[pgpool-hackers: 4224] Re: Dynamic spare process management of Pgpool-II children

[Muhammad Usama]

On Wed, Nov 9, 2022 at 5:50 AM Tatsuo Ishii <ishii at sraoss.co.jp> wrote:

> Hi Usama,
>
> Thank you for the update. New patch looks good to me. All regression
> tests passed. Please go ahead and commit/push the patch as soon as
> possible. Pengbo is waiting for your commit so that she can release
> Pgpool-II beta1, which was supposed to be released yesterday.
>

Thanks, I have pushed the commit to the master branch. We can proceed with
beta1.


> Subtle point:
>
> - there are some trailing white spaces in the patch.
>
> $ git apply ~/dynamic_spare_process_management_latest.diff
> /home/t-ishii/dynamic_spare_process_management_latest.diff:11: trailing
> whitespace.
>
> /home/t-ishii/dynamic_spare_process_management_latest.diff:37: trailing
> whitespace.
>
> /home/t-ishii/dynamic_spare_process_management_latest.diff:53: trailing
> whitespace.
>
> /home/t-ishii/dynamic_spare_process_management_latest.diff:84: trailing
> whitespace.
>
> warning: 4 lines add whitespace errors.
>
Fixed

>
> - In the document patch,
>
> +         <entry>Static</entry>
> +         <entry>
> +          All children are pre-forked at startup.
> +         </entry>
>
> If "Static" is compatible with the behavior in pre 4.4, then I would
> suggest to add wording saying so.
>

Done.


Best regards
Muhammad Usama


> Best reagards,
> --
> Tatsuo Ishii
> SRA OSS LLC
> English: http://www.sraoss.co.jp/index_en/
> Japanese:http://www.sraoss.co.jp
>
>
> > Hi,
> >
> > Thank you peng for testing and coming up with a minimal test case.
> >
> > On Mon, Oct 24, 2022 at 3:38 PM Tatsuo Ishii <ishii at sraoss.co.jp> wrote:
> >
> >> Hi Usama, Pengbo,
> >>
> >> >> after applying the patch, I have run regression test and encountered
> 7
> >> >> timeout.
> >> >>
> >> >> testing 008.dbredirect...timeout.
> >> >> testing 018.detach_primary...timeout.
> >> >> testing 033.prefer_lower_standby_delay...timeout.
> >> >> testing 034.promote_node...timeout.
> >> >> testing 075.detach_primary_left_down_node...timeout.
> >> >> testing 076.copy_hang...timeout.
> >> >> testing 077.invalid_failover_node...timeout.
> >> >
> >> > I found that some tests above failed when running pgpool_setup with 3
> >> nodes.
> >> >
> >> > It seems that after running pcp_recovery_node, all child processes
> exited
> >> > with the messages "exited with success and will not be restarted".
> >> >
> >> > It can be reproduced by running "pgpool_setup -m s -n 3" command.
> >> > The log is attached.
> >>
> >> Peng,
> >> Reliably reproduced here. Thank you for the minimal test case. This
> >> helped my investigation a lot.
> >>
> >> Usama,
> >> I have looked in to this a little bit and I have doubt in following
> >> code fragment (src/main/pgpool_main.c around line 1981)
> >>
> >>                                 if (pid == process_info[i].pid)
> >>                                 {
> >>                                         found = true;
> >>                                         /* if found, fork a new child */
> >>                                         if (!switching && !exiting &&
> >> restart_child &&
> >>
> >> pool_config->process_management = PM_DYNAMIC)
> >>
> >> Shouldn't this be as following?
> >>
> >>
> >> pool_config->process_management != PM_DYNAMIC)
> >>
> >> After this modification, all regression tests passed.
> >>
> >
> > @Tatsuo Ishii <ishii at sraoss.co.jp>  Thanks for pointing this out. It
> was a
> > silly mistake on my part.
> >
> > I am attaching the updated patch with the fix that also includes the
> > documentation updates for the feature.
> >
> > Kindly review
> >
> >
> > Thanks
> > Best  regards
> > Muhammad Usama
> >
> > Best reagards,
> >> --
> >> Tatsuo Ishii
> >> SRA OSS LLC
> >> English: http://www.sraoss.co.jp/index_en/
> >> Japanese:http://www.sraoss.co.jp
> >>
>
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