MySQL Slave Replication Heartbeat Monitor

mysql_rep_delay

#!/bin/bash
## Plug-in to Monitor MySQL Slave Replication Delay.
#
#$Author: imran $
#$Date: 2008-09-01 09:29:21 $
#$RCSfile: mysql_rep_delay,v $
#$Revision: 1.1 $

heartbeatdb=${heartbeatdb:-test}
cmd=${cmd:-`which pt-heartbeat`}
mysqluser=${mysqluser:-root}

if [ "$mysqlpassword" ]
then
    passopt="-p$mysqlpassword"
fi

fullcmd="$cmd -D $heartbeatdb --check -h localhost -u $mysqluser $passopt"

case $1 in
        config)
                cat <<'EOM'
graph_title MySQL Slave Replication Delay
graph_vlabel seconds
mysql_rep_delay.label delay
mysql_rep_delay.warning 60
mysql_rep_delay.critical 3600
graph_category mysql
EOM
                exit 0;;
        autoconf)
        if [ -e "$cmd" -a -x "$cmd" ]
        then
            $fullcmd > /dev/null
            RETVAL=$?
            if [ $RETVAL -eq 0 ]
            then
                echo "yes"
            else
                echo "pt-heartbeat check failed"
            fi
        else
            echo "$cmd is invalid"
        fi        
        ;;
        *)
        echo -n "mysql_rep_delay.value "
        $fullcmd
        ;;
esac

pt-heartbeat.conf

host=localhost
pass=password
user=username
database=test
pid=/var/run/pt-heartbeat.pid

pt-heartbeat.init

#!/bin/bash
#
# Author:          Fernando Ipar
# 
# chkconfig:   2345  65 35
# description: pt-heartbeat startup script

### BEGIN INIT INFO
# Provides: pt-heartbeat
# Required-Start: $local_fs $network $remote_fs mysql
# Required-Stop: $local_fs $network $remote_fs mysql
# Default-Start: 2 3 4 5
# Default-Stop: 0 1 6
# Short-Description: start and stop pt-heartbeat
# Description: pt-heartbeat monitors MySQL replication delay 
### END INIT INFO

# source function library
lsb_functions="/lib/lsb/init-functions"

if test -f $lsb_functions ; then
  . $lsb_functions
else
  log_success_msg()
  {
    echo " SUCCESS! $@"
  }
  log_failure_msg()
  {
    echo " ERROR! $@"
  }
fi

# test for pt-heartbeat
[ $(type pt-heartbeat 2>&1| grep -c 'pt-heartbeat is') -gt 0 ] || {
	echo "I can't find pt-heartbeat on the path">&2
	exit 1
}

CONF=/etc/pt-heartbeat.conf

# test for conf file
[ -r $CONF ] || {
   echo "I can't find or read $CONF">&2
   exit 1
}

# test for pid option
. $CONF
piderr=0
[ -z "$pid" ] && piderr=1 #if unset, error
[ -f $pid ] || {
   touch $pid || piderr=1 #if I can't touch, error
   rm -f $pid
}
[ $piderr -eq 1 ] && {
   echo "I can't find the pid option in $CONF, or it's value is invalid" >&2
   exit 1
}

op="$1"

# functions implementing options

start()
{
	echo -n "Starting pt-heartbeat ... "
	pt-heartbeat --config $CONF --daemonize --update
	[ $? -eq 0 ] && log_success_msg || log_failure_msg 
}

stop()
{
	[ -f $pid ] && [ -d /proc/$(cat $pid) ] && {
		echo -n "Stopping pt-heartbeat ... "
		kill $(cat $pid)
		log_success_msg 
	}|| {
		echo "pt-heartbeat is not running">&2
	}
}

status()
{
		[ -f $pid ] && [ -d /proc/$(cat $pid) ] && echo "pt-heartbeat is running" || echo "pt-heartbeat is not running">&2
}

case "$op" in 
	start)
      start
		;;		
	stop)	
      stop
		;;
   restart)
		stop
		start
		;;
	status) 
      status
		;;
	*)
		echo "Usage: pt-heartbeat start|stop|restart|status">&2
		exit 1
esac

exit 0

Thanks for sharing. I added this line:

@@ -72,6 +72,7 @@
     echo -n "Stopping pt-heartbeat ... "
     kill $(cat $pid)
     log_success_msg 
+    rm $pid
   }|| {
     echo "pt-heartbeat is not running">&2
   }

As I kept getting this error:

Starting pt-heartbeat ... Overwriting PID file /var/run/pt-heartbeat/pt-heartbeat.pid because the PID that it contains, 17572, is not running at /usr/bin/pt-heartbeat line 2213.
Overwriting PID file /var/run/pt-heartbeat/pt-heartbeat.pid because the PID that it contains, 17572, is not running at /usr/bin/pt-heartbeat line 2213.