Query on 'Once and only once' delivery of messages in cluster env

Hi All,

I have a non durable, concurrent subscriber in cluster IS nodes to a queue in a non-shared connection factory in UM. With this setup, occasionally (strangely only occasionally, not always!) UM is sending message to both the IS nodes and the trigger at both the nodes are processing this message. But what I want is once and only once delivery of message to any one of the cluster nodes (to ensure that the message is processed only once). Do I need to tweak any config to the trigger / queue / connection factory to get what I want?

webMethods env - 9.8

Kind regards,