Invalid Viewstate during Load Testing Web Farm

[Joe Sugden]

Hello,

We have a load balanced web farm that we want to load test.
All web servers are set to use the same machine key in web.config. The load-balancer is configured for sticky session.

We have a Web Test that executes successfully. We used it to create a Load test. However the load test is causing the following server error:

System.Web.HttpException: Validation of viewstate MAC failed. If this application is hosted by a Web Farm or cluster, ensure that configuration specifies the same validationKey and validation algorithm. AutoGenerate cannot be used in a cluster.
at System.Web.UI.ViewStateException.ThrowMacValidationError(Exception inner, String persistedState)
at System.Web.UI.ObjectStateFormatter.Deserialize(String inputString, Purpose purpose)
at System.Web.UI.Util.DeserializeWithAssert(IStateFormatter2 formatter, String serializedState, Purpose purpose)
at System.Web.UI.HiddenFieldPageStatePersister.Load()
at System.Web.UI.Page.LoadPageStateFromPersistenceMedium()
at System.Web.UI.Page.LoadAllState()
at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
at System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
at System.Web.UI.Page.ProcessRequest()
at System.Web.UI.Page.ProcessRequest(HttpContext context)
at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

If I disable mac validation in config, it still does not work and message is:

System.Web.HttpException: The state information is invalid for this page and might be corrupted.
at System.Web.UI.ViewStateException.ThrowError(Exception inner, String persistedState, String errorPageMessage, Boolean macValidationError)
at System.Web.UI.HiddenFieldPageStatePersister.Load()
at System.Web.UI.Page.LoadPageStateFromPersistenceMedium()
at System.Web.UI.Page.LoadAllState()
at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
at System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
at System.Web.UI.Page.ProcessRequest()
at System.Web.UI.Page.ProcessRequest(HttpContext context)
at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

[Joe Sugden]

I only found this old article with the same problem with of no help...http://www.telerik.com/community/forums/aspnet-ajax/async-upload/radasyncupload-in-web-farm.aspx

[Cody]

Hello Joe,

Is sounds like the ASP.NET __VIEWSTATE hidden variable is giving you problems. Did you select this as a dynamic target? If not, please check all __VIEWSTATE's listed in the dynamic target. Without it being selected the load test will simply echo what the value was at the time of recording. If it the correct value changes at run time you will run into this problem.

If that doesn't help I'll need additional information:

• A copy of your load test. This will be a .tstest file found in the project folder
• A Fiddler trace of the load test trying to run. This will show me what actually was send and received on the wire. Please configure the load test to start and end with only 1 VU so that I can follow it.

Regards,
Cody
Telerik

[Joe Sugden]

I re-recorded the test and started working with 1 user...
It did not give me an option to select the __VIEWSTATE  as a dynamic target, only query string parameters, see attached image.

However, for whatever reason it does not work now for more than one user - the dynamic query string parameters don't kick in and it is trying to request the same static URL every time...

[Cody]

Hi Joe,

Unfortunately I can't diagnose what is causing the problem having only a screen shot of the dynamic targets. To further diagnose what and where the load test is going wrong I really need:

• A copy of your load test. This will be a .tstest file found in the project folder
• A Fiddler trace of the load test trying to run. This will show me what actually was sent and received on the wire. Please configure the load test to start and end with only 1 VU so that I can follow it.

Regards,
Cody
Telerik