Tips for Setting up SSAS Access over IIS/HTTP

One of what I think is a limiting factor for Analysis Services is its lack of a “standard” authentication mechanism.  There are lots of scenarios where windows authentication just isn’t practical.  Fortunately we can setup access to an SSAS server over HTTP with IIS and and ISAPI filter.  This MSDN article does a great job explaining the steps you need to take. 

https://msdn.microsoft.com/en-us/library/gg492140.aspx

We setup an IIS server running on Windows Server 2012 R2 connecting to SSAS 2014.  The only issue I found is during the connection testing phase.  Our excel test worked perfectly from outside our network but we kept getting the following error when connecting from C# using ADOMD. 

The integrated security ‘Basic’ is not supported for HTTP or HTTPS connections.

Now I just read in the article how basic authentication is supported so you can allow access from machines outside your network.  The good news is this isn’t referring to that basic authentication.  Here is the connection string recommended by the MSDN article.

Data Source=https://<servername>/olap/msmdpump.dll; Initial Catalog=AdventureWorksDW2012; Integrated Security=Basic; User ID=XXXX; Password=XXXXX;

The highlighted part is what’s causing the error.  Remove “Integrated Security=Basic;” and your connections should work fine.  We were able to connect over http, https, and by using a high number port above 5000 just by changing the IIS website bindings and the url in the connection string.  Overall I have been very happy with how this is working out.