Have you failed to receive a response from a command?

If you have issued a command but you have not received a response, consider the following questions:

• Is the command server running?

  Work with the DSPMQMCSVR command to check the status of the command server.

  • If the response to this command indicates that the command server is not running, use the STRMQMCSVR command to start it.

  • If the response to the command indicates that the SYSTEM.ADMIN.COMMAND.QUEUE is not enabled for MQGET requests, enable the queue for MQGET requests.

• Has a reply been sent to the dead-letter queue?

  The dead-letter queue header structure contains a reason or feedback code describing the problem. See the WebSphere MQ Application Programming Reference for information about the dead-letter queue header structure (MQDLH).

  If the dead-letter queue contains messages, we can use the provided browse sample application (amqsbcg) to browse the messages using the MQGET call. The sample application steps through all the messages on a named queue for a named queue manager, displaying both the message descriptor and the message context fields for all the messages on the named queue.

• Has a message been sent to the error log?

  See Error logs for further information.

• Are the queues enabled for put and get operations?

• Is the WaitInterval long enough?

  If your MQGET call has timed out, a completion code of MQCC_FAILED and a reason code of MQRC_NO_MSG_AVAILABLE are returned. (See the WebSphere MQ Application Programming Reference for information about the WaitInterval field, and completion and reason codes from MQGET.)

• If you are using your own application program to put commands onto the SYSTEM.ADMIN.COMMAND.QUEUE, do we need to take a syncpoint?

  Unless you have specifically excluded your request message from syncpoint, we need to take a syncpoint before attempting to receive reply messages.

• Are the MAXDEPTH and MAXMSGL attributes of your queues set sufficiently high?

• Are you using the CorrelId and MsgId fields correctly?

  Set the values of MsgId and CorrelId in your application to ensure that you receive all messages from the queue.

Try stopping the command server and then restarting it, responding to any error messages that are produced.

If the system still does not respond, the problem could be with either a queue manager or the whole of the WebSphere MQ system. First try stopping individual queue managers to try and isolate a failing queue manager. If this does not reveal the problem, try stopping and restarting WebSphere MQ, responding to any messages that are produced in the error log.

If the problem still occurs after restart, contact your IBM Support Center for help.

If you have still not identified the cause of the problem, see Determining problems with WebSphere MQ applications.