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  • Silverlight Cream for April 07, 2010 -- #833

    - by Dave Campbell
    In this Issue: Alan Mendelevich, Siyamand Ayubi, Rudi Grobler(-2-), Josh Smith, VinitYadav, and Dave Campbell. Shoutouts: Jordan Knight has a demo up of a project he did for DigiGirlz: DigiGirlz, Deep Zoom and Azure, hopefully we'll get source later :) Jeremy Likness has a must-read post on his Ten Reasons to use the Managed Extensibility Framework I put this on another post earlier, but if you want some desktop bling for WP7, Ozymandias has some: I Love Windows Phone Wallpaper If you're not going to be in 'Vegas next week, Tim Heuer reminds us there's an alternative: Watch the Silverlight 4 Launch event and LIVE QA with ScottGu and others From SilverlightCream.com: Ghost Lines in Silverlight Alan Mendelevich reports an issue when drawing lines with odd coordinate values. He originated it in Silverlight 3, but it is there in SL4RC as well... check it out and leave him a comment. A Framework to Animate WPF and Silverlight Pages Similar to the PowerPoint Slides Siyamand Ayubi has an interesting post up on animating WPF or Silverlight pages to make them progress in the manner of a PPT slideshow. And it can also make phone calls… Rudi Grobler has a list of 'tasks' you can do with WP7 such as PhoneCallTask or EmailComposeTask ... looks like this should be plasticized :) Using the GPS, Accelerometer & Vibration Controller Rudi Grobler is also investigating how to use the GPS, Accelerometer, and Vibration in WP7 with a bunch of external links to back it up. Assembly-level initialization at design time Josh Smith has a solution to the problem of initializing design-time data in Blend (did you know that was an issue?) ... the solution is great and so is the running commentary between Josh and Karl Shifflett in the comments! ySurf : A Yahoo Messenger Clone built in Silverlight VinitYadav built a Yahoo Messenger app in Silverlight and has detailed out all the ugly bits for us on the post, plus made everything available. Your First Silverlight Application Dave Campbell's first post at DZone cracking open a beginner's series on Silverlight. If you're expecting something heavy-duty, skip this. If you're wanting to learn Silverlight and haven't jumped in yet, give it a try. 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

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  • C#: Adding Functionality to 3rd Party Libraries With Extension Methods

    - by James Michael Hare
    Ever have one of those third party libraries that you love but it's missing that one feature or one piece of syntactical candy that would make it so much more useful?  This, I truly think, is one of the best uses of extension methods.  I began discussing extension methods in my last post (which you find here) where I expounded upon what I thought were some rules of thumb for using extension methods correctly.  As long as you keep in line with those (or similar) rules, they can often be useful for adding that little extra functionality or syntactical simplification for a library that you have little or no control over. Oh sure, you could take an open source project, download the source and add the methods you want, but then every time the library is updated you have to re-add your changes, which can be cumbersome and error prone.  And yes, you could possibly extend a class in a third party library and override features, but that's only if the class is not sealed, static, or constructed via factories. This is the perfect place to use an extension method!  And the best part is, you and your development team don't need to change anything!  Simply add the using for the namespace the extensions are in! So let's consider this example.  I love log4net!  Of all the logging libraries I've played with, it, to me, is one of the most flexible and configurable logging libraries and it performs great.  But this isn't about log4net, well, not directly.  So why would I want to add functionality?  Well, it's missing one thing I really want in the ILog interface: ability to specify logging level at runtime. For example, let's say I declare my ILog instance like so:     using log4net;     public class LoggingTest     {         private static readonly ILog _log = LogManager.GetLogger(typeof(LoggingTest));         ...     }     If you don't know log4net, the details aren't important, just to show that the field _log is the logger I have gotten from log4net. So now that I have that, I can log to it like so:     _log.Debug("This is the lowest level of logging and just for debugging output.");     _log.Info("This is an informational message.  Usual normal operation events.");     _log.Warn("This is a warning, something suspect but not necessarily wrong.");     _log.Error("This is an error, some sort of processing problem has happened.");     _log.Fatal("Fatals usually indicate the program is dying hideously."); And there's many flavors of each of these to log using string formatting, to log exceptions, etc.  But one thing there isn't: the ability to easily choose the logging level at runtime.  Notice, the logging levels above are chosen at compile time.  Of course, you could do some fun stuff with lambdas and wrap it, but that would obscure the simplicity of the interface.  And yes there is a Logger property you can dive down into where you can specify a Level, but the Level properties don't really match the ILog interface exactly and then you have to manually build a LogEvent and... well, it gets messy.  I want something simple and sexy so I can say:     _log.Log(someLevel, "This will be logged at whatever level I choose at runtime!");     Now, some purists out there might say you should always know what level you want to log at, and for the most part I agree with them.  For the most party the ILog interface satisfies 99% of my needs.  In fact, for most application logging yes you do always know the level you will be logging at, but when writing a utility class, you may not always know what level your user wants. I'll tell you, one of my favorite things is to write reusable components.  If I had my druthers I'd write framework libraries and shared components all day!  And being able to easily log at a runtime-chosen level is a big need for me.  After all, if I want my code to really be re-usable, I shouldn't force a user to deal with the logging level I choose. One of my favorite uses for this is in Interceptors -- I'll describe Interceptors in my next post and some of my favorites -- for now just know that an Interceptor wraps a class and allows you to add functionality to an existing method without changing it's signature.  At the risk of over-simplifying, it's a very generic implementation of the Decorator design pattern. So, say for example that you were writing an Interceptor that would time method calls and emit a log message if the method call execution time took beyond a certain threshold of time.  For instance, maybe if your database calls take more than 5,000 ms, you want to log a warning.  Or if a web method call takes over 1,000 ms, you want to log an informational message.  This would be an excellent use of logging at a generic level. So here was my personal wish-list of requirements for my task: Be able to determine if a runtime-specified logging level is enabled. Be able to log generically at a runtime-specified logging level. Have the same look-and-feel of the existing Debug, Info, Warn, Error, and Fatal calls.    Having the ability to also determine if logging for a level is on at runtime is also important so you don't spend time building a potentially expensive logging message if that level is off.  Consider an Interceptor that may log parameters on entrance to the method.  If you choose to log those parameter at DEBUG level and if DEBUG is not on, you don't want to spend the time serializing those parameters. Now, mine may not be the most elegant solution, but it performs really well since the enum I provide all uses contiguous values -- while it's never guaranteed, contiguous switch values usually get compiled into a jump table in IL which is VERY performant - O(1) - but even if it doesn't, it's still so fast you'd never need to worry about it. So first, I need a way to let users pass in logging levels.  Sure, log4net has a Level class, but it's a class with static members and plus it provides way too many options compared to ILog interface itself -- and wouldn't perform as well in my level-check -- so I define an enum like below.     namespace Shared.Logging.Extensions     {         // enum to specify available logging levels.         public enum LoggingLevel         {             Debug,             Informational,             Warning,             Error,             Fatal         }     } Now, once I have this, writing the extension methods I need is trivial.  Once again, I would typically /// comment fully, but I'm eliminating for blogging brevity:     namespace Shared.Logging.Extensions     {         // the extension methods to add functionality to the ILog interface         public static class LogExtensions         {             // Determines if logging is enabled at a given level.             public static bool IsLogEnabled(this ILog logger, LoggingLevel level)             {                 switch (level)                 {                     case LoggingLevel.Debug:                         return logger.IsDebugEnabled;                     case LoggingLevel.Informational:                         return logger.IsInfoEnabled;                     case LoggingLevel.Warning:                         return logger.IsWarnEnabled;                     case LoggingLevel.Error:                         return logger.IsErrorEnabled;                     case LoggingLevel.Fatal:                         return logger.IsFatalEnabled;                 }                                 return false;             }             // Logs a simple message - uses same signature except adds LoggingLevel             public static void Log(this ILog logger, LoggingLevel level, object message)             {                 switch (level)                 {                     case LoggingLevel.Debug:                         logger.Debug(message);                         break;                     case LoggingLevel.Informational:                         logger.Info(message);                         break;                     case LoggingLevel.Warning:                         logger.Warn(message);                         break;                     case LoggingLevel.Error:                         logger.Error(message);                         break;                     case LoggingLevel.Fatal:                         logger.Fatal(message);                         break;                 }             }             // Logs a message and exception to the log at specified level.             public static void Log(this ILog logger, LoggingLevel level, object message, Exception exception)             {                 switch (level)                 {                     case LoggingLevel.Debug:                         logger.Debug(message, exception);                         break;                     case LoggingLevel.Informational:                         logger.Info(message, exception);                         break;                     case LoggingLevel.Warning:                         logger.Warn(message, exception);                         break;                     case LoggingLevel.Error:                         logger.Error(message, exception);                         break;                     case LoggingLevel.Fatal:                         logger.Fatal(message, exception);                         break;                 }             }             // Logs a formatted message to the log at the specified level.              public static void LogFormat(this ILog logger, LoggingLevel level, string format,                                          params object[] args)             {                 switch (level)                 {                     case LoggingLevel.Debug:                         logger.DebugFormat(format, args);                         break;                     case LoggingLevel.Informational:                         logger.InfoFormat(format, args);                         break;                     case LoggingLevel.Warning:                         logger.WarnFormat(format, args);                         break;                     case LoggingLevel.Error:                         logger.ErrorFormat(format, args);                         break;                     case LoggingLevel.Fatal:                         logger.FatalFormat(format, args);                         break;                 }             }         }     } So there it is!  I didn't have to modify the log4net source code, so if a new version comes out, i can just add the new assembly with no changes.  I didn't have to subclass and worry about developers not calling my sub-class instead of the original.  I simply provide the extension methods and it's as if the long lost extension methods were always a part of the ILog interface! Consider a very contrived example using the original interface:     // using the original ILog interface     public class DatabaseUtility     {         private static readonly ILog _log = LogManager.Create(typeof(DatabaseUtility));                 // some theoretical method to time         IDataReader Execute(string statement)         {             var timer = new System.Diagnostics.Stopwatch();                         // do DB magic                                    // this is hard-coded to warn, if want to change at runtime tough luck!             if (timer.ElapsedMilliseconds > 5000 && _log.IsWarnEnabled)             {                 _log.WarnFormat("Statement {0} took too long to execute.", statement);             }             ...         }     }     Now consider this alternate call where the logging level could be perhaps a property of the class          // using the original ILog interface     public class DatabaseUtility     {         private static readonly ILog _log = LogManager.Create(typeof(DatabaseUtility));                 // allow logging level to be specified by user of class instead         public LoggingLevel ThresholdLogLevel { get; set; }                 // some theoretical method to time         IDataReader Execute(string statement)         {             var timer = new System.Diagnostics.Stopwatch();                         // do DB magic                                    // this is hard-coded to warn, if want to change at runtime tough luck!             if (timer.ElapsedMilliseconds > 5000 && _log.IsLogEnabled(ThresholdLogLevel))             {                 _log.LogFormat(ThresholdLogLevel, "Statement {0} took too long to execute.",                     statement);             }             ...         }     } Next time, I'll show one of my favorite uses for these extension methods in an Interceptor.

