Well, Convoys should really be correlated on data inside the message. That’s really what makes a Convoy a Convoy (i.e. multiple messages received that relate to each other). In my case, the ID field was “some id inside the message” that was the same for each message.
Example: convoy for all orders processed today could use Date or all orders from Iowa could use the State field.
Now, there are other ways to do it, but in your case I would try to find something inside the data to use. If you are using a Request – Response (like the 2nd sample in the SQL white paper I think) then you wouldn’t need a Convoy at all.