• Basic postgres connection pool for Django using gevent ** assumes you monkeypatch somewhere when using this backend

clone via git and python setup.py install

OR

easy_install django-psycopg2-pool

Assuming you have Django installed and this app installed,

1. set ENGINE to 'django_psycopg2_pool.gevent' in your db backend settings
2. this may be required if you have south: in settings.py, have a line like:

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

3. Set POOL_SIZE to 100 or so in your db settings and tweak this number so that each worker process has adequate postgres connections available to it. If you have four worker processes and max_connections for postgres is 101, then 25 is a reasonable pool size that will still let you run manage commands like south. Each connection to postgres will fork a postgres worker, visible running pstree -pa on Linux systems. Raising max_connections in postgres can consume a lot of memory if work_mem is set high. Work_mem is necessary to do in-memory sorts before spilling to the disk, so don't set this too low just to have tons of postgres threads running.

DATABASES = {
    'default': {
        'ENGINE': 'django_psycopg2_pool.gevent', 
        'NAME': 'myproject_db',                  
        'USER': 'myproject',                    
        'PASSWORD': 'mypassword',                
        'HOST': '/var/run/postgresql',           # When running postgres on unix socket
        'PORT': '',                              # Empty if using unix socket
        'POOL_SIZE' : 20,                        # slightly less than postgres max_connections / worker processes
    }
}

This package includes a modified version of the gevent example psycopg2_pool Thank you to the author(s) of gevent and psyocopg2_pool

• feel free to contribute!
• maybe this can be done in eventlet as well? I welcome pull requests