WCF Load Test

Just published on CodePlex  –WCF Load Test tool.

Project Description from the project home page on CodePlex:

This tool takes a WCF trace file and a WCF client proxy, or a WCF interface contract, and generates a unit test that replays the same sequence of calls found in the trace file. The code generated is easily modifiable so that data variation can be introduced for the purpose of doing performance testing.
The tool generates code for both Visual Studio 2005 and Visual Studio 2008. It also installs a wizard into both editions of Visual Studio for creating the trace and processing it from inside Visual Studio. If both editions are present the tool is installed into both editions. The source code is a Visual Studio 2005 project.

Latest Release June 2009

A new beta was released in June 2009 adding support for ASMX web services. Download it from here.


The tool has the following main features:

  • Replay of captured scenario in a unit test that can be included in a load test.
  • Support for the DataContractSerializer.
  • Support for message contracts.
  • ASMX support (beta)
  • Support for proxies generated using svcutil.
  • Support for clients that create proxies at run time from contract interfaces.
  • Supports calls to multiple services in a single scenario.
  • Supports multiple calls to the same service operation.
  • Filtering by SOAP action of which messages in the trace to replay.
  • Readable and modifiable code is generated.
  • Automatic association of trace message with proxy method (requires all operations to have a unique SOAP action).
  • Support for client and server side traces.
  • A command line tool for processing traces and generating code.
  • Visual Studio 2005/2008 integration (Team Developer, Team Test, Team Suite and for 2008 also Professional)) that can be used instead of the command line tool.

WCF Impersonation With Client

If you have a service that uses Windows authentication and you want to impersonate the caller you need to configure the client and the server.

This is the client proxy. You need to give it the correct credentials.

client.ClientCredentials.Windows.ClientCredential.Domain = "DOMAINName";
client.ClientCredentials.Windows.ClientCredential.UserName = "UserName";
client.ClientCredentials.Windows.ClientCredential.Password = "Password";
client.ClientCredentials.Windows.AllowedImpersonationLevel = System.Security.Principal.TokenImpersonationLevel.Impersonation;

The server side looks like this:

using (ServiceSecurityContext.Current.WindowsIdentity.Impersonate())

This impersonate part of the method. This property impersonate all method:

[OperationBehavior(Impersonation = ImpersonationOption.Required)]

Client Impersonation in WCF

Recently I got a question about impersonation in WCF. What should we do in order to impersonate the client?

It’s simple:

Client Side

// Create a client with given client endpoint configuration
MyServiceClient client = new MyServiceClient();
client.ClientCredentials.Windows.AllowedImpersonationLevel = TokenImpersonationLevel.Impersonation;

Server Side

if (ServiceSecurityContext.Current.WindowsIdentity.ImpersonationLevel == TokenImpersonationLevel.Impersonation ||   ServiceSecurityContext.Current.WindowsIdentity.ImpersonationLevel == TokenImpersonationLevel.Delegation)
// Impersonate.
Console.WriteLine("Impersonating the caller");

svcutil.exe in Orcas Beta 2 problem

Posted also at: Maor David – The Blog.

When I trying to run WCF test service on VS 2008 beta 2 I got an error:

Unhandled Exception: System.IO.FileLoadException: Could not load file or assembly ’svcutil, Version=, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a’ or one of its dependencies. Strong name validation failed. (Exception from HRESULT: 0×8013141A)

File name: ’svcutil, Version=, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a’ —> System.Security.SecurityException: Strong name validation failed. (Exception from HRESULT: 0×8013141A)

It turns out that this is a known issue in Beta2. Svcutil.exe is not signed correctly.

I found a solution for this issue at WCF MSDN forum: http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=1932994&SiteID=1&pageid=0

The solution is:

1. Open the VS 2008 Beta 2 command prompt as Administrator (important especially in Vista).

2. Browse to the bin directory of the windows SDK ([C]:Program FilesMicrosoft SDKsWindowsv6.0ABin)

3. Type: sn –Vr svcutil.exe.


By the way,  sn -Vr will not sign it but rather tell .NET to skip signature verification for that assembly.

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WCF, WF and Windows CardSpace Samples available

Samples for Windows Communication Foundation (WCF), Windows Workflow Foundation (WF) and Windows CardSpace is available for download here. These samples are based on the .Net Framework 3.5 and were recently updated to work with Visual Studio 2008 Beta 2.

WCF performance – Is it really better?

MSDN introduce a Performance Comparison of Windows Communication Foundation (WCF) with Existing Distributed Communication Technologies.

The conclusion is that “WCF is 25%-50% faster than ASP.NET Web Services, and approximately 25% faster than .NET Remoting. Comparison with .NET Enterprise Service is load dependant, as in one case WCF is nearly 100% faster but in another scenario it is nearly 25% slower. For WSE 2.0/3.0 implementations, migrating them to WCF will obviously provide the most significant performance gains of almost 4x.”

You can fine the entire comparison here.

Enterprise Library 3.1 Released

Enterprise Library 3.1 just Released: It is a maintenance release to fix a few bugs. It also includes an extension point in the Policy Injection Application Block that allows you to replace the injection mechanism.

Changes per Tom Hollander:

Policy Injection Application Block

  • The default Remoting Policy Injector can now be replaced with alternative interception mechanisms via configuration without modifying the application block code
  • Call Handler attributes are now honored correctly when placed on interface methods
  • Fixed an issue that could cause duplicate handlers where matching rules matched both a class and its interface
  • Classes implementing COM interfaces (including those deriving from System.Windows.Forms.Form) can now be intercepted
  • TraceLogEntry class is now serializable, allowing it to be used with the MSMQ Trace Listener

Validation Application Block

  • Fixed an issue that prevented the PropertyComparisonValidator from working with the Windows Forms integration adapter
  • The message template for the PropertyComparisonValidator can now be saved using the configuration tools.

Data Access Application Block

  • Connection strings for OLEDB and ODBC connections can now be edited using custom dialog boxes from the configuration tools

You can download it here.

WCF Articles

In order to introduce Windows Communication Foundation (WCF) I'm starting a series of posts here.

Most of the applications now requires to support the SOA architecture, means that the application should provide a service interfaces to be exposed to other applications. These interfaces can be exposed using many technologies: Web Services, COM+ and so on. Each technology is completely defferent from the other, and requires special knowledge of coding.

WCF makes life better. WCF helps developers to expose service interfaces using any technology. WCF has same set of functions and attributes that will be used for all technologies (bindings).

From every post I'll refer to this post and I'll keep a TOC here so you can easily navigate in the blog.


  1. What is service ABC? Basic client/Server application.

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