Wednesday, March 30, 2011

Problems using the .NET transactionscope with DB2 on a 64 bit machine

To solve the growing need for more memory, we decided to upgrade all our development machines to a 64bit OS.  Although this allows us to install and use more memory on our machines, it also introduces a whole list of new problems.

One of them was regarding the usage of the .NET transactionscope in combination with DB2. In DB2 managing your transactions through the transactionscope will immediatelly involve the DTC coordinator. However the moment the DTC tries to open a transaction, it fails with the following error message:

The XA Transaction Manager attempted to load the XA resource manager DLL. The call to LOADLIBRARY for the XA resource manager DLL failed: DLL=C:\Program Files\IBM\SQLLIB\BIN\DB2APP.DLL, HR=0x800700c1, File=d:\w7rtm\com\complus\dtc\dtc\xatm\src\xarmconn.cpp Line=2446.

After trying almost every possible solution, we finally found a solution that worked for us. When installing the DB2 client, it doesn’t correctly register the 64bit dll’s in the register.

The following registry key HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSDTC\XADLL incorrectly referenced the db2app.dll instead of the db2app64.dll. As a consequence the MSDTC tries to load a 32bit DLL on 64bit machine, which fails. After changing the reference to the 64bit dll everything worked.

More information in this thread on the DB2 forums.

4 comments:

Pieter said...

Thx Bart for posting this fix. It solves also my issue with build servers that were upgraded to TFS2010 (64 bit).

Anonymous said...

Same thing for PostgreSQL. In this case the dll to be manually added to the registry is pgxalib.dll.
The event log shows a detailed description of the steps to fix the problem.
Thanks and regards

Rahat said...
This comment has been removed by the author.
Rahat said...

Thank for the post,,Here i share another dll failed post..He explain everything about the problem...