Re: Prepared statement does not exist

Hi,

I am not sure if sending this to the right place. I did try to get the
answer from pgpool mailing list but no luck . Would appreciate if someone
can help here.

We are receving the following error in the postgres database logs:

2009-03-19 02:14:20 PDT [2547]: [79-1] LOG: duration: 0.039 ms statement:
RESET ALL
2009-03-19 02:14:20 PDT [2547]: [80-1] LOG: duration: 0.027 ms statement:
SET SESSION AUTHORIZATION DEFAULT
2009-03-19 02:14:20 PDT [2547]: [81-1] ERROR: prepared statement "S_1" does
not exist
2009-03-19 02:14:20 PDT [2547]: [82-1] STATEMENT: DEALLOCATE "S_1"
2009-03-19 02:14:20 PDT [2547]: [83-1] ERROR: prepared statement "S_4" does
not exist
2009-03-19 02:14:20 PDT [2547]: [84-1] STATEMENT: DEALLOCATE "S_4"

We receive this errors when we start connecting the java application
thorugh pgpool. What causes this problem and how can it be avoided?

Postgres version: 8.3.3
pgpool II: 2.0.1

Thanks & Regards,
Nimesh.

--- On Thu, 19/3/09, Nimesh Satam <nimesh(dot)zedo(at)gmail(dot)com> wrote:
>
> We are receving the following error in the postgres
> database logs:
>
> 2009-03-19 02:14:20 PDT [2547]: [79-1] LOG: duration:
> 0.039 ms statement:
> RESET ALL
> 2009-03-19 02:14:20 PDT [2547]: [80-1] LOG: duration:
> 0.027 ms statement:
> SET SESSION AUTHORIZATION DEFAULT
> 2009-03-19 02:14:20 PDT [2547]: [81-1] ERROR: prepared
> statement "S_1" does
> not exist
> 2009-03-19 02:14:20 PDT [2547]: [82-1] STATEMENT:
> DEALLOCATE "S_1"
> 2009-03-19 02:14:20 PDT [2547]: [83-1] ERROR: prepared
> statement "S_4" does
> not exist
> 2009-03-19 02:14:20 PDT [2547]: [84-1] STATEMENT:
> DEALLOCATE "S_4"
>
> We receive this errors when we start connecting the java
> application
> thorugh pgpool. What causes this problem and how can it be
> avoided?

Looks like your app is dissconnecting from pgpool which is causing pgpool to send the RESET ALL, this will deallocate the prepared statement. Then the app is reconnecting to pgpool again and expecting the prepared statement to still be available, which it will not be.

Glyn Astill,

Thank for your reply. But can you confirm on this? As what I see from
the logs, its pgpool which is trying to deallocate the prepared
statement and not the application. The application just disconnects
and not tyring to use the same connection.

Regards,
Nimesh.

On Thu, Mar 19, 2009 at 5:07 PM, Glyn Astill <glynastill(at)yahoo(dot)co(dot)uk> wrote:

>
>
>
>
> --- On Thu, 19/3/09, Nimesh Satam <nimesh(dot)zedo(at)gmail(dot)com> wrote:
> >
> > We are receving the following error in the postgres
> > database logs:
> >
> > 2009-03-19 02:14:20 PDT [2547]: [79-1] LOG: duration:
> > 0.039 ms statement:
> > RESET ALL
> > 2009-03-19 02:14:20 PDT [2547]: [80-1] LOG: duration:
> > 0.027 ms statement:
> > SET SESSION AUTHORIZATION DEFAULT
> > 2009-03-19 02:14:20 PDT [2547]: [81-1] ERROR: prepared
> > statement "S_1" does
> > not exist
> > 2009-03-19 02:14:20 PDT [2547]: [82-1] STATEMENT:
> > DEALLOCATE "S_1"
> > 2009-03-19 02:14:20 PDT [2547]: [83-1] ERROR: prepared
> > statement "S_4" does
> > not exist
> > 2009-03-19 02:14:20 PDT [2547]: [84-1] STATEMENT:
> > DEALLOCATE "S_4"
> >
> > We receive this errors when we start connecting the java
> > application
> > thorugh pgpool. What causes this problem and how can it be
> > avoided?
>
> Looks like your app is dissconnecting from pgpool which is causing pgpool
> to send the RESET ALL, this will deallocate the prepared statement. Then the
> app is reconnecting to pgpool again and expecting the prepared statement to
> still be available, which it will not be.
>
>
>
>

--- On Fri, 20/3/09, Nimesh Satam <nimesh(dot)zedo(at)gmail(dot)com> wrote:

> From: Nimesh Satam <nimesh(dot)zedo(at)gmail(dot)com>
> > > We are receving the following error in the
> postgres
> > > database logs:
> > >
> > > 2009-03-19 02:14:20 PDT [2547]: [79-1] LOG:
> duration:
> > > 0.039 ms statement:
> > > RESET ALL
> > > 2009-03-19 02:14:20 PDT [2547]: [80-1] LOG:
> duration:
> > > 0.027 ms statement:
> > > SET SESSION AUTHORIZATION DEFAULT
> > > 2009-03-19 02:14:20 PDT [2547]: [81-1] ERROR:
> prepared
> > > statement "S_1" does
> > > not exist
> > > 2009-03-19 02:14:20 PDT [2547]: [82-1] STATEMENT:
> > > DEALLOCATE "S_1"
> > > 2009-03-19 02:14:20 PDT [2547]: [83-1] ERROR:
> prepared
> > > statement "S_4" does
> > > not exist
> > > 2009-03-19 02:14:20 PDT [2547]: [84-1] STATEMENT:
> > > DEALLOCATE "S_4"
> > >
> > > We receive this errors when we start connecting
> the java
> > > application
> > > thorugh pgpool. What causes this problem and how
> can it be
> > > avoided?
> >
> > Looks like your app is dissconnecting from pgpool
> which is causing pgpool
> > to send the RESET ALL, this will deallocate the
> prepared statement. Then the
> > app is reconnecting to pgpool again and expecting the
> prepared statement to
> > still be available, which it will not be.
>
> Thank for your reply. But can you confirm on this? As what
> I see from
> the logs, its pgpool which is trying to deallocate the
> prepared
> statement and not the application. The application just
> disconnects
> and not tyring to use the same connection.

There is the possibility that it's pgpool sending the deallocate in error after the reset all then. Either way, this is not relevent to the performance list, send it over to the pgpool list... and tell them your pgpool version number too - it may be a fixed bug.