Messages do not appear when expected

If messages do not appear on the queue when you are expecting them, check for the following:

Has the message been put onto the queue successfully?

Did WebSphere MQ issue a return and reason code for the MQPUT, for example:

Is the queue a shared queue?
Is the queue a cluster queue?

If it is, there might be multiple instances of the queue on different queue managers. This means the messages could be on a different queue manager.

Check any cluster-workload exit programs to see that they are processing messages as intended.

Do your gets fail?

If you cannot find anything wrong with the queue, and the queue manager itself is running, make the following checks on the process that you expected to put the message on to the queue:

If multiple transactions are serving the queue, they might occasionally conflict with one another. For example, one transaction might issue an MQGET call with a buffer length of zero to find out the length of the message, and then issue a specific MQGET call specifying the MsgId of that message. However, while this is happening, another transaction might have issued a successful MQGET call for that message, so the first application will receive a completion code of MQRC_NO_MSG_AVAILABLE. Applications that are expected to run in a multi-server environment must be designed to cope with this situation.

Have any of your systems suffered an outage? For example, if the message you were expecting should have been put on to the queue by a CICS application, and the CICS system went down, the message might be in doubt. This means that the queue manager does not know whether the message should be committed or backed out, and so has locked it until this is resolved when resynchronization takes place.

Note:
The message is deleted after resynchronization if CICS decides to back it out.

Also consider that the message could have been received, but that your application failed to process it in some way. For example, did an error in the expected format of the message cause your program to reject it? If this is the case, refer to Messages contain unexpected or corrupted information.