You won’t enable SSAS HTTP connectivity via a SharePoint site.
You followed the instructions in the Configuring HTTP Access to SQL Server 2005 Analysis Services on Microsoft Windows Server 2003 whitepaper but you get ” Failed to start monitoring directory changes” error when you try to access the SSAS server by its pump URL, such as http://www.adventure-works/olap/msmdpump.dll.
Ignore the step where you had to create an olap pool and assign the OLAP vroot to it. Instead, assign the vroot to the same IIS application pool as the one the SharePoint site belongs to, such as SharePoint -80. In addition, make sure you enable the web extension to the pump dll, as explained in the above article.
If you have created non-domain Windows accounts on the server for testing, make sure that the server and local Windows accounts (the one the user will use to log in to the user machine) are synchronized, that is, have the same name and password. For example, if I create a non-domain local account Bob on the server where SSAS is installed, Bob must log in to his machine as Bob and both accounts (user and server) must have the same password.