass password -cn "irm.oracle.demo" [oracle@irm /] java utils.ImportPrivateKey -keystore MyOwnIdentityStore.jks -storepass password -keypass password -alias trustself -certfile MyOwnSelfCA.cer.pem -keyfile MyOwnSelfKey.key.pem -keyfilepass password [oracle@irm /] keytool -import -trustcacerts -alias trustself -keystore TrustMyOwnSelf.jks -file MyOwnSelfCA.cer.der -keyalg RSA We now have two Java Key Stores, MyOwnIdentityStore.jks and TrustMyOwnSelf.jks. These contain keys and certificates which we will use in WebLogic Server. Now we need to tell the IRM server to use these stores when setting up SSL connections for incoming requests. Make sure the Admin server is running and login into the WebLogic Console at http://irm.company.intranet:7001/console and do the following; In the menu on the left, select the + next to Environment to expose the submenu, then click on Servers. You will see two servers in the list, AdminServer(admin) and IRM_server1. If the IRM server is running, shut it down either by hitting CONTROL + C in the console window it was started from, or you can switch to the CONTROL tab, select IRM_server1 and then select the Shutdown menu and then Force Shutdown Now. In the Configuration tab select IRM_server1 and switch to the Keystores tab. By default WebLogic Server uses it's own demo identity and trust. We are now going to switch to the self signed one's we've just created. So select the Change button and switch to Custom Identity and Custom Trust and hit save. Now we have to complete the resulting fields, the setting's i've used in my evaluation server are below. IdentityCustom Identity Keystore: /oracle/middleware/user_projects/domains/irm_domain/config/fmwconfig/MyOwnIdentityStore.jks Custom Identity Keystore Type: JKS Custom Identity Keystore Passphrase: password Confirm Custom Identity Keystore Passphrase: password TrustCustom Trust Keystore: /oracle/middleware/user_projects/domains/irm_domain/config/fmwconfig/TrustMyOwnSelf.jks Custom Trust Keystore Type: JKS Custom Trust Keystore Passphrase: password Confirm Custom Trust Keystore Passphrase: password Now click on the SSL tab for the IRM_server1 and enter in the alias and passphrase, in my demo here the details are; IdentityPrivate Key Alias: trustself Private Key Passphrase: password Confirm Private Key Passphrase: password And hit save. Now lets test a connection to the IRM server over HTTPS using SSL. Go back to a console window and start the IRM server, a quick reminder on how to do this is... [oracle@irm /] cd /oracle/middleware/user_projects/domains/irm_domain/bin [oracle@irm /] ./startManagedWeblogic IRM_server1 Once running, open a browser and head to the SSL port of the server. By default the IRM server will be listening on the URL https://irm.company.intranet:16101/irm_rights. Note in the example image on the right the port is 7002 because it's a system that has the IRM services installed on the Admin server, this isn't typical (or advisable). Your system is going to have a separate managed server which will be listening on port 16101. Once you open this address you will notice that your browser is going to complain that the server certificate is untrusted. The images on the right show how Firefox displays this error. You are going to be prompted every time you create a new SSL session with the server, both from the browser and more annoyingly from the IRM Desktop. If you plan on always using a self signed certificate, it is worth adding it to the Windows certificate store so that when you are accessing sealed content you do not keep being informed this certificate is not trusted. Follow these instructions (which are for Internet Explorer 8, they may vary for your version of IE.) Start Internet Explorer and open the URL to your IRM server over SSL, e.g. https://irm.company.intranet:16101/irm_rights. IE will complain that about the certificate, click on Continue to this website (not recommended). From the IE Tools menu select Internet Options and from the resulting dialog select Security and then click on Trusted Sites and then the Sites button. Add to the list of trusted sites a URL which mates the server you are accessing, e.g. https://irm.company.intranet/ and select OK. Now refresh the page you were accessing and next to the URL you should see a red cross and the words Certificate Error. Click on this button and select View Certificates. You will now see a dialog with the details of the self signed certificate and the Install Certificate... button should be enabled. Click on this to start the wizard. Click next and you'll be asked where you should install the certificate. Change the option to Place all certificates in the following store. Select browse and choose the Trusted Root Certification Authorities location and hit OK. You'll then be prompted to install the certificate and answer yes. You also need to import the root signed certificate into the same location, so once again select the red Certificate Error option and this time when viewing the certificate, switch to the Certification Path tab and you should see a CertGenCAB certificate. Select this and then click on View Certificate and go through the same process as above to import the certificate into the store. Finally close all instances of the IE browser and re-access the IRM server URL again, this time you should not receive any errors. Setting up an official SSL certificate in Apache 2.x At this point we now have an IRM server that you can communicate with over SSL. However this certificate isn't trusted by any browser because it's path of trust doesn't end in a recognized certificate authority (CA). Also you are communicating directly to the WebLogic Server over a non standard SSL port, 16101. In a production environment it is common to have another device handle the initial public internet traffic and then proxy this to the WebLogic server. The diagram below shows a very simplified view of this type of deployment. What i'm going to walk through next is configuring Apache to proxy traffic to a WebLogic server and also to use a real SSL certificate from an official CA. First step is to configure Apache to handle incoming requests over SSL. In this guide I am configuring the IRM service in Oracle Enterprise Linux 5 update 3 and Apache 2.2.3 which came with OpenSSL and mod_ssl components. Before I purchase an SSL certificate, I need to generate a certificate request from the server. Oracle.com uses Verisign and for my own personal needs I use cheaper certificates from GoDaddy. The following instructions are specific to Apache, but there are many references out there for other web servers. For Apache I have OpenSSL and the commands are; [oracle@irm /] cd /usr/bin [oracle@irm bin] openssl genrsa -des3 -out irm-apache-server.key 2048 Generating RSA private key, 2048 bit long modulus ............................+++ .........+++ e is 65537 (0x10001) Enter pass phrase for irm-apache-server.key: Verifying - Enter pass phrase for irm-apache-server.key: [oracle@irm bin] openssl req -new -key irm-apache-server.key -out irm-apache-server.csr Enter pass phrase for irm-apache-server.key: You are about to be asked to enter information that will be incorporated into your certificate request. What you are about to enter is what is called a Distinguished Name or a DN. There are quite a few fields but you can leave some blank For some fields there will be a default value, If you enter '.', the field will be left blank. ----- Country Name (2 letter code) [GB]:US State or Province Name (full name) [Berkshire]:CA Locality Name (eg, city) [Newbury]:San Francisco Organization Name (eg, company) [My Company Ltd]:Oracle Organizational Unit Name (eg, section) []:Security Common Name (eg, your name or your server's hostname) []:irm.company.com Email Address []:[email protected] Please enter the following 'extra' attributes to be sent with your certificate request A challenge password []:testing An optional company name []: You must make sure to remember the pass phrase you used in the initial key generation, you will need this when later configuring Apache. In the /usr/bin directory there are now two new files. The irm-apache-server.csr contains our certificate request and is what you cut and paste, or upload, to your certificate authority when you purchase and validate your SSL certificate. In response you will typically get two files. Your server certificate and another certificate file that will likely contain a set of certificates from your CA which validate your certificate's trust. Next we need to configure Apache to use these files. Typically there is an ssl.conf file which is where all the SSL configuration is done. On my Oracle Enterprise Linux server this file is located in /etc/httpd/conf.d/ssl.conf and i've added the following lines. <VirtualHost irm.company.com> # Setup SSL for irm.company.com ServerName irm.company.com SSLEngine On SSLCertificateFile /oracle/secure/irm.company.com.crt SSLCertificateKeyFile /oracle/secure/irm.company.com.key SSLCertificateChainFile /oracle/secure/gd_bundle.crt </VirtualHost> Restarting Apache (apachectl restart) and I can now attempt to connect to the Apache server in a web browser, https://irm.company.com/. If all is configured correctly I should now see an Apache test page delivered to me over HTTPS. Configuring Apache to proxy traffic to the IRM server Final piece in setting up SSL is to have Apache proxy requests for the IRM server but do so securely. So the requests to Apache will be over HTTPS using a legitimate certificate, but we can also configure Apache to proxy these requests internally across to the IRM server using SSL with the self signed certificate we generated at the start of this article. To do this proxying we use the WebLogic Web Server plugin for Apache which you can download here from Oracle. Download the zip file and extract onto the server. The file extraction reveals a set of zip files, each one specific to a supported web server. In my instance I am using Apache 2.2 32bit on an Oracle Enterprise Linux, 64 bit server. If you are not sure what version your Apache server is, run the command /usr/sbin/httpd -V and you'll see version and it its 32 or 64 bit. Mine is a 32bit server so I need to extract the file WLSPlugin1.1-Apache2.2-linux32-x86.zip. The from the resulting lib folder copy the file mod_wl.so into /usr/lib/httpd/modules/. First we want to test that the plug in will work for regular HTTP traffic. Edit the httpd.conf for Apache and add the following section at the bottom. LoadModule weblogic_module modules/mod_wl.so <IfModule mod_weblogic.c>    WebLogicHost irm.company.internal    WebLogicPort 16100    WLLogFile /tmp/wl-proxy.log </IfModule> <Location /irm_rights>    SetHandler weblogic-handler </Location> <Location /irm_desktop>    SetHandler weblogic-handler </Location> <Location /irm_sealing>    SetHandler weblogic-handler </Location> <Location /irm_services>    SetHandler weblogic-handler </Location> Now restart Apache again (apachectl restart) and now open a browser to http://irm.company.com/irm_rights. Apache will proxy the HTTP traffic from the port 80 of your Apache server to the IRM service listening on port 16100 of the WebLogic Managed server. Note above I have included all four of the Locations you might wish to proxy. http://irm.company.internalirm_rights is the URL to the management website, /irm_desktop is the URL used for the IRM Desktop to communicate. irm_sealing is for web services based document sealing and irm_services is for IRM server web services. The last two are typically only used when you have the IRM server integrated with another application and it is unlikely you'd be accessing these resources from the public facing Apache server. However, just in case, i've mentioned them above. Now let's enable SSL communication from Apache to WebLogic. In the ZIP file we extracted were some more modules we need to copy into the Apache folder. Looking back in the lib that we extracted, there are some more files. Copy the following into the /usr/lib/httpd/modules/ folder. libwlssl.so libnnz11.so libclntsh.so.11.1 Now the documentation states that should only need to do this, but I found that I also needed to create an environment variable called LD_LIBRARY_PATH and point this to the folder /usr/lib/httpd/modules/. If I didn't do this, starting Apache with the WebLogic module configured to SSL would throw the error. [crit] (20014)Internal error: WL SSL Init failed for server: (null) on 0 So I had to edit the file /etc/profile and add the following lines at the bottom. You may already have the LD_LIBRARY_PATH variable defined, therefore simply add this path to it. LD_LIBRARY_PATH=/usr/lib/httpd/modules/ export LD_LIBRARY_PATH Now the WebLogic plug in uses an Oracle Wallet to store the required certificates.You'll need to copy the self signed certificate from the IRM server over to the Apache server. Copy over the MyOwnSelfCA.cer.der into the same folder where you are storing your public certificates, in my example this is /oracle/secure. It's worth mentioning these files should ONLY be readable by root (the user Apache runs as). Now lets create an Oracle Wallet and import the self signed certificate from the IRM server. The file orapki was included in the bin folder of the Apache 1.1 plugin zip you extracted. orapki wallet create -wallet /oracle/secure/my-wallet -auto_login_only orapki wallet add -wallet /oracle/secure/my-wallet -trusted_cert -cert MyOwnSelfCA.cer.der -auto_login_only Finally change the httpd.conf to reflect that we want the WebLogic Apache plug-in to use HTTPS/SSL and not just plain HTTP. <IfModule mod_weblogic.c>    WebLogicHost irm.company.internal    WebLogicPort 16101    SecureProxy ON    WLSSLWallet /oracle/secure/my-wallet    WLLogFile /tmp/wl-proxy.log </IfModule> Then restart Apache once more and you can go back to the browser to test the communication. Opening the URL https://irm.company.com/irm_rights will proxy your request to the WebLogic server at https://irm.company.internal:16101/irm_rights. At this point you have a fully functional Oracle IRM service, the next step is to create a sealed document and test the entire system.

