Search Results

Search found 41348 results on 1654 pages for 'java developer'.

Page 1557/1654 | < Previous Page | 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564  | Next Page >

  • Using the RSSBus Salesforce Excel Add-In From Excel Macros (VBA)

    - by dataintegration
    The RSSBus Salesforce Excel Add-In makes it easy to retrieve and update data from Salesforce from within Microsoft Excel. In addition to the built-in wizards that make data manipulation possible without code, the full functionality of the RSSBus Excel Add-Ins is available programmatically with Excel Macros (VBA) and Excel Functions. This article shows how to write an Excel macro that can be used to perform bulk inserts into Salesforce. Although this article uses the Salesforce Excel Add-In as an example, the same process can be applied to any of the Excel Add-Ins available on our website. Step 1: Download and install the RSSBus Excel Add-In available on our website. Step 2: Open Excel and create place holder cells for the connection details that are needed from the macro. In this article, a spreadsheet will be created for batch inserts, and these cells will store the connection details, and will be used to report the job Id, the batch Id, and the batch status. Step 3: Switch to the Developer tab in Excel. Add a new button on the spreadsheet, and create a new macro associated with it. This macro will contain the code needed to insert a batch of rows into Salesforce. Step 4: Add a reference to the Excel Add-In by selecting Tools --> References --> RSSBus Excel Add-In. The macro functions of the Excel Add-In will be available once the reference has been added. The following code shows how to call a Stored Procedure. In this example, a job is created to insert Leads by calling the CreateJob stored procedure. CreateJob returns a jobId that can be used to upload a large number of Leads in one transaction. Note the use of cells B1, B2, B3, and B4 that were created in Step 2 to read the connection settings from the Excel SpreadSheet and to write out the status of the procedure. methodName = "CreateJob" module.SetProviderName ("Salesforce") nameArray = Array("ObjectName", "Action", "ConcurrencyMode") valueArray = Array("Lead", "insert", "Serial") user = Range("B1").value pass = Range("B2").value atoken = Range("B3").value If (Not user = "" And Not pass = "" And Not atoken = "") Then module.SetConnectionString ("User=" + user + ";Password=" + pass + ";Access Token=" + atoken + ";") If module.CallSP(methodName, nameArray, valueArray) Then Dim ColumnCount As Integer ColumnCount = module.GetColumnCount Dim idIndex As Integer For Count = 0 To ColumnCount - 1 Dim colName As String colName = module.GetColumnName(Count) If module.GetColumnName(Count) = "id" Then idIndex = Count End If Next While (Not module.EOF) Range("B4").value = module.GetValue(idIndex) module.MoveNext Wend Else MsgBox "The CreateJob query failed." End If Exit Sub Else MsgBox "Please specify the connection details." Exit Sub End If Error: MsgBox "ERROR: " & Err.Description Step 5: Add the code to your macro. If you use the code above, you can check the results at Salesforce.com. They can be seen at Administration Setup -> Monitoring -> Bulk Data Load Jobs. Download the attached sample file for a more complete demo. Distributing an Excel File With Macros An Excel file with macros is saved using the .xlms extension. The code for the macro remains in the Excel file, and you can distribute your Excel file to any machine where the RSSBus Salesforce Excel Add-In is already installed. Macro Sample File Please download the fully functional sample excel file that includes the code referenced here. You will also need the RSSBus Excel Add-In to make the connection. You can download a free trial here. Note: You may get an error message stating: "Can't find project or library." in Excel 2007, since this example is made using Excel 2010. To resolve this, navigate to Tools -> References and uncheck the "MISSING: RSSBus Excel Add-In", then scroll down and check the "RSSBus Excel Add-In" listed below it.

    Read the article

  • Silverlight Cream for March 31, 2010 -- #826

    - by Dave Campbell
    In this Issue: Andrea Boschin, Radenko Zec, Andrej Tozon, Bobby Diaz, Brad Abrams, Wolf Schmidt, Colin Eberhardt, Anand Iyer, Matthias Shapiro, Jaime Rodriguez, Bill Reiss, and Lee. Shoutouts: Cigdem has a post up about here MIX10 Interviewing experiences: MIX10 SilverlightShow Interviews Ian T. Lackey has his material up from his talk Silverlight SEO at the St. Louis .Net Users Group Not Silverlight but definitely WP7 cool, Michael Klucher reports that there are New Windows Phone Samples on Creators Club Online Tim Heuer posted a survey: What tools are the minimum to get started in Silverlight? From SilverlightCream.com: A RoleManager to apply roles declaratively to user interface Andrea Boschin also has a new post at SilverlightShow discussing the use of a RoleManager in WCF RIA Services to apply user roles to elements of the UI... good stuff, Andrea. Virtualization in Silverlight 4 RC Radenko Zec has a post out at SilverlightShow where he explains UI and Data Virtualization then gives some examples of their use in Silverlight 4RC, and some issues as well. MS Word Mail Merge with Silverlight 4 COM Automation Andrej Tozon has a post up at SilverlightShow that I missed in the rush of MIX10. He's doing MailMerge with COM automation and Silverlight 4... actually prett cool stuff and all the source! KISS and Tell - MVVM and the ViewModelLocator Bobby Diaz is blogging about a very popular subject right now: ViewModelLocator. He's not showing production code, but it's a thought... check it out. Silverlight 4 + RIA Services - Ready for Business: Validating Data I'm running behind, but Brad Abrams' next post in his series is about validating data in the business application. He also discusses setting up shared code validation. A One-stop Shopping XAML Namespace for Silverlight Client SDK Controls Wolf Schmidt at the Silverlight SDK has a post up highlighting the SL4 XAML namespace prefix. He starts with SL3 then demonstrates the feature's use in SL4. Binding a Silverlight 3 DataGrid to dynamic data via IDictionary (Updated) Colin Eberhardt has an update to his previous article of the same title. This one is a bug fix on an upgrade to SL3 and also an expansion of the previous post. Demo Apps from MIX10 on Windows Phone 7 Anand Iyer posted links to all the WP7 demos used at MIX10 and at least in the case of FourSquare, the source is on CodePlex. XAML Files for Location Visualizations in Silverlight and WPF Matthias Shapiro has graciously provided XAML for us for Silverlight and WPF for a bunch of different US maps... too cool, now we don't have to be asking 'where did you get that map?'... thanks Matthias! Theming in Windows Phone Jaime Rodriguez has a post up that deep-dives theming in general and demonstrates using it on WP7... end-user configurations and developer stuff. Space Rocks game step 7: Moving the ship It appears that in the heat of battle (blogging) I said Bill Reiss' Space Rocks game he's building is for WP7... obviously it's not, but it's a game folks... :) THis is Episode 7 and he's moving the ship now. SL4(RC) RichTextBox and Access Violation Lee has some code that looks like it should work for a RichTextBox in SL4RC, and it's throwing an error... see if you have a solution for him... or is it a bug? Stay in the 'Light! Twitter SilverlightNews | Twitter WynApse | WynApse.com | Tagged Posts | SilverlightCream Join me @ SilverlightCream | Phoenix Silverlight User Group Technorati Tags: Silverlight    Silverlight 3    Silverlight 4    Windows Phone MIX10

    Read the article

  • Design suggestions needed to create a MathBuilder framework

    - by Darf Zon
    Let explain what I'm trying to create. I'm creating a framework, the idea is to provide base classes to generate a math problem. Why do I need this framework? Because at first time, I realized when I create a new math problem I always do the same steps. Configuration settings such range numbers. For example if I'm developing multiplications, in beginner level only generate the first number between 2-5 or in advanced level, the first number will be between 6- 9, for example. Generate problem method. All the time I need to invoke a method like this to generate the problem. This one receives the configuration settings and generate the number according to them. And generate the object with the respective data. Validate the problem. Sometimes the problem generated is not valid. For example, supposed I'm creating fractions in most simplified, if I receive 2/4, the program should detect that this is not valid and must generate another like this one, 1/4. Load the view. All of them, have a custom view (please watch below the images). All of the problems must know how to CHECK if the user result is correct. All of this problems has answers. Some of them just require one answer, anothers may require more than one, so I guess a way to maintain flexibility to the developer has all the answers he wanna used. At the beginning I started using PRISM. Generate modules for each math problem was the idea and load it in the main system. I guess are the most important things of this idea. Let me showing some problems which I create in a WPF standalone program. Here I have a math problem about areas. When I generate the problem a set to the view the object and it draw it. In beginner level, I set in the configuration settings that just load square types. But in advance level, can load triangles and squares randomly. In this another, generate a binary problem like addition, subtraction, multiplication or division. Above just generate a single problem. The idea of this is to show a test o quiz, I mean get a worksheet (this I call as a collection of problems) where the user can answer it. I hope gets the idea with my ugly drawing. How to load this math problems? As I said above, I started using PRISM, and each module contains a math problem kind. This is a snapshot of my first demo. Below show the modules loaded, and center the respective configurations or levels. Until momment, I have no idea to start creating this software. I just know that I need a question | problem class, response class, user class. But I get lost about what properties should have to contain in it. Please give a little hand of this framework. I put much effort on this question, so if any isn't clear, let me know to clarify it.

    Read the article

  • Handling Coding Standards at Work (I'm not the boss)

    - by Josh Johnson
    I work on a small team, around 10 devs. We have no coding standards at all. There are certain things that have become the norm but some ways of doing things are completely disparate. My big one is indentation. Some use tabs, some use spaces, some use a different number of spaces, which creates a huge problem. I often end up with conflicts when I merge because someone used their IDE to auto format and they use a different character to indent than I do. I don't care which we use I just want us all to use the same one. Or else I'll open a file and some lines have curly brackets on the same line as the condition while others have them on the next line. Again, I don't mind which one so long as they are all the same. I've brought up the issue of standards to my direct manager, one on one and in group meetings, and he is not overly concerned about it (there are several others who share the same view as myself). I brought up my specific concern about indentation characters and he thought a better solution would be to, "create some kind of script that could convert all that when we push/pull from the repo." I suspect that he doesn't want to change and this solution seems overly complicated and prone to maintenance issues down the road (also, this addresses only one manifestation of a larger issue). Have any of you run into a similar situation at work? If so, how did you handle it? What would be some good points to help sell my boss on standards? Would starting a grass roots movement to create coding standards, among those of us who are interested, be a good idea? Am I being too particular, should I just let it go? Thank you all for your time. Note: Thanks everyone for the great feedback so far! To be clear, I don't want to dictate One Style To Rule Them All. I'm willing to concede my preferred way of doing something in favor of what suits everyone the best. I want consistency and I want this to be a democracy. I want it to be a group decision that everyone agrees on. True, not everyone will get their way, but I'm hoping that everyone will be mature enough to compromise for the betterment of the group. Note 2: Some people are getting caught up in the two examples I gave above. I'm more after the heart of the matter. It manifests itself with many examples: naming conventions, huge functions that should be broken up, should something go in a util or service, should something be a constant or injected, should we all use different versions of a dependency or the same, should an interface be used for this case, how should unit tests be set up, what should be unit tested, (Java specific) should we use annotations or external config. I could go on.

