Initializing BizTalk Correlation Sets In a Loop


You ever find that newsgroup post on a technical subject that absolutely saves the day? One of my projects has an orchestration that calls a web service. I call this service in a "loop" because if a call fails (for "business" or "technical" reasons), it may need to retried. So, until I set a "ProcessComplete" flag, the loop continues.

That said, if I DO get an error, I send the message out for review. If I don't get a response within an hour, I auto-retry the service again. This is done with a transactional scope (long-running) and a timeout. So naturally I have to use correlation to send a message out of my orchestration, and potentially receive a message back. However, after setting this up the first time, I got a
Correlation set may be initialized only once
error. This makes sense since I had a global correlation set, and was potentially initializing it over and over in a loop. After staring at my computer for 4 minutes thinking, I did a quick search online and came across a newsgroup post, that a *scope* can have its own local correlations sets.

Sure enough, after moving the correlation set to the local scope, everything compiled fine.