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  • Agile Development

    - by James Oloo Onyango
    Alot of literature has and is being written about agile developement and its surrounding philosophies. In my quest to find the best way to express the importance of agile methodologies, i have found Robert C. Martin's "A Satire Of Two Companies" to be both the most concise and thorough! Enjoy the read! Rufus Inc Project Kick Off Your name is Bob. The date is January 3, 2001, and your head still aches from the recent millennial revelry. You are sitting in a conference room with several managers and a group of your peers. You are a project team leader. Your boss is there, and he has brought along all of his team leaders. His boss called the meeting. "We have a new project to develop," says your boss's boss. Call him BB. The points in his hair are so long that they scrape the ceiling. Your boss's points are just starting to grow, but he eagerly awaits the day when he can leave Brylcream stains on the acoustic tiles. BB describes the essence of the new market they have identified and the product they want to develop to exploit this market. "We must have this new project up and working by fourth quarter October 1," BB demands. "Nothing is of higher priority, so we are cancelling your current project." The reaction in the room is stunned silence. Months of work are simply going to be thrown away. Slowly, a murmur of objection begins to circulate around the conference table.   His points give off an evil green glow as BB meets the eyes of everyone in the room. One by one, that insidious stare reduces each attendee to quivering lumps of protoplasm. It is clear that he will brook no discussion on this matter. Once silence has been restored, BB says, "We need to begin immediately. How long will it take you to do the analysis?" You raise your hand. Your boss tries to stop you, but his spitwad misses you and you are unaware of his efforts.   "Sir, we can't tell you how long the analysis will take until we have some requirements." "The requirements document won't be ready for 3 or 4 weeks," BB says, his points vibrating with frustration. "So, pretend that you have the requirements in front of you now. How long will you require for analysis?" No one breathes. Everyone looks around to see whether anyone has some idea. "If analysis goes beyond April 1, we have a problem. Can you finish the analysis by then?" Your boss visibly gathers his courage: "We'll find a way, sir!" His points grow 3 mm, and your headache increases by two Tylenol. "Good." BB smiles. "Now, how long will it take to do the design?" "Sir," you say. Your boss visibly pales. He is clearly worried that his 3 mms are at risk. "Without an analysis, it will not be possible to tell you how long design will take." BB's expression shifts beyond austere.   "PRETEND you have the analysis already!" he says, while fixing you with his vacant, beady little eyes. "How long will it take you to do the design?" Two Tylenol are not going to cut it. Your boss, in a desperate attempt to save his new growth, babbles: "Well, sir, with only six months left to complete the project, design had better take no longer than 3 months."   "I'm glad you agree, Smithers!" BB says, beaming. Your boss relaxes. He knows his points are secure. After a while, he starts lightly humming the Brylcream jingle. BB continues, "So, analysis will be complete by April 1, design will be complete by July 1, and that gives you 3 months to implement the project. This meeting is an example of how well our new consensus and empowerment policies are working. Now, get out there and start working. I'll expect to see TQM plans and QIT assignments on my desk by next week. Oh, and don't forget that your crossfunctional team meetings and reports will be needed for next month's quality audit." "Forget the Tylenol," you think to yourself as you return to your cubicle. "I need bourbon."   Visibly excited, your boss comes over to you and says, "Gosh, what a great meeting. I think we're really going to do some world shaking with this project." You nod in agreement, too disgusted to do anything else. "Oh," your boss continues, "I almost forgot." He hands you a 30-page document. "Remember that the SEI is coming to do an evaluation next week. This is the evaluation guide. You need to read through it, memorize it, and then shred it. It tells you how to answer any questions that the SEI auditors ask you. It also tells you what parts of the building you are allowed to take them to and what parts to avoid. We are determined to be a CMM level 3 organization by June!"   You and your peers start working on the analysis of the new project. This is difficult because you have no requirements. But from the 10-minute introduction given by BB on that fateful morning, you have some idea of what the product is supposed to do.   Corporate process demands that you begin by creating a use case document. You and your team begin enumerating use cases and drawing oval and stick diagrams. Philosophical debates break out among the team members. There is disagreement as to whether certain use cases should be connected with <<extends>> or <<includes>> relationships. Competing models are created, but nobody knows how to evaluate them. The debate continues, effectively paralyzing progress.   After a week, somebody finds the iceberg.com Web site, which recommends disposing entirely of <<extends>> and <<includes>> and replacing them with <<precedes>> and <<uses>>. The documents on this Web site, authored by Don Sengroiux, describes a method known as stalwart-analysis, which claims to be a step-by-step method for translating use cases into design diagrams. More competing use case models are created using this new scheme, but again, people can't agree on how to evaluate them. The thrashing continues. More and more, the use case meetings are driven by emotion rather than by reason. If it weren't for the fact that you don't have requirements, you'd be pretty upset by the lack of progress you are making. The requirements document arrives on February 15. And then again on February 20, 25, and every week thereafter. Each new version contradicts the previous one. Clearly, the marketing folks who are writing the requirements, empowered though they might be, are not finding consensus.   At the same time, several new competing use case templates have been proposed by the various team members. Each template presents its own particularly creative way of delaying progress. The debates rage on. On March 1, Prudence Putrigence, the process proctor, succeeds in integrating all the competing use case forms and templates into a single, all-encompassing form. Just the blank form is 15 pages long. She has managed to include every field that appeared on all the competing templates. She also presents a 159- page document describing how to fill out the use case form. All current use cases must be rewritten according to the new standard.   You marvel to yourself that it now requires 15 pages of fill-in-the-blank and essay questions to answer the question: What should the system do when the user presses Return? The corporate process (authored by L. E. Ott, famed author of "Holistic Analysis: A Progressive Dialectic for Software Engineers") insists that you discover all primary use cases, 87 percent of all secondary use cases, and 36.274 percent of all tertiary use cases before you can complete analysis and enter the design phase. You have no idea what a tertiary use case is. So in an attempt to meet this requirement, you try to get your use case document reviewed by the marketing department, which you hope will know what a tertiary use case is.   Unfortunately, the marketing folks are too busy with sales support to talk to you. Indeed, since the project started, you have not been able to get a single meeting with marketing, which has provided a never-ending stream of changing and contradictory requirements documents.   While one team has been spinning endlessly on the use case document, another team has been working out the domain model. Endless variations of UML documents are pouring out of this team. Every week, the model is reworked.   The team members can't decide whether to use <<interfaces>> or <<types>> in the model. A huge disagreement has been raging on the proper syntax and application of OCL. Others on the team just got back from a 5-day class on catabolism, and have been producing incredibly detailed and arcane diagrams that nobody else can fathom.   On March 27, with one week to go before analysis is to be complete, you have produced a sea of documents and diagrams but are no closer to a cogent analysis of the problem than you were on January 3. **** And then, a miracle happens.   **** On Saturday, April 1, you check your e-mail from home. You see a memo from your boss to BB. It states unequivocally that you are done with the analysis! You phone your boss and complain. "How could you have told BB that we were done with the analysis?" "Have you looked at a calendar lately?" he responds. "It's April 1!" The irony of that date does not escape you. "But we have so much more to think about. So much more to analyze! We haven't even decided whether to use <<extends>> or <<precedes>>!" "Where is your evidence that you are not done?" inquires your boss, impatiently. "Whaaa . . . ." But he cuts you off. "Analysis can go on forever; it has to be stopped at some point. And since this is the date it was scheduled to stop, it has been stopped. Now, on Monday, I want you to gather up all existing analysis materials and put them into a public folder. Release that folder to Prudence so that she can log it in the CM system by Monday afternoon. Then get busy and start designing."   As you hang up the phone, you begin to consider the benefits of keeping a bottle of bourbon in your bottom desk drawer. They threw a party to celebrate the on-time completion of the analysis phase. BB gave a colon-stirring speech on empowerment. And your boss, another 3 mm taller, congratulated his team on the incredible show of unity and teamwork. Finally, the CIO takes the stage to tell everyone that the SEI audit went very well and to thank everyone for studying and shredding the evaluation guides that were passed out. Level 3 now seems assured and will be awarded by June. (Scuttlebutt has it that managers at the level of BB and above are to receive significant bonuses once the SEI awards level 3.)   As the weeks flow by, you and your team work on the design of the system. Of course, you find that the analysis that the design is supposedly based on is flawedno, useless; no, worse than useless. But when you tell your boss that you need to go back and work some more on the analysis to shore up its weaker sections, he simply states, "The analysis phase is over. The only allowable activity is design. Now get back to it."   So, you and your team hack the design as best you can, unsure of whether the requirements have been properly analyzed. Of course, it really doesn't matter much, since the requirements document is still thrashing with weekly revisions, and the marketing department still refuses to meet with you.     The design is a nightmare. Your boss recently misread a book named The Finish Line in which the author, Mark DeThomaso, blithely suggested that design documents should be taken down to code-level detail. "If we are going to be working at that level of detail," you ask, "why don't we simply write the code instead?" "Because then you wouldn't be designing, of course. And the only allowable activity in the design phase is design!" "Besides," he continues, "we have just purchased a companywide license for Dandelion! This tool enables 'Round the Horn Engineering!' You are to transfer all design diagrams into this tool. It will automatically generate our code for us! It will also keep the design diagrams in sync with the code!" Your boss hands you a brightly colored shrinkwrapped box containing the Dandelion distribution. You accept it numbly and shuffle off to your cubicle. Twelve hours, eight crashes, one disk reformatting, and eight shots of 151 later, you finally have the tool installed on your server. You consider the week your team will lose while attending Dandelion training. Then you smile and think, "Any week I'm not here is a good week." Design diagram after design diagram is created by your team. Dandelion makes it very difficult to draw these diagrams. There are dozens and dozens of deeply nested dialog boxes with funny text fields and check boxes that must all be filled in correctly. And then there's the problem of moving classes between packages. At first, these diagram are driven from the use cases. But the requirements are changing so often that the use cases rapidly become meaningless. Debates rage about whether VISITOR or DECORATOR design patterns should be used. One developer refuses to use VISITOR in any form, claiming that it's not a properly object-oriented construct. Someone refuses to use multiple inheritance, since it is the spawn of the devil. Review meetings rapidly degenerate into debates about the meaning of object orientation, the definition of analysis versus design, or when to use aggregation versus association. Midway through the design cycle, the marketing folks announce that they have rethought the focus of the system. Their new requirements document is completely restructured. They have eliminated several major feature areas and replaced them with feature areas that they anticipate customer surveys will show to be more appropriate. You tell your boss that these changes mean that you need to reanalyze and redesign much of the system. But he says, "The analysis phase is system. But he says, "The analysis phase is over. The only allowable activity is design. Now get back to it."   You suggest that it might be better to create a simple prototype to show to the marketing folks and even some potential customers. But your boss says, "The analysis phase is over. The only allowable activity is design. Now get back to it." Hack, hack, hack, hack. You try to create some kind of a design document that might reflect the new requirements documents. However, the revolution of the requirements has not caused them to stop thrashing. Indeed, if anything, the wild oscillations of the requirements document have only increased in frequency and amplitude.   You slog your way through them.   On June 15, the Dandelion database gets corrupted. Apparently, the corruption has been progressive. Small errors in the DB accumulated over the months into bigger and bigger errors. Eventually, the CASE tool just stopped working. Of course, the slowly encroaching corruption is present on all the backups. Calls to the Dandelion technical support line go unanswered for several days. Finally, you receive a brief e-mail from Dandelion, informing you that this is a known problem and that the solution is to purchase the new version, which they promise will be ready some time next quarter, and then reenter all the diagrams by hand.   ****   Then, on July 1 another miracle happens! You are done with the design!   Rather than go to your boss and complain, you stock your middle desk drawer with some vodka.   **** They threw a party to celebrate the on-time completion of the design phase and their graduation to CMM level 3. This time, you find BB's speech so stirring that you have to use the restroom before it begins. New banners and plaques are all over your workplace. They show pictures of eagles and mountain climbers, and they talk about teamwork and empowerment. They read better after a few scotches. That reminds you that you need to clear out your file cabinet to make room for the brandy. You and your team begin to code. But you rapidly discover that the design is lacking in some significant areas. Actually, it's lacking any significance at all. You convene a design session in one of the conference rooms to try to work through some of the nastier problems. But your boss catches you at it and disbands the meeting, saying, "The design phase is over. The only allowable activity is coding. Now get back to it."   ****   The code generated by Dandelion is really hideous. It turns out that you and your team were using association and aggregation the wrong way, after all. All the generated code has to be edited to correct these flaws. Editing this code is extremely difficult because it has been instrumented with ugly comment blocks that have special syntax that Dandelion needs in order to keep the diagrams in sync with the code. If you accidentally alter one of these comments, the diagrams will be regenerated incorrectly. It turns out that "Round the Horn Engineering" requires an awful lot of effort. The more you try to keep the code compatible with Dandelion, the more errors Dandelion generates. In the end, you give up and decide to keep the diagrams up to date manually. A second later, you decide that there's no point in keeping the diagrams up to date at all. Besides, who has time?   Your boss hires a consultant to build tools to count the number of lines of code that are being produced. He puts a big thermometer graph on the wall with the number 1,000,000 on the top. Every day, he extends the red line to show how many lines have been added. Three days after the thermometer appears on the wall, your boss stops you in the hall. "That graph isn't growing quickly enough. We need to have a million lines done by October 1." "We aren't even sh-sh-sure that the proshect will require a m-million linezh," you blather. "We have to have a million lines done by October 1," your boss reiterates. His points have grown again, and the Grecian formula he uses on them creates an aura of authority and competence. "Are you sure your comment blocks are big enough?" Then, in a flash of managerial insight, he says, "I have it! I want you to institute a new policy among the engineers. No line of code is to be longer than 20 characters. Any such line must be split into two or more preferably more. All existing code needs to be reworked to this standard. That'll get our line count up!"   You decide not to tell him that this will require two unscheduled work months. You decide not to tell him anything at all. You decide that intravenous injections of pure ethanol are the only solution. You make the appropriate arrangements. Hack, hack, hack, and hack. You and your team madly code away. By August 1, your boss, frowning at the thermometer on the wall, institutes a mandatory 50-hour workweek.   Hack, hack, hack, and hack. By September 1st, the thermometer is at 1.2 million lines and your boss asks you to write a report describing why you exceeded the coding budget by 20 percent. He institutes mandatory Saturdays and demands that the project be brought back down to a million lines. You start a campaign of remerging lines. Hack, hack, hack, and hack. Tempers are flaring; people are quitting; QA is raining trouble reports down on you. Customers are demanding installation and user manuals; salespeople are demanding advance demonstrations for special customers; the requirements document is still thrashing, the marketing folks are complaining that the product isn't anything like they specified, and the liquor store won't accept your credit card anymore. Something has to give.    On September 15, BB calls a meeting. As he enters the room, his points are emitting clouds of steam. When he speaks, the bass overtones of his carefully manicured voice cause the pit of your stomach to roll over. "The QA manager has told me that this project has less than 50 percent of the required features implemented. He has also informed me that the system crashes all the time, yields wrong results, and is hideously slow. He has also complained that he cannot keep up with the continuous train of daily releases, each more buggy than the last!" He stops for a few seconds, visibly trying to compose himself. "The QA manager estimates that, at this rate of development, we won't be able to ship the product until December!" Actually, you think it's more like March, but you don't say anything. "December!" BB roars with such derision that people duck their heads as though he were pointing an assault rifle at them. "December is absolutely out of the question. Team leaders, I want new estimates on my desk in the morning. I am hereby mandating 65-hour work weeks until this project is complete. And it better be complete by November 1."   