Using automatic client reconnection in Java SE and Java EE environments

You can make use of IBM® MQ automatic client reconnection to facilitate various high availability (HA) and disaster recovery (DR) solutions within a Java SE and Java EE environment.

Various HA and DR solutions are available on different platforms:

Multi-instance queue managers are instances of the same queue manager configured on different servers (see Multi-instance queue managers). One instance of the queue manager is defined as the active instance and another instance is defined as the standby instance. If the active instance fails, the multi-instance queue manager restarts automatically on the standby server.
Both the active and standby queue managers have the same queue manager identifier (QMID). IBM MQ client applications that connect to a multi-instance queue manager can be configured to automatically reconnect to a standby instance of a queue manager by using automatic client reconnection.
RDQM (replicated data queue manager) is a high availability solution that is available on Linux® platforms (see RDQM high availability). An RDQM configuration consists of three servers configured in a high availability (HA) group, each with an instance of the queue manager. One instance is the running queue manager, which synchronously replicates its data to the other two instances. If the server running this queue manager fails, another instance of the queue manager starts and has current data to operate with. The three instances of the queue manager share a floating IP address, so clients only need to be configured with a single IP address. Client applications that connect to an RDQM queue manager can be configured to automatically reconnect to a standby instance of a queue manager by using automatic client reconnection.
An HA solution can also be provided by a pair of IBM MQ Appliances (see High Availability and Disaster Recovery in the IBM MQ Appliance documentation). An HA queue manager runs on one of the appliances, while synchronously replicating data to the standby instance of the queue manager on the other appliance. If the primary appliance fails, the queue manager automatically starts and runs on the other appliance. The two instances of the queue manager can be configured to share a floating IP address, so clients only need to be configured with a single IP address. Client applications that connect to an HA queue manager on an IBM MQ Appliance can be configured to automatically reconnect to the standby instance of a queue manager by using automatic client reconnection.

Note: Within Java EE environments, such as WebSphere® Application Server, automatic client reconnection with activation specifications using the functionality provided by IBM MQ classes for JMS is not supported. The IBM MQ resource adapter provides its own mechanism for reconnecting activation specifications if the queue manager that the activation specification was connecting to becomes unavailable. For more information, see Support for automatic client reconnection in Java EE environments.