In a Cluster environment, each universal event listener has a Node IDs attribute which may be used to specify which Cluster node performs the Groovy code. There are following possibilities:
No failover: Just one node ID specified - Only the specified node performs the Groovy code, however node status must be "ready". When the node isn’t ready, the code isn’t performed at all.
Failover with node concurrency: No node ID specified (empty input) - All Cluster nodes with the status "ready" concurrently perform the Groovy code. So the code is executed on each node in the specified interval.
Failover with node reservation: More node IDs specified (separated by a comma) - Just one of the specified nodes performs the Groovy code. If the node fails for any reason (or its status isn’t "ready"), any other "ready" node from the list continues with periodical Groovy code processing.
In a standalone environment, the Node IDs attribute is ignored.