Dispatching priorities mean nothing if the work is getting done. You're using the WLM; you should learn and use its terminology.
-teD Original Message From: Tracy Adams Sent: Thursday, April 28, 2016 15:57 To: IBM-MAIN@LISTSERV.UA.EDU Reply To: IBM Mainframe Discussion List Subject: Re: WLM issue with a proposed solution The importance (priority) of DB2 is set 2, as well as the CICS service class. It serves both the CICS and batch jobs. I only speak of dispatching priorities because isn't ultimately that is driven by the collective results of WLM? To Mark's question, I am not sure what is stalling those transactions, I will try to collect some delay information. -----Original Message----- From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf Of Martin Packer Sent: Thursday, April 28, 2016 3:49 PM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: WLM issue with a proposed solution Hello Tracy. What importance have you set DB2 address spaces' service class(es) to? Likewise the things it serves, such as CICS regions and CICS transactions/ If DB2 is getting locked out it could be caused by it being Imp 2 or something, rather than Imp 1 with a goal 70+. I also note you're mainly talking dispatching priorities rather than WLM language. Cheers, Martin Martin Packer, zChampion, Principal Systems Investigator, Worldwide Cloud & Systems Performance, IBM +44-7802-245-584 email: martin_pac...@uk.ibm.com Twitter / Facebook IDs: MartinPacker Blog: https://www.ibm.com/developerworks/mydeveloperworks/blogs/MartinPacker Podcast Series (With Marna Walle): https://developer.ibm.com/tv/category/mpt/ From: Tracy Adams <tad...@fbbrands.com> To: IBM-MAIN@LISTSERV.UA.EDU Date: 28/04/2016 19:22 Subject: WLM issue with a proposed solution Sent by: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> 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 Unless stated otherwise above: IBM United Kingdom Limited - Registered in England and Wales with number 741598. Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU ---------------------------------------------------------------------- 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 ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
