IS Clustering mandatory when running process models on 2 IS sharing same broker


We developped a process model that we want to run on 2 IS sharing the same broker.
The 2 IS have the same client prefix (share the same broker queues) and share the same process tracking database (process audit).
The process model sends a file to a remote system and waits for an acknowledgement message from this system. The acknowledgement step subscribes to a broker document type defined to receive acknowledgement data.
Additionaly this step has a correlation service in order to have the PRT routing the ack message to the matching process model instance.
When we run this process on 1 IS it works fine. Correlation is OK and process completes.
When we run this process with the 2 IS started, the waiting step never completes. We checked that the acknowledgment document is published and retrieved by 1 of the 2 IS.
Putting debug traces in the correlation service we discovered that the ack document is not retrieved by the same IS that sent the file. So it seems that even when sharing the same process database, 2 IS running process models can’t “work together”.

So here is my question : is wM IS clustering mandatory to run process model across 2 IS boxes ?

In advance, thanks for your help

We enabled clustering yesterday and tested the same process model.
Its works well now !
It seems that with the clustering feature enabled, wM “knows” where to trigger the correlation service in order to have the waiting process model instance re-activated on the right IS (now I can see my debug traces displayed on the same IS).


We have the same problem with the correlation service in WM 6.1 and models. Can you tell me what you changed to make it work?

Thanks for your help,