SSIS, MSDTC, and SQL Server clusters

Note to self: when receiving the following error from an SSIS package, the first thing to check is the Authentication setting for MSDTC.

Description: The SSIS Runtime has failed to enlist the OLE DB connection in a distributed transaction with error 0x8004D00E "The transaction has already been implicitly or explicitly committed or aborted".

The security setting should be set to No Authentication Required. Mutual does not appear to work with clusters. This is especially significant if, like me, you have a non-clustered instance in QA and a clustered one in Prod and you have been beating your head against the wall trying to figure out why MSDTC, with all the same settings, works in the former but not the latter.

SSIS transactions, or Another Reason To Hate Windows Firewall

I created an SSIS package today to archive a bunch of tables from a source server into one table on a destination server and then drop them on the source. I wanted the process to be idempotent, such that the tables would either be fully archived and dropped or the whole thing rolled back. Thus the process could be re-run if it failed in the middle without fear of duplicating data or prematurely dropping tables.

The obvious solution was a transaction. I set the TransactionOption property on my ForEach loop to Required and ran the package. However, MSDTC was not cooperating, and I got this failure:


With the following error message: "The transaction has already been implicitly or explicitly committed or aborted."

I checked MSDTC on both servers involved, and they each seemed to be set up correctly, albeit with slightly different settings. MSDTC on my machine was also configured correctly. Then I remembered that my desktop has Windows Firewall running. Don't ask me why, it wasn't my idea, but I can't turn it off.

So I added an exception to Windows Firewall for c:\windows\system32\msdtc.exe (port 135) and the package started working. Hooray!


Except that when I killed it midway through to simulate a network or SSIS host failure, it rolled back the whole thing. I wanted the ForEach loop to commit each table load and drop as it went so that I wouldn't have to start from scratch if the package failed after a few tables. So I created a Sequence container inside the ForEach container, set the TransactionOption to Required for that container, moved the Transfer and Drop tasks inside it, and set the TransactionOption to Supported for the ForEach.