RE: Reducing Batch Job Run Time

["Andy Nolen-Parkhouse" <aparkhouse@xxxxxxxxxxxx>]

Ray,

Determining your optimum mix of concurrent jobs could involve a
considerable investment in time; I assume that a significant improvement
would be satisfactory.

Unless you have a significant number of processors and a monster amount
of memory, I would guess that the appropriate number of concurrent jobs
is somewhere between two and ten.  Make sure that all available memory
would be available for your batch jobs (setting your performance
adjustment system value to dynamic should be sufficient).  You could
then either start with ten concurrent jobs or two.  Then adjust up or
down on subsequent runs by adjusting the characteristics of your job
queues.  You could use the run times from your single-threaded batch to
try to divide them into fairly equal chunks.  For simplicity's sake, I
would run them all in the same memory pool.

Watch your memory swapping/paging and your disk activity during these
runs.  They will improve as you adjust the number of concurrent jobs and
then decline.  Pick the number which gives the best result.

For further tweaking I would try the run with expert cache turned on and
off in the pool, see which method provides the best result.

Regards,
Andy Nolen-Parkhouse
Certified Solutions Expert, iSeries 400 Technology

> Subject: RE: Reducing Batch Job Run Time
>
> The thing I would do would be to submit each of the 10 different
> programs at one time.  If you have a single threaded job queue,
> that won't help you, so you may want to create or modify a job
> queue to allow more than one job to run at a time.
>
> SBMJOB CMD(CALL PGM(MYLIB/MYPGM1)) JOBQ(MULTIJOB)
> SBMJOB CMD(CALL PGM(MYLIB/MYPGM2)) JOBQ(MULTIJOB)
> SBMJOB CMD(CALL PGM(MYLIB/MYPGM3)) JOBQ(MULTIJOB)
> .
> .
> .
>
> That would allow them to run all at once, and you may get an
> exceptional increase in the total process time (1/10th the time
> or 24 minutes) or next to no saving at all, depending on what
> is taking the jobs so long to run (is it CPU time, DASD wait
> time, etc...)
>
>
> Regards,
>
> Jim Langston
> Programmer/Analyst
> Cels Enterprises, Inc.
>
>
> Hi all,
>
> What are the best options available to reduce the batch job run time?
> We have a daily batch job which runs about 4 hours, and which calls 10
> different programs. All these programs are independent of each other
and
> can
> be called in any sequence. Looking for best options to reduce the
batch
> job
> run time.
>
> thanks in advance.
>
> Ray