FIX: BUG: Locking Problem When Using XA Transactions

ID: Q181776

The information in this article applies to:


Microsoft Transaction Server causes database blocking problems when transactions are used against XA-compliant databases, including Oracle and DB/2. If two or more Microsoft Transaction Server components that share a transaction open connections to the same database and try to access the same database records or index sets, they collide on locks.


This problem occurs because of the way that Msdtcprx.dll generates the XA Transaction ID (XID). The XID has two parts: a Global Transaction ID (GTRID) and a Branch Qualifier (BQUAL). The XIDs contain three GUIDs. For Microsoft Transaction Server version 2.0, all three GUIDs are located in the GTRID and the BQUAL is empty. However. the first GUID should be in the GTRID and the other two GUIDS in the BQUAL. Therefore, to XA, each connection looks like it is working on a different transaction. By generating the XA XID in the new way, all of the connections work on the same transaction.


Microsoft has confirmed this to be a problem in Microsoft Transaction Server version 2.0. A supported fix is now available, but has not been fully regression- tested and should be applied only to systems experiencing this specific problem. Unless you are severely impacted by this specific problem, Microsoft recommends that you wait for the next Service Pack that contains this fix. Contact Microsoft Technical Support for more information.

Keywords          : kbbug2.00 TSrvDTC TSrvXA 
Version           : WinNT:2.0
Platform          : winnt
Issue type        : kbbug
Solution Type     : kbfix

Last Reviewed: March 3, 1998