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  • CQRS &ndash; Questions and Concerns

    - by Dylan Smith
    I’ve been doing a lot of learning on CQRS and Event Sourcing over the last little while and I have a number of questions that I haven’t been able to answer. 1. What is the benefit of CQRS when compared to a typical DDD architecture that uses Event Sourcing and properly captures intent and behavior via verb-based commands? (other than Scalability) 2. When using CQRS what do you do with complex query-based logic? I’m going to elaborate on #1 in this blog post and I’ll do a follow-up post on #2. I watched through Greg Young’s video on the business benefits of CQRS + Event Sourcing and first let me say that I thought it was an excellent presentation that really drives home a lot of the benefits to this approach to architecture (I watched it twice in a row I enjoyed it so much!). But it didn’t answer some of my questions fully (I wish I had been there to ask these of Greg in person!). So let me pick apart some of the points he makes and how they relate to my first question above. I’m completely sold on the idea of event sourcing and have a clear understanding of the benefits that it brings to the table, so I’m not going to question that. But you can use event sourcing without going to a CQRS architecture, so my main question is around the benefits of CQRS + Event Sourcing vs Event Sourcing + Typical DDD architecture Architecture with Event Sourcing + Commands on Left, CQRS on Right Greg talks about how the stereotypical architecture doesn’t support DDD, but is that only because his diagram shows DTO’s coming up from the client. If we use the same diagram but allow the client to send commands doesn’t that remove a lot of the arguments that Greg makes against the stereotypical architecture? We can now introduce verbs into the system. We can capture intent now (storing it still requires event sourcing, but you can implement event sourcing without doing CQRS) We can create a rich domain model (as opposed to an anemic domain model) Scalability is obviously a benefit that CQRS brings to the table, but like Greg says, very few of the systems we create truly need significant scalability Greg talks about the ability to scale your development efforts. He says CQRS allows you to split the system into 3 parts (Client, Domain/Commands, Reads) and assign 3 teams of developers to work on them in parallel; letting you scale your development efforts by 3x with nearly linear gains. But in the stereotypical architecture don’t you already have 2 separate modules that you can split your dev efforts between: The client that sends commands/queries and receives DTO’s, and the Domain which accepts commands/queries, and generates events/DTO’s. If this is true it’s not really a 3x scaling you achieve with CQRS but merely a 1.5x scaling which while great doesn’t sound nearly as dramatic (“I can do it with 10 devs in 12 months – let me hire 5 more and we can have it done in 8 months”). Making the Query side “stupid simple” such that you can assign junior developers (or even outsource it) sounds like a valid benefit, but I have some concerns over what you do with complex query-based logic/behavior. I’m going to go into more detail on this in a follow-up blog post shortly. He also seemed to focus on how “stupid-simple” it is doing queries against the de-normalized data store, but I imagine there is still significant complexity in the event handlers that interpret the events and apply them to the de-normalized tables. It sounds like Greg suggests that because we’re doing CQRS that allows us to apply Event Sourcing when we otherwise wouldn’t be able to (~33:30 in the video). I don’t believe this is true. I don’t see why you wouldn’t be able to apply Event Sourcing without separating out the Commands and Queries. The queries would just operate against the domain model instead of the database. But you’d still get the benefits of Event Sourcing. Without CQRS the queries would only be able to operate against the current state rather than the event history, but even in CQRS the domain behaviors can only operate against the current state and I don’t see that being a big limiting factor. If some query needs to operate against something that is not captured by the current state you would just have to update the domain model to capture that information (no different than if that statement were made about a Command under CQRS). Some of the benefits I do see being applicable are that your domain model might end up being simpler/smaller since it only needs to represent the state needed to process commands and not worry about the reads (like the Deactivate Inventory Item and associated comment example that Greg provides). And also commands that can be handled in a Transaction Script style manner by the command handler simply generating events and not touching the domain model. It also makes it easier for your senior developers to focus on the command behavior and ignore the queries, which is usually going to be a better use of their time. And of course scalability. If anybody out there has any thoughts on this and can help educate me further, please either leave a comment or feel free to get in touch with me via email:

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  • Having Fun with Coding4Fun&rsquo;s Windows Phone 7 Controls

    - by mbcrump
    I’m a big believer in having a hobby project as you can probably tell from the first sentence in my “personal webpage using Silverlight” article. One of my current hobby projects is to re-do my current WP7 application in the marketplace. I knew up front that I needed a “Loading” animation and a better “About” box. After starting to develop my own, I noticed a great set of WP7 controls by Coding4Fun and decided to use them in my new application. Before I go any further they are FREE and Open-Source. It is really simple to get started, just go to the CodePlex site and click the download button. After you have downloaded it then extract it to a Folder and you will have 4 DLL files. They are listed below: Now create a Windows Phone 7 Project and add references to the DLL’s by right clicking on the References folder and clicking “Add references”.   After adding the references, we can get started. I needed a ProgressOverlay animation or “Loading Screen” while my RSS feed is downloading. Basically, you just need to add the following namespace to whatever page you want the control on: xmlns:Controls="clr-namespace:Coding4Fun.Phone.Controls;assembly=Coding4Fun.Phone.Controls" And then the code inside your Grid or wherever you want the Loading screen placed. <Controls:ProgressOverlay Name="progressOverlay" > <Controls:ProgressOverlay.Content> <TextBlock>Loading</TextBlock> </Controls:ProgressOverlay.Content> </Controls:ProgressOverlay> Bam, you now have a great looking loading screen. Of course inside the ProgressOverlay, you may want to add a Visibility property to turn it off after your data loads if you are using MVVM or similar pattern.   Next up, I needed a nice clean “About Box” that looks good but is also functional. Meaning, if they click on my twitter name, web or email to launch the appropriate task. Again, this is only a few lines of code: var p = new AboutPrompt(); p.VersionNumber = "2.0"; p.Show("Michael Crump", "@mbcrump", "[email protected]", @"http://michaelcrump.net"); A nice clean “About” box with just a few lines of code! I’m all for code that I don’t have to write. It also comes with a pretty sweet InputPrompt for grabbing info from a user: The code for this is also very simple: InputPrompt input = new InputPrompt(); input.Completed += (s, e) => { MessageBox.Show(e.Result.ToString()); }; input.Title = "Input Box"; input.Message = "What does a \"Developer Large\" T-Shirt Mean? "; input.Show(); I also enjoyed the PhoneHelper that allows you to get data out of the WMAppManifest File very easy. So for example if I wanted the Version info from the WMAppManifest file. I could write one line and get it. PhoneHelper.GetAppAttribute("Version") Of course you would want to make sure you add the following using statement: using Coding4Fun.Phone.Controls.Data; You can’t have all these cool controls without a great set of Converters. The included BooleanToVisibility converter will convert a Boolean to and from a Visibility value. This is excellent when using something like a CheckBox to display a TextBox when its checked. See the example below: The code is below: <phone:PhoneApplicationPage.Resources> <Converters:BooleanToVisibilityConverter x:Key="BooleanToVisibilityConverter"/> </phone:PhoneApplicationPage.Resources> <CheckBox x:Name="checkBox"/> <TextBlock Text="Display Text" Visibility="{Binding ElementName=checkBox, Path=IsChecked, Converter={StaticResource BooleanToVisibilityConverter} }"/> That’s not all the goodies included. They also provide a RoundedButton, TimePicker and several other converters. The documentation is great and I would recommend you give them a shot if you need any of this functionality. Btw, thank Brian Peek for his awesome work on Coding4Fun!  Subscribe to my feed

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  • Illegal characters for SharePoint 2010 Content Type name

    - by Kelly Jones
    Quick tip: you can’t include a backslash in the name of the SharePoint 2010 Content Type.  In fact, there are several illegal characters:  \  / : * ? " # % < > { } | ~ & , two consecutive periods (..), or special characters such as a tab. What, you didn’t know that after entering one of these characters in the name?  Is it because you saw this screen: Oh, that’s right….you need to turn off custom errors in the layouts folder…See this blog post for details and you’ll also need to turn off for the web application. Once you do that, you’ll see this: I wonder why the SharePoint team just doesn’t let the user know that the content type name contains illegal characters before the user hits the create button. Here’s a copy of the complete error (for the search engines): Server Error in '/' Application. -------------------------------------------------------------------------------- The content type name 'asdfadsf\asdfasf' cannot contain: \  / : * ? " # % < > { } | ~ & , two consecutive periods (..), or special characters such as a tab. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: Microsoft.SharePoint.SPInvalidContentTypeNameException: The content type name 'asdfadsf\asdfasf' cannot contain: \  / : * ? " # % < > { } | ~ & , two consecutive periods (..), or special characters such as a tab. Source Error: An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.  Stack Trace: [SPInvalidContentTypeNameException: The content type name 'asdfadsf\asdfasf' cannot contain: \  / : * ? " # % < > { } | ~ & , two consecutive periods (..), or special characters such as a tab.]    Microsoft.SharePoint.SPContentType.ValidateName(String name) +27419522    Microsoft.SharePoint.SPContentType.ValidateNameWithResource(String strVal, String& strLocalized) +423    Microsoft.SharePoint.SPContentType.set_Name(String value) +151    Microsoft.SharePoint.SPContentType.Initialize(SPContentType parentContentType, SPContentTypeCollection collection, String name) +112    Microsoft.SharePoint.SPContentType..ctor(SPContentType parentContentType, SPContentTypeCollection collection, String name) +132    Microsoft.SharePoint.ApplicationPages.ContentTypeCreatePage.BtnOK_Click(Object sender, EventArgs e) +497    System.Web.UI.WebControls.Button.OnClick(EventArgs e) +115    System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) +140    System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +29    System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +2981   -------------------------------------------------------------------------------- Version Information: Microsoft .NET Framework Version:2.0.50727.4927; ASP.NET Version:2.0.50727.4927

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  • Craftsmanship Tour: Day 3 &amp; 4 8th Light

    - by Liam McLennan
    Thursday morning the Illinois public transport system came through for me again. I took the Metra train north from Union Station (which was seething with inbound commuters) to Prairie Crossing (Libertyville). At Prairie Crossing I met Paul and Justin from 8th Light and then Justin drove us to the office. The 8th Light office is in an small business park, in a semi-rural area, surrounded by ponds. Upstairs there are two spacious, open areas for developers. At one end of the floor is Doug Bradbury’s walk-and-code station; a treadmill with a desk and computer so that a developer can get exercise at work. At the other end of the floor is a hammock. This irregular office furniture is indicative of the 8th Light philosophy, to pursue excellence without being limited by conventional wisdom. 8th Light have a wall covered in posters, each illustrating one person’s software craftsmanship journey. The posters are a fascinating visualisation of the similarities and differences between each of our progressions. The first thing I did Thursday morning was to create my own poster and add it to the wall. Over two days at 8th Light I did some pairing with the 8th Lighters and we shared thoughts on software development. I am not accustomed to such a progressive and enlightened environment and I found the experience inspirational. At 8th Light TDD, clean code, pairing and kaizen are deeply ingrained in the culture. Friday, during lunch, 8th Light hosted a ‘lunch and learn’ event. Paul Pagel lead us through a coding exercise using micro-pomodori. We worked in pairs, focusing on the pedagogy of pair programming and TDD. After lunch I recorded this interview with Paul Pagel and Justin Martin. We discussed 8th light, craftsmanship, apprenticeships and the limelight framework. Interview with Paul Pagel and Justin Martin My time at Didit, Obtiva and 8th Light has convinced me that I need to give up some of my independence and go back to working in a team. Craftsmen advance their skills by learning from each other, and I can’t do that working at home by myself. The challenge is finding the right team, and becoming a part of it.

