Starting and stopping initiators automatically
At this stage in the batch job lifecycle, an initiator has acquired the best job and is proceeding with its execution. That initiator is one of a set that ThruPut Manager AE is managing to service its execution queues.
ThruPut Manager AE manages this set of JES2 initiators as dynamic initiators: it halts and resumes them automatically, using as many at a time as are needed to meet the workload goals within the constraints of system loading. It bases its decisions on any constraints in the current Policy and on z/OS performance information, including:
- WLM and PR/SM performance data – the same data used by WLM to start and stop its initiators.
- Loading and availability data determined by the TM AE internal routines.
- The level of service the current workload is receiving in relation to its WLM Service Classes.
ThruPut Manager AE continually evaluates system conditions, using an algorithm driven by the above considerations, and dynamically manages the number of initiators to make the best use of available resources. It ensures capacity is available before starting more jobs. Thus it prevents over-initiation, and so avoids the negative impacts on performance that occur when the system is overloaded. (If your processing power is already maxed out, adding more overhead in the form of more initiators is counter-productive.)