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vpbroker · Posted: Mon Aug 22, 2011 7:55 am Post subject:

Hi Guys,

This topic is more for clarification than reporting a problem. I'm a bit confused by Global transactions in WMB 6.1 regarding ODBC connnections!

According to the documentation, in order for an ODBC datasource to be part of a coordinated transaction, the qm.ini file must be updated to include the datasource with the message flow set to be coordinated. However, I'm not convinced about this. So here is why..........

I have a message flow that has an mq input node -> compute node 1 -> compute node 2

Now, both compute nodes update a oracle database using an odbc connection. Both perform inserts to different tables using the same datasource. The MQ input node has transaction mode set to Yes whilst the other nodes are set to automatic.

In the test, compute node 1 inserts, but then compute node 2 fails due to a database insert error. A exception is thrown which forces the message flow to go to the MQ input node. The input nodes catch and failure terminals are not connected to anything.

Now, the MQ message is backed out to a queue, and the database inserts from compute node 1 is rolled back.

My question is, how is the 2 phase commit controlled with the database? I have not configured the queue manager to include the datasource, and the deployed message flow was not set to be coordinated.

My confusion is that this shouldn't work according to the documentation! I'm sure I've missed something out but if someone could help explain this then it would be great. I've tried searching for articles but they all talk about setting up global coordination and none explain how and why the test above works.

Thanks