    Read the article

  • TechEd 2012: Day 3 &ndash; Morning TFS

    - by Tim Murphy
    My morning sessions for day three were dominated by Team Foundation Server.  This has been a hot topic for our clients lately, so this topic really stuck a chord. The speaker for the first session was from Boeing.  It was nice to hear how how a company mixes both agile and waterfall project management.   The approaches that he presented were very pragmatic.  For their needs reporting is the crucial part of their decision to use TFS.  This was interesting since this is probably the last aspect that most shops would think about. The challenge of getting users to adopt TFS was brought up by the audience.  As with the other discussion point he took a very level headed stance.  The approach he was prescribing was to eat the elephant a bite at a time instead of all at once.  If you try to convert you entire shop at once the culture shock will most likely kill the effort. Another key point he reminded us of is that you need to make sure that standards and compliance are taken into account when you setup TFS.  If you don’t implement a tool and processes around it that comply with the standards bodies that govern your business you are in for a world of hurt. Ultimately the reason they chose TFS was because it was the first tool that incorporated all the ALM features that they needed. Reduced licensing cost because of all the different tools they would need to buy to complete the same tasks.  They got to this point by doing an industry evaluation.  Although TFS came out on top he said that it still has a big gap is in the Java area.  Of course in this market there are vendors helping to close that gap. The second session was on how continuous feedback in agile is a new focus in VS2012.  The problems they intended to address included cycle time and average time to repair, root cause analysis. The speakers fired features at us as if they were firing a machine gun.  I will just say that I am looking forward to digging into the product after seeing this presentation.  Beyond that I will simply list some of the key features that caught my attention. Feature – Ability to link documents into tasks as artifacts Web access portal PowerPoint storyboards Exploratory testing Request feedback (allows users to record notes, screen shots and video/audio) See you after the second half. del.icio.us Tags: TechEd,TechEd 2012,TFS,Team Foundation Server

    Read the article

  • InSync12 and Australia Visits: UX is Global, Regional, Everywhere!

    - by ultan o'broin
    I attended the Australian Oracle User Group (AUSOUG) and Quest International User Group's InSync12 event in Melbourne, Australia: the user group conference for Oracle products in the ANZ region. I demoed Oracle Fusion Applications and then presented how Oracle crafted the world class Fusion Apps user experience (UX). I explained about the Oracle user experience design pattern strategy of uptake for all apps, not just Fusion, and what our UX pattern externalization strategy means for customers, partners, and ADF developers. A great conference, lots of energy, the InSync12 highlights for me were Oracle's Senior Vice President Cliff Godwin’s fast-moving Oracle E-Business Suite (EBS) roadshow with the killer Oracle Endeca user experience uptake, and Oracle ADF product outreachmeister Chris Muir’s (@chriscmuir) session on Oracle ADF Mobile solution and his hands-on mobile app development showing how existing ADF/JDev skills can build a secure, code once-deploy-to-many-device hybrid app solution in minutes. Cliff Godwin shows off the Oracle Endeca integration with Oracle E-Business Suite. Chris Muir talked the talk and then walked the walked with Oracle ADF Mobile. Applications UX was mixing it up with the crowd at InSync12 too, showing off cool mobile UX solutions, gathering data for future innovations, and engaging with EBS, JD Edwards, and PeopleSoft apps customers and partners. User conferences such as InSync12 are an important part of our Oracle Applications UX user-centered design process, giving real apps users the opportunity to make real inputs and a way for us to watch and to listen to their needs and wants and get views on current and emerging UX too. Eric Stilan (@icondaddy) of Applications UX uses an iPad to gather feedback on the latest UX designs from conference attendees. While in Melbourne, I also visited impressive Oracle partner, Callista for a major ADF and UX pow-wow, and was the er, star of a very proactive event hosted by another partner Park Lane Information Technology (coordinated by Bambi Price (@bambiprice) of ODTUG) where I explained what UX is about, and how partner and customers can engage, participate and deploy that Applications UX scientific insight to advantage for their entire business. I also paired up with Oracle Australia in Sydney to visit key customers while there, and back at Oracle in Melbourne I spoke with sales consultants and account managers about regional opportunities and UX strategy, and came away with an understanding of what makes the Oracle market tick in Australia. Mobile worker solution development and user experience is hot news in Australia, and this was a great opportunity to team up with Chris Muir and show how the alignment of the twin stars of UX design patterns and ADF technology enables developers to make great-looking, usable apps that really sparkle. Our UX design patterns--or functional (UI) patterns, to use the developer world language--means that developers now have not only a great tool set to build apps on Oracle ADF/FMW but proven, tested usability solutions to solve common problems they can apply in the IDE too. In all, a whirlwind UX visit, packed with events and delivery opportunities, and all too short a time in the wonderful city of Melbourne. I need to get back there soon! For those who need a reminder, there's a website explaining how to get involved with, and participate in, Applications User Experience (including the Oracle Usability Advisory Board) events and programs. Thank you to AUSOUG, Quest, InSync, Callista, Park Lane IT, everyone at Oracle Australia, Chris Muir, and all the other people who came together to make this a productive visit. Stay tuned for more UX developments and engagements in the region on the Oracle VoX blog and Usable Apps website too!

    Read the article

  • Next Generation Mobile Clients for Oracle Applications & the role of Oracle Fusion Middleware

    - by Manish Palaparthy
    Oracle Enterprise Applications have been available with modern web browser based interfaces for a while now. The web browsers available in smart phones no longer require special markup language such as WML since the processing power of these handsets is quite near to that of a typical personal computer. Modern Mobile devices such as the IPhone, Android Phones, BlackBerry, Windows 8 devices can now render XHTML & HTML quite well. This means you could potentially use your mobile browser to access your favorite enterprise application. While the Mobile browser would render the UI, you might find it difficult to use it due to the formatting & Presentation of the Native UI. Smart phones offer a lot more than just a powerful web browser, they offer capabilities such as Maps, GPS, Multi touch, pinch zoom, accelerometers, vivid colors, camera with video, support for 3G, 4G networks, cloud storage, NFC, streaming media, tethering, voice based features, multi tasking, messaging, social networking web browsers with support for HTML 5 and many more features.  While the full potential of Enterprise Mobile Apps is yet to be realized, Oracle has published a few of its applications that take advantage of the above capabilities and are available for the IPhone natively. Here are some of them Iphone Apps  Oracle Business Approvals for Managers: Offers a highly intuitive user interface built as a native mobile application to conveniently access pending actions related to expenses, purchase requisitions, HR vacancies and job offers. You can even view BI reports related to the worklist actions. Works with Oracle E-Business Suite Oracle Business Indicators : Real-time secure access to OBI reports. Oracle Business Approvals for Sales Managers: Enables sales executives to review key targeted tasks, access relevant business intelligence reports. Works with Siebel CRM, Siebel Quote & Order Capture. Oracle Mobile Sales Assistant: CRM application that provides real-time, secure access to the information your sales organization needs, complete frequent tasks, collaborate with colleagues and customers. Works with Oracle CRMOracle Mobile Sales Forecast: Designed specifically for the mobile business user to view key opportunities. Works with Oracle CRM on demand Oracle iReceipts : Part of Oracle PeopleSoft Expenses, which allows users to create and submit expense lines for cash transactions in real-time. Works with Oracle PeopleSoft expenses Now, we have seen some mobile Apps that Oracle has published, I am sure you are intrigued as to how develop your own clients for the use-cases that you deem most fit. For that Oracle has ADF Mobile ADF Mobile You could develop Mobile Applications with the SDK available with the smart phone platforms!, but you'd really have to be a mobile ninja developer to develop apps with the rich user experience like the ones above. The challenges really multiply when you have to support multiple mobile devices. ADF Mobile framework is really handy to meet this challenge ADF Mobile can in be used to Develop Apps for the Mobile browser : An application built with ADF Mobile framework installs on a smart device, renders user interface via HTML5, and has access to device services. This means the programming model is primarily web-based, which offers consistency with other enterprise applications as well as easier migration to new platforms. Develop Apps for the Mobile Client (Native Apps): These applications have access to device services, enabling a richer experience for users than a browser alone can offer. ADF mobile enables rapid and declarative development of rich, on-device mobile applications. Developers only need to write an application once and then they can deploy the same application across multiple leading smart phone platforms. Oracle SOA Suite Although the Mobile users are using the smart phone apps, and actual transactions are being executed in the underlying app, there is lot of technical wizardry that is going under the surface. All of this key technical components to make 1. WebService calls 2. Authentication 3. Intercepting Webservice calls and adding security credentials to the request 4. Invoking the services of the enterprise application 5. Integrating with the Enterprise Application via the Adapter is all being implemented at the SOA infrastructure layer.  As you can see from the above diagram. The key pre-requisites to mobile enable an Enterprise application are The core enterprise application Oracle SOA Suite ADF Mobile

    Read the article

  • Application Performance Episode 2: Announcing the Judges!

