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Daya · Posted: Thu Jun 03, 2004 5:05 am Post subject: Sub-system

Dear Experts,

One of my colleague who is basically a cobol programmer asked me one intresting question yesterday about started task.

Question is "Is it possible to run two different started task with similar names?" I immediately replied him NO, but after that he showed me two started task with similar name running in his client's mainframe. I really got stuck with my question how is it possible? as I have maintained mainframes earlier, I myself have seen duplicate error message in system console by mistake when I start the same sub-system. Then I told him probably due to system plexing from other lpar image it could be running in this lpar as part of load sharing, I told him I wasn't sure of the answer because I haven't worked in sysplex systems.

Just of curiosity I want to know whether my answer was correct. If not I would like to know the correct answer.

Hope I am clear.

Searched in manuals and forums but hard luck.

Daya

Daya · Posted: Thu Jun 03, 2004 5:14 am Post subject:

Sorry I should have mentioned the subject as "started task" because he was mentioning a started task which is not actually any of the sub-system.

Apologize me.

Daya

kolusu · Posted: Thu Jun 03, 2004 5:32 am Post subject:

Daya,

In a sysplex configuration, it is possible for the same DB2 subsystem to be started at different times on different MVS images. It is also possible to have separate DB2 subsystems of the same name defined on different MVS images within the sysplex. A DB2 subsystem that can be started on more than one MVS image within a sysplex requires the Participates in Sysplex option to be checked. From the Properties page of the Tivoli Business Systems Manager console, for a DB2 subsystem object, select Source/390, and confirm that the Participates in Sysplex option is checked (this is the default value). Conversely, if the DB2 subsystem is defined to only one MVS image, then ensure that the Participates in Sysplex option is not checked.

Having the Participates in Sysplex option selected ensures that only a single copy of data objects is kept in the Tivoli Business Systems Manager database. When the DB2 subsystem is activated in another MVS image, none of the resource types that reside beneath the data sharing resource group is rediscovered (except for new objects defined since the last discovery). Instead, only the high-level resource types such as the master address space up to the EDM Pool will be discovered under the new MVS image. This prevents creation of redundant data objects during discovery and this is also an important performance improvement. If the Participates in Sysplex option had not been selected in this situation, the subsystem would be considered as an entirely new object, and its inclusion in any business systems to which it previously belonged would not be recognized.

Hope this helps...

Cheers

Kolusu
_________________
Kolusu
www.linkedin.com/in/kolusu

warp5 · Posted: Thu Jun 03, 2004 6:11 am Post subject:

As far as I know this all depends on the task and how the programs work. Here is an example of two STC with the same name, but different address spaces:
OPSOSF OPSS002D OPSS
OPSOSF OPSS002F OPSS

Quite often we restart certain tasks that also start a task. If the second task is already running the second task start will usually say that it has already been started and terminate.

Daya · Posted: Thu Jun 03, 2004 7:01 am Post subject:

Hi Wrap5,

Adding to it, he said two started tasks have different contents with similar name.

If it can run in different address space, how can I assign different address space to these started task should I hard code anything in the proc?.

Daya

Mike Chantrey · Posted: Thu Jun 03, 2004 9:45 am Post subject:

Bill Dennis · Posted: Thu Jun 03, 2004 2:51 pm Post subject:

Started tasks are actually identified by the STEPNAME, not the JOBNAME. Many time they are the same value, but in your example of OPSOSF you see the stepnames are unique. If you wanted to cancel one you would use 'C OPSS002D' command.

Regards,
Bill

Daya · Posted: Thu Jun 03, 2004 11:52 pm Post subject:

Thanks for all your replies.