Problem determination procedures

Distributed processing problems fall into several general categories.

Abends
All programs can abnormally end (ABEND) at one time or another. Most applications have some sort of recovery processing to try to avoid actually terminating the application. VTAM® and TCP/IP are fairly typical in this respect, and usually attempt to recover before they terminate.
Performance problems and hang situations
When the problem is a hang, it can be difficult to determine the cause of the problem.
Loops
When a loop is suspected, there are various actions that can be taken.
Storage shortages
Diagnosing storage shortage problems can be difficult. However, with a dump and an idea of where the shortage occurs, the problem source can be identified.
Incorrect output
Incorrect output problems can take various forms. In general, the problems can be grouped into two categories. The first category is where the remote access request fails. An SQL return code and SNA sense code or TCP/IP return code and reason code are received. In the second category the request works, but the information that received is not correct.
Unexpected messages
Sometimes the first indication of a problem is a message received at the console.

Parent topic: Diagnosing distributed data facility (DDF) failures