Slow Running Batch Jobs on as400 Iseries

1) Is it a job running in a separate as400 iseries batch memory pool? (WRKSBS and check whether
the second column of Qbatch is a number such as 5 which is a pool on the
WRKSYSSTS screen and appears to have jobs running in it. Sometimes the
system is shipped with these jobs running in pool 2 (*Base) and this is not
so efficient, they can be affected by other work such as ODBC.)

2) If batch as400 jobs have been separated into pool 5 or whatever, is Expert
Cache turned on? It should be. If so, F11 on WRKSYSSTS will show *Calc next
to the pool. If it shows *Fixed, change it to *Calc, but only if you are
sure that all the work in that memory pool is the same type (i.e. all batch,
or all interactive.)

3) Have the files used by the batch program been getting bigger? They may
need purging. Or they may contain 'hard deleted' records, if so you need to
do a RGZPFM on them to speed things up.

4) Does the batch program use SQL to access the files? If so, you may need
indexes creating over the files. You can run the database monitor to find
out.

5) Which model of iSeries are you running on? On some models there is a
'governor' program that kicks in when the workload reaches the 'knee' of the
response time curve, and slows everything down using an interrupt called
CFINTxx - you can only see this in action on WRKSYSACT. This is more likely
to happen with interactive than batch though.

6) Have you done a RCLSTG recently? Maybe some data got corrupted.

7) Any duplicate records in the files? Sometimes the software doesn't handle
this well.

8) Sometimes you can speed up a batch job by removing logicals and
recreating them afterwards.

9) Ensure you use Visual Explain in Iseries Navigator to investigate any problems jobs with logical indexes that may need to be created on the as400 iseries