Troubleshooting WebSphere MQ JMS bindings

You can diagnose and fix problems with WebSphere® MQ JMS bindings.

Implementation exceptions

In response to various error conditions, the MQ JMS import and export implementation can return one of two types of exceptions:

Service Business Exception: this exception is returned if the fault specified on the service business interface (WSDL port type) occurred.
Service Runtime Exception: raised in all other cases. In most cases, the cause exception will contain the original exception (JMSException).
For example, an import expects only one response message for each request message. If more than one response arrives, or if a late response (one for which the SCA response expiration has expired) arrives, a Service Runtime Exception is thrown. The transaction is rolled back, and the response message is backed out of the queue or handled by the failed event manager.

WebSphere MQ JMS-based SCA messages not appearing in the failed event manager

If SCA messages originated through a WebSphere MQ JMS interaction fail, you would expect to find these messages in the failed event manager. If such messages are not appearing in the failed event manager, ensure that the value of the maximum retries property on the underlying listener port is equal to or greater than 1. Setting this value to 1 or more enables interaction with the failed event manager during SCA invocations for the MQ JMS bindings.

Misusage scenarios: comparison with WebSphere MQ bindings

The WebSphere MQ JMS binding is designed to interoperate with JMS applications deployed against WebSphere MQ, which exposes messages according to the JMS message model. The WebSphere MQ import and export, however, are principally designed to interoperate with native WebSphere MQ applications and expose the full content of the WebSphere MQ message body to mediations.

The following scenarios should be built using the WebSphere MQ JMS binding, not the WebSphere MQ binding:

Invoking a JMS message-driven bean (MDB) from an SCA module, where the MDB is deployed against the WebSphere MQ JMS provider. Use a WebSphere MQ JMS import.
Allowing the SCA module to be called from a Java EE component servlet or EJB by way of JMS. Use a WebSphere MQ JMS export.
Mediating the contents of a JMS MapMessage, in transit across WebSphere MQ. Use a WebSphere MQ JMS export and import in conjunction with the appropriate data handler or data binding.

There are situations in which the WebSphere MQ binding and WebSphere MQ JMS binding might be expected to interoperate. In particular, when you are bridging between Java EE and non-Java EE WebSphere MQ applications, use a WebSphere MQ export and WebSphere MQ JMS import (or vice versa) in conjunction with appropriate data bindings or mediation modules (or both).