MySQL multiple instance on CentOS howto

Create new database instance on new destination

mkdir /u02/mysql
mkdir /u02/mysql/data
mkdir /u02/mysql/log
mkdir /u02/mysql/run
mkdir /u02/mysql/lock

chown -R mysql:mysql /u02/mysql
mysql_install_db --datadir=/u02/mysql/data --user=mysql

Create new configuration file for new instance

/etc/my.server2.cnf

[mysqld]
port=3307
datadir=/u02/mysql/data
socket=/u02/mysql/mysql.sock
user=mysql
# Default to using old password format for compatibility with mysql 3.x
# clients (those using the mysqlclient10 compatibility package).
old_passwords=1

log-bin = /u02/mysql/log/mysql-bin.log

[mysqld_safe]
log-error=/u02/mysql/log/mysqld.log
pid-file=/u02/run/mysqld.pid

[isamchk]

[myisamchk]

Create new init script

/etc/rc.d/init.d/mysqld.server2

#!/bin/bash
#
# mysqld.server2 This shell script takes care of starting and stopping
#               the MySQL subsystem (mysqld).
#
# chkconfig: - 64 36
# description:  MySQL database server 2nd instance.
# processname: mysqld
# config: /etc/my.server2.cnf
# pidfile: /u02/mysql/run/mysqld.pid

# Source function library.
. /etc/rc.d/init.d/functions

# Source networking configuration.
. /etc/sysconfig/network

prog="MySQL"

# extract value of a MySQL option from config files
# Usage: get_mysql_option SECTION VARNAME DEFAULT
# result is returned in $result
# We use my_print_defaults which prints all options from multiple files,
# with the more specific ones later; hence take the last match.
get_mysql_option(){
        result=`/usr/bin/my_print_defaults "$1" | sed -n "s/^--$2=//p" | tail -n 1`
        if [ -z "$result" ]; then
            # not found, use default
            result="$3"
        fi
}

get_mysql_option mysqld datadir "/u02/mysql/data"
datadir="/u02/mysql/data"
get_mysql_option mysqld socket "$datadir/mysql.sock"
socketfile="$datadir/mysql.sock"
get_mysql_option mysqld_safe log-error "/u02/mysql/log/mysqld.log"
errlogfile="/u02/mysql/log/mysqld.log"
get_mysql_option mysqld_safe pid-file "/u02/mysql/run/mysqld.pid"
mypidfile="/u02/mysql/run/mysqld.pid"

start(){
        touch "$errlogfile"
        chown mysql:mysql "$errlogfile"
        chmod 0640 "$errlogfile"
        [ -x /sbin/restorecon ] && /sbin/restorecon "$errlogfile"
        if [ ! -d "$datadir/mysql" ] ; then
            action $"Initializing MySQL database: " /usr/bin/mysql_install_db
            ret=$?
            chown -R mysql:mysql "$datadir"
            if [ $ret -ne 0 ] ; then
                return $ret
            fi
        fi
        chown mysql:mysql "$datadir"
        chmod 0755 "$datadir"
        # Pass all the options determined above, to ensure consistent behavior.
        # In many cases mysqld_safe would arrive at the same conclusions anyway
        # but we need to be sure.
        /usr/bin/mysqld_safe --defaults-file=/etc/my.server2.cnf --datadir="$datadir" --socket="$socketfile" \
                --log-error="$errlogfile" --pid-file="$mypidfile" \
                >/dev/null 2>&1 &
        ret=$?
        # Spin for a maximum of N seconds waiting for the server to come up.
        # Rather than assuming we know a valid username, accept an "access
        # denied" response as meaning the server is functioning.
        if [ $ret -eq 0 ]; then
            STARTTIMEOUT=30
            while [ $STARTTIMEOUT -gt 0 ]; do
                RESPONSE=`/usr/bin/mysqladmin -uUNKNOWN_MYSQL_USER ping 2>&1` && break
                echo "$RESPONSE" | grep -q "Access denied for user" && break
                sleep 1
                let STARTTIMEOUT=${STARTTIMEOUT}-1
            done
            if [ $STARTTIMEOUT -eq 0 ]; then
                    echo "Timeout error occurred trying to start MySQL Daemon."
                    action $"Starting $prog: " /bin/false
                    ret=1
            else
                    action $"Starting $prog: " /bin/true
            fi
        else
            action $"Starting $prog: " /bin/false
        fi
        [ $ret -eq 0 ] && touch /u02/mysql/lock/mysqld
        return $ret
}

stop(){
        MYSQLPID=`cat "$mypidfile"  2>/dev/null `
        if [ -n "$MYSQLPID" ]; then
            /bin/kill "$MYSQLPID" >/dev/null 2>&1
            ret=$?
            if [ $ret -eq 0 ]; then
                STOPTIMEOUT=60
                while [ $STOPTIMEOUT -gt 0 ]; do
                    /bin/kill -0 "$MYSQLPID" >/dev/null 2>&1 || break
                    sleep 1
                    let STOPTIMEOUT=${STOPTIMEOUT}-1
                done
                if [ $STOPTIMEOUT -eq 0 ]; then
                    echo "Timeout error occurred trying to stop MySQL Daemon."
                    ret=1
                    action $"Stopping $prog: " /bin/false
                else
                    rm -f /u02/mysql/lock/mysqld
                    rm -f "$socketfile"
                    action $"Stopping $prog: " /bin/true
                fi
            else
                action $"Stopping $prog: " /bin/false
            fi
        else
            ret=1
            action $"Stopping $prog: " /bin/false
        fi
        return $ret
}

restart(){
    stop
    start
}

condrestart(){
    [ -e /u02/mysql/lock/mysqld ] && restart || :
}

# See how we were called.
case "$1" in
  start)
    start
    ;;
  stop)
    stop
    ;;
  status)
    status mysqld
    ;;
  restart)
    restart
    ;;
  condrestart)
    condrestart
    ;;
  *)
    echo $"Usage: $0 {start|stop|status|condrestart|restart}"
    exit 1
esac

exit $?

Enable auto startup for new instance and start it


chkconfig mysqld.server2 on
service mysqld.server2 start

Set new root password


mysqladmin -P 3307 --protocol=tcp -u root password 'NEWPASSWORD'

Connect new database

mysql -P 3307 --protocol=tcp -u root -p

[root@lxpsrv01 ~]# mysql -P 3307 --protocol=tcp -uroot -p
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 11
Server version: 5.0.45-log Source distribution
Type 'help;' or '\h' for help. Type '\c' to clear the buffer.
mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| test               |
+--------------------+
3 rows in set (0.00 sec)
mysql>

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