~launchpad-pqm/launchpad/devel

#!/usr/bin/python -S

#

# Copyright 2010 Canonical Ltd.  This software is licensed under the

# GNU Affero General Public License version 3 (see the file LICENSE).

"""Calculate database replication lag and cache it."""

__metaclass__ = type

__all__ = []

import _pythonpath

import sys

import time

import psycopg2

from lp.scripts.helpers import LPOptionParser

from lp.services.database.sqlbase import (

    connect,

    ISOLATION_LEVEL_AUTOCOMMIT,

    )

from lp.services.scripts import (

    db_options,

    logger,

    )

def main(args=None):

    parser = LPOptionParser()

    db_options(parser)

    parser.add_option(

        "-s", "--sleep", dest="sleep", type="int", default=5,

        metavar="SECS", help="Wait SECS seconds between refreshes.")

    (options, args) = parser.parse_args(args)

    if len(args) != 0:

        parser.error("Too many arguments.")

    log = logger(options)

    while True:

        try:

            con = connect(user="lagmon", isolation=ISOLATION_LEVEL_AUTOCOMMIT)

            cur = con.cursor()

            while True:

                cur.execute("SELECT update_replication_lag_cache()")

                if cur.fetchone()[0]:

                    log.info("Updated.")

                else:

                    log.error("update_replication_lag_cache() failed.")

                time.sleep(options.sleep)

        except psycopg2.Error, x:

            log.error("%s. Retrying.", str(x).strip())

            time.sleep(options.sleep)

if __name__ == '__main__':

    sys.exit(main())