If operator interface options of MAXSORT are enabled when MFX is installed, they will permit operator communication at selected breakpoints (e.g., at the first breakpoint after SORTTIME has expired, or when tape drives are dynamically allocated under DYNATAPE.) Operator communication allows the operator to examine the environment at execution time to decide whether or not to terminate MAXSORT at that breakpoint. If the operator decides to terminate the sort, it can be restarted later at that breakpoint. All the previously produced sorted data sets can be used without resorting.
Operator communication with MAXSORT is not a delivered default - these options must be enabled at MFX installation time.
For example, if MAXSORT’s assigned block of computer time (its SORTTIME value) has been exhausted and MFX was installed to permit operator intervention at such times, message WER375D is generated.
The operator receiving this message can decide to terminate the sort or allow it to continue, basing his decision on scheduling priorities and the estimated time of the sort. When another 30 minutes have passed, the operator will be asked again whether or not MAXSORT should be terminated.
When DYNATAPE is specified and operator communication has been enabled at installation time, message WER376D may be generated to report the results of the dynamic allocation attempt.
If the operator responds 'GO', MAXSORT will execute with four tape units. If the operator responds 'STOP', MAXSORT will terminate. If the operator responds with a number ('NN'), MAXSORT will try to allocate that total number of tape drives. Ideally, the operator should specify six for 'NN' because MAXSORT needs six tape units for best performance. If the operator requests additional tape units, message WER376D will be reissued. The operator will again be prompted for a 'GO', 'STOP' or 'NN' reply. In this way, the operator can balance the requirements of MAXSORT against the requirements of other jobs that are executing at the same time.
When DYNATAPE is specified, there may not be enough tape units available for dynamic allocation. In this case, message WER377D is generated.
The operator receiving message WER377D can wait until additional tape drives have been released and then reply 'RETRY'. Or, the operator can answer 'STOP' to terminate the job and then restart it later when more tape drives become available.
If the DYNATAPE and TAPENAME PARMs have been specified and all tape units on the system within the TAPENAME class have already been allocated, message WER378D is generated.
Message WER378D is followed by message WER376D if the number of tape drives allocated is sufficient for execution, or by message WER377D if it is not sufficient.