Is temporary storage close to being exhausted?

It could be that your task has made a reasonable request for temporary storage, but the amount of unallocated space is close to exhaustion.

To see if this could be the cause of the wait, look at the temporary storage summary in the formatted dump. If the current free space is very small, this is likely to be the reason why the task cannot obtain its requested temporary storage. In such a case, consider defining secondary extents for the data set.

Look also at the trace. If a task has made an unusually large number of WRITEQ TS requests, it could be looping. A looping task might be issuing WRITEQ TS requests repetitively, each for a reasonable amount of storage, but collectively for a very large amount. If you find evidence for a looping task, turn to Dealing with loops.

If your task has made a reasonable request and the system seems to have sufficient unallocated temporary storage, you next need to see if fragmentation of unallocated storage is causing the WRITEQ TS request to fail.