Well, a significant portion of the value proposition for WLM when it was introduced in the mid 90s was in fact to eliminate the static assignment of dispatching priorities and the fact that WLM would potentially adjust the dispatching priorities every 10 seconds to attempt to balance the performance of different workloads at different importances to optimize overall throughput of the system.
WLM makes those decisions based on how the different workloads are performing relative to their goals. But of course if the goals and importances are set "poorly" the results may not be ideal. The CPU Critical attribute can be set for service classes to keep a service class at a dispatching priority above all SCs at a lower importance. Well mostly... except for promotion that can happen for a variety of reasons to help resolve things like resource contention. But CPU Critical is generally not the first tool to be pulled out of the tool box. If you want a (relatively) quick overview of WLM, you might check the presentations section of our website: https://pivotor.com/content.html You might want to click on the topic view button at the top and scroll down to the WLM section. The "Introdution to the WLM" presentation might be a good place to start. "WLM’s Algorithms – How WLM Works" might be another good early one to look at. It sounds like "Revisiting Goals over Time" might also be of interest. :) Scott Chapman On Wed, 6 Mar 2024 08:33:14 +0400, Peter <dbajava...@gmail.com> wrote: >Hello > >I must confess that I am not a WLM expert but I just wanted to understand >how this works > >In our environment we have few started where their Service class(Velocity) >and Dispatch priority keeps changing on its own. > >Based on what constraint or definition in WLM the service class and >Dispatch priority are dynamic? Keeping a static value would be right thing >to do ? >Sometimes those task loop and freezes the entire zOS. So If I make those >started task Service class and DP static then will it help consuming the >zOS memory due to looping? > >Sorry if this question are basic and lacks some information > >Any suggestions or advice are much appreciated > >Peter > >---------------------------------------------------------------------- >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
