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.
The cause of our problem could be in:
- IBM MQ
- The network
- The application
- Other applications that we have configured to work with IBM MQ
Some initial questions to consider are listed in the subtopics. As you go through the list of questions, make a note of anything that might be relevant to the problem. Even if your observations do not suggest a cause straight away, they might be useful later if you have to carry out a systematic problem determination exercise.
- Has IBM MQ for z/OS run successfully before?
Knowing whether IBM MQ for z/OS has successfully run before can help with problem determination, and there are checks we can perform to help you. - Have you applied any APARs or PTFs?
APARs and PTFs can occasionally cause unexpected problems with IBM MQ. These fixes can have been applied to IBM MQ or to other z/OS systems. - 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. - Has the application or IBM MQ for z/OS stopped processing work?
There are several reasons why the system would unexpectedly stop processing work including problems with the queue manager, the application, z/OS, and the data sets. - Is there a problem with the IBM MQ queues?
Use this topic for investigating potential problems with IBM MQ queues. - Does the problem affect specific parts of the network?
Network problems can cause related problems for MQ for z/OS. Use this topic to review possible sources of networks problems. - Problems that occur at specific times of the day or affect specific users
Use this topic to review IBM MQ problems that occur at specific times of the day or specific groups of users. - Is the problem intermittent or does the problem occur with all z/OS, CICS, or IMS systems?
Review this topic to consider if problems are caused by application interaction or are related to other z/OS systems. - Has the application run successfully before?
Application errors can often be determined by determining if they have run successfully before or if they have produced error messages and unexpected return codes. - Have any changes been made since the last successful run?
Recent changes made since the last successful run are often the source of unexpected errors. This topic contains information about some of the changes which can be investigated as part of our problem determination. - Do you have a program error?
Use this topic to investigate if a program error is causing an IBM MQ problem. - Has there been an abend?
Use this topic to investigate common causes of abends and the different types of abend that can cause problems. - Have you obtained incorrect output?
Use this topic to review any incorrect output you have received. - Can you reproduce the problem?
Reproducing the problem can be used to assist problem determination for IBM MQ for z/OS. Use this topic to further isolate the type of problem reproduction. - Have you failed to receive a response from an MQSC command?
Use this topic for investigating problems where you fail to receive a response from an MQSC command. - Is the application or IBM MQ for z/OS running slowly?
Slow applications can be caused by the application itself or underlying software including IBM MQ. Use this topic for initial investigations into slow applications.
Parent topic: Making initial checks
Related concepts
Related tasks
- Making initial checks on UNIX, Linux, and Windows
- Making initial checks on IBM i
- Searching knowledge bases
- Contacting IBM Software Support
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