    - by Michaela Murray
    The story so far… We’re writing a new book for ASP.NET developers, and we want you to be a part of it! If you work with ASP.NET applications, and have top tips, hard-won lessons, or sage advice for avoiding, finding, and fixing performance problems, we want to hear from you! And if your app uses SQL Server, even better – interaction with the database is critical to application performance, so we’re looking for database top tips too. There’s a Microsoft Surface apiece for the person who comes up with the best tip for SQL Server and the best tip for .NET. Of course, if your suggestion is selected for the book, you’ll get full credit, by name, Twitter handle, GitHub repository, or whatever you like. To get involved, just email your nuggets of performance wisdom to [email protected] – there are examples of what we’re looking for and full competition details at Application Performance: The Best of the Web. Enter the judges… As mentioned in my last blogpost, we have a mystery panel of celebrity judges lined up to select the prize-winning performance pointers. We’re now ready to reveal their secret identities! Judging your ASP.NET  tips will be: Jean-Phillippe Gouigoux, MCTS/MCPD Enterprise Architect and MVP Connected System Developer. He’s a board member at French software company MGDIS, and teaches algorithms, security, software tests, and ALM at the Université de Bretagne Sud. Jean-Philippe also lectures at IT conferences and writes articles for programming magazines. His book Practical Performance Profiling is published by Simple-Talk. Nik Molnar,  a New Yorker, ASP Insider, and co-founder of Glimpse, an open source ASP.NET diagnostics and debugging tool. Originally from Florida, Nik specializes in web development, building scalable, client-centric solutions. In his spare time, Nik can be found cooking up a storm in the kitchen, hanging with his wife, speaking at conferences, and working on other open source projects. Mitchel Sellers, Microsoft C# and DotNetNuke MVP. Mitchel is an experienced software architect, business leader, public speaker, and educator. He works with companies across the globe, as CEO of IowaComputerGurus Inc. Mitchel writes technical articles for online and print publications and is the author of Professional DotNetNuke Module Programming. He frequently answers questions on StackOverflow and MSDN and is an active participant in the .NET and DotNetNuke communities. Clive Tong, Software Engineer at Red Gate. In previous roles, Clive spent a lot of time working with Common LISP and enthusing about functional languages, and he’s worked with managed languages since before his first real job (which was a long time ago). Long convinced of the productivity benefits of managed languages, Clive is very interested in getting good runtime performance to keep managed languages practical for real-world development. And our trio of SQL Server specialists, ready to select your top suggestion, are (drumroll): Rodney Landrum, a SQL Server MVP who writes regularly about Integration Services, Analysis Services, and Reporting Services. He’s authored SQL Server Tacklebox, three Reporting Services books, and contributes regularly to SQLServerCentral, SQL Server Magazine, and Simple–Talk. His day job involves overseeing a large SQL Server infrastructure in Orlando. Grant Fritchey, Product Evangelist at Red Gate and SQL Server MVP. In an IT career spanning more than 20 years, Grant has written VB, VB.NET, C#, and Java. He’s been working with SQL Server since version 6.0. Grant volunteers with the Editorial Committee at PASS and has written books for Apress and Simple-Talk. Jonathan Allen, leader and founder of the PASS SQL South West user group. He’s been working with SQL Server since 1999 and enjoys performance tuning, development, and using SQL Server for business solutions. He’s spoken at SQLBits and SQL in the City, as well as local user groups across the UK. He’s also a moderator at ask.sqlservercentral.com.

    Read the article

  • Database Mirroring on SQL Server Express Edition

    - by Most Valuable Yak (Rob Volk)
    Like most SQL Server users I'm rather frustrated by Microsoft's insistence on making the really cool features only available in Enterprise Edition.  And it really doesn't help that they changed the licensing for SQL 2012 to be core-based, so now it's like 4 times as expensive!  It almost makes you want to go with Oracle.  That, and a desire to have Larry Ellison do things to your orifices. And since they've introduced Availability Groups, and marked database mirroring as deprecated, you'd think they'd make make mirroring available in all editions.  Alas…they don't…officially anyway.  Thanks to my constant poking around in places I'm not "supposed" to, I've discovered the low-level code that implements database mirroring, and found that it's available in all editions! It turns out that the query processor in all SQL Server editions prepends a simple check before every edition-specific DDL statement: IF CAST(SERVERPROPERTY('Edition') as nvarchar(max)) NOT LIKE '%e%e%e% Edition%' print 'Lame' else print 'Cool' If that statement returns true, it fails. (the print statements are just placeholders)  Go ahead and test it on Standard, Workgroup, and Express editions compared to an Enterprise or Developer edition instance (which support everything). Once again thanks to Argenis Fernandez (b | t) and his awesome sessions on using Sysinternals, I was able to watch the exact process SQL Server performs when setting up a mirror.  Surprisingly, it's not actually implemented in SQL Server!  Some of it is, but that's something of a smokescreen, the real meat of it is simple filesystem primitives. The NTFS filesystem supports links, both hard links and symbolic, so that you can create two entries for the same file in different directories and/or different names.  You can create them using the MKLINK command in a command prompt: mklink /D D:\SkyDrive\Data D:\Data mklink /D D:\SkyDrive\Log D:\Log This creates a symbolic link from my data and log folders to my Skydrive folder.  Any file saved in either location will instantly appear in the other.  And since my Skydrive will be automatically synchronized with the cloud, any changes I make will be copied instantly (depending on my internet bandwidth of course). So what does this have to do with database mirroring?  Well, it seems that the mirroring endpoint that you have to create between mirror and principal servers is really nothing more than a Skydrive link.  Although it doesn't actually use Skydrive, it performs the same function.  So in effect, the following statement: ALTER DATABASE Mir SET PARTNER='TCP://MyOtherServer.domain.com:5022' Is turned into: mklink /D "D:\Data" "\\MyOtherServer.domain.com\5022$" The 5022$ "port" is actually a hidden system directory on the principal and mirror servers. I haven't quite figured out how the log files are included in this, or why you have to SET PARTNER on both principal and mirror servers, except maybe that mklink has to do something special when linking across servers.  I couldn't get the above statement to work correctly, but found that doing mklink to a local Skydrive folder gave me similar functionality. To wrap this up, all you have to do is the following: Install Skydrive on both SQL Servers (principal and mirror) and set the local Skydrive folder (D:\SkyDrive in these examples) On the principal server, run mklink /D on the data and log folders to point to SkyDrive: mklink /D D:\SkyDrive\Data D:\Data On the mirror server, run the complementary linking: mklink /D D:\Data D:\SkyDrive\Data Create your database and make sure the files map to the principal data and log folders (D:\Data and D:\Log) Viola! Your databases are kept in sync on multiple servers! One wrinkle you will encounter is that the mirror server will show the data and log files, but you won't be able to attach them to the mirror SQL instance while they are attached to the principal. I think this is a bug in the Skydrive, but as it turns out that's fine: you can't access a mirror while it's hosted on the principal either.  So you don't quite get automatic failover, but you can attach the files to the mirror if the principal goes offline.  It's also not exactly synchronous, but it's better than nothing, and easier than either replication or log shipping with a lot less latency. I will end this with the obvious "not supported by Microsoft" and "Don't do this in production without an updated resume" spiel that you should by now assume with every one of my blog posts, especially considering the date.

    Read the article

  • Silverlight Cream for May 08, 2010 -- #858

    - by Dave Campbell
    In this Issue: Phil Middlemiss, Jaime Rodriguez, Senthil Kumar, Mike Snow, DaveDev, Gergely Orosz, Kirupa, Cheryl Simmons, András Velvárt, Dan Wahlin, Michael D. Brown, and Ben Rush. Shoutouts: Erik Mork and crew have their latest up: This Week In Silverlight – Where’s the Tablet? Chris Rouw has a good link post and instructions on WCF RIA services: Deploying and Configuring Silverlight 4 and WCF RIA Services From SilverlightCream.com: Quick and Easy Sscalable Rounded Bevels Phil Middlemiss duplicates some bevel-edged rectangles in Blend, and they look great. Now you don't have to import all the other PhotoShop bits to get those things looking the way you want! A transparent Windows PHONE FAQ Jaime Rodriguez combined a bunch of information into a WP7 FAQ that he's going to keep up to date, so bookmark the page. He also has links to the Training Kit, on and offline versions. Windows Phone Developer Training Kit April Refresh is now available for Download Thanks to Senthil Kumar, I found out there is an April refresh of the WP7 Training kit at Channel 9 -- go get yours now --- I'll still be here when you get back! Silverlight Tip of the Day #16 – Working with IgnoreImageCache Mike Snow's Tip of the day #16 covers IgnoreImageCache and like many other things in life, until you read Mike's post you may be surprised at how it works. DoodlePad – A fun, free, sketching application for Windows Phone 7 DaveDev has a new WP7 App up that lets you or your kids 'Doodle' on the phone... could be a note, or could be a drawing... good post with all the links you need to get this cranked up on the emulator. Printing in Silverlight: Printing Charts and Auto Scaling Gergely Orosz's latest post is a very useful one on auto-scaling charts to fit a printed page and then getting them to print. Smoothly Scrolling a ListBox Check out the smooth scrolling Kirupa has on the ListBox near the top of his post... all good stuff... you wanna know how to do that! Plus... it's dead simple and all in Blend :) http://www.sparklingclient.com/wheres-the-silverlight-tablet/ Cheryl Simmons has a great tip up at the SilverlightSDK if you haven't burned through to figure it out yet ... changing the watermark on a DatePicker control... looks great! The story of a wicked bug András Velvárt tells a story of a bug that just defied logic or being found. Read how he tracked it down and what it actually was... could save you some time. Story learned: if I have a problem that bad, I'm calling András :) Text Trimming in Silverlight 4 Dan Wahlin gives a quick run-through of what TextBox trimming is, and then by a good real example... check it out and start using it in your projects. Enterprise Patterns with WCF RIA Services Michael D. Brown has an article in MSDN Magazine on RIA Services. Great information and link-packed article, with all the source avialable for download. Building Custom Players with the Silverlight Media Framework Ben Rush has a nice long tutorial on the Silverlight Media Framework up on the MSDN Magazine site ... lots of information in there. Stay in the 'Light! Twitter SilverlightNews | Twitter WynApse | WynApse.com | Tagged Posts | SilverlightCream Join me @ SilverlightCream | Phoenix Silverlight User Group Technorati Tags: Silverlight    Silverlight 3    Silverlight 4    Windows Phone MIX10

