FIX: ASP Session Scope Thread Affinity Problem in IIS 5.0 (301500)

SYMPTOMS

When an Active Server Pages (ASP) session accesses a session variable and then makes a call that, because of the duration of the call, blocks other calls, some of the user sessions are temporarily blocked until the call is completed.

This problem may also occur if you have a Global.asa file with the Session_OnStart method or the Session_OnEnd method. This occurs even if the method is empty.

CAUSE

Microsoft Internet Information Server (IIS) 5.0 permits multiple ASP sessions to be bound to the same physical thread.

NOTE: This behavior is a change from IIS 4.0.

If there are two sessions tied to the same physical thread, and the first session makes a call that takes awhile to complete, the second thread must wait until the call is completed to get a response for its request.

RESOLUTION

To resolve this problem, obtain Microsoft COM+ Hotfix Rollup 18.1. For additional information about the Hotfix Rollup, click the article number below to view the article in the Microsoft Knowledge Base:

313582 INFO: Availability of Windows 2000 Post-SP2 COM+ Hotfix 18.1

To resolve this problem, obtain the latest service pack for Windows 2000. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

260910 How to Obtain the Latest Windows 2000 Service Pack

STATUS

Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article. This problem was first corrected in Windows 2000 Service Pack 3.