I doubt that there is a significant difference in CPU resources between running the JVM in JZOS vs BPXBATC**.
Perhaps the differences that you are seeing have to do with not measuring all of the address spaces? For JZOS, the JVM will be in the same address space as the JES2 initiator. For BPXBATCH, it will be in a forked OMVS address space. Kirk Wolf Dovetailed Technologies http://dovetail.com On Fri, Feb 5, 2016 at 6:03 AM, Scott Chapman < scott.chap...@epstrategies.com> wrote: > On Fri, 5 Feb 2016 11:41:52 +1100, Andrew Rowley < > and...@blackhillsoftware.com> wrote: > > >I am using JZOS to run Java as a batch job, and these are my tests for > >general processing of SMF data rather than time zone conversion > >specifically. It wouldn't surprise me if the batch job is better than > >running under the shell. > > Tests I did a few years ago seemed to indicate that there was some > additional overhead from running under JZOS vs. BPXBAT* > > Workload #1: > Average CPU secs (multiple runs) > zAAPn GCP > BPXBATCH 0.50 0.20 > JZOS 0.73 0.12 > BPXBATSL 0.52 0.14 > > I figured that maybe that was just a minor startup difference, but > surprisingly a much longer workload followed the same pattern: > > Workload #2: > Average CPU secs (multiple runs) > zAAPn GCP > BPXBATCH 141.72 0.52 > JZOS 153.49 0.39 > BPXBATSL 142.09 0.45 > > But the JZOS launcher is more convenient, and unless you're very sensitive > about the consumed zAAP (now likely zIIP) time, the difference probably > doesn't matter. > > This was under Java 6, but I don't recall what the exact processor model > was. My guess is that it was a z10 5xx. > > Interestingly, IBM Java 7 seemed to add a little additional overhead. That > was somewhat expected for short-running tasks, but it seemed to be there > for long-running started tasks too, which was unexpected. It was in the > single digit percentage range, but it was consistent across multiple > different workloads. I never did get that difference understood to my > satisfaction. > > Scott Chapman > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN > ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