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  • C# tip: do not use “is” type, if you will need cast “as” later

    - by Michael Freidgeim
    We have a debate with one of my collegues, is it agood style to check, if the object of particular style, and then cast  as this  type. The perfect answer of Jon Skeet   and answers in Cast then check or check then cast? confirmed my point.//good    var coke = cola as CocaCola;    if (coke != null)    {        // some unique coca-cola only code    }    //worse    if (cola is CocaCola)    {        var coke =  cola as CocaCola;        // some unique coca-cola only code here.    }

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  • Windows Azure Evolution &ndash; Caching (Preview)

    - by Shaun
    Caching is a popular topic when we are building a high performance and high scalable system not only on top of the cloud platform but the on-premise environment as well. On March 2011 the Windows Azure AppFabric Caching had been production launched. It provides an in-memory, distributed caching service over the cloud. And now, in this June 2012 update, the cache team announce a grand new caching solution on Windows Azure, which is called Windows Azure Caching (Preview). And the original Windows Azure AppFabric Caching was renamed to Windows Azure Shared Caching.   What’s Caching (Preview) If you had been using the Shared Caching you should know that it is constructed by a bunch of cache servers. And when you want to use you should firstly create a cache account from the developer portal and specify the size you want to use, which means how much memory you can use to store your data that wanted to be cached. Then you can add, get and remove them through your code through the cache URL. The Shared Caching is a multi-tenancy system which host all cached items across all users. So you don’t know which server your data was located. This caching mode works well and can take most of the cases. But it has some problems. The first one is the performance. Since the Shared Caching is a multi-tenancy system, which means all cache operations should go through the Shared Caching gateway and then routed to the server which have the data your are looking for. Even though there are some caches in the Shared Caching system it also takes time from your cloud services to the cache service. Secondary, the Shared Caching service works as a block box to the developer. The only thing we know is my cache endpoint, and that’s all. Someone may satisfied since they don’t want to care about anything underlying. But if you need to know more and want more control that’s impossible in the Shared Caching. The last problem would be the price and cost-efficiency. You pay the bill based on how much cache you requested per month. But when we host a web role or worker role, it seldom consumes all of the memory and CPU in the virtual machine (service instance). If using Shared Caching we have to pay for the cache service while waste of some of our memory and CPU locally. Since the issues above Microsoft offered a new caching mode over to us, which is the Caching (Preview). Instead of having a separated cache service, the Caching (Preview) leverage the memory and CPU in our cloud services (web role and worker role) as the cache clusters. Hence the Caching (Preview) runs on the virtual machines which hosted or near our cloud applications. Without any gateway and routing, since it located in the same data center and same racks, it provides really high performance than the Shared Caching. The Caching (Preview) works side-by-side to our application, initialized and worked as a Windows Service running in the virtual machines invoked by the startup tasks from our roles, we could get more information and control to them. And since the Caching (Preview) utilizes the memory and CPU from our existing cloud services, so it’s free. What we need to pay is the original computing price. And the resource on each machines could be used more efficiently.   Enable Caching (Preview) It’s very simple to enable the Caching (Preview) in a cloud service. Let’s create a new windows azure cloud project from Visual Studio and added an ASP.NET Web Role. Then open the role setting and select the Caching page. This is where we enable and configure the Caching (Preview) on a role. To enable the Caching (Preview) just open the “Enable Caching (Preview Release)” check box. And then we need to specify which mode of the caching clusters we want to use. There are two kinds of caching mode, co-located and dedicate. The co-located mode means we use the memory in the instances we run our cloud services (web role or worker role). By using this mode we must specify how many percentage of the memory will be used as the cache. The default value is 30%. So make sure it will not affect the role business execution. The dedicate mode will use all memory in the virtual machine as the cache. In fact it will reserve some for operation system, azure hosting etc.. But it will try to use as much as the available memory to be the cache. As you can see, the Caching (Preview) was defined based on roles, which means all instances of this role will apply the same setting and play as a whole cache pool, and you can consume it by specifying the name of the role, which I will demonstrate later. And in a windows azure project we can have more than one role have the Caching (Preview) enabled. Then we will have more caches. For example, let’s say I have a web role and worker role. The web role I specified 30% co-located caching and the worker role I specified dedicated caching. If I have 3 instances of my web role and 2 instances of my worker role, then I will have two caches. As the figure above, cache 1 was contributed by three web role instances while cache 2 was contributed by 2 worker role instances. Then we can add items into cache 1 and retrieve it from web role code and worker role code. But the items stored in cache 1 cannot be retrieved from cache 2 since they are isolated. Back to our Visual Studio we specify 30% of co-located cache and use the local storage emulator to store the cache cluster runtime status. Then at the bottom we can specify the named caches. Now we just use the default one. Now we had enabled the Caching (Preview) in our web role settings. Next, let’s have a look on how to consume our cache.   Consume Caching (Preview) The Caching (Preview) can only be consumed by the roles in the same cloud services. As I mentioned earlier, a cache contributed by web role can be connected from a worker role if they are in the same cloud service. But you cannot consume a Caching (Preview) from other cloud services. This is different from the Shared Caching. The Shared Caching is opened to all services if it has the connection URL and authentication token. To consume the Caching (Preview) we need to add some references into our project as well as some configuration in the Web.config. NuGet makes our life easy. Right click on our web role project and select “Manage NuGet packages”, and then search the package named “WindowsAzure.Caching”. In the package list install the “Windows Azure Caching Preview”. It will download all necessary references from the NuGet repository and update our Web.config as well. Open the Web.config of our web role and find the “dataCacheClients” node. Under this node we can specify the cache clients we are going to use. For each cache client it will use the role name to identity and find the cache. Since we only have this web role with the Caching (Preview) enabled so I pasted the current role name in the configuration. Then, in the default page I will add some code to show how to use the cache. I will have a textbox on the page where user can input his or her name, then press a button to generate the email address for him/her. And in backend code I will check if this name had been added in cache. If yes I will return the email back immediately. Otherwise, I will sleep the tread for 2 seconds to simulate the latency, then add it into cache and return back to the page. 1: protected void btnGenerate_Click(object sender, EventArgs e) 2: { 3: // check if name is specified 4: var name = txtName.Text; 5: if (string.IsNullOrWhiteSpace(name)) 6: { 7: lblResult.Text = "Error. Please specify name."; 8: return; 9: } 10:  11: bool cached; 12: var sw = new Stopwatch(); 13: sw.Start(); 14:  15: // create the cache factory and cache 16: var factory = new DataCacheFactory(); 17: var cache = factory.GetDefaultCache(); 18:  19: // check if the name specified is in cache 20: var email = cache.Get(name) as string; 21: if (email != null) 22: { 23: cached = true; 24: sw.Stop(); 25: } 26: else 27: { 28: cached = false; 29: // simulate the letancy 30: Thread.Sleep(2000); 31: email = string.Format("{0}@igt.com", name); 32: // add to cache 33: cache.Add(name, email); 34: } 35:  36: sw.Stop(); 37: lblResult.Text = string.Format( 38: "Cached = {0}. Duration: {1}s. {2} => {3}", 39: cached, sw.Elapsed.TotalSeconds.ToString("0.00"), name, email); 40: } The Caching (Preview) can be used on the local emulator so we just F5. The first time I entered my name it will take about 2 seconds to get the email back to me since it was not in the cache. But if we re-enter my name it will be back at once from the cache. Since the Caching (Preview) is distributed across all instances of the role, so we can scaling-out it by scaling-out our web role. Just use 2 instances and tweak some code to show the current instance ID in the page, and have another try. Then we can see the cache can be retrieved even though it was added by another instance.   Consume Caching (Preview) Across Roles As I mentioned, the Caching (Preview) can be consumed by all other roles within the same cloud service. For example, let’s add another web role in our cloud solution and add the same code in its default page. In the Web.config we add the cache client to one enabled in the last role, by specifying its role name here. Then we start the solution locally and go to web role 1, specify the name and let it generate the email to us. Since there’s no cache for this name so it will take about 2 seconds but will save the email into cache. And then we go to web role 2 and specify the same name. Then you can see it retrieve the email saved by the web role 1 and returned back very quickly. Finally then we can upload our application to Windows Azure and test again. Make sure you had changed the cache cluster status storage account to the real azure account.   More Awesome Features As a in-memory distributed caching solution, the Caching (Preview) has some fancy features I would like to highlight here. The first one is the high availability support. This is the first time I have heard that a distributed cache support high availability. In the distributed cache world if a cache cluster was failed, the data it stored will be lost. This behavior was introduced by Memcached and is followed by almost all distributed cache productions. But Caching (Preview) provides high availability, which means you can specify if the named cache will be backup automatically. If yes then the data belongs to this named cache will be replicated on another role instance of this role. Then if one of the instance was failed the data can be retrieved from its backup instance. To enable the backup just open the Caching page in Visual Studio. In the named cache you want to enable backup, change the Backup Copies value from 0 to 1. The value of Backup Copies only for 0 and 1. “0” means no backup and no high availability while “1” means enabled high availability with backup the data into another instance. But by using the high availability feature there are something we need to make sure. Firstly the high availability does NOT means the data in cache will never be lost for any kind of failure. For example, if we have a role with cache enabled that has 10 instances, and 9 of them was failed, then most of the cached data will be lost since the primary and backup instance may failed together. But normally is will not be happened since MS guarantees that it will use the instance in the different fault domain for backup cache. Another one is that, enabling the backup means you store two copies of your data. For example if you think 100MB memory is OK for cache, but you need at least 200MB if you enabled backup. Besides the high availability, the Caching (Preview) support more features introduced in Windows Server AppFabric Caching than the Windows Azure Shared Caching. It supports local cache with notification. It also support absolute and slide window expiration types as well. And the Caching (Preview) also support the Memcached protocol as well. This means if you have an application based on Memcached, you can use Caching (Preview) without any code changes. What you need to do is to change the configuration of how you connect to the cache. Similar as the Windows Azure Shared Caching, MS also offers the out-of-box ASP.NET session provider and output cache provide on top of the Caching (Preview).   Summary Caching is very important component when we building a cloud-based application. In the June 2012 update MS provides a new cache solution named Caching (Preview). Different from the existing Windows Azure Shared Caching, Caching (Preview) runs the cache cluster within the role instances we have deployed to the cloud. It gives more control, more performance and more cost-effect. So now we have two caching solutions in Windows Azure, the Shared Caching and Caching (Preview). If you need a central cache service which can be used by many cloud services and web sites, then you have to use the Shared Caching. But if you only need a fast, near distributed cache, then you’d better use Caching (Preview).   Hope this helps, Shaun All documents and related graphics, codes are provided "AS IS" without warranty of any kind. Copyright © Shaun Ziyan Xu. This work is licensed under the Creative Commons License.

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  • light.exe : error LGHT0217: Error executing ICE action &lsquo;ICE*&rsquo; with BizTalk Deployment Framework &amp; TFS 2010 Build.