    Read the article

  • Brainless Backups

    - by Jesse
    I’m a software developer by trade which means to my friends and family I’m just a “computer guy”. It’s assumed that I know everything about every facet of computing from removing spyware to replacing hardware. I also can do all of this blindly over the phone or after hearing a five to ten word description of the problem over dinner ;-) In my position as CIO of my friends and families I’ve been in the unfortunate position of trying to recover music, pictures, or documents off of failed hard drives on more than one occasion. It’s not a great situation for anyone, and it’s always at these times that the importance of backups becomes so clear. Several months back a friend of mine found himself in this situation. The hard drive on his 8 year old laptop failed and took a good number of his digital photos with it. I think most folks can deal with losing some of their music and even some of their documents, but it really stings to lose pictures of past events and loved ones. After ordering a new laptop, my friend went out and bought an external hard drive so that he could start keeping a backup of his data. As fate would have it, several months later the drive in his new laptop failed and he learned the hard way that simply buying the external hard drive isn’t enough… you actually have to copy your stuff over every once in awhile! The importance of backup and recovery plans is (hopefully) well known in IT organizations. Well executed backup plans are in place, and hopefully the backup and recovery process is tested regularly. When you’re talking about users at home, however, the need for these backups is often understood far too late. Most typical users can’t be expected to remember to backup their data regularly and also don’t always have the know-how to setup automated backups. For my friends and family members in this situation I recommend tools like Dropbox, Carbonite, and Mozy. Here’s why I like them: They’re affordable: Dropbox and Mozy both have free offerings, though most people with lots of music and/or photos to backup will probably exceed the storage limitations of those free plans pretty quickly. Still, all three offer pretty affordable monthly or yearly plans. In my opinion, Carbonite’s unlimited storage plan for $50-$60 per year is the best value around. They’re easy to setup: Both Dropbox and Carbonite are very easy to get setup and start using. I’ve never used Mozy, but I imagine it’s similarly painless to get up and running. Backups are automatically “off-site”: A backup that is sitting on an external hard drive right next to your computer is great, but might not protect against flood damage, a power surge, or other disasters in that single location. These services exist “in the cloud” so to speak, helping mitigate those concerns. Granted, this kind of backup scheme requires some trust in the 3rd party to protect your data from both malicious people and disastrous events. This truly is a bit of a double edged sword, but I sleep well at night knowing that my data is being backed up and secured by a company made up of engineers that focus on the business of doing backups right. Backups are “brainless”: What I like most about services like these is that they work “automagically” in the background, watching for files to be updated and automatically backing up those changes. There’s no need to remember to plug in that external drive and copy your data over. Since starting to recommend these services to my friends and family I find myself wearing my “data recovery” hat far less often. The only way backups are effective for your standard computer user is if they’re completely automatic. Backups need to be brainless, or they just won’t work.

    Read the article

  • Mandatory look back at 2010

    - by Bertrand Le Roy
    Yeah, it's one of those posts, sorry. First, the mildly depressing: the most popular post on this blog this year with 47,000 hits was a post from last year about a fix to a bug in ASP.NET. A content-less post except for that link to the KB article that people should have found by going directly to the support site in the first place. Then, the really depressing: the second most popular post this year with 34,000 hits was a post from 2005 about how to display message boxes on a web page. I mean come on. This was kind of fun five years ago and it did solve one of the most common n00b mistakes VB programmers trying to move to the web were making. But come on, we've traveled about 4.7 billion miles around the Earth since then. Do people still do that kind of stuff? I should probably put a big red banner on top of this post. Oh [supernatural entity of your choice]. Hand me that gun, please. Third most popular post with 24,000 hits is from 2004. It's about how to set a session variable before redirecting. That problem has been fixed a long time ago. Oh well. Fourth most popular post. 21,000 hits. 2007. How to work around a stupid bug in ASP.NET Ajax 1.0. Fixed in ASP.NET 3.5? ASP.NET Ajax 1.0? Need I say more? The fifth one (20,000 hits) is an old post as well but I'm kind of fond of it: it's about that photo album handler I've been organically growing for a few years. It reminds me that I need to refresh it and make a new release. Good SEO title too. Back to insanity with the sixth one (16,000) that's about working around a bug in IE6. IE6. Please just refuse to pander to that browser any more. It's about time. Let's move on, please. Actually, the first post from 2010 is 15th in the list. We have a trio of these actually with server-side image resizing and FluentPath. So what happened? Well, I like the ad money, but not to the point that I'm going to write my stuff to inflate it. Actually I think if I tried I would fail miserably (I mean, I would fail worse). What really happened this year was new stuff: Orchard, FluentPath and the stuff with the Netduino. That stuff needs time to get off the ground but my hope is that it's going to be useful in the long run and that five years from now I'll be lamenting on how well those posts are still doing. So, no regret. 2010 was a good year. Oh, and I was on This Developer's Life this year! Yay! Anyways, thank you all for reading me. Please continue doing that. And happy 2011!

    Read the article

  • How Can I Improve This Card-Game AI?

    - by James Burgess
    Let me get this out there before anything else: this is a learning exercise for me. I am not a game developer by trade or hobby (at least, not seriously) and am purely delving into some AI- and 3D-related topics to broaden my horizons a bit. As part of the learning experience, I thought I'd have a go at developing a basic card game AI. I selected Pit as the card game I was going to attempt to emulate (specifically, the 'bull and bear' variation of the game as mentioned in the link above). Unfortunately, the rule-set that I'm used to playing with (an older version of the game) isn't described. The basics of it are: The number of commodities played with is equal to the number of players. The bull and bear cards are included. All but two players receive 8 cards, two receive 9 cards. A player can win the round with 7 + bull, 8, or 8 + bull (receiving double points). The bear is a penalty card. You can trade up to a maximum of 4 cards at a time. They must all be of the same type, but can optionally include the bull or bear (so, you could trade A, A, A, Bull - but not A, B, A, Bull). For those who have played the card game, it will probably have been as obvious to you as it was to me that given the nature of the game, gameplay would seem to resemble a greedy algorithm. With this in mind, I thought it might simplify my AI experience somewhat. So, here's what I've come up with for a basic AI player to play Pit... and I'd really just like any form of suggestion (from improvements to reading materials) relating to it. Here it is in something vaguely pseudo-code-ish ;) While AI does not hold 7 similar + bull, 8 similar, or 8 similar + bull, do: 1. Establish 'target' hand, by seeing which card AI holds the most of. 2. Prepare to trade next-most-numerous card type in a trade (max. held, or 4, whichever is fewer) 3. If holding the bear, add to (if trading <=3 cards) or replace in (if trading 4 cards) hand. 4. Offer cards for trade. 5. If cards are accepted for trade within X turns, continue (clearing 'failed card types'). Otherwise: a. If only one card remains in the trade, go to #6. Otherwise: i. Remove one non-penalty card from the trade. ii. Return to #5. 6. Add card type to temporary list of failed card types. 7. Repeat from #2 (excluding 'failed card types'). I'm aware this is likely to be a sub-optimal way of solving the problem, but that's why I'm posting this question. Are there any AI- or algorithm-related concepts that I've missed and should be incorporating to make a better AI? Additionally, what are the flaws with my AI at present (I'm well aware it's probably far from complete)? Thanks in advance!

    Read the article

  • SQL SERVER – Read Only Files and SQL Server Management Studio (SSMS)

    - by pinaldave
    Just like any other Developer or DBA SQL Server Management Studio is my favorite application. Any any moment of the time I have multiple instances of the same application are open and I am working on it. Recently, I have come across a very interesting feature in SSMS related to “Read Only” files. I believe it is a little unknown feature as well so decided to write a blog about the same. First create a read only SQL file. You can make any file read by Right Click >> Properties >> Select Attribute Read Only. Now open the same file in SQL Server Management Studio. You will find that besides the file name there is a small ‘lock’ icon. This small icon indicates that the file is read only. Now let us attempt to edit the read only file. It will let us edit the file any way we want, however when we attempt to save it, it gives following pop-up value. The options in the pop-up are self explanatory and I liked it. The goal of the read only file is to prevent users to make un-intended changes. However, when a user should have complete control over the user file. User should be aware that the file is read only but if he wants to edit the file or save as a new file the choices should be present in front of it and the pop-up menu precisely captures the same. Now let us check option related to this feature in SSMS. Go to Menu >> Options >> Environment >> Documents You will find the third option which is “Allow editing of read-only files; warn when attempt to save”. In the above scenario it was already checked. Let us uncheck the same and do the same exercise which we have done earlier. I closed all the earlier window to avoid confusion. With the new option selected when I attempt to even modify the Read Only file, it gives me totally different pop up screen. It gives me an option like “Edit In-Memory”, “Make Writeable” etc. When you select “Edit In-Memory” it allows you to edit the file and later you can save as new file – just like the earlier scenario which we have discussed. . If clicked on the Make Writeable it will remove the restriction of the Read Only and file can be edited as pleased. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Server Management Studio, SQL Tips and Tricks, T SQL, Technology

    Read the article

  • SQL SERVER – Introduction to LEAD and LAG – Analytic Functions Introduced in SQL Server 2012

    - by pinaldave
    SQL Server 2012 introduces new analytical function LEAD() and LAG(). This functions accesses data from a subsequent row (for lead) and previous row (for lag) in the same result set without the use of a self-join . It will be very difficult to explain this in words so I will attempt small example to explain you this function. Instead of creating new table, I will be using AdventureWorks sample database as most of the developer uses that for experiment. Let us fun following query. USE AdventureWorks GO SELECT s.SalesOrderID,s.SalesOrderDetailID,s.OrderQty, LEAD(SalesOrderDetailID) OVER (ORDER BY SalesOrderDetailID ) LeadValue, LAG(SalesOrderDetailID) OVER (ORDER BY SalesOrderDetailID ) LagValue FROM Sales.SalesOrderDetail s WHERE SalesOrderID IN (43670, 43669, 43667, 43663) ORDER BY s.SalesOrderID,s.SalesOrderDetailID,s.OrderQty GO Above query will give us following result. When we look at above resultset it is very clear that LEAD function gives us value which is going to come in next line and LAG function gives us value which was encountered in previous line. If we have to generate the same result without using this function we will have to use self join. In future blog post we will see the same. Let us explore this function a bit more. This function not only provide previous or next line but it can also access any line before or after using offset. Let us fun following query, where LEAD and LAG function accesses the row with offset of 2. USE AdventureWorks GO SELECT s.SalesOrderID,s.SalesOrderDetailID,s.OrderQty, LEAD(SalesOrderDetailID,2) OVER (ORDER BY SalesOrderDetailID ) LeadValue, LAG(SalesOrderDetailID,2) OVER (ORDER BY SalesOrderDetailID ) LagValue FROM Sales.SalesOrderDetail s WHERE SalesOrderID IN (43670, 43669, 43667, 43663) ORDER BY s.SalesOrderID,s.SalesOrderDetailID,s.OrderQty GO Above query will give us following result. You can see the LEAD and LAG functions  now have interval of  rows when they are returning results. As there is interval of two rows the first two rows in LEAD function and last two rows in LAG function will return NULL value. You can easily replace this NULL Value with any other default value by passing third parameter in LEAD and LAG function. Let us fun following query. USE AdventureWorks GO SELECT s.SalesOrderID,s.SalesOrderDetailID,s.OrderQty, LEAD(SalesOrderDetailID,2,0) OVER (ORDER BY SalesOrderDetailID ) LeadValue, LAG(SalesOrderDetailID,2,0) OVER (ORDER BY SalesOrderDetailID ) LagValue FROM Sales.SalesOrderDetail s WHERE SalesOrderID IN (43670, 43669, 43667, 43663) ORDER BY s.SalesOrderID,s.SalesOrderDetailID,s.OrderQty GO Above query will give us following result, where NULL are now replaced with value 0. Just like any other analytic function we can easily partition this function as well. Let us see the use of PARTITION BY in this clause. USE AdventureWorks GO SELECT s.SalesOrderID,s.SalesOrderDetailID,s.OrderQty, LEAD(SalesOrderDetailID) OVER (PARTITION BY SalesOrderID ORDER BY SalesOrderDetailID ) LeadValue, LAG(SalesOrderDetailID) OVER (PARTITION BY SalesOrderID ORDER BY SalesOrderDetailID ) LagValue FROM Sales.SalesOrderDetail s WHERE SalesOrderID IN (43670, 43669, 43667, 43663) ORDER BY s.SalesOrderID,s.SalesOrderDetailID,s.OrderQty GO Above query will give us following result, where now the data is partitioned by SalesOrderID and LEAD and LAG functions are returning the appropriate result in that window. As now there are smaller partition in my query, you will see higher presence of NULL. In future blog post we will see how this functions are compared to SELF JOIN. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL Function, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, T SQL, Technology

