IDS Forum

Re: Informix job scheduler issues

Posted By: John Miller iii
Date: Tuesday, 24 January 2012, at 7:21 p.m.

In Response To: Re: Informix job scheduler issues (MARK COLLINS)

What is really happening:

What happens when you create a task? The tk_next_execution time
gets sent to CURRENT and time values are sanity checked. If the time
values fit executing the task now we continue to execute the task else
we do not execute the task, but just request that the task be schedule for
the
next valid execution. This is tracked as the task running even though the
function
itself was not executed, it was work done to manage this task (often very
small).

In order to simulate the a task being executed by the scheduler
the function exetask() are availible. These force the worker
thread to execute the task now, even if the schedule indicates
it should not be run.

execute function exectask( tk_name )

OR
execute function exectask( tk_id )

Something that does not seem correct is
that the exectask() function does not take
the function to be executed, but rather the
name of the task which is is stored in tk_name
column. In version 11.50 if you called this with
an incorrect name to many times this could
serverly slow down the scheduler and a restart
of the scheduler would clena this up.

I would look at the onstat option onstat -g dbc to view any error
messages which occur during the running of your task.

John F. Miller III
STSM, Embedability Architect
miller3@us.ibm.com
503-578-5645
IBM Informix Dynamic Server (IDS)
(Embedded image moved to file: pic00070.gif)

ids-bounces@iiug.org wrote on 01/24/2012 12:26:20 PM:

> From: "MARK COLLINS" <markc@myfastmail.com>
> To: ids@iiug.org
> Date: 01/24/2012 12:32 PM
> Subject: Re: Informix job scheduler issues [26029]
> Sent by: ids-bounces@iiug.org
>
> Thanks for the response.
>
> OK, that almost makes sense about the first run. I would have thought
that
> since I created the ph_task entry prior to the scheduled start time, that
it
> would use the specified start time to determine when to try the
> first run. The
> way you describe it, if I want something to run at daily 6:00 PM starting

> today, I would have had to create the ph_task entry yesterday?
>
> I did confirm the run times and number of runs for the original posting
by
> querying ph_run.
>
> You may be onto something about the logging. No, dev_db_2 is not logged.
> Sadly, many of our databases are not logged (it's on our to-do list).
>
> However, your idea of testing it by running EXECTASK seems to indicate
that
> this is not a problem. I executed the following:
>
> database sysadmin;
> execute function exectask("dev_db_2:my_test_function(3)");
>
> and it appears to be running correctly (the function takes several
minutes to
> run, and it is taking time now. Last night, the ph_run indicated that it
was
> ending in less than a second.) Also, I am able to run the function
manually
> 'execute function my_test_function(3)' successfully when I am logged in
to
> dev_db_2. I mention this because I am not certain whether the scheduler
runs
> the task from sysadmin, or if it instead connects to dev_db_2 prior to
> attempting to execute the function.
>
> The function is defined in dev_db_2. The signature is
> my_test_function(smallint) returning integer.
>
> Can you give me more details, or tell me where to find more details,about
the
> problem calculating stop time (the problem affecting AUS) in this
version?
>
> Also, where is EXECTASK documented? I did a search in the online
> docs and came
> up with no matches.
>
> >> When you set it to run at 1H interval, it will wait that interval to
run
> >> the first time. So it would have run at around 20:05H.
> >> I don't have a good explanation to the other questions (specially the
99
> >> runs - did you verified this on ph_run?).
> >>
> >> As for why it didn't run... Your database dev_db_2 has logging?
> >> Where did you create your function?
> >> What is the function signature?
> >>
> >> For he scheduling issue I believe that version has a problem thatleads
to
> >> a bad calculation of the stop time (it affected AUS) but it
> doesn't seem to
> >> match your scenario...
> >> But I'd suggest you solve the reason why it doesn't run and then try
to
> >> check the scheduling.
> >>
> >> You can run the task manually using:
> >>
> >> DATABASE sysadmin;
> >> EXECUTE FUNCTION EXECTASK("my_test_function");
>
> Regards.
>
>
>
*******************************************************************************

> Forum Note: Use "Reply" to post a response in the discussion forum.
>

Messages In This Thread

• Informix job scheduler issues
  MARK COLLINS -- Tuesday, 24 January 2012, at 1:25 p.m.
  • Re: Informix job scheduler issues
    Fernando Nunes -- Tuesday, 24 January 2012, at 1:44 p.m.
    • Re: Informix job scheduler issues
      MARK COLLINS -- Tuesday, 24 January 2012, at 3:26 p.m.
      • RE: Informix job scheduler issues
        Bruce Simms -- Tuesday, 24 January 2012, at 3:32 p.m.
        • RE: Informix job scheduler issues
          John Miller iii -- Tuesday, 24 January 2012, at 3:58 p.m.
      • Re: Informix job scheduler issues
        Fernando Nunes -- Tuesday, 24 January 2012, at 5:35 p.m.
      • Re: Informix job scheduler issues
        John Miller iii -- Tuesday, 24 January 2012, at 7:21 p.m.
        • Re: Informix job scheduler issues
          MARK COLLINS -- Thursday, 26 January 2012, at 11:18 a.m.
          • Re: Informix job scheduler issues
            John Miller iii -- Thursday, 26 January 2012, at 11:35 a.m.
            • Re: Informix job scheduler issues
              MARK COLLINS -- Friday, 27 January 2012, at 10:34 a.m.
              • Re: Informix job scheduler issues
                Art Kagel -- Friday, 27 January 2012, at 10:44 a.m.
                • Re: Informix job scheduler issues
                  MARK COLLINS -- Friday, 27 January 2012, at 2:32 p.m.
                • Re: Informix job scheduler issues
                  MARK COLLINS -- Monday, 30 January 2012, at 5:25 p.m.
                  • Re: Informix job scheduler issues
                    Art Kagel -- Monday, 30 January 2012, at 5:39 p.m.
                    • Re: Informix job scheduler issues
                      MARK COLLINS -- Monday, 30 January 2012, at 6:35 p.m.
                    • (repost)Re: Informix job scheduler issues
                      MARK COLLINS -- Wednesday, 1 February 2012, at 4:51 p.m.

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