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How do I know my program is issuing checkpoints ?

 
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Cogito-Ergo-Sum
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PostPosted: Mon Apr 03, 2006 8:25 am    Post subject: How do I know my program is issuing checkpoints ? Reply with quote

Hi,
In my batch job spool output, I do not see the DFS681I message for checkpoints. I know, that there is a system-wide option to suppress this type of messages. Maybe/maybe not my program is issuing checkpoints.

OTOH, when I provide the CHKPT value (as, 00000001) and the 0th generation of GDG as for IMSLOGR DD name for restarting, I get a U0102 abend. This roughly means, I am not restarting correctly wrt the CHKPT id.

Is there a means to identify, if my program indeed issued a check-point ?
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kolusu
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PostPosted: Mon Apr 03, 2006 8:40 am    Post subject: Reply with quote

Quote:

In my batch job spool output, I do not see the DFS681I message for checkpoints.

Cogito-Ergo-Sum,

Look for DFS0540I messages

Kolusu
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Cogito-Ergo-Sum
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PostPosted: Mon Apr 03, 2006 11:21 am    Post subject: Reply with quote

Kolusu,
I do not see that either.

I checked some production logs and I can see the DFS681I and the DFS0540I messages. But, in our development region, I cannot see either of the messages. Maybe, both of them have been suppressed in our development system. Worse, the program is not issuing checkpoints; sounds unlikely though !

Thanks anyway, Kolusu.
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ANIL SARATHY
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PostPosted: Thu Apr 13, 2006 7:34 am    Post subject: Reply with quote

first check the program flow to see wether contro reaches check or xrst calls.

and also the data of checkpoint. some prorammers use count and others
have theri own way of defining data for checkpoint like time stamp.

Some reasons could be for U0102 abend:

DISP=OLD on an output file is causing the file pointer to go back to the beginning on a restart. it should be MOD.

the application program is issuing an explicit re-open of the GSAM on a restart.
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PostPosted: Thu Apr 13, 2006 9:28 am    Post subject: Reply with quote

Quote:
first check the program flow to see wether contro reaches check or xrst calls.


Yes, this was the problem. Embarassed
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ANIL SARATHY
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PostPosted: Thu Apr 13, 2006 10:16 am    Post subject: Reply with quote

In our shop ,lot of programs had chekcpoint restart logic. This was some years back.

Now still the code exists , but program is modified not to execute this code.

I couldn't figured why they have done like this. Need to talk to DBA , to
know about this, he may give some info.
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MFdigger
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PostPosted: Thu Jun 29, 2006 3:14 pm    Post subject: Reply with quote

Hi Anil

In our shop too, lot of programs are having the Check point and restart logic but they were commented out.

when ever the jobs are abended, DBA's go for the restoring of the databases from the image copies instead of backing out the databases from the last commit point.

Can anybody please through on some light on this?
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ANIL SARATHY
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PostPosted: Wed Jul 05, 2006 11:05 am    Post subject: Reply with quote

if there is not commit then , how changes done to DB in the middle of execution getting commited
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PostPosted: Tue Jul 11, 2006 9:49 am    Post subject: Reply with quote

Hi Anil,

As far as i know, If the program is not abending in the middle of the execution then IMS will commit all the changes once the program omes to an end ( i mean after the program completes the execution).
if there is an abend in between the execution, then DBA's will restore the whole database with the last image copy taken for that particular database (the image copy can be taken just before the execution of the job) so that all the changes revert back to the same as the image copy taken before the execution of the job.

I didnt understand the point here that why they have to comment the checkpoint and restart logic in the programs when the batch backout from the last commit point takes less time than the restoring the database from the last image copy which will take more time in dumping the whole database back to normal
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