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Is it safe to do a forced shutdown of WebSphere MQ?

Question & Answer


Question

Is it safe to use the WebSphere MQ (WMQ) forced shutdown command stop qmgr mode(force) to shutdown the MQ MSTR address space? I entered 'stop qmgr' to do a normal MQ shutdown. However, the MSTR address space is still hung during shutdown.

Answer

You can perform a forced shutdown of your queue manager by entering stop qmgr mode(force). It is safe and there is no associated data integrity problems. In the worst case, a unit of work (UOW) will be left indoubt. However, the indoubt UOW can be resynchronized upon reconnection of CICS and WebSphere MQ. For more information, refer to the following documentation in the IBM Knowledge Center:

To prevent WebSphere MQ from hanging during a quiesced shutdown would require significant changes to CICS that are beyond the scope of an APAR fix. A request for enhancement (RFE) 73742 has been submitted to request improvements to this area in CICS. If you would like to increase the chances of this enhancement request being completed, click on the link for the RFE, then signon using your IBMid, scroll to the bottom of the page, and click on "vote" to vote for it.

If you find that your WebSphere MQ MSTR address space is still hung after entering stop qmgr, you might be able to enter the MQ command **DIS THREAD()* to determine if there are any threads active within CICS.

When looking at a CICS dump, you can display the MQ domain by entering VERBX DFHPDxxx 'MQ' (where xxx is your release level of CICS like 690 for CICS TS 5.2). The MQ domain will show you the connection status. In this case, the connection status was "Pending" but the disconnection was complete. By entering VERBX DFHPDxxx 'KE' to look at the KE domain, you can determine if the MQ task has completed. In this case, the MQ task had completed successfully and the L8 TCB was subsequently being used by another long running non-MQ task which caused this problem at MQ shutdown.

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Product Synonym

CICS/TS CICSTS CICS TS CICS Transaction Server

Document Information

Modified date:
08 July 2015

UID

dwa1200665