Orchestration are single threaded?

Question

Can anyone confirm if a BizTalk orchestration is executed on a single thread? or multiple? During dehydration/resuming, would BizTalk engine create new thread or suspend/awake the same thread. I'm thinking of using Thread Context to store a unique request Id, that will be used to group activity logs in database

Thanks

Answer 1

Your only guarantee is that a single shape will be executed in a single thread without interruption. The next shape might be executed on a different thread, a different processor or even a different machine!

So using ThreadContext to store data between different shapes is definitely a bad idea. There is a reason why Orchestration variables exist and why they must be serializable!

If you want to group your activity logs, use the Orchestration Instance ID, which is guaranteed to stay the same over the lifetime of the orchestration.