FIX: MTS or IIS with ODBC Connection Pooling May Hang If Database Becomes Unavailable

When ODBC connection pooling is enabled, if database servers are down or unavailable due to network connectivity issues, Internet Information Server (IIS) or Microsoft Transaction Server (MTS) may stop responding (hang).

This behavior is caused by a bug in the resource dispenser (Mtxdm.dll). The threads that perform connection pooling wait for the ODBC thread that is trying to perform an ODBC call, which results in a deadlock condition.

The resource dispenser has been modified to resolve this problem. To obtain the corrected version of Mtxdm.dll, install Microsoft Data Access Components (MDAC) version 2.5 or later from the following Microsoft Web Site: You can also obtain this fix by installing Microsoft Windows NT 4.0 Service Pack 6a or later. For more information, see the following Web site:

Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.

This problem has been corrected in MDAC version 2.5 and later, and in Windows NT 4.0 Service Pack 6a and later.