    Read the article

  • Software Architecture verses Software Design

    Recently, I was asked what the differences between software architecture and software design are. At a very superficial level both architecture and design seem to mean relatively the same thing. However, if we examine both of these terms further we will find that they are in fact very different due to the level of details they encompass. Software Architecture can be defined as the essence of an application because it deals with high level concepts that do not include any details as to how they will be implemented. To me this gives stakeholders a view of a system or application as if someone was viewing the earth from outer space. At this distance only very basic elements of the earth can be detected like land, weather and water. As the viewer comes closer to earth the details in this view start to become more defined. Details about the earth’s surface will start to actually take form as well as mane made structures will be detected. The process of transitioning a view from outer space to inside our earth’s atmosphere is similar to how an architectural concept is transformed to an architectural design. From this vantage point stakeholders can start to see buildings and other structures as if they were looking out of a small plane window. This distance is still high enough to see a large area of the earth’s surface while still being able to see some details about the surface. This viewing point is very similar to the actual design process of an application in that it takes the very high level architectural concept or concepts and applies concrete design details to form a software design that encompasses the actual implementation details in the form of responsibilities and functions. Examples of these details include: interfaces, components, data, and connections. In review, software architecture deals with high level concepts without regard to any implementation details. Software design on the other hand takes high level concepts and applies concrete details so that software can be implemented. As part of the transition between software architecture to the creation of software design an evaluation on the architecture is recommended. There are several benefits to including this step as part of the transition process. It allows for projects to ensure that they are on the correct path as to meeting the stakeholder’s requirement goals, identifies possible cost savings and can be used to find missing or nonspecific requirements that cause ambiguity in a design. In the book “Evaluating Software Architectures: Methods and Case Studies”, they define key benefits to adding an architectural review process to ensure that an architecture is ready to move on to the design phase. Benefits to evaluating software architecture: Gathers all stakeholders to communicate about the project Goals are clearly defined in regards to the creation or validation of specific requirements Goals are prioritized so that when conflicts occur decisions will be made based on goal priority Defines a clear expectation of the architecture so that all stakeholders have a keen understanding of the project Ensures high quality documentation of the architecture Enables discoveries of architectural reuse  Increases the quality of architecture practices. I can remember a few projects that I worked on that could have really used an architectural review prior to being passed on to developers. This project was to create some new advertising space on the company’s website in order to sell space based on the location and some other criteria. I was one of the developer selected to lead this project and I was given a high level design concept and a long list of ever changing requirements due to the fact that sales department had no clear direction as to what exactly the project was going to do or how they were going to bill the clients once they actually agreed to purchase the Ad space. In my personal opinion IT should have pushed back to have the requirements further articulated instead of forcing programmers to code blindly attempting to build such an ambiguous project.  Unfortunately, we had to suffer with this project for about 4 months when it should have only taken 1.5 to complete due to the constantly changing and unclear requirements. References  Clements, P., Kazman, R., & Klein, M. (2002). Evaluating Software Architectures. Westford, Massachusetts: Courier Westford. 

    Read the article

  • Is there a better term than "smoothness" or "granularity" to describe this language feature?

    - by Chris Stevens
    One of the best things about programming is the abundance of different languages. There are general purpose languages like C++ and Java, as well as little languages like XSLT and AWK. When comparing languages, people often use things like speed, power, expressiveness, and portability as the important distinguishing features. There is one characteristic of languages I consider to be important that, so far, I haven't heard [or been able to come up with] a good term for: how well a language scales from writing tiny programs to writing huge programs. Some languages make it easy and painless to write programs that only require a few lines of code, e.g. task automation. But those languages often don't have enough power to solve large problems, e.g. GUI programming. Conversely, languages that are powerful enough for big problems often require far too much overhead for small problems. This characteristic is important because problems that look small at first frequently grow in scope in unexpected ways. If a programmer chooses a language appropriate only for small tasks, scope changes can require rewriting code from scratch in a new language. And if the programmer chooses a language with lots of overhead and friction to solve a problem that stays small, it will be harder for other people to use and understand than necessary. Rewriting code that works fine is the single most wasteful thing a programmer can do with their time, but using a bazooka to kill a mosquito instead of a flyswatter isn't good either. Here are some of the ways this characteristic presents itself. Can be used interactively - there is some environment where programmers can enter commands one by one Requires no more than one file - neither project files nor makefiles are required for running in batch mode Can easily split code across multiple files - files can refeence each other, or there is some support for modules Has good support for data structures - supports structures like arrays, lists, and especially classes Supports a wide variety of features - features like networking, serialization, XML, and database connectivity are supported by standard libraries Here's my take on how C#, Python, and shell scripting measure up. Python scores highest. Feature C# Python shell scripting --------------- --------- --------- --------------- Interactive poor strong strong One file poor strong strong Multiple files strong strong moderate Data structures strong strong poor Features strong strong strong Is there a term that captures this idea? If not, what term should I use? Here are some candidates. Scalability - already used to decribe language performance, so it's not a good idea to overload it in the context of language syntax Granularity - expresses the idea of being good just for big tasks versus being good for big and small tasks, but doesn't express anything about data structures Smoothness - expresses the idea of low friction, but doesn't express anything about strength of data structures or features Note: Some of these properties are more correctly described as belonging to a compiler or IDE than the language itself. Please consider these tools collectively as the language environment. My question is about how easy or difficult languages are to use, which depends on the environment as well as the language.

    Read the article

  • Starting to create a MathBuilder framework, help to start creating the design

    - by Darf Zon
    Let explain what I'm trying to create. I'm creating a framework, the idea is to provide base classes to generate a math problem. Why do I need this framework? Because at first time, I realized when I create a new math problem I always do the same steps. Configuration settings such range numbers. For example if I'm developing multiplications, in beginner level only generate the first number between 2-5 or in advanced level, the first number will be between 6- 9, for example. Generate problem method. All the time I need to invoke a method like this to generate the problem. This one receives the configuration settings and generate the number according to them. And generate the object with the respective data. Validate the problem. Sometimes the problem generated is not valid. For example, supposed I'm creating fractions in most simplified, if I receive 2/4, the program should detect that this is not valid and must generate another like this one, 1/4. Load the view. All of them, have a custom view (please watch below the images). All of the problems must know how to CHECK if the user result is correct. All of this problems has answers. Some of them just require one answer, anothers may require more than one, so I guess a way to maintain flexibility to the developer has all the answers he wanna used. At the beginning I started using PRISM. Generate modules for each math problem was the idea and load it in the main system. I guess are the most important things of this idea. Let me showing some problems which I create in a WPF standalone program. Here I have a math problem about areas. When I generate the problem a set to the view the object and it draw it. In beginner level, I set in the configuration settings that just load square types. But in advance level, can load triangles and squares randomly. In this another, generate a binary problem like addition, subtraction, multiplication or division. Above just generate a single problem. The idea of this is to show a test o quiz, I mean get a worksheet (this I call as a collection of problems) where the user can answer it. I hope gets the idea with my ugly drawing. How to load this math problems? As I said above, I started using PRISM, and each module contains a math problem kind. This is a snapshot of my first demo. Below show the modules loaded, and center the respective configurations or levels. Until momment, I have no idea to start creating this software. I just know that I need a question | problem class, response class, user class. But I get lost about what properties should have to contain in it. Please give a little hand of this framework. I put much effort on this question, so if any isn't clear, let me know to clarify it.

    Read the article

  • Understanding the JSF Lifecycle and ADF Optimized Lifecycle

    - by Steven Davelaar
    While coaching ADF development teams over the years, I have noticed that many developers lack a basic understanding of Java Server Faces, in particular the JSF lifecycle and how ADF optimizes this lifecycle in specific situations. As a result, ADF developers who are tasked to build a seemingly simple ADF page, can get extremely frustrated by the -in their eyes- unexpected or unlogical behavior of ADF.  They start to play with the immediate property and the partialTriggers property in a trial-and-error manner. Often, they play with these properties until their specific issue is solved, unaware of other more severe bugs that might be introduced by the values they choose for these properties. So, I decided to submit a presentation for the UKOUG entitled "What you need to know about JSF to be succesful with ADF".  The abstract was accepted, and I started putting together the presentation and demo application. I built up a demo application step-by-step, trying to cover the JSF-related  top issues and challenges I encountered over the years in a simple "Hello World" demo. This turned out to be both a very time-consuming and very interesting journey. I had never thought I would learn so much myself in preparing this presentation. I never thought I would end up with potentially controversial conclusions like "Never set immediate=true on an editable component".  I did not realize the sometimes immense implications of the ADF optimized lifecycle beforehand. I never thought that "Hello World" demo's could get so complex. But as I went on I was confident this was valuable material, even for experienced ADF developers with a good understanding of JSF. When I finished, I realized the original title and abstract was misleading, as was the target audience. Yes, it was covering the JSF lifecycle, but no other aspects of JSF you need to know for ADF development. Yes, it was covering some JSF basics as mentioned in the abstract, but all in all it had become a pretty advanced presentation. At the same time, the issues discussed are very common, novice ADF developers might easily run into them while building their first pages. I ran out of time, so I decided to just present what I had, apologizing at the beginning for the misleading title, showing a second slide with a better title "18 invaluable lessons about ADF-JSF interaction". I think the presentation was well received overall, although people who don't like it or don't understand it, usually don't come and tell you afterwards.... I am still struggling with the title, for this blog post I used yet another title, anyway, you can download the presentation-that-still-lacks-a-good-title here. The finished JDev 11.1.1.6 demo app can be downloaded here.  The 18 lessons mentioned in the presentation are summarized here. As mentioned on the last slide, print out the lessons, and learn them by heart, I am pretty sure it will save you lots of time and frustration!

