The usual recommendation to configure Adapter Runtime based adapters in an Integration Server cluster is to deploy all the adapter packages and services on one Integration Server. Then, replicate them to the other servers in the cluster. Adapter listeners ensure that only one node in an Integration Server cluster receives a notification per event.

This behavior is different for AS/400 Adapter.

When you configure a Data Queue Listener to the same queue in an Integration Server cluster and activate it on every Integration Server, the listener receives the same data from the data queue on all the Integration Server nodes. This causes multiple notifications for the same entry on the data queue.

AS/400 system identifies the listener connection from each Integration Server node in the cluster as a unique client and delivers message to every connection causing duplicate messages.

To ensure that the Data Queue Listener in a cluster receives notifications only once per message in the queue, Software AG recommends enabling the listener only on one node in the cluster.