IBM MQ extended transactional client applications

Use this page to determine how IBM MQ extended transactional client applications can use the GROUP unit of recovery disposition.

An example of an IBM MQ extended transactional client application is one that uses JMS and runs in WebSphere Application Server, connecting to IBM MQ over TCP/IP, rather than local bindings. These client applications connect to IBM MQ for z/OS over network connections, such as via TCP/IP. For these applications, it is the value specified for the QMNAME parameter of the xa_info string passed in the xa_open call that specifies whether a QMGR or GROUP unit of recovery disposition is used. For more information about xa_open, see The format of an xa_open string and Additional error processing for xa_open. For JMS applications this is done by specifying the name of the queue sharing group (QSG) in the ConnectionFactory instead of the name of a specific queue manager.

For XA client applications to take advantage of using the GROUP unit of recovery disposition you must configure your TCP/IP setup to allow your client applications to be routed to the queue managers in the queue sharing group that have the GROUPUR attribute enabled, rather than a specific queue manager. One of the dynamic virtual IP address technologies used to do this is the z/OS SysPlex Distributor. See z/OS Communications Server and z/OS Basic Skills: Dynamic virtual addressing for more details. To enable GROUP units of recovery on a subset of the queue managers in your queue sharing group, ensure that your client applications cannot be routed to those on which it is not enabled. This includes any queue manager at a version earlier than Version 7.0.1.

To use the group unit of recovery disposition feature in a JMS client application we must use the Version 7.0.1 JMS client libraries. Earlier levels of JMS client libraries use queue manager (QMGR) unit of recovery disposition.

Your client applications do not have to connect to the queue sharing group using shared channels.

Parent topic: Application support