Re: pgbouncer

> If I set 3, and I tried to connect from 4 shells, I am still able to
connect.

That would be the point - pgbouncer is sharing the 3 connections it
keeps with PostgreSQL between the 4 client connections made to it.

Mmh, my pool_mode is per session. The 4 sessions were active, not doing any
query, but connected to the shell.
So that's what my doubt

Il giorno gio 17 gen 2019 alle ore 16:32 David G. Johnston <
david(dot)g(dot)johnston(at)gmail(dot)com> ha scritto:

> On Thu, Jan 17, 2019 at 8:18 AM Nicola Contu <nicola(dot)contu(at)gmail(dot)com>
> wrote:
> >
> > Hello,
> > I am a bit confused about the settings in pgbouncer
> >
> > What's exactly the pool_size?
>
> Roughly, the number of open connections pgbouncer will keep to PostgreSQL.
>
> > If I set 3, and I tried to connect from 4 shells, I am still able to
> connect.
>
> That would be the point - pgbouncer is sharing the 3 connections it
> keeps with PostgreSQL between the 4 client connections made to it.
>
> > Same thing for max_db_connections. I set this to 1 and I am able to
> connect from 2 shells.
>
> Same as pool_size but basically a fail-safe since pools are
> per-user/per-database while this limit is per-database only.
>
> > This is kind of confusing and I'm not really cleared reading the
> documentation.
>
> For each setting you need to understand whether it limits
> pgbouncer->PostgreSQL or client->pgbouncer
>
> Configurations in [databases] limit the former; [pgbouncer] options
> either provide defaults for the [databases] or limit clients.
>
> > [databases]
> > cmdwela = host=127.0.0.1 port=5432 dbname=cmdwela auth_user=pgbouncer
> pool_size=120
> > cicciopasticcio = host=127.0.0.1 port=5432 dbname=cicciopasticcio
> auth_user=pgbouncer pool_size=2
> >
> > [pgbouncer]
> > listen_port = 6543
> > listen_addr = *
> > auth_type = md5
> > auth_file = /etc/pgbouncer/users.txt
> > auth_query = select uname,phash from user_lookup($1)
> > logfile = /var/log/pgbouncer.log
> > pidfile = /home/postgres/pgbouncer.pid
> > admin_users = admin
> > user=postgres
>
> > max_db_connections=1
> So one open connection max per database/user pool but it is shared -
> i.e., actively executing queries running in parallel are limited to
> this number.
>
> > max_client_conn=5
> > I just want to limit connections from the app etc.
>
> That limit is 5
>
> David J.
>