Clustering support for connector listeners
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 two cluster support modes are available for connector listeners:
Multi-Node mode - Any connector listener instance can process events, but for a given event,
exactly one connector listener instance will process the events.
Single-Node mode - A
designated connector listener instance processes the events.
If the designated connector listener instance stops listening due to an Integration Server restart or any other reason, a different connector listener instance takes over the processing of the events and this connector listener instance will now be the designated connector listener instance.
For both modes, all instances of a connector listener will actively listen on all the deployed Integration Server nodes of a cluster.
Note:
The choice of a cluster support mode for a connector listener is predefined by the connector developer for a back end. The administrator or solution developer will not be able to select or change the cluster mode for a connector listener.
