Troubleshooting queue manager problems

Use the advice given here to help you to resolve common problems that can arise when you use queue managers.

Queue manager unavailable error

  • Scenario: You receive a queue manager unavailable error.
  • Explanation: Configuration file errors typically prevent queue managers from being found, and result in queue manager unavailable errors. On Windows, problems in the qm.ini file can cause queue manager unavailable errors when a queue manager is started.
  • Solution: Ensure that the configuration files exist, and that the IBM® MQ configuration file references the correct queue manager and log directories. On Windows, check for problems in the qm.ini file.
[MQ 9.3.4 Oct 2023]

Log I/O operation exceeded threshold message

  • Scenario:You receive an AMQ6729WLog I/O operation exceeded threshold in the queue manager error log,
  • Explanation: IBM MQ has detected that log read and write or input and output operations are taking longer than anticipated. This might be due to problems with the operating system or storage system and can impact the queue manager performance.
  • Solution: Use the AMQ_IODELAY, AMQ_IODELAY_INMS and AMQ_IODELAY_FFST environment variables to either aid in diagnosing storage performance issues, or to increase tolerance for such delays. For more information, see AMQ_IODELAY, AMQ_IODELAY_INMS and AMQ_IODELAY_FFST.

IBM MQ coordinating with Db2 as the resource manager error

  • Scenario: You start your queue managers from the IBM MQ Explorer and are having problems when coordinating Db2®. When you check your queue manager error logs, you see an error like the one shown in the following example: 
    23/09/2008 15:43:54 - Process(5508.1) User(MUSR_MQADMIN) Program(amqzxma0.exe)
Host(HOST_1) Installation(Installation1)
VMRF(7.1.0.0) QMgr(A.B.C)
AMQ7604: The XA resource manager 'DB2 MQBankDB database' was not available when called
for xa_open. The queue manager is continuing without this resource manager.
  • Explanation: The user ID (default name is MUSR_MQADMIN) which runs the IBM MQ Service process amqsvc.exe is still running with an access token which does not contain group membership information for the group DB2USERS.
  • Solution: After you have ensured that the IBM MQ Service user ID is a member of DB2USERS, use the following sequence of commands:
    1. Stop the service.
    2. Stop any other processes running under the same user ID.
    3. Restart these processes.

    Rebooting the machine would ensure the previous steps, but is not necessary.