%MessageID% different from BTS.MessageID

Question

I am trying to identify the messages I am saving in a folder using MessageID property. However the MessageID values are different from the values I get when I use BTS.MessageID. Why?

In my orchestration I receive a message "myMsg" from a receive port (with receive pipeline: XML Receive). After that I check myMsg(BTS.MessageID) value with

System.Diagnostics.EventLog.WriteEntry("MessageID", System.String.Format("The Value = {0}", myMsg(BTS.MessageID)));

and I get for example this value: c9953bec-72a8-4274-9ea3-d7770c52d4ab

Then I send my message through a send port (with send pipeline: PassThruTransmit)

When the message is saved, the name is: {EE2AB9A1-FA3C-4737-BB02-6AC0C0EA5EBC}.xml

Why are they different? I thought they would be the same.

Answer 1

Each message is unique. Assume you have 2 send ports where that orchestration message would go to. Would you expect it to have the same message id as the one from the orchestration? I hope not, because you would have 2 instances of a message with the same message id. (Actually 3 because you should also count your orchestration message is).

I guess what you're looking for is the InterchangeID, this one stays the same.

Answer 2

What you are seeing is the expected behavior.

A Message is a single publication to the MessageBox so the Message published by the Receive Port is different from the Message published by the Orchestration, hence different MessageID values.

While you might 'know' it's the same message, to BizTalk, they're not.