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Initiators in mainframes.
Posted: Thu Mar 16, 2017 12:25 pm
by Shahid
Hi,
What is the difference between "WLM initiator" and "JES initiator"? Could someone please guide me on this?
Re: Initiators in mainframes.
Posted: Thu Mar 16, 2017 4:56 pm
by nicc
Initiators are initiators. But...they can be managed by JES or WLM. Doing my research I used Google - did you? One of the results was this
ftp://public.dhe.ibm.com/eserver/zserie ... Minits.pdf.
Re: Initiators in mainframes.
Posted: Thu Mar 16, 2017 5:09 pm
by Robert Sample
WLM initiators are managed by WLM while JES initiators are managed by JES. One of the many differences is that WLM can allocate more or fewer initiators when needed by the workload, whereas JES initiators must be allocated or removed by operator command. From the applications programmer viewpoint, an initiator is an initiator is an initiator; where the WLM / JES becomes important is for operator commands and system programmers' management of the system. System programmers can convert a system from JES to WLM initiators (or back), but this is rarely done.
Re: Initiators in mainframes.
Posted: Fri Mar 17, 2017 6:19 pm
by nicc
Is your query satisfied by the answers and link given? We, and others searching, would like to know.
Re: Initiators in mainframes.
Posted: Mon Mar 20, 2017 2:27 pm
by Shahid
Thanks. I did read about initiators and searche dbaout them.
Actually for a requirement client has told us that they have to change the priotity of a job if it's delayed for some reason. They said that they want WLM to use the correct intiator instead of manually doing it. We are still discussing on this but I thought we can just change priority of a job using the scheduler and we can not choose initiators as such.
Re: Initiators in mainframes.
Posted: Mon Mar 20, 2017 2:29 pm
by Shahid
Robert Sample wrote: WLM initiators are managed by WLM while JES initiators are managed by JES. One of the many differences is that WLM can allocate more or fewer initiators when needed by the workload, whereas JES initiators must be allocated or removed by operator command. From the applications programmer viewpoint, an initiator is an initiator is an initiator; where the WLM / JES becomes important is for operator commands and system programmers' management of the system. System programmers can convert a system from JES to WLM initiators (or back), but this is rarely done.
For a production environment, is it not good to change a JES initiator manually, right, on daily basis? Then how can we avaoid it?
Re: Initiators in mainframes.
Posted: Mon Mar 20, 2017 5:07 pm
by Robert Sample
First, from
https://www.ibm.com/support/knowledgece ... obschp.htm (the z/OS 2.2
JES2 Initialization and Tuning Guide manual) we find:
Jobs in JES2 controlled job classes are queued FIFO within priority within job class. Priority is not used directly to order jobs in WLM managed classes, but can be used as a criteria for determining service class.
So if WLM initiators are used, your client will be able to change job priority but it will not have much of an impact on the job, almost certainly not the impact they expect.
For a production environment, is it not good to change a JES initiator manually, right, on daily basis? Then how can we avaoid it?
JES initiators are changed every day at sites still using them -- initiators are added or removed, and it is not unusual to add or remove job classes to initiators as well. Why do you think it is not good to change JES initiators in a production environment?