CloudStreams supports the use of clustering by either distributing the processing load for streaming API events across Integration Server instances or limiting the processing to a single Integration Server node, while guaranteeing processing in each mode exactly once.

In v10.3 and earlier releases, CloudStreams connector listeners were not cluster aware. So when connector listeners were active on multiple nodes of an Integration Server cluster, each of them received and processed events independently as in a standalone Integration Server. This resulted in unwanted duplicate invocations of actions associated with the connector listeners. For example, if a connector listener is configured with the service invocation action and the same connector listener is replicated in an enabled state across other nodes of the Integration Server cluster, then the configured service invocation action is invoked on all the nodes of the cluster for each inbound subscribed event. From the CloudStreams v10.3 Fix 4 release, all connector listeners are cluster aware.

The following cluster support mode is available for connector listeners:

Multi-Node mode: In this mode, all instances of a connector listener actively listen on all deployed Integration Server nodes within a cluster. Any instance of the connector listener can process events, but for a given event, only one instance will handle it.