Django-PostgresPool

May 21, 2015 · View on GitHub

This is a simple Postgres Connection Pooling backend for Django 1.4+, powered by the lovely and beautiful SQLAlchemy.

Usage

Using Django-PostgresPool is simple, just set django_postgrespool as your connection engine:

::

DATABASES = {
    'default': {
        'ENGINE': 'django_postgrespool'

If you're using the dj-database-url <https://crate.io/packages/dj-database-url/>_ module:

::

import dj_database_url

DATABASES = {'default': dj_database_url.config(engine='django_postgrespool')}

If you're using south <http://south.aeracode.org>_:

::

SOUTH_DATABASE_ADAPTERS = {
    'default': 'south.db.postgresql_psycopg2'
}

Everything should work as expected.

Installation

Installing Django-PostgresPool is simple, with pip::

$ pip install django-postgrespool

Configuration

Optionally, you can provide additional options to pass to SQLAlchemy's pool creation::

DATABASE_POOL_ARGS = {
    'max_overflow': 10,
    'pool_size': 5,
    'recycle': 300
}

Here's a basic explanation of two of these options:

  • pool_size – The minimum number of connections to maintain in the pool.
  • max_overflow – The maximum overflow size of the pool. This is not the maximum size of the pool.

The total number of "sleeping" connections the pool will allow is pool_size. The total simultaneous connections the pool will allow is pool_size + max_overflow.

As an example, databases in the Heroku Postgres <https://postgres.heroku.com>_ starter tier have a maximum connection limit of 20. In that case your pool_size and max_overflow, when combined, should not exceed 20.

Check out the official SQLAlchemy Connection Pooling <http://docs.sqlalchemy.org/en/latest/core/pooling.html#sqlalchemy.pool.QueuePool.__init__>_ docs to learn more about the optoins that can be defined in DATABASE_POOL_ARGS.

Django 1.3 Support

django-postgrespool currently supports Django 1.4 and greater. See this ticket <https://github.com/kennethreitz/django-postgrespool/pull/9>_ for 1.3 support.