Job initiators for WLM-managed job classes are controlled dynamically by workload management (WLM). These initiators run under the master subsystem and are not assigned JES2 job numbers. WLM can adjust the number of initiators on each system based on:

• The queue of jobs awaiting execution in WLM-managed classes.
• The performance goals and relative importance of this work.
• The success of meeting these goals.
• The capacity of each system to do more work.

The following must also be true for WLM-managed initiators to be active:

• WLM must be operating in goal mode.
• All members of the MAS must be in goal mode for consistent operation.

Although workload management dynamically controls its initiators, there are several mechanisms by which you can manage them with JES2 commands:

• Limit the number of jobs in each class that can execute simultaneously on a member of the MAS by using the XEQMEMBER(membername)=MAX= parameter on a $T JOBCLASS command. You can also limit the number of jobs in execution by class on an individual system basis by using the XEQMEMBER(membername)=MAX= operand.
• Stop or start the selection of batch jobs by JES or WLM managed initiators on an individual system with the $P XEQ and $S XEQ commands. The initial setting when JES2 first initializes is to allow selection. If you want to prevent this, place a $P XEQ command in your JES2 initialization deck.
• Stop or start the selection of batch jobs by JES or WLM initiators on an individual system and service class or by jobclass.
  • To stop selection of jobs in a given service class on a given member, issue $T SRVCLASS(service_class),QAFF=-membername.
  • To stop selection of jobs in a given jobclass on a given member, issue $T JOBCLASS(jobclass),QAFF=-membername.
  • To resume selection, use QAFF=+membername on the example commands.
• Immediately start the execution of a batch job in a WLM managed job class, with the $S Job operator command. Workload management will select the job for immediate execution from the list of systems where the job is eligible to run (based on SYSAFF and SCHENV parameters as well as SECLABEL affinity if active). This is processed even if the job is held.