[pgpool-general: 8227] Re: Pg_stat_activity hung queries issue

[Avi Raboah]

Hi,

After investigating the code I found that the patch you provided is fixing
the problem only for simple query. In extended query the issue still exist.

Do you know where is the right place to add the transaction failure
verification in extended query process?
On Mon, 9 May 2022 at 16:17 Tatsuo Ishii <ishii at sraoss.co.jp> wrote:

> The patch (plus more fix) has been committed to master and 4.3 stable
> branches.
>
> https://www.pgpool.net/pipermail/pgpool-committers/2022-May/008592.html
> https://www.pgpool.net/pipermail/pgpool-committers/2022-May/008591.html
>
> The patches will appear in the next release (May 19, 2022).
>
> I have not pushed to other stable branches because the fix is not
> small and I wanted to minimize risks.
>
> > Thanks a lot for the patch have a great weekend
> >
> > On Sat, 7 May 2022 at 13:35 Tatsuo Ishii <ishii at sraoss.co.jp> wrote:
> >
> >> > Hi,
> >> >
> >> > Still thinking.
> >> >
> >> > Best reagards,
> >> > --
> >> > Tatsuo Ishii
> >> > SRA OSS, Inc. Japan
> >> > English: http://www.sraoss.co.jp/index_en.php
> >> > Japanese:http://www.sraoss.co.jp
> >> >
> >> >
> >> >> Hi,
> >> >>
> >> >> Any news about this thread?
> >> >>
> >> >> Thanks,
> >> >> Avi.
> >> >>
> >> >> On Mon, 25 Apr 2022 at 11:13 Avi Raboah <avi.raboah at gmail.com>
> wrote:
> >> >>
> >> >>> It will be perfect thanks a lot!
> >> >>>
> >> >>> On Mon, 25 Apr 2022 at 10:47 Tatsuo Ishii <ishii at sraoss.co.jp>
> wrote:
> >> >>>
> >> >>>> > No, it doesn't.
> >> >>>> > In that case when you make the select statement, piggy internal
> >> queries
> >> >>>> > failed and the session rebooted
> >> >>>>
> >> >>>> I see it now.
> >> >>>>
> >> >>>> test=# begin;
> >> >>>> BEGIN
> >> >>>> test=*# insert into ttt values(1);
> >> >>>> ERROR:  relation "ttt" does not exist
> >> >>>> LINE 1: insert into ttt values(1);
> >> >>>>                     ^
> >> >>>> test=!# select * from t1;
> >> >>>> FATAL:  Backend throw an error message
> >> >>>> DETAIL:  Exiting current session because of an error from backend
> >> >>>> HINT:  BACKEND Error: "current transaction is aborted, commands
> >> ignored
> >> >>>> until end of transaction block"
> >> >>>> server closed the connection unexpectedly
> >> >>>>         This probably means the server terminated abnormally
> >> >>>>         before or while processing the request.
> >> >>>> The connection to the server was lost. Attempting reset: Succeeded.
> >> >>>>
> >> >>>> I think pgpool could remember that current transaction is in abort
> >> >>>> status and does not issue the piggyback query when the selec is
> >> >>>> issued. Let me see what we can do for this.
> >>
> >> I have come up with a patch. In this patch pgpool checks if current
> >> transaction is in abort status. If so, it does not accept new query at
> >> all and just reply back frontend with the message:
> >>
> >> "current transaction is aborted, commands ignored until end of
> transaction
> >> block"
> >>
> >> until commit or abort command is sent from frontend. After applying
> >> the patch the example session above looks like this:
> >>
> >> test=# begin;
> >> BEGIN
> >> test=*# insert into ttt values(1);
> >> ERROR:  relation "ttt" does not exist
> >> LINE 1: insert into ttt values(1);
> >>                     ^
> >> test=!# select * from t1;
> >> ERROR:  current transaction is aborted, commands ignored until end of
> >> transaction block
> >>
> >> The patch was tested in master branch, but I believe it can be
> >> applied to 4.3 stable branch as well.
> >>
> >> Best reagards,
> >> --
> >> Tatsuo Ishii
> >> SRA OSS, Inc. Japan
> >> English: http://www.sraoss.co.jp/index_en.php
> >> Japanese:http://www.sraoss.co.jp
> >>
>
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