    - by Vishal
    Hi there, Recently I was working with BizTalk Deployment Framework v5.0 for my BizTalk Sever 2009 projects and TFS 2010 Builds. I had followed all the steps mentioned in the BTDF documentation to create the build definition and also followed the steps to setup the Build Server with BTDF. After few hiccups I was stuck at this light.exe validation error. The detailed error is as below: light.exe : error LGHT0217: Error executing ICE action 'ICE06'. The most common cause of this kind of ICE failure is an incorrectly registered scripting engine. See http://wix.sourceforge.net/faq.html#Error217 for details and how to solve this problem. The following string format was not expected by the external UI message logger: "The Windows Installer Service could not be accessed. This can occur if the Windows Installer is not correctly installed. Contact your support personnel for assistance." I found few blog posts and forum answers out there which had steps to resolve the error but all of them mentioned different things. Like: Some mentioned that disable the validation itself so that the VBScript would not be called. (I didn’t want to disable the validation.) Another said to put NT AUTHORITY\NETWORK SERVICE in the local Administrators group but this is not recommended as it opens up network security holes. But what actually worked for me was: TFS Build Service Account was part of the Administrator group on the Build Server which is OK. But somehow it was also part of the IIS_IUSR Group. I removed the TFS Build Service Account from the IIS_IUSR group. Queued up my TFS Build but same error. Again after some digging, I found that I had not restarted the Visual Studio Team Build Service. In a Nutshell: Remove TFS Build Service Account from IIS_IUSR Group. Restart the Visual Studio Team Build Service, either from Services or TFS Console.   Hope this resolves the issue for someone and not waste bunch of hours.   Thanks, Vishal Mody

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  • Silverlight Cream for May 19, 2010 -- #865

    - by Dave Campbell
    In this Issue: Michael Washington, Mike Snow(-2-), Justin Angel(-2-), Jeremy Likness, and David Kelley. Shoutout: Erik Mork and crew have their latest up: Silverlight Week – Silverlight Android? From SilverlightCream.com: Simple Silverlight 4 Example Using oData and RX Extensions Michael Washington has a follow-on tutorial up on ViewModel, Rx, and lashed up to OData... good detailed tutorial with external links for more information. Silverlight Tip of the Day #21 – Animation Easing Mike Snow has a couple new tips up -- this first one is about easing... great diagrams to help visualize and a cool demo application to boot. Silverlight Tip of the Day #22 – Data Validation Mike Snow's second tip (#22) is about validation and again he has a great demo app on the post. Windows Phone 7 - Emulator Automation Justin Angel has a WP7 post up about Automating the emulator... and in the process, loading the emulator from something other than VS2010... lots of good information. TFS2010 WP7 Continuous Integration Justin Angel hinted at continuous integration for WP7 in the last post, and he pays off with this one... even without all the bits installed on the build server. Making the ScrollViewer Talk in Silverlight 4 Jeremy Likness tried to respond to a user query about knowing when a user scrolled to the bottom of a ScrollViewer... Jeremy resolved it by listening to the right property. MEF (Microsoft Extensibility Framework) made simple (ish) David Kelley is discussing MEF and using a real-world example while doing so. Good discussion and code available in his code browser app... check thecomments. 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

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  • Not Playing Nice Together

    - by David Douglass
    One of the things I’ve noticed is that two industry trends are not playing nice together, those trends being multi-core CPUs and massive hard drives.  It’s not a problem if you keep your cores busy with compute intensive work, but for software developers the beauty of multi-core CPUs (along with gobs of RAM and a 64 bit OS) is virtualization.  But when you have only one hard drive (who needs another when it holds 2 TB of data?) you wind up with a serious hard drive bottleneck.  A solid state drive would definitely help, and might even be a complete solution, but the cost is ridiculous.  Two TB of solid state storage will set you back around $7,000!  A spinning 2 TB drive is only $150. I see a couple of solutions for this.  One is the mainframe concept of near and far storage: put the stuff that will be heavily access on a solid state drive and the rest on a spinning drive.  Another solution is multiple spinning drives.  Instead of a single 2 TB drive, get four 500 GB drives.  In total, the four 500 GB drives will cost about $100 more than the single 2 TB drive.  You’ll need to be smart about what drive you place things on so that the load is spread evenly.  Another option, for better performance, would be four 10,000 RPM 300 GB drives, but that would cost about $800 more than the singe 2 TB drive and would deliver only 1.2 TB of space. All pricing based on Microcenter as of March 14, 2010.

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  • So No TECH job so far.

    - by Ratman21
    O I found some temp work for the US Census and I have managed to keep the house (so far) but, it looks like I/we are going to have to do a short sale and the temp job will be ending soon.   On top of that it looks like the unemployment fund for me is drying up. I will have about one month left after the Census job is done. I am now down to Appling for work at the KFC.   This is type a work I started with, before I was a tech geek and really I didn’t think I would be doing this kind of work in my later years but, I have a wife and kid. So I got to suck it up and do it.   Oh and here is my new resume…go ahead I know you want to tare it up. I really don’t care any more.   Scott L. Newman 45219 Dutton Way, Callahan, FL32011 H: (904)879-4880 C: (352)356-0945 E: [email protected] Web:  http://beingscottnewman.webs.com/                                                       ______                                                                                 OBJECTIVE To obtain a Network or Technical support position     KEYWORD SUMMARY CompTIA A+, Network+, and Security+ Certified., Network Operation, Technical Support, Client/Vendor Relations, Networking/Administration, Cisco Routers/Switches, Helpdesk, Microsoft Office Suite, Website Design/Dev./Management, Frame Relay, ISDN, Windows NT/98/XP, Visio, Inventory Management, CICS, Programming, COBOL IV, Assembler, RPG   QUALIFICATIONS SUMMARY Twenty years’ experience in computer operations, technical support, and technical writing. Also have two and half years’ experience in internet / intranet operations.   PROFESSIONAL EXPERIENCE October 2009 – Present*   Volunteer Web site and PC technician – Part time       True Faith Christian Fellowship Church – Callahan, FL, Project: Create and maintain web site for Church to give it a worldwide exposure Aug 2008 – September 2009:* Volunteer Church sound and video technician – Part time      Thomas Creek Baptist Church – Callahan, FL   *Note Jobs were for the learning and/or keeping updated on skills, while looking for a tech job and training for new skills.   February 2005 to October 2008: Client Server Dev/Analyst I, Fidelity National Information Services, Jacksonville, FL (FNIS acquired Certegy in 2005 and out of 20 personal, was one of three kept on.) August 2003 to February 2005: Senior NetOps Operator, Certegy, St.Pete, Fl. (August 2003, Certegy terminated contract with EDS and out of 40 personal, was one of six kept on.) Projects: Creation and update of listing and placement for all raised floor equipment at St.Pete site. Listing was made up of, floor plan of the raised floor and equipment racks diagrams showing the placement of all devices using Visio. This was cross-referenced with an inventory excel document showing what dept was responsible for each device. Sole creator of Network operation and Server Operation procedures guide (NetOps Guide).  Expertise: Resolving circuit and/or router issues or assist circuit carrier in resolving issue from the company Network Operation Center (NOC). As well as resolving application problems or assist application support in resolution of it.     July 1999 to August 2003: Senior NetOps Operator,EDS (Certegy Account), St.Pete, FL Same expertise and on going projects as listed above for FNIS/Certegy. (Equifax outsourced the NetOps dept. to EDS in 1999)         January 1991 to July 1999: NetOps/Tandem Operator, Equifax, St.Pete & Tampa, FL Same as all of the above for FNIS/Certegy/EDS except for circuit and router issues   EDUCATION ? New Horizons Computer Learning Center, Jacksonville, Florida - CompTIA A+, Security+, and     Network+ Certified.                        Currently working on CCNA Certification 07/30/10 ? Mott Community College, Flint, Michigan – Associates Degree - Data Processing and General Education ? Currently studying Japanese

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  • Restful Services, oData, and Rest Sharp

