Doubt on JWT,JOBCLASS,TIME parameters



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Doubt on JWT,JOBCLASS,TIME parameters

Postby Viswanathchandru » Tue Sep 27, 2011 6:54 pm

Dear all,
I have a very specific clarification on various parameters which refers to TIME in the z/OS environment. We have (upto my knowledge) JWT parmeter in SMFPRM, TIME parameter in Jobclass of JESPARM, and TIME in the Jobcard of a JCL. Which refers the original time parameter. If i say the TIME parameter in the Jobcard overrides the TIME in JESPARM, then what is the use of JWT. Googled and found this thread
http://www.mail-archive.com/ibm-main@bama.ua.edu/msg17082.html
from which i can't get any input. Here in my shop i have TIME in JESPARM(jobclass) as 1440, JWT as 120. Hope i'm clear!. Please let me know in case if i need to give more inputs. Apologize if i'm wrong.

Thanks,
Viswa
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Re: Doubt on JWT,JOBCLASS,TIME parameters

 

Re: Doubt on JWT,JOBCLASS,TIME parameters

Postby Robert Sample » Tue Sep 27, 2011 7:25 pm

JWT is for wait time -- not execution time. From the Initialization and Tuning Reference manual:
JWT (hhmm)


| Specifies the maximum amount of time that a job or TSO/E user address
| space is allowed to wait continuously, where hh is the amount of real
| time in hours and mm is in minutes. "Continuous wait time" is defined
| as time spent waiting while the application program is in control. For
| example, the time required to recall a data set from HSM Migration
| Levels 1 or 2, or the time required to mount a tape is counted towards
| the job's continuous wait time if the allocation of the data set is
| dynamic (that is, issued while the program was running), while the
| time required for those activities will not be counted towards the
| job's continuous wait time if the allocation is static (that is, for a
| DD statement).


| If the specified time limit expires, the system passes control to the
| SMF time limit exit, IEFUTL (if active). IEFUTL either extends the
| wait time or allows the system to end the job or TSO/E user address
| space abnormally.


| Note: If TIME=1440 is coded on the JOB or EXEC JCL statement, IEFUTL
| is not invoked for that job.


You've completely overlooked the impact of the JES parameter(s) regarding execution time and the JES exit(s) regarding execution time. Your JOB statement specification may be completely ignored if the job class is limited in JES.
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Re: Doubt on JWT,JOBCLASS,TIME parameters

Postby steve-myers » Tue Sep 27, 2011 11:07 pm

The other issue is the CPU time in the JOBCLASS JES2 initialization statement (or the JES3 equivalent) is for job steps, not for all steps of a job. The STEP limit (regardless of its source) does not override the JOB limit.
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Re: Doubt on JWT,JOBCLASS,TIME parameters

Postby Viswanathchandru » Wed Sep 28, 2011 11:55 am

Thanks Robert and Steve for your valuable time and replies!!

A small clarification

Rober wrote:Your JOB statement specification may be completely ignored if the job class is limited in JES.
. Does this means if my TIME in JES is
JOBCLASS(*) AUTH=ALL,
TIME=(15,0),
and my job statement looks of this kind
//ZEAL804$ JOB NOTIFY=&SYSUID,PRTY=15,TIME=1440,REGION=5M
. Which will be taken into action. I mean to say will the TIME in job statement will be neglected. :? Apologize if i'm wrong.

Thanks
Viswa
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Re: Doubt on JWT,JOBCLASS,TIME parameters

Postby steve-myers » Wed Sep 28, 2011 5:25 pm

TIME=1440 is a special case, which you can discover for yourself in the JCL Reference Manual.

//A JOB ,TIME=1440
//A EXEC PGM=whatever,TIME=15

will fail at 15 minutes, based on the EXEC statement. The JCL manual discusses this. Go to the JCL manual and tel us what this JCL does.

//A JOB ,TIME=15
//A EXEC PGM=whatever,TIME=1440

(Many sites have exit code that forbids the use of TIME=1440.)
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