On Thu, Jan 17, 2019 at 8:18 AM Nicola Contu <nicola.contu@xxxxxxxxx> 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.
