RSR Postgres connections

[kardan]

Background

Django 1.6 supports keeping connection between requests. At the moment we create new connections for new requests, which is a bit expensive. We should review if we want to use that, and if so what settings to use.

State of the RSR

• 1 "instance" running 5 gunicorn workers with no connection pooling

  State of Postgres

• default 100 max_connections configured.

It's difficult to know if the change of connections will generate a noticeable effect since we don't have a lot of traffic. But still seems like something we should review.

To be decided

Do we think we can use unlimited persistent connections from RSR or should we use a TTL? Is the default 100 connections a reasonable setting?

Ref

https://docs.djangoproject.com/en/1.6/ref/settings/#std:setting-CONN_MAX_AGE http://www.postgresql.org/docs/9.1/static/runtime-config-connection.html

[kardan]

@orifito @carlio you guys have any insights in this?

[orifito]

We are not going to generate an immediate palpable effect, but for sure it's so much better to use connection pooling. Actually, we could also contemplate the use of a standalone pooler like PgBouncer https://wiki.postgresql.org/wiki/PgBouncer. Need to investigate to take a decision, but taking into account that now we have both mysql and psql running into the same host, I would not increase the default max connections. All in all, it seems PgBouncer could give us potential benefits, and even more if we could use it in transaction pooling mode.