With Workload Management (WLM), you can manage the performance and number of application servant regions in WebSphere Application Server for z/OS. WLM manages the response time and throughput of WebSphere transactions according to their assigned service class, the associated performance objectives, and the availability of system resources. To meet these goals, WLM sometimes needs to control or override the number of servant regions that are active.
WebSphere applications are deployed within a WebSphere generic server. One or more server instances must be defined on one or more systems within the WebSphere node. Each server instance consists of a controller region and one or more servant regions. The controller regions are started by MVS as started tasks, and servant regions are started by WLM, as they are needed.
If you have WLM dynamic application environments enabled on your system (z/OS Release 2 plus APAR OW54622 or later), WLM honors the specifications for the number of servant regions. If you are using static application environments (specified through the WLM ISPF panels), then you must also enable multiple servant regions by indicating No limit in the WLM ISPF panels.
Note: Be aware of the following regarding multiple servant regions: