Dealing with waits and loops

 

To perform the tests shown in this chapter, we need access to the z/OS console, and to be able to issue operator commands.

Waits and loops are characterized by unresponsiveness. However, it can be quite difficult to distinguish between waits, loops, and poor performance.

Any of the following symptoms could be caused by a wait or a loop, or by a badly tuned or overloaded system:

• An application that appears to have stopped running (if WebSphere MQ for z/OS is still responsive, this is probably an application problem)

• An MQSC command that does not produce a response

• Excessive use of processor time (CPU)