Running XA Transactions in Client (Outbound) Mode

The outbound WebSphere MQ Adapter supports XA transactions with WebSphere MQ Manager servers running on Solaris, AIX, HP-UX, Linux or Windows (not supported for OS/400 or z/OS). If your Sun Java Composite Application Platform Suite is installed on a different computer than your WebSphere MQ server, XA mode requires that you first install the WebSphere MQ base client, and then the WebSphere MQ Extended Transactional client, on the Application Server.

The transaction manager of the WebSphere MQ Adapter in XA mode, runs in the Sun Integration Server. The Integration Server (IS) requires two JAR files, com.ibm.mq.jar and com.ibm.mqetclient.jar, to be added to the Integration Server classpath..

The IBM document WebSphere MQ External Transactional Clients, provides information on distributed XA transactions and limitations, such as WebSphere MQ API that cannot be issued in XA mode.

According to IBM, when using the WebSphere MQ Extended Transactional client, a client application can be connected to only one queue manager at a time within a single thread. This restriction applies to the WebSphere MQ Extended Transactional client. (The WebSphere MQ base client can be connected to more than one queue manager concurrently within a single thread.) For the WebSphere MQ Adapter this means, in one deployment, you are only allowed to have one outbound XA mode Adapter connecting to a WebSphere MQ external system. You cannot have multiple XA outbound connections to different WebSphere MQ external systems and expect the Integration Server Transactional manager to handle XA transaction for multiple WebSphere MQ queue managers.