    Read the article

  • Focus on Social Relationship Management at Oracle OpenWorld

    - by Pat Ma
    v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} 0 0 1 422 2408 involver 20 5 2825 14.0 Normal 0 false false false false EN-US JA X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:Cambria; mso-ascii-font-family:Cambria; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Cambria; mso-hansi-theme-font:minor-latin;} Greetings from Oracle OpenWorld 2012. Today, we’re going to focus on Social Relationship Management at Oracle OpenWorld.?Social networking is touching all businesses today.  Customers are speaking about your brand right now on social media sites. Your employees are speaking to one another on social media sites. In an Oracle survey, 40% of consumers factor in Facebook recommendations when making purchasing decisions. Despite the rise of social networking, 70% of marketers report having little understanding of social media conversations happening around their brand. Oracle has invested in technologies that will help companies leverage social media technologies for their enterprise. Our suite of social products is collectively known as Social Relationship Management. Customers are using Social Relationship Management to get analytics to social media conversations around their brand, manage multiple social media channels while keeping their brand consistent, optimize internal workflows and processes, and create better customer relationships and experiences. In this example, using Social Relationship Management, a high-end national grocery chain is able to see that “Coconut Water” is trending in San Francisco. They are now able to send a $2-off coconut water coupon to shoppers who have checked into their San Francisco locations. This promotion further drives sales of coconut water in San Francisco. In another example, using Social Relationship Management, a technology company creates multiple Facebook pages and runs campaigns on them. These social campaigns are now integrated and tracked as another marketing channel in Oracle Fusion CRM. The technology company can now track and respond to a particular customer as he moves across multiple channels – without having to restart the conversation each time the customer contacts the company. Furthermore, the technology company can see in one interface what marketing channels – including social – is performing best for each promotion. Besides being a Software-as-a-Service solution, social is also a Platform-as-a-Service solution. The benefit here is that customers can extend the functionality of our social applications to suit their particular needs or create their own social application from scratch. During the Social Developer track, developers are learning how to use Java and other industry-standard programming languages to plug in social functionality to enterprise applications. To see how Social Relationship Management can help your business build better relationships and experience with customers, visit us on the web at oracle.com/social. There are a lot more social-oriented sessions left at OpenWorld. To view a schedule of the upcoming social-oriented sessions, go here.

    Read the article

  • Brendan Gregg's "Systems Performance: Enterprise and the Cloud"

    - by user12608550
    Long ago, the prerequisite UNIX performance book was Adrian Cockcroft's 1994 classic, Sun Performance and Tuning: Sparc & Solaris, later updated in 1998 as Java and the Internet. As Solaris evolved to include the invaluable DTrace observability features, new essential performance references have been published, such as Solaris Performance and Tools: DTrace and MDB Techniques for Solaris 10 and OpenSolaris (2006)  by McDougal, Mauro, and Gregg, and DTrace: Dynamic Tracing in Oracle Solaris, Mac OS X and FreeBSD (2011), also by Mauro and Gregg. Much has occurred in Solaris Land since those books appeared, notably Oracle's acquisition of Sun Microsystems in 2010 and the demise of the OpenSolaris community. But operating system technologies have continued to improve markedly in recent years, driven by stunning advances in multicore processor architecture, virtualization, and the massive scalability requirements of cloud computing. A new performance reference was needed, and I eagerly waited for something that thoroughly covered modern, distributed computing performance issues from the ground up. Well, there's a new classic now, authored yet again by Brendan Gregg, former Solaris kernel engineer at Sun and now Lead Performance Engineer at Joyent. Systems Performance: Enterprise and the Cloud is a modern, very comprehensive guide to general system performance principles and practices, as well as a highly detailed reference for specific UNIX and Linux observability tools used to examine and diagnose operating system behaviour.  It provides thorough definitions of terms, explains performance diagnostic Best Practices and "Worst Practices" (called "anti-methods"), and covers key observability tools including DTrace, SystemTap, and all the traditional UNIX utilities like vmstat, ps, iostat, and many others. The book focuses on operating system performance principles and expands on these with respect to Linux (Ubuntu, Fedora, and CentOS are cited), and to Solaris and its derivatives [1]; it is not directed at any one OS so it is extremely useful as a broad performance reference. The author goes beyond the intricacies of performance analysis and shows how to interpret and visualize statistical information gathered from the observability tools.  It's often difficult to extract understanding from voluminous rows of text output, and techniques are provided to assist with summarizing, visualizing, and interpreting the performance data. Gregg includes myriad useful references from the system performance literature, including a "Who's Who" of contributors to this great body of diagnostic tools and methods. This outstanding book should be required reading for UNIX and Linux system administrators as well as anyone charged with diagnosing OS performance issues.  Moreover, the book can easily serve as a textbook for a graduate level course in operating systems [2]. [1] Solaris 11, of course, and Joyent's SmartOS (developed from OpenSolaris) [2] Gregg has taught system performance seminars for many years; I have also taught such courses...this book would be perfect for the OS component of an advanced CS curriculum.

    Read the article

  • News you can use, PeopleTools gems at OpenWorld 2012

    - by PeopleTools Strategy
    Here are some of the sessions which may not have caught your eyes during your scheduling of events you would like to attend at this year's Open World! CON9183 PeopleSoft Technology Roadmap Jeff Robbins Mon, Oct 1 4:45 PM Moscone West, Room 3002/4 Jeff's session is always very well attended. Come to hear, and see, what's going to be delivered in the new release and get some thoughts on where PeopleTools and the industry is heading. CON9186 Delivering a Ground-Breaking User Interface with PeopleTools Matt Haavisto Steve Elcock Wed, Oct 3 3:30 PM Moscone West, Room 3009 This session will be wonderfully engaging for participants.  As part of our demonstration, audience members will be able to interact live and real-time with our demo using their smart phones and tablets as if you are users of the system. CON9188 A Great User Experience via PeopleSoft Applications Portal Matt Haavisto Jim Marion Pramod Agrawal Mon, Oct 1 12:15 PM Moscone West, Room 3009 This session covers not only the PeopleSoft Portal, but new features like Workcenters and Dashboards, and how they all work together to form the PeopleSoft ecosystem. CON9192 Implementing a PeopleSoft Maintenance Strategy with My Update Manager Mike Thompson Mike Krajicek Tue, Oct 2 1:15 PM Moscone West, Room 3009 The LCM development team will show Oracle's My Update Manager for PeopleSoft and how it drastically simplifies deciding what updates are required for your specific environment. CON9193 Understanding PeopleSoft Maintenance Tools & How They Fit Together Mike Krajicek Wed, Oct 3 10:15 AM Moscone West, Room 3002/4 Learn about the portfolio of maintenance tools including some of the latest enhancements such as Oracle's My Update Manager for PeopleSoft, Application Data Sets, and the PeopleSoft Test Framework, and see what they can do for you. CON9200 PeopleTools Product Team Panel Discussion Jeff Robbins Willie Suh Virad Gupta Ravi Shankar Mike Krajicek Wed, Oct 3 5:00 PM Moscone West, Room 3009 Attend this session to engage in an open discussion with key members of Oracle's PeopleTools senior management team. You will be able to ask questions, hear their thoughts, and gain their insight into the PeopleTools product direction. CON9205 Securing Your PeopleSoft Integration Infrastructure Greg Kelly Keith Collins Tue, Oct 2 10:15 AM Moscone West, Room 3011 This session, with the senior integration developer, will outline Oracle's best practices for securing your integration infrastructure so that you know your web services and REST services are as secure as the rest of your PeopleSoft environment. CON9210 Performance Tuning for the PeopleSoft Administrator Tim Bower David Kurtz Mon, Oct 1 10:45 AM Moscone West, Room 3009 Meet long time technical consultants with deep knowledge of system tuning, Tim Bower of the Center of Excellence and David Kurtz, author of "PeopleSoft for the Oracle DBA". System administrators new to tuning a PeopleSoft environment as well as seasoned experts will come away with new techniques that will help them improve the performance of their PeopleSoft system. CON9055 Advanced Management of Oracle PeopleSoft with Oracle Enterprise Manager Greg Kelly Milten Garia Greg Bouras Thurs Oct 4 12:45 PM Moscone West, Room 3009 This promises to be a really interesting session as Milten Garia from CSU discusses lessons learned during the implementation of Oracle's Enterprise Manager with the PeopleSoft plug-in across a multi campus environment. There are some surprising things about Solaris 10 and the Bourne shell. Some creative work by the Unix administrators so the well tried scripts and system replication processes were largely unaffected. CON8932 New Functional PeopleTools Capabilities for the Line of Business User Jeff Robbins Tues, Oct 2 5:00 PM Moscone West, Room 3007 Using PeopleTools 8.5x capabilities like: related content, embedded help, pivot grids, hover-over, and more, Jeff will discuss how these can deliver business value and innovation which will positively impact your business without the high costs associated with upgrading your PeopleSoft applications. Check out a more detailed list here. We look forward to meeting you all there!

    Read the article

  • PHP and Ruby: how to leverage both? and, is it worth it?

