Ok,thank you, it's a good point. Need to review & make fixes with what I have. Thanks, Dzmitry On 8/24/13 6:14 PM, "Scott Ribe" <scott_ribe@xxxxxxxxxxxxxxxx> wrote: >On Aug 19, 2013, at 9:55 AM, Dzmitry <dzmitry.nikitsin@xxxxxxxxx> wrote: > >> No, I am not using pgbouncer, I am using pgpool. >> >> Total - I have 440 connections to postgres(I have rails application >> running on some servers - each application setup 60 connections to DB >>and >> keep if forever(until will not be killed), also I have some machines >>that >> do background processing, that keep connections too). >> >> Part that do a lot of writes(that update jobs from xml feed every >>night) - >> have 40 threads and keep 40 connections. > >That's extreme, and probably counter-productive. > >How many cores do you have on those rails servers? Probably not 64, >right? Not 32? 16? 12? 8, even? Assuming <64, what advantage do you >expect from 60 connections? Same comment applies to the 40 connections >doing the update jobs--more connections than cores is unlikely to be >helping anything, and more connections than 2x cores is almost guaranteed >to be worse than fewer. > >Postgres connections are of the heavy-weight variety: process per >connection, not thread per connection, not thread-per core event-driven. >In particular, I'd worry about work_mem in your configuration. You've >either got to set it really low and live with queries going to disk too >quickly for sorts and so on, or have it a decent size and have the risk >that too many queries at once will trigger OOM. > >Given your configuration, I wouldn't even start with pgbouncer for >connection pooling. I'd first just slash the number of connections >everywhere by 1/2, or even 1/4 and see what effect that had. Then as a >second step I'd look at where connection pooling might be used >effectively. > >-- >Scott Ribe >scott_ribe@xxxxxxxxxxxxxxxx >http://www.elevated-dev.com/ >(303) 722-0567 voice > > > > -- Sent via pgsql-admin mailing list (pgsql-admin@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-admin
