"Report is unavailable or session has expired."

[AH]

Hello there.

I am using Telerik Reporting in Silverlight and for the most part, it works pretty well. I start the report from my Silverlight-project and  Silverlight ReportViewer opens. Then I have ReportLibrary where I have reports. My reports uses objectdatasources which search data from database. Datasource is a class in ReportLibrary, datamember is IQueryable-method in that class and then there's couple of parameters. With this kind of solution reports gets data from our database.

But especially reports with more than one objectdatasource occasionally gives the error "Report is unavailable or session has expired.", even though rendering haven't taken that much time.

After I press refresh button once or twice, the error disappears and Silverlight reportviewer shows the report correctly.

I know that there is an article about that error, but I would still like to know what is the most likely reason for this kind of behavior?

Thanks.

[Steve]

Hello Asku,

Reading your description of the problem, it sound like you experience #2 Session is lost. You can review the possible reasons for this problem and make the necessary changes i.e. check whether you're not running out of memory if the report is large, apply out-proc session handling if this is a web farm and check windows error logs for any sign of problems. Additionally if you're running an Azure project, in Azure when you use multiple web roles, you have to use an out-proc session i.e. multiple roles act similar to web farm and you need common session. Adding ASP.NET Session State Provider for Windows Azure should prevent the "Report is unavailable or session has expired" error and reports should appear consistently.

Regards,
Steve
the Telerik team

[ajpetersen]

Asku,

Thank you for your answer. I believe this is the solution I need, but can you give me an example of how to Add the ASP.NET Session State Provider for Windows Azure for my Telerik Report?

I am using windows azure for my project and I am having the same problem as the OP except I have a very small report.

Below is a snippet of my SessionState in the web.config.

<sessionState mode="InProc" customProvider="DefaultSessionProvider">
      <providers>
        <add name="DefaultSessionProvider" type="System.Web.Providers.DefaultSessionStateProvider, System.Web.Providers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" connectionStringName="DefaultConnection" />
      </providers>
</sessionState>

Thanks for your help!

[Stef]

Hello Claude,

Please, check the following articles:

•  Managing session state in Windows Azure: What are the options?
• Azure and In Proc Session
• Azure session management
• Using SQL Azure for Session State

If you are using multiple instances then you have to use an out-proc session to preserve the viewer's state between the different instances. In Azure using the AppFabric Cache Provider is the only feasible solution as Microsoft does not support SQL Session State Management using SQL Azure databases.

I hope this helps.

Regards,
Stef
the Telerik team