As he leaves the conference room, he is heard to mutter: "Empowermentbah!" * * * Your boss is bald; his points are mounted on BB's wall. The fluorescent lights reflecting off his pate momentarily dazzle you. "Do you have anything to drink?" he asks. Having just finished your last bottle of Boone's Farm, you pull a bottle of Thunderbird from your bookshelf and pour it into his coffee mug. "What's it going to take to get this project done? " he asks. "We need to freeze the requirements, analyze them, design them, and then implement them," you say callously. "By November 1?" your boss exclaims incredulously. "No way! Just get back to coding the damned thing." He storms out, scratching his vacant head.   A few days later, you find that your boss has been transferred to the corporate research division. Turnover has skyrocketed. Customers, informed at the last minute that their orders cannot be fulfilled on time, have begun to cancel their orders. Marketing is re-evaluating whether this product aligns with the overall goals of the company. Memos fly, heads roll, policies change, and things are, overall, pretty grim. Finally, by March, after far too many sixty-five hour weeks, a very shaky version of the software is ready. In the field, bug-discovery rates are high, and the technical support staff are at their wits' end, trying to cope with the complaints and demands of the irate customers. Nobody is happy.   In April, BB decides to buy his way out of the problem by licensing a product produced by Rupert Industries and redistributing it. The customers are mollified, the marketing folks are smug, and you are laid off.     Rupert Industries: Project Alpha   Your name is Robert. The date is January 3, 2001. The quiet hours spent with your family this holiday have left you refreshed and ready for work. You are sitting in a conference room with your team of professionals. The manager of the division called the meeting. "We have some ideas for a new project," says the division manager. Call him Russ. He is a high-strung British chap with more energy than a fusion reactor. He is ambitious and driven but understands the value of a team. Russ describes the essence of the new market opportunity the company has identified and introduces you to Jane, the marketing manager, who is responsible for defining the products that will address it. Addressing you, Jane says, "We'd like to start defining our first product offering as soon as possible. When can you and your team meet with me?" You reply, "We'll be done with the current iteration of our project this Friday. We can spare a few hours for you between now and then. After that, we'll take a few people from the team and dedicate them to you. We'll begin hiring their replacements and the new people for your team immediately." "Great," says Russ, "but I want you to understand that it is critical that we have something to exhibit at the trade show coming up this July. If we can't be there with something significant, we'll lose the opportunity."   "I understand," you reply. "I don't yet know what it is that you have in mind, but I'm sure we can have something by July. I just can't tell you what that something will be right now. In any case, you and Jane are going to have complete control over what we developers do, so you can rest assured that by July, you'll have the most important things that can be accomplished in that time ready to exhibit."   Russ nods in satisfaction. He knows how this works. Your team has always kept him advised and allowed him to steer their development. He has the utmost confidence that your team will work on the most important things first and will produce a high-quality product.   * * *   "So, Robert," says Jane at their first meeting, "How does your team feel about being split up?" "We'll miss working with each other," you answer, "but some of us were getting pretty tired of that last project and are looking forward to a change. So, what are you people cooking up?" Jane beams. "You know how much trouble our customers currently have . . ." And she spends a half hour or so describing the problem and possible solution. "OK, wait a second" you respond. "I need to be clear about this." And so you and Jane talk about how this system might work. Some of her ideas aren't fully formed. You suggest possible solutions. She likes some of them. You continue discussing.   During the discussion, as each new topic is addressed, Jane writes user story cards. Each card represents something that the new system has to do. The cards accumulate on the table and are spread out in front of you. Both you and Jane point at them, pick them up, and make notes on them as you discuss the stories. The cards are powerful mnemonic devices that you can use to represent complex ideas that are barely formed.   At the end of the meeting, you say, "OK, I've got a general idea of what you want. I'm going to talk to the team about it. I imagine they'll want to run some experiments with various database structures and presentation formats. Next time we meet, it'll be as a group, and we'll start identifying the most important features of the system."   A week later, your nascent team meets with Jane. They spread the existing user story cards out on the table and begin to get into some of the details of the system. The meeting is very dynamic. Jane presents the stories in the order of their importance. There is much discussion about each one. The developers are concerned about keeping the stories small enough to estimate and test. So they continually ask Jane to split one story into several smaller stories. Jane is concerned that each story have a clear business value and priority, so as she splits them, she makes sure that this stays true.   The stories accumulate on the table. Jane writes them, but the developers make notes on them as needed. Nobody tries to capture everything that is said; the cards are not meant to capture everything but are simply reminders of the conversation.   As the developers become more comfortable with the stories, they begin writing estimates on them. These estimates are crude and budgetary, but they give Jane an idea of what the story will cost.   At the end of the meeting, it is clear that many more stories could be discussed. It is also clear that the most important stories have been addressed and that they represent several months worth of work. Jane closes the meeting by taking the cards with her and promising to have a proposal for the first release in the morning.   * * *   The next morning, you reconvene the meeting. Jane chooses five cards and places them on the table. "According to your estimates, these cards represent about one perfect team-week's worth of work. The last iteration of the previous project managed to get one perfect team-week done in 3 real weeks. If we can get these five stories done in 3 weeks, we'll be able to demonstrate them to Russ. That will make him feel very comfortable about our progress." Jane is pushing it. The sheepish look on her face lets you know that she knows it too. You reply, "Jane, this is a new team, working on a new project. It's a bit presumptuous to expect that our velocity will be the same as the previous team's. However, I met with the team yesterday afternoon, and we all agreed that our initial velocity should, in fact, be set to one perfectweek for every 3 real-weeks. So you've lucked out on this one." "Just remember," you continue, "that the story estimates and the story velocity are very tentative at this point. We'll learn more when we plan the iteration and even more when we implement it."   Jane looks over her glasses at you as if to say "Who's the boss around here, anyway?" and then smiles and says, "Yeah, don't worry. I know the drill by now."Jane then puts 15 more cards on the table. She says, "If we can get all these cards done by the end of March, we can turn the system over to our beta test customers. And we'll get good feedback from them."   You reply, "OK, so we've got our first iteration defined, and we have the stories for the next three iterations after that. These four iterations will make our first release."   "So," says Jane, can you really do these five stories in the next 3 weeks?" "I don't know for sure, Jane," you reply. "Let's break them down into tasks and see what we get."   So Jane, you, and your team spend the next several hours taking each of the five stories that Jane chose for the first iteration and breaking them down into small tasks. The developers quickly realize that some of the tasks can be shared between stories and that other tasks have commonalities that can probably be taken advantage of. It is clear that potential designs are popping into the developers' heads. From time to time, they form little discussion knots and scribble UML diagrams on some cards.   Soon, the whiteboard is filled with the tasks that, once completed, will implement the five stories for this iteration. You start the sign-up process by saying, "OK, let's sign up for these tasks." "I'll take the initial database generation." Says Pete. "That's what I did on the last project, and this doesn't look very different. I estimate it at two of my perfect workdays." "OK, well, then, I'll take the login screen," says Joe. "Aw, darn," says Elaine, the junior member of the team, "I've never done a GUI, and kinda wanted to try that one."   "Ah, the impatience of youth," Joe says sagely, with a wink in your direction. "You can assist me with it, young Jedi." To Jane: "I think it'll take me about three of my perfect workdays."   One by one, the developers sign up for tasks and estimate them in terms of their own perfect workdays. Both you and Jane know that it is best to let the developers volunteer for tasks than to assign the tasks to them. You also know full well that you daren't challenge any of the developers' estimates. You know these people, and you trust them. You know that they are going to do the very best they can.   The developers know that they can't sign up for more perfect workdays than they finished in the last iteration they worked on. Once each developer has filled his or her schedule for the iteration, they stop signing up for tasks.   Eventually, all the developers have stopped signing up for tasks. But, of course, tasks are still left on the board.   "I was worried that that might happen," you say, "OK, there's only one thing to do, Jane. We've got too much to do in this iteration. What stories or tasks can we remove?" Jane sighs. She knows that this is the only option. Working overtime at the beginning of a project is insane, and projects where she's tried it have not fared well.   So Jane starts to remove the least-important functionality. "Well, we really don't need the login screen just yet. We can simply start the system in the logged-in state." "Rats!" cries Elaine. "I really wanted to do that." "Patience, grasshopper." says Joe. "Those who wait for the bees to leave the hive will not have lips too swollen to relish the honey." Elaine looks confused. Everyone looks confused. "So . . .," Jane continues, "I think we can also do away with . . ." And so, bit by bit, the list of tasks shrinks. Developers who lose a task sign up for one of the remaining ones.   The negotiation is not painless. Several times, Jane exhibits obvious frustration and impatience. Once, when tensions are especially high, Elaine volunteers, "I'll work extra hard to make up some of the missing time." You are about to correct her when, fortunately, Joe looks her in the eye and says, "When once you proceed down the dark path, forever will it dominate your destiny."   In the end, an iteration acceptable to Jane is reached. It's not what Jane wanted. Indeed, it is significantly less. But it's something the team feels that can be achieved in the next 3 weeks.   And, after all, it still addresses the most important things that Jane wanted in the iteration. "So, Jane," you say when things had quieted down a bit, "when can we expect acceptance tests from you?" Jane sighs. This is the other side of the coin. For every story the development team implements,   Jane must supply a suite of acceptance tests that prove that it works. And the team needs these long before the end of the iteration, since they will certainly point out differences in the way Jane and the developers imagine the system's behaviour.   "I'll get you some example test scripts today," Jane promises. "I'll add to them every day after that. You'll have the entire suite by the middle of the iteration."   * * *   The iteration begins on Monday morning with a flurry of Class, Responsibilities, Collaborators sessions. By midmorning, all the developers have assembled into pairs and are rapidly coding away. "And now, my young apprentice," Joe says to Elaine, "you shall learn the mysteries of test-first design!"   "Wow, that sounds pretty rad," Elaine replies. "How do you do it?" Joe beams. It's clear that he has been anticipating this moment. "OK, what does the code do right now?" "Huh?" replied Elaine, "It doesn't do anything at all; there is no code."   "So, consider our task; can you think of something the code should do?" "Sure," Elaine said with youthful assurance, "First, it should connect to the database." "And thereupon, what must needs be required to connecteth the database?" "You sure talk weird," laughed Elaine. "I think we'd have to get the database object from some registry and call the Connect() method. "Ah, astute young wizard. Thou perceives correctly that we requireth an object within which we can cacheth the database object." "Is 'cacheth' really a word?" "It is when I say it! So, what test can we write that we know the database registry should pass?" Elaine sighs. She knows she'll just have to play along. "We should be able to create a database object and pass it to the registry in a Store() method. And then we should be able to pull it out of the registry with a Get() method and make sure it's the same object." "Oh, well said, my prepubescent sprite!" "Hay!" "So, now, let's write a test function that proves your case." "But shouldn't we write the database object and registry object first?" "Ah, you've much to learn, my young impatient one. Just write the test first." "But it won't even compile!" "Are you sure? What if it did?" "Uh . . ." "Just write the test, Elaine. Trust me." And so Joe, Elaine, and all the other developers began to code their tasks, one test case at a time. The room in which they worked was abuzz with the conversations between the pairs. The murmur was punctuated by an occasional high five when a pair managed to finish a task or a difficult test case.   As development proceeded, the developers changed partners once or twice a day. Each developer got to see what all the others were doing, and so knowledge of the code spread generally throughout the team.   Whenever a pair finished something significant whether a whole task or simply an important part of a task they integrated what they had with the rest of the system. Thus, the code base grew daily, and integration difficulties were minimized.   The developers communicated with Jane on a daily basis. They'd go to her whenever they had a question about the functionality of the system or the interpretation of an acceptance test case.   Jane, good as her word, supplied the team with a steady stream of acceptance test scripts. The team read these carefully and thereby gained a much better understanding of what Jane expected the system to do. By the beginning of the second week, there was enough functionality to demonstrate to Jane. She watched eagerly as the demonstration passed test case after test case. "This is really cool," Jane said as the demonstration finally ended. "But this doesn't seem like one-third of the tasks. Is your velocity slower than anticipated?"   You grimace. You'd been waiting for a good time to mention this to Jane but now she was forcing the issue. "Yes, unfortunately, we are going more slowly than we had expected. The new application server we are using is turning out to be a pain to configure. Also, it takes forever to reboot, and we have to reboot it whenever we make even the slightest change to its configuration."   Jane eyes you with suspicion. The stress of last Monday's negotiations had still not entirely dissipated. She says, "And what does this mean to our schedule? We can't slip it again, we just can't. Russ will have a fit! He'll haul us all into the woodshed and ream us some new ones."   You look Jane right in the eyes. There's no pleasant way to give someone news like this. So you just blurt out, "Look, if things keep going like they're going, we're not going to be done with everything by next Friday. Now it's possible that we'll figure out a way to go faster. But, frankly, I wouldn't depend on that. You should start thinking about one or two tasks that could be removed from the iteration without ruining the demonstration for Russ. Come hell or high water, we are going to give that demonstration on Friday, and I don't think you want us to choose which tasks to omit."   "Aw forchrisakes!" Jane barely manages to stifle yelling that last word as she stalks away, shaking her head. Not for the first time, you say to yourself, "Nobody ever promised me project management would be easy." You are pretty sure it won't be the last time, either.   Actually, things went a bit better than you had hoped. The team did, in fact, have to drop one task from the iteration, but Jane had chosen wisely, and the demonstration for Russ went without a hitch. Russ was not impressed with the progress, but neither was he dismayed. He simply said, "This is pretty good. But remember, we have to be able to demonstrate this system at the trade show in July, and at this rate, it doesn't look like you'll have all that much to show." Jane, whose attitude had improved dramatically with the completion of the iteration, responded to Russ by saying, "Russ, this team is working hard, and well. When July comes around, I am confident that we'll have something significant to demonstrate. It won't be everything, and some of it may be smoke and mirrors, but we'll have something."   Painful though the last iteration was, it had calibrated your velocity numbers. The next iteration went much better. Not because your team got more done than in the last iteration but simply because the team didn't have to remove any tasks or stories in the middle of the iteration.   By the start of the fourth iteration, a natural rhythm has been established. Jane, you, and the team know exactly what to expect from one another. The team is running hard, but the pace is sustainable. You are confident that the team can keep up this pace for a year or more.   The number of surprises in the schedule diminishes to near zero; however, the number of surprises in the requirements does not. Jane and Russ frequently look over the growing system and make recommendations or changes to the existing functionality. But all parties realize that these changes take time and must be scheduled. So the changes do not cause anyone's expectations to be violated. In March, there is a major demonstration of the system to the board of directors. The system is very limited and is not yet in a form good enough to take to the trade show, but progress is steady, and the board is reasonably impressed.   The second release goes even more smoothly than the first. By now, the team has figured out a way to automate Jane's acceptance test scripts. The team has also refactored the design of the system to the point that it is really easy to add new features and change old ones. The second release was done by the end of June and was taken to the trade show. It had less in it than Jane and Russ would have liked, but it did demonstrate the most important features of the system. Although customers at the trade show noticed that certain features were missing, they were very impressed overall. You, Russ, and Jane all returned from the trade show with smiles on your faces. You all felt as though this project was a winner.   Indeed, many months later, you are contacted by Rufus Inc. That company had been working on a system like this for its internal operations. Rufus has canceled the development of that system after a death-march project and is negotiating to license your technology for its environment.   Indeed, things are looking up!

