Slow HTTP access to AS2000 with Win2K3 RTM without SP1

Thanks to Microsoft support for Analysis Services (one of my customers opened an incident), I just discovered an issue that is not indexed anywhere in Google, so I write a post hoping to save time of the next unlucky user…

I you use HTTP access to Analysis Services 2000 and you have Analysis Services installed on Windows 2003 Server RTM, there is a problem with IIS 6.0 described in KB840875. Apparently it is not related to Analysis Services, but when you use HTTP access you are using an ASP page (MSOLAP.ASP) that indirectly uses the API described in the kb article. This issue is solved by Windows Server 2003 SP1.

For this reason, if you have Windows 2003 Server RTM without SP1 and you want to access to Analysis Services via HTTP, you can rely on two choices:

• Upgrade the server to Windows Server 2003 SP1. This is the suggested one.
• If you cannot upgrade to SP1, you can use a workaround modifying the MSOLAP.ASP page: simply change the Response.Buffer line into this:
  

  <%Response.Buffer=TRUE%>
  
  The original value is FALSE. I found only one reference to this fix into an old post in the newsgroups, which didn’t correlate the problems (probably it was something else, because at that time Win2K3 Servere were still in beta test.

Analysis Services 2005 is not affected by this issue.