    - by jkrebsbach
    After a great presentation by Jason Sheehan at MDC about RestSharp, I decided to implement it. RestSharp is a .Net framework for consuming restful data sources via either Json or XML. My first step was to put together a Restful data source for RestSharp to consume.  Staying entirely withing .Net, I decided to use Microsoft's oData implementation, built on System.Data.Services.DataServices.  Natively, these support Json, or atom+pub xml.  (XML with a few bells and whistles added on) There are three main steps for creating an oData data source: 1)  override CreateDSPMetaData This is where the metadata data is returned.  The meta data defines the structure of the data to return.  The structure contains the relationships between data objects, along with what properties the objects expose.  The meta data can and should be somehow cached so that the structure is not rebuild with every data request. 2) override CreateDataSource The context contains the data the data source will publish.  This method is the conduit which will populate the metadata objects to be returned to the requestor. 3) implement static InitializeService At this point we can set up security, along with setting up properties of the web service (versioning, etc)   Here is a web service which publishes stock prices for various Products (stocks) in various Categories. namespace RestService {     public class RestServiceImpl : DSPDataService<DSPContext>     {         private static DSPContext _context;         private static DSPMetadata _metadata;         /// <summary>         /// Populate traversable data source         /// </summary>         /// <returns></returns>         protected override DSPContext CreateDataSource()         {             if (_context == null)             {                 _context = new DSPContext();                 Category utilities = new Category(0);                 utilities.Name = "Electric";                 Category financials = new Category(1);                 financials.Name = "Financial";                                 IList products = _context.GetResourceSetEntities("Products");                 Product electric = new Product(0, utilities);                 electric.Name = "ABC Electric";                 electric.Description = "Electric Utility";                 electric.Price = 3.5;                 products.Add(electric);                 Product water = new Product(1, utilities);                 water.Name = "XYZ Water";                 water.Description = "Water Utility";                 water.Price = 2.4;                 products.Add(water);                 Product banks = new Product(2, financials);                 banks.Name = "FatCat Bank";                 banks.Description = "A bank that's almost too big";                 banks.Price = 19.9; // This will never get to the client                 products.Add(banks);                 IList categories = _context.GetResourceSetEntities("Categories");                 categories.Add(utilities);                 categories.Add(financials);                 utilities.Products.Add(electric);                 utilities.Products.Add(electric);                 financials.Products.Add(banks);             }             return _context;         }         /// <summary>         /// Setup rules describing published data structure - relationships between data,         /// key field, other searchable fields, etc.         /// </summary>         /// <returns></returns>         protected override DSPMetadata CreateDSPMetadata()         {             if (_metadata == null)             {                 _metadata = new DSPMetadata("DemoService", "DataServiceProviderDemo");                 // Define entity type product                 ResourceType product = _metadata.AddEntityType(typeof(Product), "Product");                 _metadata.AddKeyProperty(product, "ProductID");                 // Only add properties we wish to share with end users                 _metadata.AddPrimitiveProperty(product, "Name");                 _metadata.AddPrimitiveProperty(product, "Description");                 EntityPropertyMappingAttribute att = new EntityPropertyMappingAttribute("Name",                     SyndicationItemProperty.Title, SyndicationTextContentKind.Plaintext, true);                 product.AddEntityPropertyMappingAttribute(att);                 att = new EntityPropertyMappingAttribute("Description",                     SyndicationItemProperty.Summary, SyndicationTextContentKind.Plaintext, true);                 product.AddEntityPropertyMappingAttribute(att);                 // Define products as a set of product entities                 ResourceSet products = _metadata.AddResourceSet("Products", product);                 // Define entity type category                 ResourceType category = _metadata.AddEntityType(typeof(Category), "Category");                 _metadata.AddKeyProperty(category, "CategoryID");                 _metadata.AddPrimitiveProperty(category, "Name");                 _metadata.AddPrimitiveProperty(category, "Description");                 // Define categories as a set of category entities                 ResourceSet categories = _metadata.AddResourceSet("Categories", category);                 att = new EntityPropertyMappingAttribute("Name",                     SyndicationItemProperty.Title, SyndicationTextContentKind.Plaintext, true);                 category.AddEntityPropertyMappingAttribute(att);                 att = new EntityPropertyMappingAttribute("Description",                     SyndicationItemProperty.Summary, SyndicationTextContentKind.Plaintext, true);                 category.AddEntityPropertyMappingAttribute(att);                 // A product has a category, a category has products                 _metadata.AddResourceReferenceProperty(product, "Category", categories);                 _metadata.AddResourceSetReferenceProperty(category, "Products", products);             }             return _metadata;         }         /// <summary>         /// Based on the requesting user, can set up permissions to Read, Write, etc.         /// </summary>         /// <param name="config"></param>         public static void InitializeService(DataServiceConfiguration config)         {             config.SetEntitySetAccessRule("*", EntitySetRights.All);             config.DataServiceBehavior.MaxProtocolVersion = DataServiceProtocolVersion.V2;             config.DataServiceBehavior.AcceptProjectionRequests = true;         }     } }     The objects prefixed with DSP come from the samples on the oData site: http://www.odata.org/developers The products and categories objects are POCO business objects with no special modifiers. Three main options are available for defining the MetaData of data sources in .Net: 1) Generate Entity Data model (Potentially directly from SQL Server database).  This requires the least amount of manual interaction, and uses the edmx WYSIWYG editor to generate a data model.  This can be directly tied to the SQL Server database and generated from the database if you want a data access layer tightly coupled with your database. 2) Object model decorations.  If you already have a POCO data layer, you can decorate your objects with properties to statically inform the compiler how the objects are related.  The disadvantage is there are now tags strewn about your business layer that need to be updated as the business rules change.  3) Programmatically construct metadata object.  This is the object illustrated above in CreateDSPMetaData.  This puts all relationship information into one central programmatic location.  Here business rules are constructed when the DSPMetaData response object is returned.   Once you have your service up and running, RestSharp is designed for XML / Json, along with the native Microsoft library.  There are currently some differences between how Jason made RestSharp expect XML with how atom+pub works, so I found better results currently with the Json implementation - modifying the RestSharp XML parser to make an atom+pub parser is fairly trivial though, so use what implementation works best for you. I put together a sample console app which calls the RestSvcImpl.svc service defined above (and assumes it to be running on port 2000).  I used both RestSharp as a client, and also the default Microsoft oData client tools. namespace RestConsole {     class Program     {         private static DataServiceContext _ctx;         private enum DemoType         {             Xml,             Json         }         static void Main(string[] args)         {             // Microsoft implementation             _ctx = new DataServiceContext(new System.Uri("http://localhost:2000/RestServiceImpl.svc"));             var msProducts = RunQuery<Product>("Products").ToList();             var msCategory = RunQuery<Category>("/Products(0)/Category").AsEnumerable().Single();             var msFilteredProducts = RunQuery<Product>("/Products?$filter=length(Name) ge 4").ToList();             // RestSharp implementation                          DemoType demoType = DemoType.Json;             var client = new RestClient("http://localhost:2000/RestServiceImpl.svc");             client.ClearHandlers(); // Remove all available handlers             // Set up handler depending on what situation dictates             if (demoType == DemoType.Json)                 client.AddHandler("application/json", new RestSharp.Deserializers.JsonDeserializer());             else if (demoType == DemoType.Xml)             {                 client.AddHandler("application/atom+xml", new RestSharp.Deserializers.XmlDeserializer());             }                          var request = new RestRequest();             if (demoType == DemoType.Json)                 request.RootElement = "d"; // service root element for json             else if (demoType == DemoType.Xml)             {                 request.XmlNamespace = "http://www.w3.org/2005/Atom";             }                              // Return all products             request.Resource = "/Products?$orderby=Name";             RestResponse<List<Product>> productsResp = client.Execute<List<Product>>(request);             List<Product> products = productsResp.Data;             // Find category for product with ProductID = 1             request.Resource = string.Format("/Products(1)/Category");             RestResponse<Category> categoryResp = client.Execute<Category>(request);             Category category = categoryResp.Data;             // Specialized queries             request.Resource = string.Format("/Products?$filter=ProductID eq {0}", 1);             RestResponse<Product> productResp = client.Execute<Product>(request);             Product product = productResp.Data;                          request.Resource = string.Format("/Products?$filter=Name eq '{0}'", "XYZ Water");             productResp = client.Execute<Product>(request);             product = productResp.Data;         }         private static IEnumerable<TElement> RunQuery<TElement>(string queryUri)         {             try             {                 return _ctx.Execute<TElement>(new Uri(queryUri, UriKind.Relative));             }             catch (Exception ex)             {                 throw ex;             }         }              } }   Feel free to step through the code a few times and to attach a debugger to the service as well to see how and where the context and metadata objects are constructed and returned.  Pay special attention to the response object being returned by the oData service - There are several properties of the RestRequest that can be used to help troubleshoot when the structure of the response is not exactly what would be expected.

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  • Awesome Read: Buck Woody&rsquo;s post on the proper use of the Windows Azure VM Role

    - by Enrique Lima
    I have heard some service providers (or cloud providers), hosting companies and such complain, criticize or even venture to call foul on Microsoft’s Azure VM Role.  The problem:  None of them have gone through the effort of truly understanding (or perhaps not wanting to know) what is going on there.  Many have jumped right into the “purist” definition of IaaS, or PaaS for that matter. Ok, Buck’s post is a true gem (my opinion) in the sense it gives you parallels of what the VM Role is and is not.  And it brings Hyper-V and SCVMM to the forefront explaining what it is and what it also offers to the IaaS Microsoft offers. Here is an excerpt of the summary, but please go on over to read his post it will clear a lot if you are wondering when and how to use the Windows Azure VM Role. The excerpt: “Virtualizing servers alone has limitations of scale, availability and recovery. Microsoft’s offering in this area is Hyper-V and System Center, not the VM Role. The VM Role is still used for running Stateless code, just like the Web and Worker Roles, with the exception that it allows you more control over the environment of where that code runs.” The source and post:  Buck Woody -http://blogs.msdn.com/b/buckwoody/archive/2010/12/28/the-proper-use-of-the-vm-role-in-windows-azure.aspx?wa=wsignin1.0

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  • SQL Server DATA Tools CTP4 Released!

    - by hassanfadili
    SQL Server team has released the new SQL Server Data Tools CTP4. Congratulations and Thanks to Gert Drapers and his team with this great milestone. To lear more about this SSDT CTP4 Release, check: What’s new in SQL Server Data Tools CTP4?http://blogs.msdn.com/b/ssdt/archive/2011/11/21/what-s-new-in-sql-server-data-tools-ctp4.aspxSQL Server Data Tools CTP4 vs. VS2010 Database Projectshttp://blogs.msdn.com/b/ssdt/archive/2011/11/21/sql-server-data-tools-ctp4-vs-vs2010-database-projects.aspxTop VSDB->SSDT Project Conversion Issueshttp://blogs.msdn.com/b/ssdt/archive/2011/11/21/top-vsdb-gt-ssdt-project-conversion issues.aspxUninstalling SQL Server Developer Tools CTP3 (Code-named “Juneau”) http://blogs.msdn.com/b/ssdt/archive/2011/11/21/uninstalling-ssdt-ctp3-code-named-juneau.aspxThis actually points to a nifty PowerShell script to help you uninstall.Have Fun.v

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  • Introducing .NET 4.0 with Visual Studio 2010 by Alex Mackey - Book review

    - by Malisa L. Ncube
    Alex (http://simpleisbest.co.uk/) does a very good job in covering the new features of .NET 4.0 and Visual Studio 2010. His focus is on the developers that have experience in development using previous versions of Visual Studio, more specifically Visual Studio 2008.     The following are my views towards his book. 1. Scope / Coverage Even as the book is labeled as introduction, it is covers a broad spectrum of technologies, features and references that are focused into helping a developer quickly decide what to use in the new .NET framework. a. Content The content included covers as much as possible the new additions that are included in the new .NET version 4.0. He shows the Visual Studio 2010 new features and quickly shows how to extend it using Managed Extensibility Framework. Some of my favorites are parallel debugging enhancements. The author delves into JQuery, which Microsoft has decided to support. Some of the very interesting content is on the out-of-band releases including ASP.NET MVC, Windows Azure Silverlight 3 and WCF Data Services. b. What is not included? Windows Phone 7 Series. This was only talked about in the MIX10. The data may not have been available at the time of writing. Microsoft Pinpoint (Microsoft code name "Dallas") Windows Embedded development. c. Table of Contents Chapter 1: Introduction Chapter 2: Visual Studio IDE and MEF Chapter 3: Language and Dynamic Changes Chapter 4: CLR and BCL Changes Chapter 5: Parallelization and Threading Enhancements Chapter 6: Windows Workflow Foundation 4 Chapter 7: Windows Communication Foundation Chapter 8: Entity Framework Chapter 9: WCF Data Services Chapter 10: ASPNET Chapter 11: Microsoft AJAX Library Chapter 12: jQuery Chapter 13: ASPNET MVC Chapter 14: Silverlight Introduction Chapter 15: WPF 4.0 and Silverlight 3.0 Chapter 16: Windows Azure 2. Depth Avoids getting into depth on the topics presented, to present the new concepts in assumption of the developer’s existing knowledge. Code samples are on book and exist mostly as snippets and very easy to follow. There are no downloadable examples. 3. Complexity The book is written in a very simple way and easy to follow. There are no irrelevant intimidating details. So it’s a book that you can grab and never put down until you’ve finished reading the entire book. 4. References The author includes reference links to blogs, Wikis and a lot of online resources including the MSDN documentation, which is a very convenient strategy to avoid flooding the reader with details which may not be of interest to them. Most sites do not use url routing and that is really not nice. There are notes from interviews between the author and people behind the new technologies, in which they explain what some specific areas that need clarifications and what their future views are in relation to the features they are working on. 5. Target The author targets experts that want to make a transition from .NET 3.5 to 4.0. Some obvious 3.5 features have been purposely excluded from the text 6. Overrall It is evident that the author has made extensive research into the breadth of what MS is working on, in relation to .NET and Visual Studio and has also been watching the online community. What I would like to see in the next edition are some details on OData protocol, Expression Blend 4 and Embedded development and Windows Phone development. I should say I’m one of the beneficiaries of this book. Excellent work Alex.   Technorati Tags: .NET,Book-Review,Visual Studio

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  • Entity Framework v1 &ndash; tips and Tricks Part 3