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  • Guide to reduce TFS database growth using the Test Attachment Cleaner

    - by terje
    Recently there has been several reports on TFS databases growing too fast and growing too big.  Notable this has been observed when one has started to use more features of the Testing system.  Also, the TFS 2010 handles test results differently from TFS 2008, and this leads to more data stored in the TFS databases. As a consequence of this there has been released some tools to remove unneeded data in the database, and also some fixes to correct for bugs which has been found and corrected during this process.  Further some preventive practices and maintenance rules should be adopted. A lot of people have blogged about this, among these are: Anu’s very important blog post here describes both the problem and solutions to handle it.  She describes both the Test Attachment Cleaner tool, and also some QFE/CU releases to fix some underlying bugs which prevented the tool from being fully effective. Brian Harry’s blog post here describes the problem too This forum thread describes the problem with some solution hints. Ravi Shanker’s blog post here describes best practices on solving this (TBP) Grant Holidays blogpost here describes strategies to use the Test Attachment Cleaner both to detect space problems and how to rectify them.   The problem can be divided into the following areas: Publishing of test results from builds Publishing of manual test results and their attachments in particular Publishing of deployment binaries for use during a test run Bugs in SQL server preventing total cleanup of data (All the published data above is published into the TFS database as attachments.) The test results will include all data being collected during the run.  Some of this data can grow rather large, like IntelliTrace logs and video recordings.   Also the pushing of binaries which happen for automated test runs, including tests run during a build using code coverage which will include all the files in the deployment folder, contributes a lot to the size of the attached data.   In order to handle this systematically, I have set up a 3-stage process: Find out if you have a database space issue Set up your TFS server to minimize potential database issues If you have the “problem”, clean up the database and otherwise keep it clean   Analyze the data Are your database( s) growing ?  Are unused test results growing out of proportion ? To find out about this you need to query your TFS database for some of the information, and use the Test Attachment Cleaner (TAC) to obtain some  more detailed information. If you don’t have too many databases you can use the SQL Server reports from within the Management Studio to analyze the database and table sizes. Or, you can use a set of queries . I find queries often faster to use because I can tweak them the way I want them.  But be aware that these queries are non-documented and non-supported and may change when the product team wants to change them. If you have multiple Project Collections, find out which might have problems: (Disclaimer: The queries below work on TFS 2010. They will not work on Dev-11, since the table structure have been changed.  I will try to update them for Dev-11 when it is released.) Open a SQL Management Studio session onto the SQL Server where you have your TFS Databases. Use the query below to find the Project Collection databases and their sizes, in descending size order.  use master select DB_NAME(database_id) AS DBName, (size/128) SizeInMB FROM sys.master_files where type=0 and substring(db_name(database_id),1,4)='Tfs_' and DB_NAME(database_id)<>'Tfs_Configuration' order by size desc Doing this on one of our SQL servers gives the following results: It is pretty easy to see on which collection to start the work   Find out which tables are possibly too large Keep a special watch out for the Tfs_Attachment table. Use the script at the bottom of Grant’s blog to find the table sizes in descending size order. In our case we got this result: From Grant’s blog we learnt that the tbl_Content is in the Version Control category, so the major only big issue we have here is the tbl_AttachmentContent.   Find out which team projects have possibly too large attachments In order to use the TAC to find and eventually delete attachment data we need to find out which team projects have these attachments. The team project is a required parameter to the TAC. Use the following query to find this, replace the collection database name with whatever applies in your case:   use Tfs_DefaultCollection select p.projectname, sum(a.compressedlength)/1024/1024 as sizeInMB from dbo.tbl_Attachment as a inner join tbl_testrun as tr on a.testrunid=tr.testrunid inner join tbl_project as p on p.projectid=tr.projectid group by p.projectname order by sum(a.compressedlength) desc In our case we got this result (had to remove some names), out of more than 100 team projects accumulated over quite some years: As can be seen here it is pretty obvious the “Byggtjeneste – Projects” are the main team project to take care of, with the ones on lines 2-4 as the next ones.  Check which attachment types takes up the most space It can be nice to know which attachment types takes up the space, so run the following query: use Tfs_DefaultCollection select a.attachmenttype, sum(a.compressedlength)/1024/1024 as sizeInMB from dbo.tbl_Attachment as a inner join tbl_testrun as tr on a.testrunid=tr.testrunid inner join tbl_project as p on p.projectid=tr.projectid group by a.attachmenttype order by sum(a.compressedlength) desc We then got this result: From this it is pretty obvious that the problem here is the binary files, as also mentioned in Anu’s blog. Check which file types, by their extension, takes up the most space Run the following query use Tfs_DefaultCollection select SUBSTRING(filename,len(filename)-CHARINDEX('.',REVERSE(filename))+2,999)as Extension, sum(compressedlength)/1024 as SizeInKB from tbl_Attachment group by SUBSTRING(filename,len(filename)-CHARINDEX('.',REVERSE(filename))+2,999) order by sum(compressedlength) desc This gives a result like this:   Now you should have collected enough information to tell you what to do – if you got to do something, and some of the information you need in order to set up your TAC settings file, both for a cleanup and for scheduled maintenance later.    Get your TFS server and environment properly set up Even if you have got the problem or if have yet not got the problem, you should ensure the TFS server is set up so that the risk of getting into this problem is minimized.  To ensure this you should install the following set of updates and components. The assumption is that your TFS Server is at SP1 level. Install the QFE for KB2608743 – which also contains detailed instructions on its use, download from here. The QFE changes the default settings to not upload deployed binaries, which are used in automated test runs. Binaries will still be uploaded if: Code coverage is enabled in the test settings. You change the UploadDeploymentItem to true in the testsettings file. Be aware that this might be reset back to false by another user which haven't installed this QFE. The hotfix should be installed to The build servers (the build agents) The machine hosting the Test Controller Local development computers (Visual Studio) Local test computers (MTM) It is not required to install it to the TFS Server, test agents or the build controller – it has no effect on these programs. If you use the SQL Server 2008 R2 you should also install the CU 10 (or later).  This CU fixes a potential problem of hanging “ghost” files.  This seems to happen only in certain trigger situations, but to ensure it doesn’t bite you, it is better to make sure this CU is installed. There is no such CU for SQL Server 2008 pre-R2 Work around:  If you suspect hanging ghost files, they can be – with some mental effort, deduced from the ghost counters using the following SQL query: use master SELECT DB_NAME(database_id) as 'database',OBJECT_NAME(object_id) as 'objectname', index_type_desc,ghost_record_count,version_ghost_record_count,record_count,avg_record_size_in_bytes FROM sys.dm_db_index_physical_stats (DB_ID(N'<DatabaseName>'), OBJECT_ID(N'<TableName>'), NULL, NULL , 'DETAILED') The problem is a stalled ghost cleanup process.  Restarting the SQL server after having stopped all components that depends on it, like the TFS Server and SPS services – that is all applications that connect to the SQL server. Then restart the SQL server, and finally start up all dependent processes again.  (I would guess a complete server reboot would do the trick too.) After this the ghost cleanup process will run properly again. The fix will come in the next CU cycle for SQL Server R2 SP1.  The R2 pre-SP1 and R2 SP1 have separate maintenance cycles, and are maintained individually. Each have its own set of CU’s. When it comes I will add the link here to that CU. The "hanging ghost file” issue came up after one have run the TAC, and deleted enourmes amount of data.  The SQL Server can get into this hanging state (without the QFE) in certain cases due to this. And of course, install and set up the Test Attachment Cleaner command line power tool.  This should be done following some guidelines from Ravi Shanker: “When you run TAC, ensure that you are deleting small chunks of data at regular intervals (say run TAC every night at 3AM to delete data that is between age 730 to 731 days) – this will ensure that small amounts of data are being deleted and SQL ghosted record cleanup can catch up with the number of deletes performed. “ This rule minimizes the risk of the ghosted hang problem to occur, and further makes it easier for the SQL server ghosting process to work smoothly. “Run DBCC SHRINKDB post the ghosted records are cleaned up to physically reclaim the space on the file system” This is the last step in a 3 step process of removing SQL server data. First they are logically deleted. Then they are cleaned out by the ghosting process, and finally removed using the shrinkdb command. Cleaning out the attachments The TAC is run from the command line using a set of parameters and controlled by a settingsfile.  The parameters point out a server uri including the team project collection and also point at a specific team project. So in order to run this for multiple team projects regularly one has to set up a script to run the TAC multiple times, once for each team project.  When you install the TAC there is a very useful readme file in the same directory. When the deployment binaries are published to the TFS server, ALL items are published up from the deployment folder. That often means much more files than you would assume are necessary. This is a brute force technique. It works, but you need to take care when cleaning up. Grant has shown how their settings file looks in his blog post, removing all attachments older than 180 days , as long as there are no active workitems connected to them. This setting can be useful to clean out all items, both in a clean-up once operation, and in a general There are two scenarios we need to consider: Cleaning up an existing overgrown database Maintaining a server to avoid an overgrown database using scheduled TAC   1. Cleaning up a database which has grown too big due to these attachments. This job is a “Once” job.  We do this once and then move on to make sure it won’t happen again, by taking the actions in 2) below.  In this scenario you should only consider the large files. Your goal should be to simply reduce the size, and don’t bother about  the smaller stuff. That can be left a scheduled TAC cleanup ( 2 below). Here you can use a very general settings file, and just remove the large attachments, or you can choose to remove any old items.  Grant’s settings file is an example of the last one.  A settings file to remove only large attachments could look like this: <!-- Scenario : Remove large files --> <DeletionCriteria> <TestRun /> <Attachment> <SizeInMB GreaterThan="10" /> </Attachment> </DeletionCriteria> Or like this: If you want only to remove dll’s and pdb’s about that size, add an Extensions-section.  Without that section, all extensions will be deleted. <!-- Scenario : Remove large files of type dll's and pdb's --> <DeletionCriteria> <TestRun /> <Attachment> <SizeInMB GreaterThan="10" /> <Extensions> <Include value="dll" /> <Include value="pdb" /> </Extensions> </Attachment> </DeletionCriteria> Before you start up your scheduled maintenance, you should clear out all older items. 2. Scheduled maintenance using the TAC If you run a schedule every night, and remove old items, and also remove them in small batches.  It is important to run this often, like every night, in order to keep the number of deleted items low. That way the SQL ghost process works better. One approach could be to delete all items older than some number of days, let’s say 180 days. This could be combined with restricting it to keep attachments with active or resolved bugs.  Doing this every night ensures that only small amounts of data is deleted. <!-- Scenario : Remove old items except if they have active or resolved bugs --> <DeletionCriteria> <TestRun> <AgeInDays OlderThan="180" /> </TestRun> <Attachment /> <LinkedBugs> <Exclude state="Active" /> <Exclude state="Resolved"/> </LinkedBugs> </DeletionCriteria> In my experience there are projects which are left with active or resolved workitems, akthough no further work is done.  It can be wise to have a cleanup process with no restrictions on linked bugs at all. Note that you then have to remove the whole LinkedBugs section. A approach which could work better here is to do a two step approach, use the schedule above to with no LinkedBugs as a sweeper cleaning task taking away all data older than you could care about.  Then have another scheduled TAC task to take out more specifically attachments that you are not likely to use. This task could be much more specific, and based on your analysis clean out what you know is troublesome data. <!-- Scenario : Remove specific files early --> <DeletionCriteria> <TestRun > <AgeInDays OlderThan="30" /> </TestRun> <Attachment> <SizeInMB GreaterThan="10" /> <Extensions> <Include value="iTrace"/> <Include value="dll"/> <Include value="pdb"/> <Include value="wmv"/> </Extensions> </Attachment> <LinkedBugs> <Exclude state="Active" /> <Exclude state="Resolved" /> </LinkedBugs> </DeletionCriteria> The readme document for the TAC says that it recognizes “internal” extensions, but it does recognize any extension. To run the tool do the following command: tcmpt attachmentcleanup /collection:your_tfs_collection_url /teamproject:your_team_project /settingsfile:path_to_settingsfile /outputfile:%temp%/teamproject.tcmpt.log /mode:delete   Shrinking the database You could run a shrink database command after the TAC has run in cases where there are a lot of data being deleted.  In this case you SHOULD do it, to free up all that space.  But, after the shrink operation you should do a rebuild indexes, since the shrink operation will leave the database in a very fragmented state, which will reduce performance. Note that you need to rebuild indexes, reorganizing is not enough. For smaller amounts of data you should NOT shrink the database, since the data will be reused by the SQL server when it need to add more records.  In fact, it is regarded as a bad practice to shrink the database regularly.  So on a daily maintenance schedule you should NOT shrink the database. To shrink the database you do a DBCC SHRINKDATABASE command, and then follow up with a DBCC INDEXDEFRAG afterwards.  I find the easiest way to do this is to create a SQL Maintenance plan including the Shrink Database Task and the Rebuild Index Task and just execute it when you need to do this.

