Dealing with applications that are running slowly or have stopped on z/OS

Waits and loops can exhibit similar symptoms. Use the links in this topic to help differentiate between waits and loops on z/OS®.

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

Any of the following symptoms might 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 IBM MQ for z/OS is still responsive, this problem is probably caused by an application problem)
• An MQSC command that does not produce a response
• Excessive use of processor time

To perform the tests shown in these topics, you need access to the z/OS console, and to be able to issue operator commands.

• Distinguishing between waits and loops on z/OS
• Dealing with waits on z/OS
• Dealing with loops on z/OS