    - by Rohit Gupta
    General Tips on Entity Framework v1 & Linq to Entities: ToTraceString() If you need to know the underlying SQL that the EF generates for a Linq To Entities query, then use the ToTraceString() method of the ObjectQuery class. (or use LINQPAD) Note that you need to cast the LINQToEntities query to ObjectQuery before calling TotraceString() as follows: 1: string efSQL = ((ObjectQuery)from c in ctx.Contact 2: where c.Address.Any(a => a.CountryRegion == "US") 3: select c.ContactID).ToTraceString(); ================================================================================ MARS or MultipleActiveResultSet When you create a EDM Model (EDMX file) from the database using Visual Studio, it generates a connection string with the same name as the name of the EntityContainer in CSDL. In the ConnectionString so generated it sets the MultipleActiveResultSet attribute to true by default. So if you are running the following query then it streams multiple readers over the same connection: 1: using (BAEntities context = new BAEntities()) 2: { 3: var cons = 4: from con in context.Contacts 5: where con.FirstName == "Jose" 6: select con; 7: foreach (var c in cons) 8: { 9: if (c.AddDate < new System.DateTime(2007, 1, 1)) 10: { 11: c.Addresses.Load(); 12: } 13: } 14: } ================================================================================= Explicitly opening and closing EntityConnection When you call ToList() or foreach on a LINQToEntities query the EF automatically closes the connection after all the records from the query have been consumed. Thus if you need to run many LINQToEntities queries over the same connection then explicitly open and close the connection as follows: 1: using (BAEntities context = new BAEntities()) 2: { 3: context.Connection.Open(); 4: var cons = from con in context.Contacts where con.FirstName == "Jose" 5: select con; 6: var conList = cons.ToList(); 7: var allCustomers = from con in context.Contacts.OfType<Customer>() 8: select con; 9: var allcustList = allCustomers.ToList(); 10: context.Connection.Close(); 11: } ====================================================================== Dispose ObjectContext only if required After you retrieve entities using the ObjectContext and you are not explicitly disposing the ObjectContext then insure that your code does consume all the records from the LinqToEntities query by calling .ToList() or foreach statement, otherwise the the database connection will remain open and will be closed by the garbage collector when it gets to dispose the ObjectContext. Secondly if you are making updates to the entities retrieved using LinqToEntities then insure that you dont inadverdently dispose of the ObjectContext after the entities are retrieved and before calling .SaveChanges() since you need the SAME ObjectContext to keep track of changes made to the Entities (by using ObjectStateEntry objects). So if you do need to explicitly dispose of the ObjectContext do so only after calling SaveChanges() and only if you dont need to change track the entities retrieved any further. ======================================================================= SQL InjectionAttacks under control with EFv1 LinqToEntities and LinqToSQL queries are parameterized before they are sent to the DB hence they are not vulnerable to SQL Injection attacks. EntitySQL may be slightly vulnerable to attacks since it does not use parameterized queries. However since the EntitySQL demands that the query be valid Entity SQL syntax and valid native SQL syntax at the same time. So the only way one can do a SQLInjection Attack is by knowing the SSDL of the EDM Model and be able to write the correct EntitySQL (note one cannot append regular SQL since then the query wont be a valid EntitySQL syntax) and append it to a parameter. ====================================================================== Improving Performance You can convert the EntitySets and AssociationSets in a EDM Model into precompiled Views using the edmgen utility. for e.g. the Customer Entity can be converted into a precompiled view using edmgen and all LinqToEntities query against the contaxt.Customer EntitySet will use the precompiled View instead of the EntitySet itself (the same being true for relationships (EntityReference & EntityCollections of a Entity)). The advantage being that when using precompiled views the performance will be much better. The syntax for generating precompiled views for a existing EF project is : edmgen /mode:ViewGeneration /inssdl:BAModel.ssdl /incsdl:BAModel.csdl /inmsl:BAModel.msl /p:Chap14.csproj Note that this will only generate precompiled views for EntitySets and Associations and not for existing LinqToEntities queries in the project.(for that use CompiledQuery.Compile<>) Secondly if you have a LinqToEntities query that you need to run multiple times, then one should precompile the query using CompiledQuery.Compile method. The CompiledQuery.Compile<> method accepts a lamda expression as a parameter, which denotes the LinqToEntities query  that you need to precompile. The following is a example of a lamda that we can pass into the CompiledQuery.Compile() method 1: Expression<Func<BAEntities, string, IQueryable<Customer>>> expr = (BAEntities ctx1, string loc) => 2: from c in ctx1.Contacts.OfType<Customer>() 3: where c.Reservations.Any(r => r.Trip.Destination.DestinationName == loc) 4: select c; Then we call the Compile Query as follows: 1: var query = CompiledQuery.Compile<BAEntities, string, IQueryable<Customer>>(expr); 2:  3: using (BAEntities ctx = new BAEntities()) 4: { 5: var loc = "Malta"; 6: IQueryable<Customer> custs = query.Invoke(ctx, loc); 7: var custlist = custs.ToList(); 8: foreach (var item in custlist) 9: { 10: Console.WriteLine(item.FullName); 11: } 12: } Note that if you created a ObjectQuery or a Enitity SQL query instead of the LINQToEntities query, you dont need precompilation for e.g. 1: An Example of EntitySQL query : 2: string esql = "SELECT VALUE c from Contacts AS c where c is of(BAGA.Customer) and c.LastName = 'Gupta'"; 3: ObjectQuery<Customer> custs = CreateQuery<Customer>(esql); 1: An Example of ObjectQuery built using ObjectBuilder methods: 2: from c in Contacts.OfType<Customer>().Where("it.LastName == 'Gupta'") 3: select c This is since the Query plan is cached and thus the performance improves a bit, however since the ObjectQuery or EntitySQL query still needs to materialize the results into Entities hence it will take the same amount of performance hit as with LinqToEntities. However note that not ALL EntitySQL based or QueryBuilder based ObjectQuery plans are cached. So if you are in doubt always create a LinqToEntities compiled query and use that instead ============================================================ GetObjectStateEntry Versus GetObjectByKey We can get to the Entity being referenced by the ObjectStateEntry via its Entity property and there are helper methods in the ObjectStateManager (osm.TryGetObjectStateEntry) to get the ObjectStateEntry for a entity (for which we know the EntityKey). Similarly The ObjectContext has helper methods to get an Entity i.e. TryGetObjectByKey(). TryGetObjectByKey() uses GetObjectStateEntry method under the covers to find the object, however One important difference between these 2 methods is that TryGetObjectByKey queries the database if it is unable to find the object in the context, whereas TryGetObjectStateEntry only looks in the context for existing entries. It will not make a trip to the database ============================================================= POCO objects with EFv1: To create POCO objects that can be used with EFv1. We need to implement 3 key interfaces: IEntityWithKey IEntityWithRelationships IEntityWithChangeTracker Implementing IEntityWithKey is not mandatory, but if you dont then we need to explicitly provide values for the EntityKey for various functions (for e.g. the functions needed to implement IEntityWithChangeTracker and IEntityWithRelationships). Implementation of IEntityWithKey involves exposing a property named EntityKey which returns a EntityKey object. Implementation of IEntityWithChangeTracker involves implementing a method named SetChangeTracker since there can be multiple changetrackers (Object Contexts) existing in memory at the same time. 1: public void SetChangeTracker(IEntityChangeTracker changeTracker) 2: { 3: _changeTracker = changeTracker; 4: } Additionally each property in the POCO object needs to notify the changetracker (objContext) that it is updating itself by calling the EntityMemberChanged and EntityMemberChanging methods on the changeTracker. for e.g.: 1: public EntityKey EntityKey 2: { 3: get { return _entityKey; } 4: set 5: { 6: if (_changeTracker != null) 7: { 8: _changeTracker.EntityMemberChanging("EntityKey"); 9: _entityKey = value; 10: _changeTracker.EntityMemberChanged("EntityKey"); 11: } 12: else 13: _entityKey = value; 14: } 15: } 16: ===================== Custom Property ==================================== 17:  18: [EdmScalarPropertyAttribute(IsNullable = false)] 19: public System.DateTime OrderDate 20: { 21: get { return _orderDate; } 22: set 23: { 24: if (_changeTracker != null) 25: { 26: _changeTracker.EntityMemberChanging("OrderDate"); 27: _orderDate = value; 28: _changeTracker.EntityMemberChanged("OrderDate"); 29: } 30: else 31: _orderDate = value; 32: } 33: } Finally you also need to create the EntityState property as follows: 1: public EntityState EntityState 2: { 3: get { return _changeTracker.EntityState; } 4: } The IEntityWithRelationships involves creating a property that returns RelationshipManager object: 1: public RelationshipManager RelationshipManager 2: { 3: get 4: { 5: if (_relManager == null) 6: _relManager = RelationshipManager.Create(this); 7: return _relManager; 8: } 9: } ============================================================ Tip : ProviderManifestToken – change EDMX File to use SQL 2008 instead of SQL 2005 To use with SQL Server 2008, edit the EDMX file (the raw XML) changing the ProviderManifestToken in the SSDL attributes from "2005" to "2008" ============================================================= With EFv1 we cannot use Structs to replace a anonymous Type while doing projections in a LINQ to Entities query. While the same is supported with LINQToSQL, it is not with LinqToEntities. For e.g. the following is not supported with LinqToEntities since only parameterless constructors and initializers are supported in LINQ to Entities. (the same works with LINQToSQL) 1: public struct CompanyInfo 2: { 3: public int ID { get; set; } 4: public string Name { get; set; } 5: } 6: var companies = (from c in dc.Companies 7: where c.CompanyIcon == null 8: select new CompanyInfo { Name = c.CompanyName, ID = c.CompanyId }).ToList(); ;

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  • Finding the problem on a partially succeeded build

    - by Martin Hinshelwood
    Now that I have the Build failing because of a genuine bug and not just because of a test framework failure, lets see if we can trace through to finding why the first test in our new application failed. Lets look at the build and see if we can see why there is a red cross on it. First, lets open that build list. On Team Explorer Expand your Team Project Collection | Team Project and then Builds. Double click the offending build. Figure: Opening the Build list is a key way to see what the current state of your software is.   Figure: A test is failing, but we can now view the Test Results to find the problem      Figure: You can quite clearly see that the test has failed with “The device is not ready”. To me the “The Device is not ready” smacks of a System.IO exception, but it passed on my local computer, so why not on the build server? Its a FaultException so it is most likely coming from the Service and not the client, so lets take a look at the client method that the test is calling: bool IProfileService.SaveDefaultProjectFile(string strComputerName) { ProjectFile file = new ProjectFile() { ProjectFileName = strComputerName + "_" + System.DateTime.Now.ToString("yyyyMMddhhmmsss") + ".xml", ConnectionString = "persist security info=False; pooling=False; data source=(local); application name=SSW.SQLDeploy.vshost.exe; integrated security=SSPI; initial catalog=SSWSQLDeployNorthwindSample", DateCreated = System.DateTime.Now, DateUpdated = System.DateTime.Now, FolderPath = @"C:\Program Files\SSW SQL Deploy\SampleData\", IsComplete=false, Version = "1.3", NewDatabase = true, TimeOut = 5, TurnOnMSDE = false, Mode="AutomaticMode" }; string strFolderPath = "D:\\"; //LocalSettings.ProjectFileBasePath; string strFileName = strFolderPath + file.ProjectFileName; try { using (FileStream fs = new FileStream(strFileName, FileMode.Create)) { DataContractSerializer serializer = new DataContractSerializer(typeof(ProjectFile)); using (XmlDictionaryWriter writer = XmlDictionaryWriter.CreateTextWriter(fs)) { serializer.WriteObject(writer, file); } } } catch (Exception ex) { //TODO: Log the exception throw ex; return false; } return true; } Figure: You can see on lines 9 and 18 that there are calls being made to specific folders and disks. What is wrong with this code? What assumptions mistakes could the developer have made to make this look OK: That every install would be to “C:\Program Files\SSW SQL Deploy” That every computer would have a “D:\\” That checking in code at 6pm because the had to go home was a good idea. lets solve each of these problems: We are in a web service… lets store data within the web root. So we can call “Server.MapPath(“~/App_Data/SSW SQL Deploy\SampleData”) instead. Never reference an explicit path. If you need some storage for your application use IsolatedStorage. Shelve your code instead. What else could have been done? Code review before check-in – The developer should have shelved their code and asked another dev to look at it. Use Defensive programming – Make sure that any code that has the possibility of failing has checks. Any more options? Let me know and I will add them. What do we do? The correct things to do is to add a Bug to the backlog, but as this is probably going to be fixed in sprint, I will add it directly to the sprint backlog. Right click on the failing test Select “Create Work Item | Bug” Figure: Create an associated bug to add to the backlog. Set the values for the Bug making sure that it goes into the right sprint and Area. Make your steps to reproduce as explicit as possible, but “See test” is valid under these circumstances.   Figure: Add it to the correct Area and set the Iteration to the Area name or the Sprint if you think it will be fixed in Sprint and make sure you bring it up at the next Scrum Meeting. Note: make sure you leave the “Assigned To” field blank as in Scrum team members sign up for work, you do not give it to them. The developer who broke the test will most likely either sign up for the bug, or say that they are stuck and need help. Note: Visual Studio has taken care of associating the failing test with the Bug. Save… Technorati Tags: WCF,MSTest,MSBuild,Team Build 2010,Team Test 2010,Team Build,Team Test