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  • Metro, Authentication, and the ASP.NET Web API

    - by Stephen.Walther
    Imagine that you want to create a Metro style app written with JavaScript and you want to communicate with a remote web service. For example, you are creating a movie app which retrieves a list of movies from a movies service. In this situation, how do you authenticate your Metro app and the Metro user so not just anyone can call the movies service? How can you identify the user making the request so you can return user specific data from the service? The Windows Live SDK supports a feature named Single Sign-On. When a user logs into a Windows 8 machine using their Live ID, you can authenticate the user’s identity automatically. Even better, when the Metro app performs a call to a remote web service, you can pass an authentication token to the remote service and prevent unauthorized access to the service. The documentation for Single Sign-On is located here: http://msdn.microsoft.com/en-us/library/live/hh826544.aspx In this blog entry, I describe the steps that you need to follow to use Single Sign-On with a (very) simple movie app. We build a Metro app which communicates with a web service created using the ASP.NET Web API. Creating the Visual Studio Solution Let’s start by creating a Visual Studio solution which contains two projects: a Windows Metro style Blank App project and an ASP.NET MVC 4 Web Application project. Name the Metro app MovieApp and the ASP.NET MVC application MovieApp.Services. When you create the ASP.NET MVC application, select the Web API template: After you create the two projects, your Visual Studio Solution Explorer window should look like this: Configuring the Live SDK You need to get your hands on the Live SDK and register your Metro app. You can download the latest version of the SDK (version 5.2) from the following address: http://www.microsoft.com/en-us/download/details.aspx?id=29938 After you download the Live SDK, you need to visit the following website to register your Metro app: https://manage.dev.live.com/build Don’t let the title of the website — Windows Push Notifications & Live Connect – confuse you, this is the right place. Follow the instructions at the website to register your Metro app. Don’t forget to follow the instructions in Step 3 for updating the information in your Metro app’s manifest. After you register, your client secret is displayed. Record this client secret because you will need it later (we use it with the web service): You need to configure one more thing. You must enter your Redirect Domain by visiting the following website: https://manage.dev.live.com/Applications/Index Click on your application name, click Edit Settings, click the API Settings tab, and enter a value for the Redirect Domain field. You can enter any domain that you please just as long as the domain has not already been taken: For the Redirect Domain, I entered http://superexpertmovieapp.com. Create the Metro MovieApp Next, we need to create the MovieApp. The MovieApp will: 1. Use Single Sign-On to log the current user into Live 2. Call the MoviesService web service 3. Display the results in a ListView control Because we use the Live SDK in the MovieApp, we need to add a reference to it. Right-click your References folder in the Solution Explorer window and add the reference: Here’s the HTML page for the Metro App: <!DOCTYPE html> <html> <head> <meta charset="utf-8" /> <title>MovieApp</title> <!-- WinJS references --> <link href="//Microsoft.WinJS.1.0.RC/css/ui-dark.css" rel="stylesheet" /> <script src="//Microsoft.WinJS.1.0.RC/js/base.js"></script> <script src="//Microsoft.WinJS.1.0.RC/js/ui.js"></script> <!-- Live SDK --> <script type="text/javascript" src="/LiveSDKHTML/js/wl.js"></script> <!-- WebServices references --> <link href="/css/default.css" rel="stylesheet" /> <script src="/js/default.js"></script> </head> <body> <div id="tmplMovie" data-win-control="WinJS.Binding.Template"> <div class="movieItem"> <span data-win-bind="innerText:title"></span> <br /><span data-win-bind="innerText:director"></span> </div> </div> <div id="lvMovies" data-win-control="WinJS.UI.ListView" data-win-options="{ itemTemplate: select('#tmplMovie') }"> </div> </body> </html> The HTML page above contains a Template and ListView control. These controls are used to display the movies when the movies are returned from the movies service. Notice that the page includes a reference to the Live script that we registered earlier: <!-- Live SDK --> <script type="text/javascript" src="/LiveSDKHTML/js/wl.js"></script> The JavaScript code looks like this: (function () { "use strict"; var REDIRECT_DOMAIN = "http://superexpertmovieapp.com"; var WEBSERVICE_URL = "http://localhost:49743/api/movies"; function init() { WinJS.UI.processAll().done(function () { // Get element and control references var lvMovies = document.getElementById("lvMovies").winControl; // Login to Windows Live var scopes = ["wl.signin"]; WL.init({ scope: scopes, redirect_uri: REDIRECT_DOMAIN }); WL.login().then( function(response) { // Get the authentication token var authenticationToken = response.session.authentication_token; // Call the web service var options = { url: WEBSERVICE_URL, headers: { authenticationToken: authenticationToken } }; WinJS.xhr(options).done( function (xhr) { var movies = JSON.parse(xhr.response); var listMovies = new WinJS.Binding.List(movies); lvMovies.itemDataSource = listMovies.dataSource; }, function (xhr) { console.log(xhr.statusText); } ); }, function(response) { throw WinJS.ErrorFromName("Failed to login!"); } ); }); } document.addEventListener("DOMContentLoaded", init); })(); There are two constants which you need to set to get the code above to work: REDIRECT_DOMAIN and WEBSERVICE_URL. The REDIRECT_DOMAIN is the domain that you entered when registering your app with Live. The WEBSERVICE_URL is the path to your web service. You can get the correct value for WEBSERVICE_URL by opening the Project Properties for the MovieApp.Services project, clicking the Web tab, and getting the correct URL. The port number is randomly generated. In my code, I used the URL  “http://localhost:49743/api/movies”. Assuming that the user is logged into Windows 8 with a Live account, when the user runs the MovieApp, the user is logged into Live automatically. The user is logged in with the following code: // Login to Windows Live var scopes = ["wl.signin"]; WL.init({ scope: scopes, redirect_uri: REDIRECT_DOMAIN }); WL.login().then(function(response) { // Do something }); The scopes setting determines what the user has permission to do. For example, access the user’s SkyDrive or access the user’s calendar or contacts. The available scopes are listed here: http://msdn.microsoft.com/en-us/library/live/hh243646.aspx In our case, we only need the wl.signin scope which enables Single Sign-On. After the user signs in, you can retrieve the user’s Live authentication token. The authentication token is passed to the movies service to authenticate the user. Creating the Movies Service The Movies Service is implemented as an API controller in an ASP.NET MVC 4 Web API project. Here’s what the MoviesController looks like: using System.Collections.Generic; using System.Linq; using System.Net; using System.Net.Http; using System.Web.Http; using JWTSample; using MovieApp.Services.Models; namespace MovieApp.Services.Controllers { public class MoviesController : ApiController { const string CLIENT_SECRET = "NtxjF2wu7JeY1unvVN-lb0hoeWOMUFoR"; // GET api/values public HttpResponseMessage Get() { // Authenticate // Get authenticationToken var authenticationToken = Request.Headers.GetValues("authenticationToken").FirstOrDefault(); if (authenticationToken == null) { return new HttpResponseMessage(HttpStatusCode.Unauthorized); } // Validate token var d = new Dictionary<int, string>(); d.Add(0, CLIENT_SECRET); try { var myJWT = new JsonWebToken(authenticationToken, d); } catch { return new HttpResponseMessage(HttpStatusCode.Unauthorized); } // Return results return Request.CreateResponse( HttpStatusCode.OK, new List<Movie> { new Movie {Title="Star Wars", Director="Lucas"}, new Movie {Title="King Kong", Director="Jackson"}, new Movie {Title="Memento", Director="Nolan"} } ); } } } Because the Metro app performs an HTTP GET request, the MovieController Get() action is invoked. This action returns a set of three movies when, and only when, the authentication token is validated. The Movie class looks like this: using Newtonsoft.Json; namespace MovieApp.Services.Models { public class Movie { [JsonProperty(PropertyName="title")] public string Title { get; set; } [JsonProperty(PropertyName="director")] public string Director { get; set; } } } Notice that the Movie class uses the JsonProperty attribute to change Title to title and Director to director to make JavaScript developers happy. The Get() method validates the authentication token before returning the movies to the Metro app. To get authentication to work, you need to provide the client secret which you created at the Live management site. If you forgot to write down the secret, you can get it again here: https://manage.dev.live.com/Applications/Index The client secret is assigned to a constant at the top of the MoviesController class. The MoviesController class uses a helper class named JsonWebToken to validate the authentication token. This class was created by the Windows Live team. You can get the source code for the JsonWebToken class from the following GitHub repository: https://github.com/liveservices/LiveSDK/blob/master/Samples/Asp.net/AuthenticationTokenSample/JsonWebToken.cs You need to add an additional reference to your MVC project to use the JsonWebToken class: System.Runtime.Serialization. You can use the JsonWebToken class to get a unique and validated user ID like this: var user = myJWT.Claims.UserId; If you need to store user specific information then you can use the UserId property to uniquely identify the user making the web service call. Running the MovieApp When you first run the Metro MovieApp, you get a screen which asks whether the app should have permission to use Single Sign-On. This screen never appears again after you give permission once. Actually, when I first ran the app, I get the following error: According to the error, the app is blocked because “We detected some suspicious activity with your Online Id account. To help protect you, we’ve temporarily blocked your account.” This appears to be a bug in the current preview release of the Live SDK and there is more information about this bug here: http://social.msdn.microsoft.com/Forums/en-US/messengerconnect/thread/866c495f-2127-429d-ab07-842ef84f16ae/ If you click continue, and continue running the app, the error message does not appear again.  Summary The goal of this blog entry was to describe how you can validate Metro apps and Metro users when performing a call to a remote web service. First, I explained how you can create a Metro app which takes advantage of Single Sign-On to authenticate the current user against Live automatically. You learned how to register your Metro app with Live and how to include an authentication token in an Ajax call. Next, I explained how you can validate the authentication token – retrieved from the request header – in a web service. I discussed how you can use the JsonWebToken class to validate the authentication token and retrieve the unique user ID.

