Synchronizing multiple watches on the same queue

You can synchronize multiple watches on the same queue to help ensure that only one MQ Adapter attempts to process a message. If multiple adapters do attempt to process the same message, only one adapter processes the message. The other adapters cannot access the message and report a failure. Synchronize the time frame for processing pending maps with the mark interval of the queue to prevent multiple adapters from attempting to process the same message.


  1. On the input card of the watched queue, set the Pending Instance Thresholds - High Launcher setting to a value that limits the number of messages that can be processed within a particular time frame.
  2. Set the mark interval of the watched queue to a time (in milliseconds) that is, at a minimum, long enough for the Launcher to process the maximum number of pending messages that you set in step 1. Run the following command within the IBM® MQ runmqsc application to set the mark interval of the watched queue:

    ALTER QMGR MARKINT [time in milliseconds | NOLIMIT]