I'm using SSAS through HTTP with MSMDPUMP.dll. I have setup the MSMDPUMP.dll web to use only Basic Authentication and then I provide the User Id and Password in the ConnectionString. Everything works but it's too slow to be usable. I have enabled Failed Request Tracing in IIS and I have noticed that I get thousands 401.2 errors with the following information:
ModuleName IIS Web Core
ErrorCode Access is denied. (0x80070005)
I believe this is the overhead and the reason why it is slow? If I change the authentication to Anonymous, everything works fast. Unfortunately this is not an option so I need to resolve this issue with Basic Authentication performance. Any ideas?
EDIT It seems that it tries first Anonymous auth and only after failing goes with basic. I don't have anonymous auth even enabled so I don't know why this is happening.