A question from a colleague had me wondering about the following restriction stated in the WebSphere Application Server Version 6.1 pre-reqs:
IBM WebSphere MQ 5.3 CSD 12 and IBM WebSphere MQ 5.3.1 for z/OS + PK10303 are supported for client mode connections only.
Fortunately, Paul Titheridge from the service team was able to provide me with an explanation. The use of the WebSphere MQ 5.3 JMS client is not supported in a Java 5 JVM which is, of course, what Version 6.1 of the application server is running on. For a client connection, you should use the WebSphere MQ Version 6 JAR files which are supported under Java 5, and also provide backwards compatibility when making a client connection to a Version 5.3 queue manager.
That said, with WebSphere MQ Version 5.3 due to go out of service at the end of next month then this is probably a largely academic discussion.
Updated: Paul’s explanation of the reasoning behind this statement is entirely correct but, it transpires, that statement is now out-of-date and only tells part of the story. WebSphere MQ 5.3 is now supported with WebSphere Application Server 6.1 providing you have at least CSD 13 of the former and 184.108.40.206 (220.127.116.11 on z/OS) of the latter. You also need to set the MQ_INSTALL_VERSION WebSphere variable as explained in the InfoCenter and this tech note. Thanks to Alasdair Nottingham for picking me up on this.