Обсуждение: LOG: statistics buffer is full

Hello,

        We use 7.4.6 version and now we have a bad performance on our
production server. We detected several strange messages in a log file :

    LOG:  statistics buffer is full
    LOG:  statistics buffer is full
    LOG:  statistics buffer is full

When i search on mailings list archive, i found a patch to increase the
buffer size in src/include/pgstat.h

-#define PGSTAT_RECVBUFFERSZ ((int) (1024 * sizeof(PgStat_Msg)))
+#define PGSTAT_RECVBUFFERSZ ((int) (16384 * sizeof(PgStat_Msg)))

And when i look the same file on the subversion trunk, the
"PGSTAT_RECVBUFFERSZ" constant is defined in a new file :
src/backend/postmaster/pgstat.c but with a same value.

Can you explain this statistics buffer problem ? And increase this
buffer size is a good resolution ?

Thanks for your help

Best Regards,
Jérôme BENOIS.
--
Share'nGo Team
http://www.sharengo.org

On Jun 22, 2006, at 2:24 AM, Jérôme BENOIS wrote:
>         We use 7.4.6 version and now we have a bad performance on our

You should upgrade to the latest 7.4 version.

> production server. We detected several strange messages in a log
> file :
>
>     LOG:  statistics buffer is full
>     LOG:  statistics buffer is full
>     LOG:  statistics buffer is full
>
> When i search on mailings list archive, i found a patch to increase
> the
> buffer size in src/include/pgstat.h
>
> -#define PGSTAT_RECVBUFFERSZ ((int) (1024 * sizeof(PgStat_Msg)))
> +#define PGSTAT_RECVBUFFERSZ ((int) (16384 * sizeof(PgStat_Msg)))
>
> And when i look the same file on the subversion trunk, the
> "PGSTAT_RECVBUFFERSZ" constant is defined in a new file :
> src/backend/postmaster/pgstat.c but with a same value.
>
> Can you explain this statistics buffer problem ? And increase this
> buffer size is a good resolution ?

Do you have stats_command_string=on? If so, your best bet is probably
to disable that, because it has a very high overhead (I've seen as
much as over 50%). FWIW, Tom recently made changes in HEAD that
essentially remove the overhead for using stats_command_string.
--
Jim C. Nasby, Sr. Engineering Consultant      jnasby@pervasive.com
Pervasive Software      http://pervasive.com    work: 512-231-6117
vcard: http://jim.nasby.net/pervasive.vcf       cell: 512-569-9461

Hello,

   Thanks Jim, i change stats_command_string=false and i wait but it's
works now :-)

Jérôme.

Le jeudi 22 juin 2006 à 21:00 -0500, Jim Nasby a écrit :
> On Jun 22, 2006, at 2:24 AM, Jérôme BENOIS wrote:
> >         We use 7.4.6 version and now we have a bad performance on our
>
> You should upgrade to the latest 7.4 version.
>
> > production server. We detected several strange messages in a log
> > file :
> >
> >     LOG:  statistics buffer is full
> >     LOG:  statistics buffer is full
> >     LOG:  statistics buffer is full
> >
> > When i search on mailings list archive, i found a patch to increase
> > the
> > buffer size in src/include/pgstat.h
> >
> > -#define PGSTAT_RECVBUFFERSZ ((int) (1024 * sizeof(PgStat_Msg)))
> > +#define PGSTAT_RECVBUFFERSZ ((int) (16384 * sizeof(PgStat_Msg)))
> >
> > And when i look the same file on the subversion trunk, the
> > "PGSTAT_RECVBUFFERSZ" constant is defined in a new file :
> > src/backend/postmaster/pgstat.c but with a same value.
> >
> > Can you explain this statistics buffer problem ? And increase this
> > buffer size is a good resolution ?
>
> Do you have stats_command_string=on? If so, your best bet is probably
> to disable that, because it has a very high overhead (I've seen as
> much as over 50%). FWIW, Tom recently made changes in HEAD that
> essentially remove the overhead for using stats_command_string.
> --
> Jim C. Nasby, Sr. Engineering Consultant      jnasby@pervasive.com
> Pervasive Software      http://pervasive.com    work: 512-231-6117
> vcard: http://jim.nasby.net/pervasive.vcf       cell: 512-569-9461
>
>
>