mongo_repl_lag

#!/usr/bin/env python
import os
import sys
import re

try:
    import pymongo
except:
    print "need to install pymongo"
    sys.exit(2)

host = os.environ.get('HOST', 'localhost')
port = os.environ.get('PORT', 27017)

def escape_munin(s):
    return re.sub('[-.]', '_', s)

def get_master():
    con = pymongo.Connection(host, port, slave_okay=True)

    isMasterStatus = con.admin.command("ismaster", "1")
    if not isMasterStatus['ismaster']:
        primary = isMasterStatus['primary']
        con = pymongo.Connection("mongodb://"+primary)
    return con

def do_config():
    con = get_master()

    print "graph_title Replication lag"
    print "graph_vlabel ms"
    print "graph_category MongoDB"
    print "graph_args --lower-limit 0"
    print "graph_scale no"

    slaves = con.local.slaves.find()
    for slave in slaves:
        host = slave['host']
        escaped_host = escape_munin(host)
        print "%s.label %s" % (escaped_host, host)
        print "%s.type GAUGE" % escaped_host
        print "%s.min 0" % escaped_host

def do_data():
    con = get_master()

    masterOpLog = con.local['oplog.rs']
    lastMasterOpTime = masterOpLog.find_one(sort=[('$natural', -1)])['ts'].time
    slaves = con.local.slaves.find()

    for slave in slaves:
        lastSlaveOpTime = slave['syncedTo'].time
        replicationLag = lastMasterOpTime - lastSlaveOpTime
        print "%s.value %s" % (escape_munin(slave['host']), replicationLag)

if __name__ == '__main__':
    if len(sys.argv) > 1 and sys.argv[1] == 'config':
        do_config()
    else:
        do_data()