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  • Cold Start

    - by antony.reynolds
    Well we had snow drifts 3ft deep on Saturday so it must be spring time.  In preparation for Spring we decided to move the lawn tractor.  Of course after sitting in the garage all winter it refused to start.  I then come into the office and need to start my 11g SOA Suite installation.  I thought about this and decided my tractor might be cranky but at least I can script the startup of my SOA Suite 11g installation. So with this in mind I created 6 scripts.  I created them for Linux but they should translate to Windows without too many problems.  This is left as an exercise to the reader, note you will have to hardcode more than I did in the Linux scripts and create separate script files for the sqlplus and WLST sections. Order to start things I believe there should be order in all things, especially starting the SOA Suite.  So here is my preferred order. Start Database This is need by EM and the rest of SOA Suite so best to start it before the Admin Server and managed servers. Start Node Manager on all machines This is needed if you want the scripts to work across machines. Start Admin Server Once this is done in theory you can manually stat the managed servers using WebLogic console.  But then you have to wait for console to be available.  Scripting it all is quicker and easier way of starting. Start Managed Servers & Clusters Best to start them one per physical machine at a time to avoid undue load on the machines.  Non-clustered install will have just soa_server1 and bam_serv1 by default.  Clusters will have at least SOA and BAM clusters that can be started as a group or individually.  I have provided scripts for standalone servers, but easy to change them to work with clusters. Starting Database I have provided a very primitive script (available here) to start the database, the listener and the DB console.  The section highlighted in red needs to match your database name. #!/bin/sh echo "##############################" echo "# Setting Oracle Environment #" echo "##############################" . oraenv <<-EOF orcl EOF echo "#####################" echo "# Starting Database #" echo "#####################" sqlplus / as sysdba <<-EOF startup exit EOF echo "#####################" echo "# Starting Listener #" echo "#####################" lsnrctl start echo "######################" echo "# Starting dbConsole #" echo "######################" emctl start dbconsole read -p "Hit <enter> to continue" Starting SOA Suite My script for starting the SOA Suite (available here) breaks the task down into five sections. Setting the Environment First set up the environment variables.  The variables highlighted in red probably need changing for your environment. #!/bin/sh echo "###########################" echo "# Setting SOA Environment #" echo "###########################" export MW_HOME=~oracle/Middleware11gPS1 export WL_HOME=$MW_HOME/wlserver_10.3 export ORACLE_HOME=$MW_HOME/Oracle_SOA export DOMAIN_NAME=soa_std_domain export DOMAIN_HOME=$MW_HOME/user_projects/domains/$DOMAIN_NAME Starting the Node Manager I start node manager with a nohup to stop it exiting when the script terminates and I redirect the standard output and standard error to a file in a logs directory. cd $DOMAIN_HOME echo "#########################" echo "# Starting Node Manager #" echo "#########################" nohup $WL_HOME/server/bin/startNodeManager.sh >logs/NodeManager.out 2>&1 & Starting the Admin Server I had problems starting the Admin Server from Node Manager so I decided to start it using the command line script.  I again use nohup and redirect output. echo "#########################" echo "# Starting Admin Server #" echo "#########################" nohup ./startWebLogic.sh >logs/AdminServer.out 2>&1 & Starting the Managed Servers I then used WLST (WebLogic Scripting Tool) to start the managed servers.  First I waited for the Admin Server to come up by putting a connect command in a loop.  I could have put the WLST commands into a separate script file but I wanted to reduce the number of files I was using and so used redirected input (here syntax). $ORACLE_HOME/common/bin/wlst.sh <<-EOF import time sleep=time.sleep print "#####################################" print "# Waiting for Admin Server to Start #" print "#####################################" while True:   try:     connect(adminServerName="AdminServer")     break   except:     sleep(10) I then start the SOA server and tell WLST to wait until it is started before returning.  If starting a cluster then the start command would be modified accordingly to start the SOA cluster. print "#######################" print "# Starting SOA Server #" print "#######################" start(name="soa_server1", block="true") I then start the BAM server in the same way as the SOA server. print "#######################" print "# Starting BAM Server #" print "#######################" start(name="bam_server1", block="true") EOF Finally I let people know the servers are up and wait for input in case I am running in a separate window, in which case the result would be lost without the read command. echo "#####################" echo "# SOA Suite Started #" echo "#####################" read -p "Hit <enter> to continue" Stopping the SOA Suite My script for shutting down the SOA Suite (available here)  is basically the reverse of my startup script.  After setting the environment I connect to the Admin Server using WLST and shut down the managed servers and the admin server.  Again the script would need modifying for a cluster. Stopping the Servers If I cannot connect to the Admin Server I try to connect to the node manager, in case the Admin Server is down but the managed servers are up. #!/bin/sh echo "###########################" echo "# Setting SOA Environment #" echo "###########################" export MW_HOME=~oracle/Middleware11gPS1 export WL_HOME=$MW_HOME/wlserver_10.3 export ORACLE_HOME=$MW_HOME/Oracle_SOA export DOMAIN_NAME=soa_std_domain export DOMAIN_HOME=$MW_HOME/user_projects/domains/$DOMAIN_NAME cd $DOMAIN_HOME $MW_HOME/Oracle_SOA/common/bin/wlst.sh <<-EOF try:   print("#############################")   print("# Connecting to AdminServer #")   print("#############################")   connect(username='weblogic',password='welcome1',url='t3://localhost:7001') except:   print "#########################################"   print "#   Unable to connect to Admin Server   #"   print "# Attempting to connect to Node Manager #"   print "#########################################"   nmConnect(domainName=os.getenv("DOMAIN_NAME")) print "#######################" print "# Stopping BAM Server #" print "#######################" shutdown('bam_server1') print "#######################" print "# Stopping SOA Server #" print "#######################" shutdown('soa_server1') print "#########################" print "# Stopping Admin Server #" print "#########################" shutdown('AdminServer') disconnect() nmDisconnect() EOF Stopping the Node Manager I stopped the node manager by searching for the java node manager process using the ps command and then killing that process. echo "#########################" echo "# Stopping Node Manager #" echo "#########################" kill -9 `ps -ef | grep java | grep NodeManager |  awk '{print $2;}'` echo "#####################" echo "# SOA Suite Stopped #" echo "#####################" read -p "Hit <enter> to continue" Stopping the Database Again my script for shutting down the database is the reverse of my start script.  It is available here.  The only change needed might be to the database name. #!/bin/sh echo "##############################" echo "# Setting Oracle Environment #" echo "##############################" . oraenv <<-EOF orcl EOF echo "######################" echo "# Stopping dbConsole #" echo "######################" emctl stop dbconsole echo "#####################" echo "# Stopping Listener #" echo "#####################" lsnrctl stop echo "#####################" echo "# Stopping Database #" echo "#####################" sqlplus / as sysdba <<-EOF shutdown immediate exit EOF read -p "Hit <enter> to continue" Cleaning Up Cleaning SOA Suite I often run tests and want to clean up all the log files.  The following script (available here) does this for the WebLogic servers in a given domain on a machine.  After setting the domain I just remove all files under the servers logs directories.  It also cleans up the log files I created with my startup scripts.  These scripts could be enhanced to copy off the log files if you needed them but in my test environments I don’t need them and would prefer to reclaim the disk space. #!/bin/sh echo "###########################" echo "# Setting SOA Environment #" echo "###########################" export MW_HOME=~oracle/Middleware11gPS1 export WL_HOME=$MW_HOME/wlserver_10.3 export ORACLE_HOME=$MW_HOME/Oracle_SOA export DOMAIN_NAME=soa_std_domain export DOMAIN_HOME=$MW_HOME/user_projects/domains/$DOMAIN_NAME echo "##########################" echo "# Cleaning SOA Log Files #" echo "##########################" cd $DOMAIN_HOME rm -Rf logs/* servers/*/logs/* read -p "Hit <enter> to continue" Cleaning Database I also created a script to clean up the dump files of an Oracle database instance and also the EM log files (available here).  This relies on the machine name being correct as the EM log files are stored in a directory that is based on the hostname and the Oracle SID. #!/bin/sh echo "##############################" echo "# Setting Oracle Environment #" echo "##############################" . oraenv <<-EOF orcl EOF echo "#############################" echo "# Cleaning Oracle Log Files #" echo "#############################" rm -Rf $ORACLE_BASE/admin/$ORACLE_SID/*dump/* rm -Rf $ORACLE_HOME/`hostname`_$ORACLE_SID/sysman/log/* read -p "Hit <enter> to continue" Summary Hope you find the above scripts useful.  They certainly stop me hanging around waiting for things to happen on my test machine and make it easy to run a test, change parameters, bounce the SOA Suite and clean the logs between runs so I can see exactly what is happening. Now I need to get that mower started…

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  • Load and Web Performance Testing using Visual Studio Ultimate 2010-Part 3

    - by Tarun Arora
    Welcome back once again, 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 Part 2 of Load and Web Performance Testing using Visual Studio 2010 I discussed 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. In part 3 I’ll be discussing Test Result Analysis, Test Result Drill through, Test Report Generation, Test Run Comparison, Asp.net Profiler and some closing thoughts. Test Results – I see some creepy worms! In Part 2 we put together a web performance test and a load test, lets run the test to see load test to see how the Web site responds to the load simulation. While the load test is running you will be able to see close to real time analysis in the Load Test Analyser window. You can use the Load Test Analyser to conduct load test analysis in three ways: Monitor a running load test - A condensed set of the performance counter data is maintained in memory. To prevent the results memory requirements from growing unbounded, up to 200 samples for each performance counter are maintained. This includes 100 evenly spaced samples that span the current elapsed time of the run and the most recent 100 samples.         After the load test run is completed - The test controller spools all collected performance counter data to a database while the test is running. Additional data, such as timing details and error details, is loaded into the database when the test completes. The performance data for a completed test is loaded from the database and analysed by the Load Test Analyser. Below you can see a screen shot of the summary view, this provides key results in a format that is compact and easy to read. You can also print the load test summary, this is generated after the test has completed or been stopped.         Analyse the load test results of a previously run load test – We’ll see this in the section where i discuss comparison between two test runs. The performance counters can be plotted on the graphs. You also have the option to highlight a selected part of the test and view details, drill down to the user activity chart where you can hover over to see more details of the test run.   Generate Report => Test Run Comparisons The level of reports you can generate using the Load Test Analyser is astonishing. You have the option to create excel reports and conduct side by side analysis of two test results or to track trend analysis. The tools also allows you to export the graph data either to MS Excel or to a CSV file. You can view the ASP.NET profiler report to conduct further analysis as well. View Data and Diagnostic Attachments opens the Choose Diagnostic Data Adapter Attachment dialog box to select an adapter to analyse the result type. For example, you can select an IntelliTrace adapter, click OK and open the IntelliTrace summary for the test agent that was used in the load test.   Compare results This creates a set of reports that compares the data from two load test results using tables and bar charts. I have taken these screen shots from the MSDN documentation, I would highly recommend exploring the wealth of knowledge available on MSDN. Leaving Thoughts While load testing the application with an excessive load for a longer duration of time, i managed to bring the IIS to its knees by piling up a huge queue of requests waiting to be processed. This clearly means that the IIS had run out of threads as all the threads were busy processing existing request, one easy way of fixing this is by increasing the default number of allocated threads, but this might escalate the problem. The better suggestion is to try and drill down to the actual root cause of the problem. When ever the garbage collection runs it stops processing any pages so all requests that come in during that period are queued up, but realistically the garbage collection completes in fraction of a a second. To understand this better lets look at the .net heap, it is divided into large heap and small heap, anything greater than 85kB in size will be allocated to the Large object heap, the Large object heap is non compacting and remember large objects are expensive to move around, so if you are allocating something in the large object heap, make sure that you really need it! The small object heap on the other hand is divided into generations, so all objects that are supposed to be short-lived are suppose to live in Gen-0 and the long living objects eventually move to Gen-2 as garbage collection goes through.  As you can see in the picture below all < 85 KB size objects are first assigned to Gen-0, when Gen-0 fills up and a new object comes in and finds Gen-0 full, the garbage collection process is started, the process checks for all the dead objects and assigns them as the valid candidate for deletion to free up memory and promotes all the remaining objects in Gen-0 to Gen-1. So in the future when ever you clean up Gen-1 you have to clean up Gen-0 as well. When you fill up Gen – 0 again, all of Gen – 1 dead objects are drenched and rest are moved to Gen-2 and Gen-0 objects are moved to Gen-1 to free up Gen-0, but by this time your Garbage collection process has started to take much more time than it usually takes. Now as I mentioned earlier when garbage collection is being run all page requests that come in during that period are queued up. Does this explain why possibly page requests are getting queued up, apart from this it could also be the case that you are waiting for a long running database process to complete.      Lets explore the heap a bit more… What is really a case of crisis is when the objects are living long enough to make it to Gen-2 and then dying, this is definitely a high cost operation. But sometimes you need objects in memory, for example when you cache data you hold on to the objects because you need to use them right across the user session, which is acceptable. But if you wanted to see what extreme caching can do to your server then write a simple application that chucks in a lot of data in cache, run a load test over it for about 10-15 minutes, forcing a lot of data in memory causing the heap to run out of memory. If you get to such a state where you start running out of memory the IIS as a mode of recovery restarts the worker process. It is great way to free up all your memory in the heap but this would clear the cache. The problem with this is if the customer had 10 items in their shopping basket and that data was stored in the application cache, the user basket will now be empty forcing them either to get frustrated and go to a competitor website or if the customer is really patient, give it another try! How can you address this, well two ways of addressing this; 1. Workaround – A x86 bit processor only allows a maximum of 4GB of RAM, this means the machine effectively has around 3.4 GB of RAM available, the OS needs about 1.5 GB of RAM to run efficiently, the IIS and .net framework also need their share of memory, leaving you a heap of around 800 MB to play with. Because Team builds by default build your application in ‘Compile as any mode’ it means the application is build such that it will run in x86 bit mode if run on a x86 bit processor and run in a x64 bit mode if run on a x64 but processor. The problem with this is not all applications are really x64 bit compatible specially if you are using com objects or external libraries. So, as a quick win if you compiled your application in x86 bit mode by changing the compile as any selection to compile as x86 in the team build, you will be able to run your application on a x64 bit machine in x86 bit mode (WOW – By running Windows on Windows) and what that means is, you could use 8GB+ worth of RAM, if you take away everything else your application will roughly get a heap size of at least 4 GB to play with, which is immense. If you need a heap size of more than 4 GB you have either build a software for NASA or there is something fundamentally wrong in your application. 2. Solution – Now that you have put a workaround in place the IIS will not restart the worker process that regularly, which means you can take a breather and start working to get to the root cause of this memory leak. But this begs a question “How do I Identify possible memory leaks in my application?” Well i won’t say that there is one single tool that can tell you where the memory leak is, but trust me, ‘Performance Profiling’ is a great start point, it definitely gets you started in the right direction, let’s have a look at how. Performance Wizard - Start the Performance Wizard and select Instrumentation, this lets you measure function call counts and timings. Before running the performance session right click the performance session settings and chose properties from the context menu to bring up the Performance session properties page and as shown in the screen shot below, check the check boxes in the group ‘.NET memory profiling collection’ namely ‘Collect .NET object allocation information’ and ‘Also collect the .NET Object lifetime information’.    Now if you fire off the profiling session on your pages you will notice that the results allows you to view ‘Object Lifetime’ which shows you the number of objects that made it to Gen-0, Gen-1, Gen-2, Large heap, etc. Another great feature about the profile is that if your application has > 5% cases where objects die right after making to the Gen-2 storage a threshold alert is generated to alert you. Since you have the option to also view the most expensive methods and by capturing the IntelliTrace data you can drill in to narrow down to the line of code that is the root cause of the problem. Well now that we have seen how crucial memory management is and how easy Visual Studio Ultimate 2010 makes it for us to identify and reproduce the problem with the best of breed tools in the product. Caching One of the main ways to improve performance is Caching. Which basically means you tell the web server that instead of going to the database for each request you keep the data in the webserver and when the user asks for it you serve it from the webserver itself. BUT that can have consequences! Let’s look at some code, trust me caching code is not very intuitive, I define a cache key for almost all searches made through the common search page and cache the results. The approach works fine, first time i get the data from the database and second time data is served from the cache, significant performance improvement, EXCEPT when two users try to do the same operation and run into each other. But it is easy to handle this by adding the lock as you can see in the snippet below. So, as long as a user comes in and finds that the cache is empty, the user locks and starts to get the cache no more concurrency issues. But lets say you are processing 10 requests per second, by the time i have locked the operation to get the results from the database, 9 other users came in and found that the cache key is null so after i have come out and populated the cache they will still go in to get the results again. The application will still be faster because the next set of 10 users and so on would continue to get data from the cache. BUT if we added another null check after locking to build the cache and before actual call to the db then the 9 users who follow me would not make the extra trip to the database at all and that would really increase the performance, but didn’t i say that the code won’t be very intuitive, may be you should leave a comment you don’t want another developer to come in and think what a fresher why is he checking for the cache key null twice !!! The downside of caching is, you are storing the data outside of the database and the data could be wrong because the updates applied to the database would make the data cached at the web server out of sync. So, how do you invalidate the cache? Well if you only had one way of updating the data lets say only one entry point to the data update you can write some logic to say that every time new data is entered set the cache object to null. But this approach will not work as soon as you have several ways of feeding data to the system or your system is scaled out across a farm of web servers. The perfect solution to this is Micro Caching which means you cache the query for a set time duration and invalidate the cache after that set duration. The advantage is every time the user queries for that data with in the time span for which you have cached the results there are no calls made to the database and the data is served right from the server which makes the response immensely quick. Now figuring out the appropriate time span for which you micro cache the query results really depends on the application. Lets say your website gets 10 requests per second, if you retain the cache results for even 1 minute you will have immense performance gains. You would reduce 90% hits to the database for searching. Ever wondered why when you go to e-bookers.com or xpedia.com or yatra.com to book a flight and you click on the book button because the fare seems too exciting and you get an error message telling you that the fare is not valid any more. Yes, exactly => That is a cache failure! These travel sites or price compare engines are not going to hit the database every time you hit the compare button instead the results will be served from the cache, because the query results are micro cached, its a perfect trade-off, by micro caching the results the site gains 100% performance benefits but every once in a while annoys a customer because the fare has expired. But the trade off works in the favour of these sites as they are still able to process up to 30+ page requests per second which means cater to the site traffic by may be losing 1 customer every once in a while to a competitor who is also using a similar caching technique what are the odds that the user will not come back to their site sooner or later? Recap   Resources Below are some Key resource you might like to review. I would highly recommend the documentation, walkthroughs and videos available on MSDN. You can always make use of Fiddler to debug Web Performance Tests. Some community test extensions and plug ins available on Codeplex might also be of interest to you. The Road Ahead Thank you for taking the time out and reading this blog post, you may also want to read Part I and Part II if you haven’t so far. If you enjoyed the post, remember to subscribe to http://feeds.feedburner.com/TarunArora. Questions/Feedback/Suggestions, etc please leave a comment. Next ‘Load Testing in the cloud’, I’ll be working on exploring the possibilities of running Test controller/Agents in the Cloud. See you on the other side! Thank You!   Share this post : CodeProject

