On 28/06/2024 9:30 pm, Scott Chapman wrote:
From 2011:
SMF 30 and End-of-job Accounting
The choice of BPXBATCH vs. BPXBATSL vs. JZOS directly impacts the SMF 30
records that are created for a Java batch job. Note that there are USS
environment variables that may impact the details presented here. In
particular, _BPX_BATCH_SPAWN, _BPX_SPAWN_SCRIPT, and _BPX_SHAREAS seem like
they should impact the operation of BPXBATCH, but in my limited testing they
didn’t. Again, testing in your own particular environment is highly suggested!
If you expect to run a single batch job with a single step and get a single SMF
30 step record (subtype 4) and a single SMF 30 job record (subtype 5), you may
be surprised. In my testing that was only true when using BPXBATSL. When using
BPXBATCH, I got 4 job records and 6 step records. When using JZOS, I got 2 job
records and 2 step records.
JZOS batch launcher is pretty good, while it does use a secondary
address space (for setup I think) and ends up with additional SMF
records, the child resource usage is very low and the main work ends up
in the main job address space.
Running Java under BPXBATCH gives separate SMF records for BPXBATCH,
shell and java with most of the work running in a BPXAS address space,
not the original job. I expect Python is the same.
Unix work in general gives multiple SMF records. I think a shell script
will generate SMF records for each new program that is executed i.e.
anything other than built in shell commands. If you have a shell script
with a loop, you can end up with very large quantities of records e.g.
in my testing, a shell script generated about 20,000 type 30 records in
1 minute. There are ways to prevent commands from running in a different
address space, but I suspect it restricts the functionality available.
This isn't really how SMF 30 records were designed to work. Maybe IBM
could create a new workload type and instead of generating OMVS workload
records, generate records based on session id (or maybe process group)
where work from the same session is grouped together rather than
generating individual OMVS records...
--
Andrew Rowley
Black Hill Software
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