Making initial checks on z/OS

Before you start problem determination in detail on z/OS®, consider whether there is an obvious cause of the problem, or an area of investigation that is likely to give useful results. This approach to diagnosis can often save a lot of work by highlighting a simple error, or by narrowing down the range of possibilities.

1. Identify characteristics of the problem
   There are some initial questions that you can consider to help you to identify the cause of the problem:

   • Has IBM MQ for z/OS run successfully before?
   • Are there any error messages, return codes or other error conditions?
   • Can you reproduce the problem?
   • Have you applied any APARs or PTFs?
   • Have any changes been made since the last successful run?
   • Has the application run successfully before?
   • Does the problem affect specific parts of the network?
   • Does the problem occur at specific times of the day or affect specific users?
   • Is the problem intermittent or does the problem occur with all z/OS, CICS®, or IMS systems?
   • Do you have a program error?
2. Look at the problem in more detail
   There are some further questions to look at when you have established that no changes have been made to your system, and that there are no problems with your application programs, but the preliminary checks have not enabled you to solve your problem.

   • Have you received some incorrect output?
   • Have you received an unexpected error message or return code?
   • Has there been an abend?
   • Have you received no response from an MQSC command?
   • Is there a problem with the IBM MQ queues?
   • Are some of your queues working?
   • Are the correct queues defined?
   • Does the problem affect only remote or cluster queues?
   • Does the problem affect only shared queues?
   • Is your application or IBM MQ for z/OS running slowly?
   • Has your application or IBM MQ for z/OS stopped processing work?
3. If you need further information to help you with identifying the cause of the problem, see Detailed troubleshooting.