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  • Silverlight Cream for March 08, 2010 -- #809

    - by Dave Campbell
    In this Issue: Michael Washington, Tim Greenfield, Bobby Diaz(-2-), Glenn Block(-2-), Nikhil Kothari, Jianqiang Bao(-2-), and Christopher Bennage. Shoutouts: Adam Kinney announced a Big update for the Project Rosetta site today Arpit Gupta has opened a new blog with a great logo: I think therefore I am dangerous :) From SilverlightCream.com: DotNetNuke Silverlight Traffic Module If it's DNN and Silverlight, it has to be my buddy Michael Washington :) ... Michael has combined those stunning gauges you've seen with website traffic... just too cool!... grab the code and display yours too! Cool demonstration of Silverlight VideoBrush This is a no-code post by Tim Greenfield, but I like the UX on this Jigsaw Puzzle page... and you can make your own. Introducing the Earthquake Locator – A Bing Maps Silverlight Application, part 1 Bobby Diaz has an informative post up on combining earthquake data with BingMaps in Silverlight 3... check it out, the grab the recently posted Live Demo and Source Code Adding Volcanos and Options - Earthquake Locator, part 2 Bobby Diaz also added volcanic activity to his earthquake BinMaps app, and updated the downloadable code and live demo. Building Hello MEF – Part IV – DeploymentCatalog Glenn Block posted a pair of MEF posts yesterday... made me think I missed one :) .. the first one is about the DeploymentCatalog. Note he is going to be using the CodePlex bits in his posts. Building HelloMEF – Part V – Refactoring to ViewModel Glenn Block's part V is about MEF and MVVM -- no, really! ... he is refactoring MVVM into the app with a nod to Josh Smith and Laurent Bugnion... get your head around this... The Case for ViewModel Nikhil Kothari has a post up about the ViewModel, and how it facilitates designer/developer workflow, jumpstarts development, improves scaling, and makes asynch programming development simpler MMORPG programming in Silverlight Tutorial (12)Map Instance (Part I) Jianqiang Bao has part 12 of his MMORPG game up... this one is showing how to deal with obstuctions on maps. MMORPG programming in Silverlight Tutorial (13)Perfect moving mechanism Jianqiang Bao also has part 13 up, and this second one is about sprite movement around the obstructions. 1 Simple Step for Commanding in Silverlight Christopher Bennage blogged about Commanding in Silverlight, he begins with a blog post about commands in Silverlight 4 then goes on to demonstrate the Caliburn way of doing commanding. 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    MIX10

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  • An end to the static &hellip;

    - by Dave Oliver
    Last October I learnt my company wanted to put together a new blog/social networking policy. I decided that out of respect for my employer I wouldn’t blog until this was sorted out. This was perhaps was an easy decision to make as I was separating from my ex-wife at the time and frankly needed the time to concentrate on other things. So now the company has a brand new policy and I’m back into the dating game I thought I would blow off the cobwebs and get back to what I enjoy doing. First and foremost SQL Server 2008 R2 is almost here and to mark that fact I will be in London on Thursday at the Microsoft UK Tech-Day’s event. The subjects I most want to see are … Power Pivot – this is such an exciting technology! I’ve been a fan of Qlikview for years so it will be good to see how it compares SQL Azure – Cloud Computing is big right now, so it will be interesting to see what the RTM product can do. I have afew ideas for its use and will be interesting to see if SQL Azure is the right product … more on this in the next few weeks. Master Data Services – This is one of those technologies that Microsoft hasn’t been making much noise about … and frankly should have because it is a game changer. Hmmm, queue future “What is … ?” post StreamInsight – An exciting events technology, again another “What is … ?” post is around the corner on that. So, you thought that SQL Server 2008 R2 was just a release to make sure the years between SQL Server 2008 and SQL Server 2010 weren’t so long? I am however disappointed that Clustering across Subnets didn’t make it and not sure if Control Points made it but all will be revealed later on this week. Till then I will have to wait! Technorati Tags: Microsoft,Techdays,SQL Server 2008 R2

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  • Performance considerations for common SQL queries

    - by Jim Giercyk
    Originally posted on: http://geekswithblogs.net/NibblesAndBits/archive/2013/10/16/performance-considerations-for-common-sql-queries.aspxSQL offers many different methods to produce the same results.  There is a never-ending debate between SQL developers as to the “best way” or the “most efficient way” to render a result set.  Sometimes these disputes even come to blows….well, I am a lover, not a fighter, so I decided to collect some data that will prove which way is the best and most efficient.  For the queries below, I downloaded the test database from SQLSkills:  http://www.sqlskills.com/sql-server-resources/sql-server-demos/.  There isn’t a lot of data, but enough to prove my point: dbo.member has 10,000 records, and dbo.payment has 15,554.  Our result set contains 6,706 records. The following queries produce an identical result set; the result set contains aggregate payment information for each member who has made more than 1 payment from the dbo.payment table and the first and last name of the member from the dbo.member table.   /*************/ /* Sub Query  */ /*************/ SELECT  a.[Member Number] ,         m.lastname ,         m.firstname ,         a.[Number Of Payments] ,         a.[Average Payment] ,         a.[Total Paid] FROM    ( SELECT    member_no 'Member Number' ,                     AVG(payment_amt) 'Average Payment' ,                     SUM(payment_amt) 'Total Paid' ,                     COUNT(Payment_No) 'Number Of Payments'           FROM      dbo.payment           GROUP BY  member_no           HAVING    COUNT(Payment_No) > 1         ) a         JOIN dbo.member m ON a.[Member Number] = m.member_no         /***************/ /* Cross Apply  */ /***************/ SELECT  ca.[Member Number] ,         m.lastname ,         m.firstname ,         ca.[Number Of Payments] ,         ca.[Average Payment] ,         ca.[Total Paid] FROM    dbo.member m         CROSS APPLY ( SELECT    member_no 'Member Number' ,                                 AVG(payment_amt) 'Average Payment' ,                                 SUM(payment_amt) 'Total Paid' ,                                 COUNT(Payment_No) 'Number Of Payments'                       FROM      dbo.payment                       WHERE     member_no = m.member_no                       GROUP BY  member_no                       HAVING    COUNT(Payment_No) > 1                     ) ca /********/                    /* CTEs  */ /********/ ; WITH    Payments           AS ( SELECT   member_no 'Member Number' ,                         AVG(payment_amt) 'Average Payment' ,                         SUM(payment_amt) 'Total Paid' ,                         COUNT(Payment_No) 'Number Of Payments'                FROM     dbo.payment                GROUP BY member_no                HAVING   COUNT(Payment_No) > 1              ),         MemberInfo           AS ( SELECT   p.[Member Number] ,                         m.lastname ,                         m.firstname ,                         p.[Number Of Payments] ,                         p.[Average Payment] ,                         p.[Total Paid]                FROM     dbo.member m                         JOIN Payments p ON m.member_no = p.[Member Number]              )     SELECT  *     FROM    MemberInfo /************************/ /* SELECT with Grouping   */ /************************/ SELECT  p.member_no 'Member Number' ,         m.lastname ,         m.firstname ,         COUNT(Payment_No) 'Number Of Payments' ,         AVG(payment_amt) 'Average Payment' ,         SUM(payment_amt) 'Total Paid' FROM    dbo.payment p         JOIN dbo.member m ON m.member_no = p.member_no GROUP BY p.member_no ,         m.lastname ,         m.firstname HAVING  COUNT(Payment_No) > 1   We can see what is going on in SQL’s brain by looking at the execution plan.  The Execution Plan will demonstrate which steps and in what order SQL executes those steps, and what percentage of batch time each query takes.  SO….if I execute all 4 of these queries in a single batch, I will get an idea of the relative time SQL takes to execute them, and how it renders the Execution Plan.  We can settle this once and for all.  Here is what SQL did with these queries:   Not only did the queries take the same amount of time to execute, SQL generated the same Execution Plan for each of them.  Everybody is right…..I guess we can all finally go to lunch together!  But wait a second, I may not be a fighter, but I AM an instigator.     Let’s see how a table variable stacks up.  Here is the code I executed: /********************/ /*  Table Variable  */ /********************/ DECLARE @AggregateTable TABLE     (       member_no INT ,       AveragePayment MONEY ,       TotalPaid MONEY ,       NumberOfPayments MONEY     ) INSERT  @AggregateTable         SELECT  member_no 'Member Number' ,                 AVG(payment_amt) 'Average Payment' ,                 SUM(payment_amt) 'Total Paid' ,                 COUNT(Payment_No) 'Number Of Payments'         FROM    dbo.payment         GROUP BY member_no         HAVING  COUNT(Payment_No) > 1   SELECT  at.member_no 'Member Number' ,         m.lastname ,         m.firstname ,         at.NumberOfPayments 'Number Of Payments' ,         at.AveragePayment 'Average Payment' ,         at.TotalPaid 'Total Paid' FROM    @AggregateTable at         JOIN dbo.member m ON m.member_no = at.member_no In the interest of keeping things in groupings of 4, I removed the last query from the previous batch and added the table variable query.  Here’s what I got:     Since we first insert into the table variable, then we read from it, the Execution Plan renders 2 steps.  BUT, the combination of the 2 steps is only 22% of the batch.  It is actually faster than the other methods even though it is treated as 2 separate queries in the Execution Plan.  The argument I often hear against Table Variables is that SQL only estimates 1 row for the table size in the Execution Plan.  While this is true, the estimate does not come in to play until you read from the table variable.  In this case, the table variable had 6,706 rows, but it still outperformed the other queries.  People argue that table variables should only be used for hash or lookup tables.  The fact is, you have control of what you put IN to the variable, so as long as you keep it within reason, these results suggest that a table variable is a viable alternative to sub-queries. If anyone does volume testing on this theory, I would be interested in the results.  My suspicion is that there is a breaking point where efficiency goes down the tubes immediately, and it would be interesting to see where the threshold is. Coding SQL is a matter of style.  If you’ve been around since they introduced DB2, you were probably taught a little differently than a recent computer science graduate.  If you have a company standard, I strongly recommend you follow it.    If you do not have a standard, generally speaking, there is no right or wrong answer when talking about the efficiency of these types of queries, and certainly no hard-and-fast rule.  Volume and infrastructure will dictate a lot when it comes to performance, so your results may vary in your environment.  Download the database and try it!

