Natasa, you didn't say what your definition of "lowest priority" is. Since years we have a constrained system with capping periods and the same problem as you, that batch gets more CPU resources than expected, even during capping. What we see is that Online workload doesn't match it's goal and batch still runs in an acceptable speed, although it's defined as discretionary However, on rare occasions and for very short times batch was limited to almost zero cpu. Anyway, I decided to define a resource group with just 100 SUs to force batch down. Surprisingly batch still used up to 2000 SUs, because WLM promoted the batch workload due to any blockings, enqueues or locks batch held. So promotion by WLM might be another reason at your site that batch runs better than expected. You can verify this with the Workload Activity report, it includes a column "Service" and "Promoted".
Regards, Werner Kuehnel IMD-Gesellschaft für Informatik und Datenverarbeitung mbH Augustaanlage 66 68165 Mannheim Tel: +49.621.457-4885, Fax: -4046 E-Mail: [email protected] IMD-Gesellschaft für Informatik und Datenverarbeitung mbH Sitz Mannheim, Amtsgericht Mannheim HRB 7460 Geschäftsführer: Norbert Koch Von: Natasa Savinc <[email protected]> An: [email protected] Datum: 19.02.2013 11:53 Betreff: Low priority workload Gesendet von: IBM Mainframe Discussion List <[email protected]> Hello! >From time to time (certain days in a month) we hit group or system limit. We have different types of workload defined in WLM. Among others, most batch jobs have the lowest priority. At the peek times they apparently get no CPU resources, but when we make report at the end of the day, they managed to get some CPU seconds. We would prefer that those seconds were allocated to important online transaction. There are two opinions amoung our sysprogs: one is that we should cancel all low priority workload in order to help our online get all the resources, the other is that that is not necessary, as batch isn't getting any online's CPU resources anyway. It seams that when you hit the limits things become more complicated. Any thoughts about our dilemma? Any experiences with life on the edge? Regards, Natasa ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
