Re: pgpool

From: Tatsuo Ishii <t-ishii(at)sra(dot)co(dot)jp>
To: fatbobo(at)gmail(dot)com
Cc: peter_e(at)gmx(dot)net, pgsql-general(at)postgresql(dot)org
Subject: Re: pgpool
Date: 2005-01-18 00:19:37
Message-ID: 20050118.091937.02274289.t-ishii@sra.co.jp
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> So - would it then be worth doing pgpool?

You could limit the number of connections to PostgreSQL.
--
Tatsuo Ishii

> On Sat, 15 Jan 2005 11:12:04 +0900 (JST), Tatsuo Ishii
> <t-ishii(at)sra(dot)co(dot)jp> wrote:
> > > John Cunningham wrote:
> > > > concerned that if I drop the number of connections to less than the
> > > > number of databases I have, that pgpool would open the limit of
> > > > connections, hold them open and not allow any connections to the
> > > > remaining databases. Is this a concern? If I set up pgpool will I
> > > > have to have the same number of connections as I have databases?
> > >
> > > That depends on how you configure pgpool. pgpool is not aware of the
> > > connection limit count in the PostgreSQL server, so it will happily
> > > open connections until there are no more slots available.
> > >
> > > pgpool will require max_pool * num_init_children connection slots.
> > >
> > > max_pool should be the number of database/user combinations you use
> > > (300 in your case, assuming only one database user account),
> >
> > Not really. If a user connects to pgpool and all onnection slots are
> > already full, then pgpool will release the oldest connection slot and
> > reuse it for the new connection. So even if there are 300
> > database/user combinations, it's ok to set max_pool as low as, for
> > example, 4. Of course this will have unwanted side effect in that
> > connection caches are not very well kept, though.
> > --
> > Tatsuo Ishii
> >
> > > and
> > > num_init_children should be on the order of how many concurrent
> > > connections you expect to each combination ("several" in your case).
> > > So you should have at least 300 * several PostgreSQL connection slots,
> > > which is probably more than the 1000 or so that is the default.
> > >
> > > --
> > > Peter Eisentraut
> > > http://developer.postgresql.org/~petere/
> > >
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> >
>
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In response to

  • Re: pgpool at 2005-01-17 16:05:27 from John Cunningham

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