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  • Continuous Integration for SQL Server Part II – Integration Testing

    - by Ben Rees
    My previous post, on setting up Continuous Integration for SQL Server databases using GitHub, Bamboo and Red Gate’s tools, covered the first two parts of a simple Database Continuous Delivery process: Putting your database in to a source control system, and, Running a continuous integration process, each time changes are checked in. However there is, of course, a lot more to to Continuous Delivery than that. Specifically, in addition to the above: Putting some actual integration tests in to the CI process (otherwise, they don’t really do much, do they!?), Deploying the database changes with a managed, automated approach, Monitoring what you’ve just put live, to make sure you haven’t broken anything. This post will detail how to set up a very simple pipeline for implementing the first of these (continuous integration testing). NB: A lot of the setup in this post is built on top of the configuration from before, so it might be difficult to implement this post without running through part I first. There’ll then be a third post on automated database deployment followed by a final post dealing with the last item – monitoring changes on the live system. In the previous post, I used a mixture of Red Gate products and other 3rd party software – GitHub and Atlassian Bamboo specifically. This was partly because I believe most people work in an heterogeneous environment, using software from different vendors to suit their purposes and I wanted to show how this could work for this process. For example, you could easily substitute Atlassian’s BitBucket or Stash for GitHub, depending on your needs, or use an alternative CI server such as TeamCity, TFS or Jenkins. However, in this, post, I’ll be mostly using Red Gate products only (other than tSQLt). I would do this, firstly because I work for Red Gate. However, I also think that in the area of Database Delivery processes, nobody else has the offerings to implement this process fully – so I didn’t have any choice!   Background on Continuous Delivery For me, a great source of information on what makes a proper Continuous Delivery process is the Jez Humble and David Farley classic: Continuous Delivery – Reliable Software Releases through Build, Test, and Deployment Automation This book is not of course, primarily about databases, and the process I outline here and in the previous article is a gross simplification of what Jez and David describe (not least because it’s that much harder for databases!). However, a lot of the principles that they describe can be equally applied to database development and, I would argue, should be. As I say however, what I describe here is a very simple version of what would be required for a full production process. A couple of useful resources on handling some of these complexities can be found in the following two references: Refactoring Databases – Evolutionary Database Design, by Scott J Ambler and Pramod J. Sadalage Versioning Databases – Branching and Merging, by Scott Allen In particular, I don’t deal at all with the issues of multiple branches and merging of those branches, an issue made particularly acute by the use of GitHub. The other point worth making is that, in the words of Martin Fowler: Continuous Delivery is about keeping your application in a state where it is always able to deploy into production.   I.e. we are not talking about continuously delivery updates to the production database every time someone checks in an amendment to a stored procedure. That is possible (and what Martin calls Continuous Deployment). However, again, that’s more than I describe in this article. And I doubt I need to remind DBAs or Developers to Proceed with Caution!   Integration Testing Back to something practical. The next stage, building on our set up from the previous article, is to add in some integration tests to the process. As I say, the CI process, though interesting, isn’t enormously useful without some sort of test process running. For this we’ll use the tSQLt framework, an open source framework designed specifically for running SQL Server tests. tSQLt is part of Red Gate’s SQL Test found on http://www.red-gate.com/products/sql-development/sql-test/ or can be downloaded separately from www.tsqlt.org - though I’ll provide a step-by-step guide below for setting this up. Getting tSQLt set up via SQL Test Click on the link http://www.red-gate.com/products/sql-development/sql-test/ and click on the blue Download button to download the Red Gate SQL Test product, if not already installed. Follow the install process for SQL Test to install the SQL Server Management Studio (SSMS) plugin on to your machine, if not already installed. Open SSMS. You should now see SQL Test under the Tools menu:   Clicking this link will give you the basic SQL Test dialogue: As yet, though we’ve installed the SQL Test product we haven’t yet installed the tSQLt test framework on to any particular database. To do this, we need to add our RedGateApp database using this dialogue, by clicking on the + Add Database to SQL Test… link, selecting the RedGateApp database and clicking the Add Database link:   In the next screen, SQL Test describes what will be installed on the database for the tSQLt framework. Also in this dialogue, uncheck the “Add SQL Cop tests” option (shown below). SQL Cop is a great set of pre-defined tests that work within the tSQLt framework to check the general health of your SQL Server database. However, we won’t be using them in this particular simple example: Once you’ve clicked on the OK button, the changes described in the dialogue will be made to your database. Some of these are shown in the left-hand-side below: We’ve now installed the framework. However, we haven’t actually created any tests, so this will be the next step. But, before we proceed, we’ve made an update to our database so should, again check this in to source control, adding comments as required:   Also worth a quick check that your build still runs with the new additions!: (And a quick check of the RedGateAppCI database shows that the changes have been made).   Creating and Testing a Unit Test There are, of course, a lot of very interesting unit tests that you could and should set up for a database. The great thing about the tSQLt framework is that you can write these in SQL. The example I’m going to use here is pretty Mickey Mouse – our database table is going to include some email addresses as reference data and I want to check whether these are all in a correct email format. Nothing clever but it illustrates the process and hopefully shows the method by which more interesting tests could be set up. Adding Reference Data to our Database To start, I want to add some reference data to my database, and have this source controlled (as well as the schema). First of all I need to add some data in to my solitary table – this can be done a number of ways, but I’ll do this in SSMS for simplicity: I then add some reference data to my table: Currently this reference data just exists in the database. For proper integration testing, this needs to form part of the source-controlled version of the database – and so needs to be added to the Git repository. This can be done via SQL Source Control, though first a Primary Key needs to be added to the table. Right click the table, select Design, then right-click on the first “id” row. Then click on “Set Primary Key”: NB: once this change is made, click Save to save the change to the table. Then, to source control this reference data, right click on the table (dbo.Email) and selecting the following option:   In the next screen, link the data in the Email table, by selecting it from the list and clicking “save and close”: We should at this point re-commit the changes (both the addition of the Primary Key, and the data) to the Git repo. NB: From here on, I won’t show screenshots for the GitHub side of things – it’s the same each time: whenever a change is made in SQL Source Control and committed to your local folder, you then need to sync this in the GitHub Windows client (as this is where the build server, Bamboo is taking it from). An interesting point to note here, when these changes are committed in SQL Source Control (right-click database and select “Commit Changes to Source Control..”): The display gives a warning about possibly needing a migration script for the “Add Primary Key” step of the changes. This isn’t actually necessary in this case, but this mechanism would allow you to create override scripts to replace the default change scripts created by the SQL Compare engine (which runs underneath SQL Source Control). Ignoring this message (!), we add a comment and commit the changes to Git. I then sync these, run a build (or the build gets run automatically), and check that the data is being deployed over to the target RedGateAppCI database:   Creating and Running the Test As I mention, the test I’m going to use here is a very simple one - are the email addresses in my reference table valid? This isn’t of course, a full test of email validation (I expect the email addresses I’ve chosen here aren’t really the those of the Fab Four) – but just a very basic check of format used. I’ve taken the relevant SQL from this Stack Overflow article. In SSMS select “SQL Test” from the Tools menu, then click on + New Test: In the next screen, give your new test a name, and also enter a name in the Test Class box (test classes are schemas that help you keep things organised). Also check that the database in which the test is going to be created is correct – RedGateApp in this example: Click “Create Test”. After closing a couple of subsequent dialogues, you’ll see a dummy script for the test, that needs filling in:   We now need to define the SQL for our test. As mentioned before, tSQLt allows you to write your unit tests in T-SQL, and the code I’m going to use here is as below. This needs to be copied and pasted in to the query window, to replace the default given by tSQLt: –  Basic email check test ALTER PROCEDURE [MyChecks].[test Check Email Addresses] AS BEGIN SET NOCOUNT ON         Declare @Output VarChar(max)     Set @Output = ”       SELECT  @Output = @Output + Email +Char(13) + Char(10) FROM dbo.Email WHERE email NOT LIKE ‘%_@__%.__%’       If @Output > ”         Begin             Set @Output = Char(13) + Char(10)                           + @Output             EXEC tSQLt.Fail@Output         End   END;   Once this script is entered, hit execute to add the Stored Procedure to the database. Before committing the test to source control,  it’s worth just checking that it works! For a positive test, click on “SQL Test” from the Tools menu, then click Run Tests. You should see output like the following: - a green tick to indicate success! But of course, what we also need to do is test that this is actually doing something by showing a failed test. Edit one of the email addresses in your table to an incorrect format: Now, re-run the same SQL Test as before and you’ll see the following: Great – we now know that our test is really doing something! You’ll also see a useful error message at the bottom of SSMS: (leave the email address as invalid for now, for the next steps). The next stage is to check this new test in to source control again, by right-clicking on the database and checking in the changes with a commit message (and not forgetting to sync in the GitHub client):   Checking that the Tests are Running as Integration Tests After the changes above are made, and after a build has run on Bamboo (manual or automatic), looking at the Stored Procedures for the RedGateAppCI, the SPROC for the new test has been moved over to the database. However this is not exactly what we were after. We didn’t want to just copy objects from one database to another, but actually run the tests as part of the build/integration test process. I.e. we’re continuously checking any changes we make (in this case, to the reference data emails), to ensure we’re not breaking a test that we’ve set up. The behaviour we want to see is that, if we check in static data that is incorrect (as we did in step 9 above) and we have the tSQLt test set up, then our build in Bamboo should fail. However, re-running the build shows the following: - sadly, a successful build! To make sure the tSQLt tests are run as part of the integration test, we need to amend a switch in the Red Gate CI config file. First, navigate to file sqlCI.targets in your working folder: Edit this document, make the following change, save the document, then commit and sync this change in the GitHub client: <!-- tSQLt tests --> <!-- Optional --> <!-- To run tSQLt tests in source control for the database, enter true. --> <enableTsqlt>true</enableTsqlt> Now, if we re-run the build in Bamboo (NB: I’ve moved to a new server here, hence different address and build number): - superb, a broken build!! The error message isn’t great here, so to get more detailed info, click on the full build log link on this page (below the fold). The interesting part of the log shown is towards the bottom. Pulling out this part:   21-Jun-2013 11:35:19 Build FAILED. 21-Jun-2013 11:35:19 21-Jun-2013 11:35:19 "C:\Users\Administrator\bamboo-home\xml-data\build-dir\RGA-RGP-JOB1\sqlCI.proj" (default target) (1) -> 21-Jun-2013 11:35:19 (sqlCI target) -> 21-Jun-2013 11:35:19 EXEC : sqlCI error occurred: RedGate.Deploy.SqlServerDbPackage.Shared.Exceptions.InvalidSqlException: Test Case Summary: 1 test case(s) executed, 0 succeeded, 1 failed, 0 errored. [C:\Users\Administrator\bamboo-home\xml-data\build-dir\RGA-RGP-JOB1\sqlCI.proj] 21-Jun-2013 11:35:19 EXEC : sqlCI error occurred: [MyChecks].[test Check Email Addresses] failed: [C:\Users\Administrator\bamboo-home\xml-data\build-dir\RGA-RGP-JOB1\sqlCI.proj] 21-Jun-2013 11:35:19 EXEC : sqlCI error occurred: ringo.starr@beatles [C:\Users\Administrator\bamboo-home\xml-data\build-dir\RGA-RGP-JOB1\sqlCI.proj] 21-Jun-2013 11:35:19 EXEC : sqlCI error occurred: [C:\Users\Administrator\bamboo-home\xml-data\build-dir\RGA-RGP-JOB1\sqlCI.proj] 21-Jun-2013 11:35:19 EXEC : sqlCI error occurred: +----------------------+ [C:\Users\Administrator\bamboo-home\xml-data\build-dir\RGA-RGP-JOB1\sqlCI.proj] 21-Jun-2013 11:35:19 EXEC : sqlCI error occurred: |Test Execution Summary| [C:\Users\Administrator\bamboo-home\xml-data\build-dir\RGA-RGP-JOB1\sqlCI.proj]   As a final check, we should make sure that, if we now fix this error, the build succeeds. So in SSMS, I’m going to correct the invalid email address, then check this change in to SQL Source Control (with a comment), commit to GitHub, and re-run the build:   This should have fixed the build: It worked! Summary This has been a very quick run through the implementation of CI for databases, including tSQLt tests to test whether your database updates are working. The next post in this series will focus on automated deployment – we’ve tested our database changes, how can we now deploy these to target sites?  