    - by dukeofgaming
    As you might have noticed from the title, this is not a "PHP or Ruby", or a "PHP vs. Ruby" question. This is a question on how to leverage PHP + Ruby in the same business. I myself am a PHP developer, I love the language because of its convenience and I specially love the ecosystem of resources that surround it: Joomla, Drupal, Wordpress, Symfony2, Doctrine2, etc. However, the language itself can be a little disappointing sometimes. OTOH, Ruby looks like a very beautiful language and —from studying it superficially in several aspects— I could say it is leaner than Python as a language per se. However, from what I've seen there is pretty much only RoR making noise, and I don't like RoR so much (mainly because its model layer). As Co-CEO and CTO at my company I'm trying to think outside of the box since I want to start to focus on the human side of technology and see if its sane to use both PHP and Ruby. Here are some random thoughts: Ruby folk seem to be generally better suited programmers than PHP folk (in terms of averages), I know the previous statement is somewhat baloney because very good and well architected PHP can be written, but I'd say the Ruby programmer culture is better than PHP's. The thing about Ruby is that it seems better suited for rapid development, I don't really know if this is only the case for RoR, but I do know that there are certain practices (perhaps not so good) like monkey patching that let business needs be satified quicker. From a marketing point of view (yep, sometimes you need to leverage the marketing BS for the sake of your company) Ruby seems better while PHP carries some stigmas. PHP 5.4 is bringing traits, and that is better/cleaner than mixins. That could really make PHP as lean as Ruby —or more— for certain stuff. Now, concretely, my questions: Would a PHP programmer want to learn Ruby?, I know I do, but conversely, would a Ruby programmer want to learn PHP?. What kinds of projects or situations would be better suited for Ruby that are not suited for PHP?. What is the actual ecosystem of Ruby?, aside from RoR, I have not seen other hyped technologies/frameworks (I've seen RSpec, but I confess being a total noob on what BDD really consists of and its implications). Supposing there are a certain type of projects ideal for Ruby, would there be a moment that its better to move it to PHP?. I know PHP can handle lots of stuff, but I've read that Ruby has its limitations when scaling (or is that RoR?, or is that baloney for both?). Finally and most importantly, would it be sane to maintain projects in two languages?, or is that just stupid. As I said, it looks like Ruby is leaner on the short term and that can make a project happen and succeed, but I'm not so sure about that on the long run. I'm looking for insights mainly from people that know well the strengths and weaknesses of the languages —preferably both of them— and Ruby's ecosystem in real practice, meaning: frameworks and applications like the ones I quoted from PHP's ecosystem. Best regards and thanks for your time.

    Read the article

  • Tablet design guide, Endeca patterns now available

    - by JuergenKress
    UX Direct, an Oracle program that offers consultants, partners, and customers the same scientifically proven and reusable user experience best practices that Oracle uses to build Oracle Applications, recently added links to a new design guide for creating tablet-based solutions for enterprise applications, and to the recently published Endeca User Interface Design Pattern Library. The tablet design guide is available from the UX Direct Home page. Tap the button under “Latest patterns & tools” for “Oracle Applications UX Tablet Guide.” It provides basic help for designers, developers, and project managers trying to approach tablet design and testing from an enterprise point of view. To hear what developers are saying about it, follow the links from this post on the User Experience Assistance blog. The newly released Endeca User Interface Design Pattern Library is also available from the UX Direct Home page and from a post on the User Experience Assistance blog. It describes principled ways to solve common user interface (UI) design problems related to search, faceted navigation, and discovery. The link between Simplified UI and Oracle UX strategy, plus content you can share on the cloud, ADf, tailoring, and more Simplified User Interface in Oracle Fusion Applications Fronts Oracle Cloud Offerings This new article on Simplified UI has just been posted on Usable Apps. Learn about the three themes - simplicity, mobility, and extensibility – that Simplified UI embodies. These same principles are guiding the development of the next generation of the Oracle user experience. Oracle's Applications User Experience Strategy: One Cloud User Experience, with Optimized UIs Where and How You Want This podcast from Misha Vaughan, Director, User Experience, is now available on the Oracle University Knowledge Center. It is available for partners and Oracle employees at this iLearning Link. Oracle Partner Builds User Experience That Hits Right Note for New Employees This new article on the Usable Apps website explores the experience of consultants at IntraSee as they implement a PeopleSoft onboarding process for Invesco, a global asset management company. The Feng Shui of Fusion This article in Oracle Scene is from Grant Ronald, Director of Product Management, on the Tools of Fusion: Oracle JDeveloper and Oracle ADF. Hands-On Workshop with Fusion Applications and ADF UX Desktop Design Patterns This post on the Voice of User Experience, or VoX, blog from Misha Vaughan describes a new kind of workshop for partners and a handful of internal Oracle sales folks on extending Oracle Fusion Applications and building custom applications with Application Development Framework (ADF) while maintaining the Oracle user experience. To learn more about the content that was delivered during this three-day workshop, visit the Usable Apps blog. Recent posts from a new blog series take a look at several of the topics discussed during the workshop. Applications User Experience Fundamentals Visual Design for any Enterprise User Interface / Art School in a Box Wireframing / Blueprinting Usable Applications Concepts. Tailoring videos This blog post from Richard Bingham, Applications Architect, on the Fusion Applications Developer Relations blog provides links to several videos that show many customization and development tasks using the Oracle Fusion Applications platform. SOA & BPM Partner Community For regular information on Oracle SOA Suite become a member in the SOA & BPM Partner Community for registration please visit www.oracle.com/goto/emea/soa (OPN account required) If you need support with your account please contact the Oracle Partner Business Center. Blog Twitter LinkedIn Facebook Wiki Mix Forum Technorati Tags: UX,Architecture,SOA Community,Oracle SOA,Oracle BPM,Community,OPN,Jürgen Kress

