So here is my issue: We have a soft capped LPAR that runs our DB2 and CICS regions and during the day some "marketing batch". On Wednesdays, the marketing batch (online submit via CICS) increases and by afternoon we hit our 4 hour soft cap. Once or twice while we are capped, the busiest CICS slow down to the point where some old automation kicks in to kill transactions over 45 seconds old, some of these transactions dump through DumpMaster, we then go to max sockets and more transactions dump and in 10 - 30 seconds all is fine again.
What I see: The CICS regions have a DP around EC and are meeting their service goal of 99% under .5 seconds. But there are tens of thousands transactions that have led to this. The batch jobs (3-5 of them), while running 10 - 15 % cpu have a DP of C0 and are in a discretionary level of the service class. I believe the problem lies with the DB2 service class. That has a definition of velocity at 66 and it tends to run below that when there is more contention in the system. The DP of the DB2 region is F6. My theory: when this brown out occurs the resources are maxed out and the CICS regions being the ones that have meet their goal and will have to suffer many transactions missing the service goal to make the DP go up. They get hung up just long enough to cause the delays that trigger the "panic" automation to clear the stalled transactions. Chaos breaks out! My proposal: A. limit the batch jobs to a max of three by controlling open initiators for their job class. B. change the DB2 velocity to 60 C. Starve the CICS service goal by reducing it to 99% in .4 forcing his DP to be a little more desperate. Thoughts? TIA, Tracy ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
