Making initial checks on UNIX, Linux, and Windows

Before you start problem determination in detail on UNIX, Linux, and Windows, 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.

About this task

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 run successfully before?
  
• Have any changes been made since the last successful run?
  Changes that have been made to the IBM MQ configuration, maintenance updates, or changes to other programs that interact with IBM MQ could be the cause of our problem.
• Are there any error messages or return codes to explain the problem?
  We might find error messages or return codes that help you to determine the location and cause of our problem.
• Can you reproduce the problem?
  
• Are you receiving an error code when creating or starting a queue manager on Windows?
  If the IBM MQ Explorer, or the amqmdain command, fails to create or start a queue manager, indicating an authority problem, it might be because the user under which the IBM MQ Windows service is running has insufficient rights.
• Does the problem affect only remote queues?
  Things to check if the problem affects only remote queues.
• Have you obtained incorrect output?
  In this section, incorrect output refers to the application: not receiving a message that you were expecting it to receive; receiving a message containing unexpected or corrupted information; receiving a message that you were not expecting it to receive, for example, one that was destined for a different application.
• Are some of our queues failing?
  If you suspect that the problem occurs with only a subset of queues, check the local queues that you think are having problems.
• Have you failed to receive a response from a PCF command?
  Considerations if you have issued a command but have not received a response.
• Has the application run successfully before?
  Use the information in this topic to help diagnose common problems with applications.
• Is the application or system running slowly?
  If the application is running slowly, it might be in a loop, or waiting for a resource that is not available, or there might be a performance problem.
• Does the problem affect specific parts of the network?
  
• Does the problem occur at specific times of the day?
  
• Is the problem intermittent?
  
• Resource problems
  How you determine and resolve problems connected to IBM MQ resources, including resource usage by IBM MQ processes, determining and resolving problems related to insufficient resources, and your resource limit configurations.

Parent topic: Making initial checks

Related concepts

• IBM Support Assistant (ISA)
• Reason codes and exceptions

Related tasks

• Making initial checks on z/OS
• Making initial checks on IBM i
• Searching knowledge bases
• Contacting IBM Software Support

Related reference

• PCF reason codes

Related information

• Troubleshooting and support reference