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  • Knockoutjs - stringify to handling observables and custom events

    - by Renso
    Goal: Once you viewmodel has been built and populated with data, at some point it goal of it all is to persist the data to the database (or some other media). Regardless of where you want to save it, your client-side viewmodel needs to be converted to a JSON string and sent back to the server. Environment considerations: jQuery 1.4.3+ Knockoutjs version 1.1.2   How to: So let’s set the stage, you are using Knockoutjs and you have a viewmodel with some Knockout dependencies. You want to make sure it is in the proper JSON format and via ajax post it to the server for persistence.   First order of business is to deal with the viewmodel (JSON) object. To most the JSON stringifier sounds familiar. The JSON stringifier converts JavaScript data structures into JSON text. JSON does not support cyclic data structures, so be careful to not give cyclical structures to the JSON stringifier. You may ask, is this the best way to do it? What about those observables and other Knockout properties that I don’t want to persist or want their actual value persisted and not their function, etc. Not sure if you were aware, but KO already has a method; ko.utils.stringifyJson() - it's mostly just a wrapper around JSON.stringify. (which is native in some browsers, and can be made available by referencing json2.js in others). What does it do that the regular stringify does not is that it automatically converts observable, dependentObservable, or observableArray to their underlying value to JSON. Hold on! There is a new feature in this version of Knockout, the ko.toJSON. It is part of the core library and it will clone the view model’s object graph, so you don’t mess it up after you have stringified  it and unwrap all its observables. It's smart enough to avoid reference cycles. Since you are using the MVVM pattern it would assume you are not trying to reference DOM nodes from your view. Wait a minute. I can already see this info on the http://knockoutjs.com/examples/contactsEditor.html website, why mention it all here? First of this is a much nicer blog, no orange ? At this time, you may want to have a look at the blog and see what I am talking about. See the save event, how they stringify the view model’s contacts only? That’s cool but what if your view model is a representation of your object you want to persist, meaning it has no property that represents the json object you want to persist, it is the view model itself. The example in http://knockoutjs.com/examples/contactsEditor.html assumes you have a list of contacts you may want to persist. In the example here, you want to persist the view model itself. The viewmodel here looks something like this:     var myViewmodel = {         accountName: ko.observable(""),         accountType: ko.observable("Active")     };     myViewmodel.isItActive = ko.dependentObservable(function () {         return myViewmodel.accountType() == "Active";     });     myViewmodel.clickToSaveMe = function() {         SaveTheAccount();     }; Here is the function in charge of saving the account: Function SaveTheAccount() {     $.ajax({         data: ko.toJSON(viewmodel),         url: $('#ajaxSaveAccountUrl').val(),         type: "POST",         dataType: "json",         async: false,         success: function (result) {             if (result && result.Success == true) {                 $('#accountMessage').html('<span class="fadeMyContainerSlowly">The account has been saved</span>').show();                 FadeContainerAwaySlowly();             }         },         error: function (xmlHttpRequest, textStatus, errorThrown) {             alert('An error occurred: ' + errorThrown);         }     }); //ajax }; Try run this and your browser will eventually freeze up or crash. Firebug will tell you that you have a repetitive call to the first function call in your model that keeps firing infinitely.  What is happening is that Knockout serializes the view model to a JSON string by traversing the object graph and firing off the functions, again-and-again. Not sure why it does that, but it does. So what is the work around: Nullify your function calls and then post it:         var lightweightModel = viewmodel.clickToSaveMe = null;         data: ko.toJSON(lightweightModel), So then I traced the JSON string on the server and found it having issues with primitive types. C#, by the way. So I changed ko.toJSON(model) to ko.toJS(model), and that solved my problem. Of course you could just create a property on the viewmodel for the account itself, so you only have to serialize the property and not the entire viewmodel. If that is an option then that would be the way to go. If your view model contains other properties in the view model that you also want to post then that would not be an option and then you’ll know what to watch out for. Hope this helps.

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  • Silverlight Cream for March 10, 2010 -- #810

    - by Dave Campbell
    In this Issue: Andrea Boschin, Jeremy Likness(-2-), Andrew Veresov, Nokola, SilverLaw, Gill Cleeren, Jim Wightman and Jeremy Likness, Viktor Larsson(-2-), and Walter Ferrari. Shoutouts: Viktor Larsson has a post up about Silverlight Market Penetration ... hope to meet you at MIX10, Viktor! Gergely Orosz has posted the Slides and code for the presentation “An Introduction to Silverlight” It appears that if I miss a day, I can pretty much do an all-submittal post :) From SilverlightCream.com: Writing an AsyncLoader to enqueue long running operations Andrea Boschin has a tutorial on SilverlightShow where he's building up an asynch service to deal with a long-running app on the server. MVVM with MEF in Silverlight: Video Tutorial Jeremy Likness has a video tutorial up for helping beginners wire up MVVM and MEF to Silverlight. Source code for the app in the video is downloadable. MVVM with MEF in Silverlight Video Tutorial Part 2: Plugins and Metadata In part 2, Jeremy Likness redesigns the app using metadata to turn the shapes into objects, and then show how easy it is to add a new plugin... and the source for the app is downloadable. Binding a Converter Parameter Andrew Veresov has a nice code-filled solution up for those times that you need to bind a ConverterParameter value. EasyPainter: Lion Hair styling Nokola has not been idle with Easy Painter... now he's added "Lion Hair" to the list of stylings you can apply... guess if you want to change someone's 'mane' ... sorry! Twisting Navigation - Silverlight 3 SilverLaw has another control up - a "Twisting Navigation" control... very cool :) ... and since I'm behind the curve, he already has an update in the Expression Gallery as noted in his post, and a video tutorial on implementing it in an application... and if you understand German, turn up the sound :) Uploading and downloading images using a WCF service with Silverlight Gill Cleeren has a tutorial up at SilverlightShow on uploading and downloading images using WCF Services in Silverlight New Windows Phone 7 Community Developer Hub Jim Wightman and Jeremy Likness have a very cool Silverlight page up where you can paste the URL of your XAP in and have it display in a "Windows 7 Series Phone" ... and that's all I'm saying about that. XAML Transformation 101 Viktor Larsson is discussing Transforms in XAML and has a nice tutorial up that is easily the beginning of a carousel... you may also want to check out his other posts... I'm adding him to my list. Silverlight 4 Webcam Demo In this post, Viktor Larsson has a tutorial up for using the WebCam. This is from a beginner perspective, so if you haven't jumped in, now's a good time. How to extend Bing Maps Silverlight with an elevation profile graph - Part 1 Walter Ferrari has a post up at SilverlightShow discussing extensions to BingMaps such as creating routes using GeoCoding and Route Services plus drawing lines on the maps and getting coordinates of the points. 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    MIX10

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  • Expression Studio 4 - without SketchFlow&hellip;

    - by mbcrump
    is kinda like an explosion with no “Ka-Boom”… I was excited to hear the news yesterday at Microsoft Teched that Expression Studio 4 had officially launched. MSDN subscribers could log in and download the full release. So, I logged into my MSDN account and started downloading Expression Studio 4 Premium thinking that I was only minutes away from trying out SketchFlow 4. To my dismay, I launched Blend 4 and noticed it did not say SketchFlow on the splash screen. So, I went to New Project and the template was not available. After some digging around on the net, I learned my premium MSDN subscription did not include SketchFlow and I would need to purchase the Ultimate Edition. Below is a excerpt directly from Microsoft: Q: What products are included in the Microsoft Expression Studio 4 Ultimate? A: Expression Studio 4 Ultimate is comprised of 4 products, Expression Web 4, Microsoft Expression Blend® 4 + SketchFlow, Expression Encoder 4 Pro and Expression Design 4. Expression Blend 4 includes SketchFlow in Expression Studio 4 Ultimate product only. Q: What products are included in the Microsoft Expression Studio 4 Premium? A: Expression Studio 4 Premium is comprised of 4 products, Expression Web 4, Microsoft Expression Blend 4, Expression Encoder 4 and Expression Design 4. Expression Studio 4 Premium is not available for retail purchase. Q: What products are included in the Microsoft Expression Studio 4 Web Professional? A: Expression Studio 4 Web Professional is comprised of 3 products, Expression Web 4, Expression Encoder 4 and Expression Design 4. As you can see, we got screwed on this deal and plenty of people are complaining: Kiran Says: 6.07.2010 at 5:07 PM No SketchFlow for Expression Studio 4 Premium? What a bumper for Microsoft Partners!! Martin Says: 6.07.2010 at 6:18 PM Why does Expression Professional Subscription not include upgrades and new releases of Expression Studio. Good question hey. I bought my subscription 5 days ago thinking I would get what i purchased but no Expression upgrades or new releases for me, what a waste of money. I think I am not the only long term user of this software that feels disgruntled. Sorry john just had to tell someone. shaggygi Says: 6.07.2010 at 7:31 PM SketchFlow NOT included in Studio 4? WTF! I repeat.... WT...Freaking.... F! This is totally unacceptable. My development team purchased VS 2010 Premium w/ MSDN with the impression by Adam Kinney, Scott Guthrie, etc. that this would be included in the Premium package or some sort of free upgrade. I understand this is a Marketing thing, but come on! I believe, at very least, this should have been explained in detail before this release. John Papa... as a rep to give feedback to the team... Please please and please.... tell powers-at-be to fix this problem. Sorry for the rant. Besides this issue, I believe it is a very good product:) Thanks Vaclav Elias Says: 6.08.2010 at 4:30 AM Well, I am also not happy that SketchFlow is only for the chosen ones :-) It is very nice product. Actually, kind of foundation for web development so they could really support any MSDN subscribers.. :-( I am hoping that Microsoft will make this right for all of us with MSDN premier subscriptions. In the meantime,  you can check out the 5 day training series available here.

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  • Service Level Loggin/Tracing

    - by Ahsan Alam
    We all love to develop services, right? First timers want to learn technologies like WCF and Web Services. Some simply want to build services; whereas, others may find services as natural architectural decision for particular systems. Whatever the reason might be, services are commonly used in building wide range of systems. Developers often encapsulates various functionality (small or big) within one or more services, and expose them for multiple applications. Sometimes from day one (and definitely over time) these services may evolve into a set of black boxes. Services or not, black boxes or not, issues and exceptions are sometimes hard to avoid, especially in highly evolving and transactional systems. We can try to be methodical with our unit testing, QA and overall process; but we may not be able to avoid some type of system issues. When issues arise from one or more highly transactional services, it becomes necessary to resolve them very quickly. When systems handle thousands of transaction in matter of hours, some issues may not surface immediately. That is when service level logging becomes very useful. Technologies such as WCF, allow us to enable service level tracing with minimal effort; but that may not provide us with complete picture. Developers may need to add tracing within critical areas of the code with various degrees of verbosity. Programmer can always utilize some logging framework such as the 'Logging Application Block' to get the job done. It may seem overkill sometimes; but I have noticed from my experience that service level logging helps programmer trace many issues very quickly.

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