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  • C#/.NET Little Wonders: The Joy of Anonymous Types

    - 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 .NET 3 Framework, Microsoft introduced the concept of anonymous types, which provide a way to create a quick, compiler-generated types at the point of instantiation.  These may seem trivial, but are very handy for concisely creating lightweight, strongly-typed objects containing only read-only properties that can be used within a given scope. Creating an Anonymous Type In short, an anonymous type is a reference type that derives directly from object and is defined by its set of properties base on their names, number, types, and order given at initialization.  In addition to just holding these properties, it is also given appropriate overridden implementations for Equals() and GetHashCode() that take into account all of the properties to correctly perform property comparisons and hashing.  Also overridden is an implementation of ToString() which makes it easy to display the contents of an anonymous type instance in a fairly concise manner. To construct an anonymous type instance, you use basically the same initialization syntax as with a regular type.  So, for example, if we wanted to create an anonymous type to represent a particular point, we could do this: 1: var point = new { X = 13, Y = 7 }; Note the similarity between anonymous type initialization and regular initialization.  The main difference is that the compiler generates the type name and the properties (as readonly) based on the names and order provided, and inferring their types from the expressions they are assigned to. It is key to remember that all of those factors (number, names, types, order of properties) determine the anonymous type.  This is important, because while these two instances share the same anonymous type: 1: // same names, types, and order 2: var point1 = new { X = 13, Y = 7 }; 3: var point2 = new { X = 5, Y = 0 }; These similar ones do not: 1: var point3 = new { Y = 3, X = 5 }; // different order 2: var point4 = new { X = 3, Y = 5.0 }; // different type for Y 3: var point5 = new {MyX = 3, MyY = 5 }; // different names 4: var point6 = new { X = 1, Y = 2, Z = 3 }; // different count Limitations on Property Initialization Expressions The expression for a property in an anonymous type initialization cannot be null (though it can evaluate to null) or an anonymous function.  For example, the following are illegal: 1: // Null can't be used directly. Null reference of what type? 2: var cantUseNull = new { Value = null }; 3:  4: // Anonymous methods cannot be used. 5: var cantUseAnonymousFxn = new { Value = () => Console.WriteLine(“Can’t.”) }; Note that the restriction on null is just that you can’t use it directly as the expression, because otherwise how would it be able to determine the type?  You can, however, use it indirectly assigning a null expression such as a typed variable with the value null, or by casting null to a specific type: 1: string str = null; 2: var fineIndirectly = new { Value = str }; 3: var fineCast = new { Value = (string)null }; All of the examples above name the properties explicitly, but you can also implicitly name properties if they are being set from a property, field, or variable.  In these cases, when a field, property, or variable is used alone, and you don’t specify a property name assigned to it, the new property will have the same name.  For example: 1: int variable = 42; 2:  3: // creates two properties named varriable and Now 4: var implicitProperties = new { variable, DateTime.Now }; Is the same type as: 1: var explicitProperties = new { variable = variable, Now = DateTime.Now }; But this only works if you are using an existing field, variable, or property directly as the expression.  If you use a more complex expression then the name cannot be inferred: 1: // can't infer the name variable from variable * 2, must name explicitly 2: var wontWork = new { variable * 2, DateTime.Now }; In the example above, since we typed variable * 2, it is no longer just a variable and thus we would have to assign the property a name explicitly. ToString() on Anonymous Types One of the more trivial overrides that an anonymous type provides you is a ToString() method that prints the value of the anonymous type instance in much the same format as it was initialized (except actual values instead of expressions as appropriate of course). For example, if you had: 1: var point = new { X = 13, Y = 42 }; And then print it out: 1: Console.WriteLine(point.ToString()); You will get: 1: { X = 13, Y = 42 } While this isn’t necessarily the most stunning feature of anonymous types, it can be handy for debugging or logging values in a fairly easy to read format. Comparing Anonymous Type Instances Because anonymous types automatically create appropriate overrides of Equals() and GetHashCode() based on the underlying properties, we can reliably compare two instances or get hash codes.  For example, if we had the following 3 points: 1: var point1 = new { X = 1, Y = 2 }; 2: var point2 = new { X = 1, Y = 2 }; 3: var point3 = new { Y = 2, X = 1 }; If we compare point1 and point2 we’ll see that Equals() returns true because they overridden version of Equals() sees that the types are the same (same number, names, types, and order of properties) and that the values are the same.   In addition, because all equal objects should have the same hash code, we’ll see that the hash codes evaluate to the same as well: 1: // true, same type, same values 2: Console.WriteLine(point1.Equals(point2)); 3:  4: // true, equal anonymous type instances always have same hash code 5: Console.WriteLine(point1.GetHashCode() == point2.GetHashCode()); However, if we compare point2 and point3 we get false.  Even though the names, types, and values of the properties are the same, the order is not, thus they are two different types and cannot be compared (and thus return false).  And, since they are not equal objects (even though they have the same value) there is a good chance their hash codes are different as well (though not guaranteed): 1: // false, different types 2: Console.WriteLine(point2.Equals(point3)); 3:  4: // quite possibly false (was false on my machine) 5: Console.WriteLine(point2.GetHashCode() == point3.GetHashCode()); Using Anonymous Types Now that we’ve created instances of anonymous types, let’s actually use them.  The property names (whether implicit or explicit) are used to access the individual properties of the anonymous type.  The main thing, once again, to keep in mind is that the properties are readonly, so you cannot assign the properties a new value (note: this does not mean that instances referred to by a property are immutable – for more information check out C#/.NET Fundamentals: Returning Data Immutably in a Mutable World). Thus, if we have the following anonymous type instance: 1: var point = new { X = 13, Y = 42 }; We can get the properties as you’d expect: 1: Console.WriteLine(“The point is: ({0},{1})”, point.X, point.Y); But we cannot alter the property values: 1: // compiler error, properties are readonly 2: point.X = 99; Further, since the anonymous type name is only known by the compiler, there is no easy way to pass anonymous type instances outside of a given scope.  The only real choices are to pass them as object or dynamic.  But really that is not the intention of using anonymous types.  If you find yourself needing to pass an anonymous type outside of a given scope, you should really consider making a POCO (Plain Old CLR Type – i.e. a class that contains just properties to hold data with little/no business logic) instead. Given that, why use them at all?  Couldn’t you always just create a POCO to represent every anonymous type you needed?  Sure you could, but then you might litter your solution with many small POCO classes that have very localized uses. It turns out this is the key to when to use anonymous types to your advantage: when you just need a lightweight type in a local context to store intermediate results, consider an anonymous type – but when that result is more long-lived and used outside of the current scope, consider a POCO instead. So what do we mean by intermediate results in a local context?  Well, a classic example would be filtering down results from a LINQ expression.  For example, let’s say we had a List<Transaction>, where Transaction is defined something like: 1: public class Transaction 2: { 3: public string UserId { get; set; } 4: public DateTime At { get; set; } 5: public decimal Amount { get; set; } 6: // … 7: } And let’s say we had this data in our List<Transaction>: 1: var transactions = new List<Transaction> 2: { 3: new Transaction { UserId = "Jim", At = DateTime.Now, Amount = 2200.00m }, 4: new Transaction { UserId = "Jim", At = DateTime.Now, Amount = -1100.00m }, 5: new Transaction { UserId = "Jim", At = DateTime.Now.AddDays(-1), Amount = 900.00m }, 6: new Transaction { UserId = "John", At = DateTime.Now.AddDays(-2), Amount = 300.00m }, 7: new Transaction { UserId = "John", At = DateTime.Now, Amount = -10.00m }, 8: new Transaction { UserId = "Jane", At = DateTime.Now, Amount = 200.00m }, 9: new Transaction { UserId = "Jane", At = DateTime.Now, Amount = -50.00m }, 10: new Transaction { UserId = "Jaime", At = DateTime.Now.AddDays(-3), Amount = -100.00m }, 11: new Transaction { UserId = "Jaime", At = DateTime.Now.AddDays(-3), Amount = 300.00m }, 12: }; So let’s say we wanted to get the transactions for each day for each user.  That is, for each day we’d want to see the transactions each user performed.  We could do this very simply with a nice LINQ expression, without the need of creating any POCOs: 1: // group the transactions based on an anonymous type with properties UserId and Date: 2: byUserAndDay = transactions 3: .GroupBy(tx => new { tx.UserId, tx.At.Date }) 4: .OrderBy(grp => grp.Key.Date) 5: .ThenBy(grp => grp.Key.UserId); Now, those of you who have attempted to use custom classes as a grouping type before (such as GroupBy(), Distinct(), etc.) may have discovered the hard way that LINQ gets a lot of its speed by utilizing not on Equals(), but also GetHashCode() on the type you are grouping by.  Thus, when you use custom types for these purposes, you generally end up having to write custom Equals() and GetHashCode() implementations or you won’t get the results you were expecting (the default implementations of Equals() and GetHashCode() are reference equality and reference identity based respectively). As we said before, it turns out that anonymous types already do these critical overrides for you.  This makes them even more convenient to use!  Instead of creating a small POCO to handle this grouping, and then having to implement a custom Equals() and GetHashCode() every time, we can just take advantage of the fact that anonymous types automatically override these methods with appropriate implementations that take into account the values of all of the properties. Now, we can look at our results: 1: foreach (var group in byUserAndDay) 2: { 3: // the group’s Key is an instance of our anonymous type 4: Console.WriteLine("{0} on {1:MM/dd/yyyy} did:", group.Key.UserId, group.Key.Date); 5:  6: // each grouping contains a sequence of the items. 7: foreach (var tx in group) 8: { 9: Console.WriteLine("\t{0}", tx.Amount); 10: } 11: } And see: 1: Jaime on 06/18/2012 did: 2: -100.00 3: 300.00 4:  5: John on 06/19/2012 did: 6: 300.00 7:  8: Jim on 06/20/2012 did: 9: 900.00 10:  11: Jane on 06/21/2012 did: 12: 200.00 13: -50.00 14:  15: Jim on 06/21/2012 did: 16: 2200.00 17: -1100.00 18:  19: John on 06/21/2012 did: 20: -10.00 Again, sure we could have just built a POCO to do this, given it an appropriate Equals() and GetHashCode() method, but that would have bloated our code with so many extra lines and been more difficult to maintain if the properties change.  Summary Anonymous types are one of those Little Wonders of the .NET language that are perfect at exactly that time when you need a temporary type to hold a set of properties together for an intermediate result.  While they are not very useful beyond the scope in which they are defined, they are excellent in LINQ expressions as a way to create and us intermediary values for further expressions and analysis. Anonymous types are defined by the compiler based on the number, type, names, and order of properties created, and they automatically implement appropriate Equals() and GetHashCode() overrides (as well as ToString()) which makes them ideal for LINQ expressions where you need to create a set of properties to group, evaluate, etc. Technorati Tags: C#,CSharp,.NET,Little Wonders,Anonymous Types,LINQ

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  • SQL CLR Assembly Error 80131051 when late binding to a registered C# COM .dll

    - by Shanubus
    I must have hit an unusual one, because I can't find any reference to this specific failing anywhere... Scenario: I have a legacy SQL function used to transform(encrypt) data. This function is called from within many stored procedures used by multiple applications. I say this, because the obvious answer of 'just call it from your code' is not really an option (or at least one I'd prefer not explore). The legacy function used sp_OA with an ActiveX dll on SQL2000 to perform its work. The new function is targeted at SQL2008 x64. I am ditching the sp_OA call in favor of CLR assembly; and am getting rid of the ActiveX dll and using a COM+ .dll (3rd party) to perform the same work. This 3rd party COM+ is required to be used based on spec given to me, so can't get rid of this piece either. Problem: After multiple attempts at getting this to work I have eliminated the following approaches 1) Create a Sql Assembly to call the local COM+ directly -- Can't do this as it requires a reference to System.EnterpriseServices. Including this requires that a whole slew of unsupported assemblies be registered which I don't want. The COM+ requires it's methods to be accessed via an Interface, so my attempts at late binding to it directly have not been successful (late binding would allow me to drop the unsupported references). 2) Create a Sql Assembly which references a C# class library that then calls the COM+. -- Same issue as #1; since the referenced dll uses System.EnterpriseServices and will be added as a dependency when referenced in the Sql Assembly, again trying to load all the unsupported libraries 3) Create a Sql Assembly which late binds to an ActiveX COM dll that calls the COM+. -- Worked in my dev environment, but can't go to x64 in production with ActiveX dll's written in VB6 (not to mention I hate backtracking anyway)... again failure... I am now onto an approach that is almost working, with of course one last hangup. I now have -a Sql Assembly that late binds to a C# COM dll, eliminating the need for including System.EnterpriseServices and eliminating the need to reference the C# COM in the SqlAssembly itself. The C# COM does reference System.EnterpriseServices to call the COM+, but since I am late binding to it from the SqlAssembly, I bypass the need for Sql to actually load them as referenced assemblies. Works in debugger.. Works on my dev box when the SqlAssembly dll is referenced in a test console app and called directly Installs to Sql2008 just fine Executing the actual UDF works, but returns no data due to a failure reporting from the late bound dll! So the SqlAssembly is instanciated just fine. It actually fails on it's late binding to the C# COM, which is working from a test console app on the same machine. It appears to be a difference in behavior based on whether called from within the SQL UDF or not. Since it is working on the same box from my console app, I am assuming it's on the SQL side. My steps to install were. --Install the COM+ dll and ensure it can be called successfully (as from with in the console app) --Register the C# COM dll (which calls the COM+) and get it to the GAC (again proofed to be working from console app) --Create my Assymetric Key CREATE ASYMMETRIC KEY SqlCryptoKey FROM EXECUTABLE FILE = 'D:\SqlEx.dll' CREATE LOGIN SqlExLogin FROM ASYMMETRIC KEY SqlExKey GRANT UNSAFE ASSEMBLY TO SqlExLogin GO --Add the assembly CREATE ASSEMBLY SqlEx FROM 'D:\SqlEx.dll' WITH PERMISSION_SET = UNSAFE; GO --Create the function CREATE FUNCTION dbo.f_SqlEx( @clearText [nvarchar](512) ) RETURNS nvarchar(512) WITH EXECUTE AS CALLER AS EXTERNAL NAME SqlEx.[SqlEx.SqlEx].Ex GO With all that done, I can now call my function SELECT dbo.f_SqlEx('test') But get this error in the event log... Retrieving the COM class factory for component with CLSID {F69D6320-5884-323F-936A-7657946604BE} failed due to the following error: 80131051. I can't really provide direct code examples, due to internal security implications; but all the code itself seems to work, I am suspecting perms or something of the like... I just find it odd that I can't find any reference to error 80131051. If someone out there believe some 'indirect' code samples will help, I will be happy to provide. Any assistance is appreciated.

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