Loops

A loop is the repeated execution of some code. If you have not planned the loop, or if you have designed it into your application but it does not terminate for some reason, you get a set of symptoms that vary depending on what the code is doing, and how any interfacing components and products react to it. In some cases, at first, a loop might be diagnosed as a wait or performance problem, because the looping task competes for system resources with other tasks that are not involved in the loop. However, a loop consumes resources but a wait does not.

An apparent loop problem in your system could be caused by any of the following:

• An application doing a lot more processing than usual and therefore taking much longer to complete

• A loop in application logic

• A loop with MQI calls

• A loop with CICS or IMS calls

• A loop in CICS or IMS code

• A loop in WebSphere MQ for z/OS