If the brokers in your conventional cluster are using file-based data stores, use the following procedure to convert to an enhanced cluster.
Drain down your messaging system of all persistent data.
Stop all producer clients from producing messages, and wait for all messages in the system to be consumed.
Shut down all client applications.
Shut down all brokers in the conventional cluster.
Reconfigure all brokers for an enhanced cluster.
See Enhanced Broker Cluster Properties. It is recommended that you use a cluster configuration file to specify cluster configuration property values, such as the imq.cluster.clusterid, imq.persist.store, and additional shared JDBC database properties.
Start all brokers in the enhanced cluster.
Configure client applications to re-connect to failover brokers.
Client re-connection behavior is specified by connection handling attributes of the connection factory administered objects (see the Connection Handling). In the case of enhanced broker clusters, the imqAddressList, imqAddressListBehavior, and imqAddressListIterations attributes are ignored, however the imqReconnectAttempts attribute should be set to a value of -1 (unlimited).
Start all client applications.
Resume messaging operations