MS DTC Problems With Oracle Linked Server & Windows 2008 x64 R2 Cluster (Server: Msg 7391, Level 16, State 1)

If you are getting this error (Server: Msg 7391, Level 16, State 1) trying to run a transaction using a linked Oracle server then I may have the fix you're looking for. I had to troubleshoot a problem with a new Windows 2008 Enterprise R2 x64 cluster today that was a real pain.

To get things ready normally you need to at least do the following:

• install the Oracle drivers & reboot
• set "allow in process" on the provider in SQL
• ensure the default DTC is the clustered resource
• enabled DTC for network access and set correct authentication.

Normally things would work at this point. No such luck today though! No matter what I did I couldn't get a specific stored procedure a user wrote to without firing off the "unable to enlist" error. Other DTC transactions worked just fine.

The solution was simple (but tricky for non-Oracle DBAs); I had to install the "Oracle Services for Microsoft Transaction Server 11.1.0.7.0" service and reboot.
Now, I *could* have re-written the query but since it was already working on another QA box and the user is going to be re-working the whole solution shortly I didn't see much point. Plus I wanted to know HOW or IF it could be made to work on this cluster! ;)

Hope this helps someone else out there!
-A