Beginning with Integration Server 9.5, an adapter listener can be active either on multiple nodes or on a single node in an Integration Server cluster.

If the adapter back end supports the non-duplication of messages to which multiple clients are subscribed, the listener is multi-node. It is active on all nodes in the Integration Server cluster. In this case, each node retrieves and processes a different message.

If the adapter back end does not support the non-duplication of messages to which multiple clients are subscribed, the listener is single-node. It is active on a single node in the cluster - the active or primary node - thus avoiding duplicate messages. If the active node goes down, another node in the cluster becomes active, providing failover support. The active node stores incoming events from the back end in the distributed (shared) cache. In this way, message processing continues when the active node goes down.

You can enable, disable, or suspend a listener on a single node or on all nodes in a cluster by changing the listener state on one of the nodes. For information about changing listener states in a cluster, see Enabling Listeners in a Cluster and Disabling Listeners in a Cluster.