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Are there any error messages, return codes or other error conditions?

Use this topic to investigate error messages, return codes, and conditions where the queue manager or channel initiator terminated.

The problem might produce the following types of error message or return codes:


Have you received an unexpected error message or return code?

If our application has received an unexpected error message, consider whether the error message has originated from IBM MQ or from another program.


Check for error messages

Issue the DISPLAY THREAD(*) command to check if the queue manager is running. For more information about the command, see DISPLAY THREAD. If the queue manager has stopped running, look for any message that might explain the situation. Messages are displayed on the z/OS console, or on your terminal if you are using the operations and control panels. Use the DISPLAY DQM command to see if the channel initiator is working, and the listeners are active. The z/OS command
DISPLAY R,L
lists messages with outstanding replies. Check to see whether any of these replies are relevant. In some circumstances, for example, when it has used all its active logs, IBM MQ for z/OS waits for operator intervention.


No error messages issued

If no error messages have been issued, perform the following procedure to determine what is causing the problem:
  1. Issue the z/OS commands
    DISPLAY A,xxxxMSTR
    DISPLAY A,xxxxCHIN
    
    (where xxxx is the IBM MQ for z/OS subsystem name). If you receive a message telling you that the queue manager or channel initiator has not been found, this message indicates that the subsystem has terminated. This condition could be caused by an abend or by operator shutdown of the system.
  2. If the subsystem is running, you receive message IEE105I. This message includes the CT=nnnn field, which contains information about the processor time being used by the subsystem. Note the value of this field, and reissue the command.

    • If the CT= value has not changed, this indicates that the subsystem is not using any processor time. This could indicate that the subsystem is in a wait state (or that it has no work to do). If we can issue a command like DISPLAY DQM and you get output back, this indicates there is no work to do rather than a hang condition.
    • If the CT= value has changed dramatically, and continues to do so over repeated displays, this could indicate that the subsystem is busy or possibly in a loop.
    • If the reply indicates that the subsystem is now not found, this indicates that it was in the process of terminating when the first command was issued. If a dump is being taken, the subsystem might take a while to terminate. A message is produced at the console before terminating.

      To check that the channel initiator is working, issue the DISPLAY DQM command. If the response does not show the channel initiator working this could be because it is getting insufficient resources (like the processor). In this case, use the z/OS monitoring tools, such as RMF, to determine if there is a resource problem. If it is not, restart the channel initiator.


Has the queue manager or channel initiator terminated abnormally?

Look for any messages saying that the queue manager or channel initiator address space has abnormally terminated. If you get a message for which the system action is to terminate IBM MQ, find out whether a system dump was produced, see IBM MQ dumps.


IBM MQ for z/OS might still be running

Consider also that IBM MQ for z/OS might still be running, but only slowly. If it is running slowly, you probably have a performance problem. To confirm this, see Is our application or IBM MQ for z/OS running slowly. Refer to Dealing with performance problems for advice about what to do next.