Preliminary checks
Before you start problem determination in detail, it is worth considering the facts to see if there is an obvious cause of the problem, or a likely area in which to start your investigation. This approach to debugging can often save a lot of work by highlighting a simple error, or by narrowing down the range of possibilities.
The cause of your problem could be in any of the following:
- Queue manager address space
- A queue manager in your queue-sharing group
- Channel initiator address space
- CICS address space
- IMS region
- Batch or TSO address space
- The z/OS system (including ARM, RRS, or the Coupling Facility)
- The network (including APPC or TCP/IP)
- Another system, for example a queue manager on another platform, or a WebSphere MQ client
- The external security manager product, for example RACF or ACF2
- DB2
The sections that follow raise some fundamental questions that we need to consider.
As you go through the questions, make a note of anything that might be relevant to the problem. Even if your observations do not suggest a cause straightaway, they could be useful later if you have to carry out a systematic problem determination exercise.
Table 1 summarizes the preliminary checks that you should make.