Sequential Receives

Today I came across an interesting compile time error, given a scenario I had never exercised before. I had a vanilla orchestration that was receiving the same message type (same schema different message instance) using two different receive ports. I wanted to correlate the orchestration, so the first receive shape was set to activate with an “Initialising Correlation Set” and the second receive shape was set with a “Following Correlation Set”. This setup produced the following compile time error:

C:\BizTalkApp\Flows\ProcessA.odx(221,13): error X2259: in a sequential convoy the ports must be identical
C:\BizTalkApp\Flows\ProcessA.odx(215,22): could be 'TestPortA'
C:\BizTalkApp\Flows\ProcessA.odx(221,13): or 'TestPortB'

Awesome. My convoy knowledge is not very deep, so I spent some time with a high quality MSDN article written by Stephen Thomas titled BizTalk Server 2004 Convoy Deep Dive. This helped fill some gaps on the subtle’s of doing sequential convoys.

There seem to be a couple of common options to this error:

  • Don’t define multiple receive ports. The one receive port can be connected to both correlating configured receive shapes. This wasn’t an option in my scenario, as I needed to bind the logical ports to two different physical ports (e.g. HTTP and MSMQ).
  • Don’t intialise the correlation set using a receive shape—use a send shape instead. Thanks to Bruno Spinelli for posting this option up on the wrox forums.