Fabric posrgres tunning

gistfile1.py

def postgres_tunning(pgversion=9.1):
    # Use postgres conservative values, for about 1GB RAM machine
    # Following ideas from:
    # * http://www.juancarlosmoral.es/postgresql-hardware-tunning
    # * http://doc.nuxeo.com/display/ADMINDOC/Configuring+PostgreSQL#ConfiguringPostgreSQL-Performancetuning
    # * http://wiki.postgresql.org/wiki/Tuning_Your_PostgreSQL_Server/es

    fabtools.require.service.started("postgresql")

    postgresql_conf = "/etc/postgresql/%s/main/postgresql.conf" % pgversion

    # To Change postgres shared_buffers we need change kernel config first
    sysctl_file = "/etc/sysctl.d/30-postgresql-shm.conf"
    shmax_original = "#kernel.shmmax = 33554432"
    shmmax = "kernel.shmmax = %i" % (120 * 1024 * 1024)  # 120MB
    if not fabric.contrib.files.contains(sysctl_file, shmmax, exact=True):
        fabric.contrib.files.sed(sysctl_file, shmax_original, shmmax,
                                 use_sudo=True, backup='')

    # Do settings doing replacements from original debian postgresql.conf
    replacements = [
        ("#shared_buffers = 24MB", "shared_buffers = 100MB"),  # (10% of total)
        ("#work_mem = 1MB", "work_mem = 40MB"),  # Work Memoy work_men (4% of total)
        ("#effective_cache_size = 128MB", "effective_cache_size = 512MB",),
        ("#maintenance_work_mem = 16MB", "maintenance_work_mem = 128MB",),
        ("#random_page_cost = 4.0", "random_page_cost = 2.0",),
        ("max_connections = 100", "max_connections = 64"),
    ]
    with fabtools.files.watch(postgresql_conf) as config:
        for orig, repl in replacements:
            if not fabric.contrib.files.contains(postgresql_conf, repl):
                fabric.contrib.files.sed(postgresql_conf, orig, repl, use_sudo=True)
    if config.changed:
        sudo('etckeeper commit "Postgres configuration"')

    fabtools.require.service.started("pgbouncer")
    with fabtools.files.watch(postgresql_conf) as config:
        # pg_bouncer
        fabtools.require.files.template_file("/etc/pgbouncer/pgbouncer.ini",
                                             template_source="templates/pgbouncer.ini",
                                             use_sudo=True, owner="postgres",
                                             group="postgres", mode="640")
        fabtools.require.files.template_file("/etc/default/pgbouncer",
                                             template_contents="START=1",
                                             use_sudo=True, owner="root",
                                             group="root", mode="644")
    if config.changed:
        sudo("service pgbouncer reload")