**VIP: 10.110.0.213**
server1: 10.110.0.81
server2: 10.110.0.94

### Install keepalived on both servers
```
yum install keepalived
```

### /etc/keepalived/keepalived.conf
```
! Configuration File for keepalived

global_defs {
   notification_email {
     denis.myasnychenko@intexsys.lv
   }
   notification_email_from denis.myasnychenko@intexsys.lv
   smtp_server intexsys.lv
   smtp_connect_timeout 30
   router_id ecenty-1
}

vrrp_script check_mysql {
    script "/etc/keepalived/check_mysql.sh" ##script for check mysql
    interval 1     ## every 1 seconds
    fall 3 ## counts errors before chanch VIP to another server
}

vrrp_instance Mysql-VIP {
    state BACKUP
    interface enp0s3 ##interface to bind VIP
    virtual_router_id 10
    priority 101 ##VRRP prior for server, for the second server is 100
    advert_int 1
    unicast_peer {
        10.110.0.94 ## for second server is 10.110.0.81
    }
    authentication {
        auth_type PASS
        auth_pass myvrrp
    }
    track_script {
        check_mysql
    }
    nopreempt ##do not change VIP if Master come back
    smtp_alert ##enable email notification
    virtual_ipaddress {
        10.110.0.213
    }
    notify_master "/etc/keepalived/check_mysql.sh master"
    notify_backup "/etc/keepalived/check_mysql.sh backup"
    notify_fault "/etc/keepalived/check_mysql.sh fault"
}

```

### /etc/keepalived/my.cnf
```
[client]
user = super_user
password = super_pass
```

### /etc/keepalived/mysql_check.sh
```
#!/bin/bash
#This script is used by keepalived for checking mysqld work
#Additional info about keepalived work you can find in /var/log/messages

state=$1
host=`hostname`
current_date=`/bin/date +"%b %d %H:%M:%S"`
logfile='/var/log/messages'

case $state in
    master)
        echo "$current_date Keepalived: $host now Master server with VIP on it" >> $logfile
    ;;
    backup)
        echo "$current_date Keepalived: $host now Backup server" >> $logfile
    ;;
    fault)
        echo "$current_date Keepalived: $host server fault. Mysql check failed. Trying switchover" >> $logfile
    ;;
    *)
        mysql --defaults-extra-file=/etc/keepalived/my.conf --connect_timeout=2 -e "select version();" 2>/dev/null
    ;;
esac
```

### another version to check mysql with analyze Seconds_Behind_Master
```
#!/bin/bash
# monitor mysql status
# if this node mysql is dead and its slave delay less than 120 seconds, then stop its keepalived. The other node will bind the IP.

export MYSQL_HOME=/mysql
export PATH=$MYSQL_HOME/bin:$PATH

mysql="/usr/bin/mysql"
delay_file="$MYSQL_HOME/slave_delay_second.log"
slave_host=$1

/usr/bin/mysqladmin ping| grep 'mysqld is alive' > /dev/null 2>&1

if [ $? -ne 0 ]; then
 delayseconds=`cat $delay_file`
 if [ $delayseconds -le 120 ]; then
   systemctl stop keepalived
 fi
 exit 1 #bad
fi

# Get slave delay time and save it
$mysql --defaults-extra-file=/path/my.conf --connect_timeout=3 -e"select version();" > /dev/null 2>&1
if [ $? -eq 0 ]; then
  delayseconds=`$mysql --defaults-extra-file=/path/my.conf --connect_timeout=3 -e"show slave status\G"|grep Seconds_Behind_Master|awk '{print $2}'` > /dev/null 2>&1
  echo "MySQL delay_seconds=$delayseconds" >> /var/log/messages
  if [[ "$delayseconds" =~ ^[0-9]+$ ]] ; then
     echo "$delayseconds" > $delay_file
  else
     echo "9999" > $delay_file
  fi
fi
exit 0 #good
```