I have the following setup and problem:
Sharepoint 2013 with SSRS in Sharepoint integrated mode
SSAS 2012 SP1 with http access (IIS + msmdpump) enabled on the same box as SSAS
Every component I have tried works fine with this (PerformancePoint, .bism connections, SSIS packages etc.), connecting over http using Kerberos and windows integrated authentication.
SSRS (.rsds) connections in Sharepoint fail a connection test when using the same http connection string + Windows integrated authentication which works for everything else. The error is: "Unsupported data format: -> Microsoft.ReportingServices.DataExtensions.AdomdTestConnectionException: Unsupported data format:"
SQL server profiler shows that the windows username is reaching the SSAS server is all cases.
Kerberos delegation is set up for SSAS and is working.
Switching the .rsds connection to saved credentials (same user as I tried with Windows integrated auth) works fine and SQL server profile logs look the same as the Windows integrated case.
So, everything seems to work with Kerberos + http apart from SSRS ... any idea welcome. I did read that SSPI is not supported for http connections but then again, there are sites which give examples of exactly such connection strings. I can't find any mention of this case or exact problem anywhere ...