    Read the article

  • PTLQueue : a scalable bounded-capacity MPMC queue

    - by Dave
    Title: Fast concurrent MPMC queue -- I've used the following concurrent queue algorithm enough that it warrants a blog entry. I'll sketch out the design of a fast and scalable multiple-producer multiple-consumer (MPSC) concurrent queue called PTLQueue. The queue has bounded capacity and is implemented via a circular array. Bounded capacity can be a useful property if there's a mismatch between producer rates and consumer rates where an unbounded queue might otherwise result in excessive memory consumption by virtue of the container nodes that -- in some queue implementations -- are used to hold values. A bounded-capacity queue can provide flow control between components. Beware, however, that bounded collections can also result in resource deadlock if abused. The put() and take() operators are partial and wait for the collection to become non-full or non-empty, respectively. Put() and take() do not allocate memory, and are not vulnerable to the ABA pathologies. The PTLQueue algorithm can be implemented equally well in C/C++ and Java. Partial operators are often more convenient than total methods. In many use cases if the preconditions aren't met, there's nothing else useful the thread can do, so it may as well wait via a partial method. An exception is in the case of work-stealing queues where a thief might scan a set of queues from which it could potentially steal. Total methods return ASAP with a success-failure indication. (It's tempting to describe a queue or API as blocking or non-blocking instead of partial or total, but non-blocking is already an overloaded concurrency term. Perhaps waiting/non-waiting or patient/impatient might be better terms). It's also trivial to construct partial operators by busy-waiting via total operators, but such constructs may be less efficient than an operator explicitly and intentionally designed to wait. A PTLQueue instance contains an array of slots, where each slot has volatile Turn and MailBox fields. The array has power-of-two length allowing mod/div operations to be replaced by masking. We assume sensible padding and alignment to reduce the impact of false sharing. (On x86 I recommend 128-byte alignment and padding because of the adjacent-sector prefetch facility). Each queue also has PutCursor and TakeCursor cursor variables, each of which should be sequestered as the sole occupant of a cache line or sector. You can opt to use 64-bit integers if concerned about wrap-around aliasing in the cursor variables. Put(null) is considered illegal, but the caller or implementation can easily check for and convert null to a distinguished non-null proxy value if null happens to be a value you'd like to pass. Take() will accordingly convert the proxy value back to null. An advantage of PTLQueue is that you can use atomic fetch-and-increment for the partial methods. We initialize each slot at index I with (Turn=I, MailBox=null). Both cursors are initially 0. All shared variables are considered "volatile" and atomics such as CAS and AtomicFetchAndIncrement are presumed to have bidirectional fence semantics. Finally T is the templated type. I've sketched out a total tryTake() method below that allows the caller to poll the queue. tryPut() has an analogous construction. Zebra stripping : alternating row colors for nice-looking code listings. See also google code "prettify" : https://code.google.com/p/google-code-prettify/ Prettify is a javascript module that yields the HTML/CSS/JS equivalent of pretty-print. -- pre:nth-child(odd) { background-color:#ff0000; } pre:nth-child(even) { background-color:#0000ff; } border-left: 11px solid #ccc; margin: 1.7em 0 1.7em 0.3em; background-color:#BFB; font-size:12px; line-height:65%; " // PTLQueue : Put(v) : // producer : partial method - waits as necessary assert v != null assert Mask = 1 && (Mask & (Mask+1)) == 0 // Document invariants // doorway step // Obtain a sequence number -- ticket // As a practical concern the ticket value is temporally unique // The ticket also identifies and selects a slot auto tkt = AtomicFetchIncrement (&PutCursor, 1) slot * s = &Slots[tkt & Mask] // waiting phase : // wait for slot's generation to match the tkt value assigned to this put() invocation. // The "generation" is implicitly encoded as the upper bits in the cursor // above those used to specify the index : tkt div (Mask+1) // The generation serves as an epoch number to identify a cohort of threads // accessing disjoint slots while s-Turn != tkt : Pause assert s-MailBox == null s-MailBox = v // deposit and pass message Take() : // consumer : partial method - waits as necessary auto tkt = AtomicFetchIncrement (&TakeCursor,1) slot * s = &Slots[tkt & Mask] // 2-stage waiting : // First wait for turn for our generation // Acquire exclusive "take" access to slot's MailBox field // Then wait for the slot to become occupied while s-Turn != tkt : Pause // Concurrency in this section of code is now reduced to just 1 producer thread // vs 1 consumer thread. // For a given queue and slot, there will be most one Take() operation running // in this section. // Consumer waits for producer to arrive and make slot non-empty // Extract message; clear mailbox; advance Turn indicator // We have an obvious happens-before relation : // Put(m) happens-before corresponding Take() that returns that same "m" for T v = s-MailBox if v != null : s-MailBox = null ST-ST barrier s-Turn = tkt + Mask + 1 // unlock slot to admit next producer and consumer return v Pause tryTake() : // total method - returns ASAP with failure indication for auto tkt = TakeCursor slot * s = &Slots[tkt & Mask] if s-Turn != tkt : return null T v = s-MailBox // presumptive return value if v == null : return null // ratify tkt and v values and commit by advancing cursor if CAS (&TakeCursor, tkt, tkt+1) != tkt : continue s-MailBox = null ST-ST barrier s-Turn = tkt + Mask + 1 return v The basic idea derives from the Partitioned Ticket Lock "PTL" (US20120240126-A1) and the MultiLane Concurrent Bag (US8689237). The latter is essentially a circular ring-buffer where the elements themselves are queues or concurrent collections. You can think of the PTLQueue as a partitioned ticket lock "PTL" augmented to pass values from lock to unlock via the slots. Alternatively, you could conceptualize of PTLQueue as a degenerate MultiLane bag where each slot or "lane" consists of a simple single-word MailBox instead of a general queue. Each lane in PTLQueue also has a private Turn field which acts like the Turn (Grant) variables found in PTL. Turn enforces strict FIFO ordering and restricts concurrency on the slot mailbox field to at most one simultaneous put() and take() operation. PTL uses a single "ticket" variable and per-slot Turn (grant) fields while MultiLane has distinct PutCursor and TakeCursor cursors and abstract per-slot sub-queues. Both PTL and MultiLane advance their cursor and ticket variables with atomic fetch-and-increment. PTLQueue borrows from both PTL and MultiLane and has distinct put and take cursors and per-slot Turn fields. Instead of a per-slot queues, PTLQueue uses a simple single-word MailBox field. PutCursor and TakeCursor act like a pair of ticket locks, conferring "put" and "take" access to a given slot. PutCursor, for instance, assigns an incoming put() request to a slot and serves as a PTL "Ticket" to acquire "put" permission to that slot's MailBox field. To better explain the operation of PTLQueue we deconstruct the operation of put() and take() as follows. Put() first increments PutCursor obtaining a new unique ticket. That ticket value also identifies a slot. Put() next waits for that slot's Turn field to match that ticket value. This is tantamount to using a PTL to acquire "put" permission on the slot's MailBox field. Finally, having obtained exclusive "put" permission on the slot, put() stores the message value into the slot's MailBox. Take() similarly advances TakeCursor, identifying a slot, and then acquires and secures "take" permission on a slot by waiting for Turn. Take() then waits for the slot's MailBox to become non-empty, extracts the message, and clears MailBox. Finally, take() advances the slot's Turn field, which releases both "put" and "take" access to the slot's MailBox. Note the asymmetry : put() acquires "put" access to the slot, but take() releases that lock. At any given time, for a given slot in a PTLQueue, at most one thread has "put" access and at most one thread has "take" access. This restricts concurrency from general MPMC to 1-vs-1. We have 2 ticket locks -- one for put() and one for take() -- each with its own "ticket" variable in the form of the corresponding cursor, but they share a single "Grant" egress variable in the form of the slot's Turn variable. Advancing the PutCursor, for instance, serves two purposes. First, we obtain a unique ticket which identifies a slot. Second, incrementing the cursor is the doorway protocol step to acquire the per-slot mutual exclusion "put" lock. The cursors and operations to increment those cursors serve double-duty : slot-selection and ticket assignment for locking the slot's MailBox field. At any given time a slot MailBox field can be in one of the following states: empty with no pending operations -- neutral state; empty with one or more waiting take() operations pending -- deficit; occupied with no pending operations; occupied with one or more waiting put() operations -- surplus; empty with a pending put() or pending put() and take() operations -- transitional; or occupied with a pending take() or pending put() and take() operations -- transitional. The partial put() and take() operators can be implemented with an atomic fetch-and-increment operation, which may confer a performance advantage over a CAS-based loop. In addition we have independent PutCursor and TakeCursor cursors. Critically, a put() operation modifies PutCursor but does not access the TakeCursor and a take() operation modifies the TakeCursor cursor but does not access the PutCursor. This acts to reduce coherence traffic relative to some other queue designs. It's worth noting that slow threads or obstruction in one slot (or "lane") does not impede or obstruct operations in other slots -- this gives us some degree of obstruction isolation. PTLQueue is not lock-free, however. The implementation above is expressed with polite busy-waiting (Pause) but it's trivial to implement per-slot parking and unparking to deschedule waiting threads. It's also easy to convert the queue to a more general deque by replacing the PutCursor and TakeCursor cursors with Left/Front and Right/Back cursors that can move either direction. Specifically, to push and pop from the "left" side of the deque we would decrement and increment the Left cursor, respectively, and to push and pop from the "right" side of the deque we would increment and decrement the Right cursor, respectively. We used a variation of PTLQueue for message passing in our recent OPODIS 2013 paper. ul { list-style:none; padding-left:0; padding:0; margin:0; margin-left:0; } ul#myTagID { padding: 0px; margin: 0px; list-style:none; margin-left:0;} -- -- There's quite a bit of related literature in this area. I'll call out a few relevant references: Wilson's NYU Courant Institute UltraComputer dissertation from 1988 is classic and the canonical starting point : Operating System Data Structures for Shared-Memory MIMD Machines with Fetch-and-Add. Regarding provenance and priority, I think PTLQueue or queues effectively equivalent to PTLQueue have been independently rediscovered a number of times. See CB-Queue and BNPBV, below, for instance. But Wilson's dissertation anticipates the basic idea and seems to predate all the others. Gottlieb et al : Basic Techniques for the Efficient Coordination of Very Large Numbers of Cooperating Sequential Processors Orozco et al : CB-Queue in Toward high-throughput algorithms on many-core architectures which appeared in TACO 2012. Meneghin et al : BNPVB family in Performance evaluation of inter-thread communication mechanisms on multicore/multithreaded architecture Dmitry Vyukov : bounded MPMC queue (highly recommended) Alex Otenko : US8607249 (highly related). John Mellor-Crummey : Concurrent queues: Practical fetch-and-phi algorithms. Technical Report 229, Department of Computer Science, University of Rochester Thomasson : FIFO Distributed Bakery Algorithm (very similar to PTLQueue). Scott and Scherer : Dual Data Structures I'll propose an optimization left as an exercise for the reader. Say we wanted to reduce memory usage by eliminating inter-slot padding. Such padding is usually "dark" memory and otherwise unused and wasted. But eliminating the padding leaves us at risk of increased false sharing. Furthermore lets say it was usually the case that the PutCursor and TakeCursor were numerically close to each other. (That's true in some use cases). We might still reduce false sharing by incrementing the cursors by some value other than 1 that is not trivially small and is coprime with the number of slots. Alternatively, we might increment the cursor by one and mask as usual, resulting in a logical index. We then use that logical index value to index into a permutation table, yielding an effective index for use in the slot array. The permutation table would be constructed so that nearby logical indices would map to more distant effective indices. (Open question: what should that permutation look like? Possibly some perversion of a Gray code or De Bruijn sequence might be suitable). As an aside, say we need to busy-wait for some condition as follows : "while C == 0 : Pause". Lets say that C is usually non-zero, so we typically don't wait. But when C happens to be 0 we'll have to spin for some period, possibly brief. We can arrange for the code to be more machine-friendly with respect to the branch predictors by transforming the loop into : "if C == 0 : for { Pause; if C != 0 : break; }". Critically, we want to restructure the loop so there's one branch that controls entry and another that controls loop exit. A concern is that your compiler or JIT might be clever enough to transform this back to "while C == 0 : Pause". You can sometimes avoid this by inserting a call to a some type of very cheap "opaque" method that the compiler can't elide or reorder. On Solaris, for instance, you could use :"if C == 0 : { gethrtime(); for { Pause; if C != 0 : break; }}". It's worth noting the obvious duality between locks and queues. If you have strict FIFO lock implementation with local spinning and succession by direct handoff such as MCS or CLH,then you can usually transform that lock into a queue. Hidden commentary and annotations - invisible : * And of course there's a well-known duality between queues and locks, but I'll leave that topic for another blog post. * Compare and contrast : PTLQ vs PTL and MultiLane * Equivalent : Turn; seq; sequence; pos; position; ticket * Put = Lock; Deposit Take = identify and reserve slot; wait; extract & clear; unlock * conceptualize : Distinct PutLock and TakeLock implemented as ticket lock or PTL Distinct arrival cursors but share per-slot "Turn" variable provides exclusive role-based access to slot's mailbox field put() acquires exclusive access to a slot for purposes of "deposit" assigns slot round-robin and then acquires deposit access rights/perms to that slot take() acquires exclusive access to slot for purposes of "withdrawal" assigns slot round-robin and then acquires withdrawal access rights/perms to that slot At any given time, only one thread can have withdrawal access to a slot at any given time, only one thread can have deposit access to a slot Permissible for T1 to have deposit access and T2 to simultaneously have withdrawal access * round-robin for the purposes of; role-based; access mode; access role mailslot; mailbox; allocate/assign/identify slot rights; permission; license; access permission; * PTL/Ticket hybrid Asymmetric usage ; owner oblivious lock-unlock pairing K-exclusion add Grant cursor pass message m from lock to unlock via Slots[] array Cursor performs 2 functions : + PTL ticket + Assigns request to slot in round-robin fashion Deconstruct protocol : explication put() : allocate slot in round-robin fashion acquire PTL for "put" access store message into slot associated with PTL index take() : Acquire PTL for "take" access // doorway step seq = fetchAdd (&Grant, 1) s = &Slots[seq & Mask] // waiting phase while s-Turn != seq : pause Extract : wait for s-mailbox to be full v = s-mailbox s-mailbox = null Release PTL for both "put" and "take" access s-Turn = seq + Mask + 1 * Slot round-robin assignment and lock "doorway" protocol leverage the same cursor and FetchAdd operation on that cursor FetchAdd (&Cursor,1) + round-robin slot assignment and dispersal + PTL/ticket lock "doorway" step waiting phase is via "Turn" field in slot * PTLQueue uses 2 cursors -- put and take. Acquire "put" access to slot via PTL-like lock Acquire "take" access to slot via PTL-like lock 2 locks : put and take -- at most one thread can access slot's mailbox Both locks use same "turn" field Like multilane : 2 cursors : put and take slot is simple 1-capacity mailbox instead of queue Borrow per-slot turn/grant from PTL Provides strict FIFO Lock slot : put-vs-put take-vs-take at most one put accesses slot at any one time at most one put accesses take at any one time reduction to 1-vs-1 instead of N-vs-M concurrency Per slot locks for put/take Release put/take by advancing turn * is instrumental in ... * P-V Semaphore vs lock vs K-exclusion * See also : FastQueues-excerpt.java dice-etc/queue-mpmc-bounded-blocking-circular-xadd/ * PTLQueue is the same as PTLQB - identical * Expedient return; ASAP; prompt; immediately * Lamport's Bakery algorithm : doorway step then waiting phase Threads arriving at doorway obtain a unique ticket number Threads enter in ticket order * In the terminology of Reed and Kanodia a ticket lock corresponds to the busy-wait implementation of a semaphore using an eventcount and a sequencer It can also be thought of as an optimization of Lamport's bakery lock was designed for fault-tolerance rather than performance Instead of spinning on the release counter, processors using a bakery lock repeatedly examine the tickets of their peers --

    Read the article

< Previous Page | 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564  | Next Page >