Why I get "Error in getting session data" error when running report?

Question

Hello,
I have reporting services on one server, and SharePoint 2010 on other server. When I view report from browser, I got blank page. From Report Server Log file, I got below error:
v VERBOSE: writting session cookie: ekkrjbubp00t5wzc3rzspvzb
v VERBOSE: Saved report snapshot to session in a background thread <for same session id>
e ERROR: Throwing Microsoft.ReportingServices.Diagnostics.Utilities.ReportServerStorageException: , An error occurred within the report server database.  This may be due to a connection failure, timeout or low disk condition within the database.;
e ERROR: Error in getting session data: Expired Session: ekkrjbubp00t5wzc3rzspvzb
e ERROR: Throwing Microsoft.ReportingServices.Diagnostics.Utilities.ExecutionNotFoundException: , Microsoft.ReportingServices.Diagnostics.Utilities.ExecutionNotFoundException: The report execution ekkrjbubp00t5wzc3rzspvzb has expired or cannot be found
Are there anyone getting the same issue as mine? I did not see any solutions for this issue when I searched.
Thanks,
Megan

Answer 1

There are a number of timeouts in SSRS; session timeout, report execution timeouts, http request timeouts.  A session timeout in SSRS is not the same as a session timeout in ASP.NET.  Below are some articles that can help you understand the timeouts
and hopefully lead you down the path of discovery.
This articles is a good article as it discusses the session timeout and the keep alive that is sent from the report viewer.
http://blogs.msdn.com/b/jgalla/archive/2006/10/11/session-timeout-during-execution.aspx
This article is good as well in describing some of the timeouts.
http://blogs.msdn.com/b/dynamicsaxbi/archive/2013/02/14/how-to-addressing-ssrs-session-timeouts.aspx