2355 (0933) (RC2355): MQRC_UOW_MIX_NOT_SUPPORTED

Explanation

This reason code occurs on Windows when we are running a version of the queue manager before Version 5.2. It also occurs on HP Integrity NonStop Server.

• The mixture of calls that is used by the application to perform operations within a unit of work is not supported. In particular, it is not possible to mix within the same process a local unit of work that is coordinated by the queue manager with a global unit of work that is coordinated by DTC (Distributed Transaction Coordinator).
• An application might cause this mixture to arise if some objects in a package are coordinated by DTC and others are not. It can also occur if transactional MQI calls from an MTS client are mixed with transactional MQI calls from a library package transactional MTS object.
• No problem arises if all transactional MQI calls originate from transactional MTS objects, or all transactional MQI calls originate from non-transactional MTS objects. But when a mixture of styles is used, the first style that is used fixes the style for the unit of work, and subsequent attempts to use the other style within the process fail with reason code MQRC_UOW_MIX_NOT_SUPPORTED.
• When an application is run twice, scheduling factors in the operating system mean that it is possible for the queue manager-coordinated transactional calls to fail in one run, and for the DTC-coordinated transactional calls to fail in the other run.

On HP Integrity NonStop Server it is not possible, within a single IBM MQ connection, to issue transactional MQI calls under the coordination of the Transaction Management Facility (TMF) if transactional MQI calls have already been made within a local unit of work that is coordinated by the queue manager until the local unit of work is completed by issuing either MQCMIT or MQBACK.

Completion code

MQCC_FAILED

Programmer response

On Windows, check that the MTS Transaction Support attribute defined for the object's class is set correctly. If necessary, modify the application so that objects that run within different units of work do not try to use the same connection handle.

On HP Integrity NonStop Server, if a local unit of work that is coordinated by the queue manager is in progress, it must either be completed by issuing MQCMIT, or rolled back by issuing MQBACK before issuing any transactional MQI calls under the coordination of TMF.