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amitjain_20001 Beginner
Joined: 04 Jul 2006 Posts: 3 Topics: 1
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Posted: Fri Jul 07, 2006 11:06 pm Post subject: Why started task doesnot require initiator ? |
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Hi
There are some jobs that need to be made as started task which doesnot requires initiator.
Why started task doesnot require initiator ?
What type of jobs can be converted into started task?
Thanks
Amit |
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shekar123 Advanced
Joined: 22 Jul 2005 Posts: 528 Topics: 90 Location: Bangalore India
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Posted: Sat Jul 08, 2006 12:02 am Post subject: |
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amitjain_20001,
Are you talking about something like jobs which are started automatically on a particular time and day in a Scheduling kind of Jobs environment by a Schedular like CA 7 / CA 11 / OPC ?
There can be jobs which can be triggered based on some conditions like :
1.Successful completion of a job.
2.Arrival of an input dataset.
3.Can Trigger one more job after a particular flow and could be many more.
Actually jobs are scheduled to run in any Schedular as per a particular plan designed for Business Flow.Hope this helps. _________________ Shekar
Grow Technically |
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amitjain_20001 Beginner
Joined: 04 Jul 2006 Posts: 3 Topics: 1
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Posted: Sat Jul 08, 2006 1:03 am Post subject: |
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Thanks for your reply Shekar .
Started tasks are run through OPC schedular when other dependent jobs have run sucessfully.
As we know that to run any job initiator is required. Job class determines which initiator will be used.But in started task there is no job card and no initiator is required.
I have a job which executes IEBGENER step ( merge 6 datasets into output dataset).Output dataset of IEBGENER is used to load data in Teradata table (Teradata is RDBMS database ).This job is started task, it does not have any job card and doesnot require initiator.
I want to know why above mentioned job doesnot require initiator.?
There are jobs which run parallel and have to wait for the initiaor to free.Can someone tell me what type of jobs can be converted in started task ?
If a job executing a sort and cobol pgm , can it be converted into started task ?
Thanks
Amit |
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semigeezer Supermod
Joined: 03 Jan 2003 Posts: 1014 Topics: 13 Location: Atlantis
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Posted: Sat Jul 08, 2006 3:02 am Post subject: |
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Generally, started tasks are long running server tasks, similar to daemons in Unix. They usually provide some sort of system services such as opeating system related tasks (JES, ALLOCAS, RACF, VLF) , transaction monitors (CICS) or other shared services (web servers, library managers, etc). Jobs are intended for the 'real work' in the system (compiles, batch processing, etc). Started tasks are managed very differently from jobs both by the system (dispatching, security, etc) and by people (for example, started tasks must be started by the operator or by operator automation software). Unless you have a need to provide services to other address spaces, you should not be considering use of a started task. Of course, everything I said has exceptions (not all started tasks are long running, for example), but the initiators exist to manage end user work.
Also, since started tasks have a different operating environment than jobs. Control blocks differ, some facilities may not be available, etc. |
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Bill Dennis Advanced
Joined: 03 Dec 2002 Posts: 579 Topics: 1 Location: Iowa, USA
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Posted: Mon Jul 10, 2006 7:57 am Post subject: |
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More simply, a job is usually made into a started task when it is important that it run immediately when needed. This is difficult to control with normal initiators. Unlike initiators, there is no set number of started tasks that can be active. _________________ Regards,
Bill Dennis
Disclaimer: My comments on this foorum are my own and do not represent the opinions or suggestions of any other person or business entity. |
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amitjain_20001 Beginner
Joined: 04 Jul 2006 Posts: 3 Topics: 1
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Posted: Tue Jul 11, 2006 2:26 am Post subject: |
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Thanks for your reply
I have got some information regarding initiator It is as follows:-
if job A and job B must both write to a particular data set, the system (through the initiator) does not permit both jobs to run at the same time. Instead, whichever job starts first causes an initiator attempting to run the other job to wait until the first job completes.
Does Anyone have any suggestion regarding this ? |
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Bill Dennis Advanced
Joined: 03 Dec 2002 Posts: 579 Topics: 1 Location: Iowa, USA
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Posted: Tue Jul 11, 2006 8:03 am Post subject: |
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The initiator knows nothing about which data sets will be used. You would need to follow a rule where jobs A and B must use the same job CLASS and only one initiator would be assigned to that job CLASS.
If both jobs DO get selected by initiators, the system allocation function may cause the second job to wait due to reserved data set names. However, this is not a function of the initiator. _________________ Regards,
Bill Dennis
Disclaimer: My comments on this foorum are my own and do not represent the opinions or suggestions of any other person or business entity. |
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German Castillo Beginner
Joined: 23 Dec 2005 Posts: 83 Topics: 2 Location: Caracas, Venezuela
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Posted: Wed Jul 26, 2006 3:56 am Post subject: |
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amitjain_20001 wrote: | ... the system (through the initiator) does not permit both jobs to run at the same time.... |
It depends. I think you are talking about datasets other than VSAM, in which case and depending upon the shareoption used your jobs wont be enqueued over the resource. Anyway, your jobs should be aware of read/write consistencies and behave accordingly. But even in this case an enq could posible arise at the record level for simultaneous updates! _________________ Best wishes,
German Castillo |
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