After deploying some reports to our reporting services environment, the first time I try to load a report, it always failed with the following error message:
An error has occurred during report processing. (rsProcessingAborted)
Cannot create a connection to data source 'dsNorthwind'. (rsErrorOpeningConnection)
For more information about this error navigate to the report server on the local server
As the error suggested I could get more information if I browse to the report server locally. So I logged into the report server and ran the report again. This time I got a timeout error telling me that it took too long to connect to the database. Similar information could be found in the log files located at:
%programfiles%\Microsoft SQL Server\<SQL Server Instance>\Reporting Services\LogFiles\
I was able to fix the issue by updating the timeout value inside the shared datasource.