MySQL mysqld configuration example for CentOS Linux 6

Get the default configuration file mysqld for MySQL, optimized for CentOS Linux 6. This example configuration ensures optimal compatibility and performance for MySQL, making it easy to set up and adjust to meet your needs.

Find and download the configuration file here: /etc/rc.d/init.d/mysqld.

For more configurations and setup guides, visit our related files section to further customize your system.

    #!/bin/sh
#
# mysqld	This shell script takes care of starting and stopping
#		the MySQL subsystem (mysqld).
#
# chkconfig: - 64 36
# description:	MySQL database server.
# processname: mysqld
# config: /etc/my.cnf
# pidfile: /var/run/mysqld/mysqld.pid
### BEGIN INIT INFO
# Provides: mysqld
# Required-Start: $local_fs $remote_fs $network $named $syslog $time
# Required-Stop: $local_fs $remote_fs $network $named $syslog $time
# Short-Description: start and stop MySQL server
# Description: MySQL database server
### END INIT INFO

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

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


exec="/usr/bin/mysqld_safe"
prog="mysqld"

# Set timeouts here so they can be overridden from /etc/sysconfig/mysqld
STARTTIMEOUT=120
STOPTIMEOUT=60

[ -e /etc/sysconfig/$prog ] && . /etc/sysconfig/$prog

lockfile=/var/lock/subsys/$prog


# 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 "/var/lib/mysql"
datadir="$result"
get_mysql_option mysqld socket "$datadir/mysql.sock"
socketfile="$result"
get_mysql_option mysqld_safe log-error "/var/log/mysqld.log"
errlogfile="$result"
get_mysql_option mysqld_safe pid-file "/var/run/mysqld/mysqld.pid"
mypidfile="$result"


start(){
    [ -x $exec ] || exit 5
    # check to see if it's already running
    MYSQLDRUNNING=0
    if [ -f "$mypidfile" ]; then
	MYSQLPID=`cat "$mypidfile" 2>/dev/null`
	if [ -n "$MYSQLPID" ] && [ -d "/proc/$MYSQLPID" ] ; then
	    MYSQLDRUNNING=1
	fi
    fi
    RESPONSE=`/usr/bin/mysqladmin --socket="$socketfile" --user=UNKNOWN_MYSQL_USER ping 2>&1`
    if [ $MYSQLDRUNNING = 1 ] && [ $? = 0 ]; then
	# already running, do nothing
	action $"Starting $prog: " /bin/true
	ret=0
    elif [ $MYSQLDRUNNING = 1 ] && echo "$RESPONSE" | grep -q "Access denied for user"
    then
	# already running, do nothing
	action $"Starting $prog: " /bin/true
	ret=0
    else
    	# prepare for start
	touch "$errlogfile" 2>/dev/null
	if [ $? -ne 0 ]; then
	     # failed to touch log file, probably insufficient permissions
	    action $"Starting $prog: " /bin/false
	    return 4
	fi
	chown mysql:mysql "$errlogfile" 
	chmod 0640 "$errlogfile"
	[ -x /sbin/restorecon ] && /sbin/restorecon "$errlogfile"
	if [ ! -d "$datadir/mysql" ] ; then
	    # First, make sure $datadir is there with correct permissions
	    if [ ! -e "$datadir" -a ! -h "$datadir" ]
	    then
		mkdir -p "$datadir" || exit 1
	    fi
	    chown mysql:mysql "$datadir"
	    chmod 0755 "$datadir"
	    [ -x /sbin/restorecon ] && /sbin/restorecon "$datadir"
	    # Now create the database
	    action $"Initializing MySQL database: " /usr/bin/mysql_install_db --datadir="$datadir" --user=mysql
	    ret=$?
	    chown -R mysql:mysql "$datadir"
	    if [ $ret -ne 0 ] ; then
		return $ret
	    fi
	fi
	chown mysql:mysql "$datadir"
	chmod 0755 "$datadir"
	# We check if there is already a process using the socket file,
	# since otherwise this init script could report false positive
	# result and mysqld_safe would remove the socket file, which
	# actually uses a different daemon.
	if fuser "$socketfile" &>/dev/null ; then
	    echo "Socket file $socketfile exists. Is another MySQL daemon already running with the same unix socket?"
	    action $"Starting $prog: " /bin/false
	    return 1
	fi
	# 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.  (An exception is that we don't force the
	# log-error setting, since this script doesn't really depend on that,
	# and some users might prefer to configure logging to syslog.)
	# Note: set --basedir to prevent probes that might trigger SELinux
	# alarms, per bug #547485
	$exec   --datadir="$datadir" --socket="$socketfile" \
		--pid-file="$mypidfile" \
		--basedir=/usr --user=mysql >/dev/null 2>&1 &
	safe_pid=$!
	# Spin for a maximum of N seconds waiting for the server to come up;
	# exit the loop immediately if mysqld_safe process disappears.
	# Rather than assuming we know a valid username, accept an "access
	# denied" response as meaning the server is functioning.
	ret=0
	TIMEOUT="$STARTTIMEOUT"
	while [ $TIMEOUT -gt 0 ]; do
	    RESPONSE=`/usr/bin/mysqladmin --socket="$socketfile" --user=UNKNOWN_MYSQL_USER ping 2>&1`
	    mret=$?
	    if [ $mret -eq 0 ]; then
		break
	    fi
	    # exit codes 1, 11 (EXIT_CANNOT_CONNECT_TO_SERVICE) are expected,
	    # anything else suggests a configuration error
	    if [ $mret -ne 1 -a $mret -ne 11 ]; then
		echo "$RESPONSE"
		echo "Cannot check for MySQL Daemon startup because of mysqladmin failure."
		ret=1
		break
	    fi
	    echo "$RESPONSE" | grep -q "Access denied for user" && break
	    if ! /bin/kill -0 $safe_pid 2>/dev/null; then
		echo "MySQL Daemon failed to start."
		ret=1
		break
	    fi
	    sleep 1
	    let TIMEOUT=${TIMEOUT}-1
	done
	if [ $TIMEOUT -eq 0 ]; then
	    echo "Timeout error occurred trying to start MySQL Daemon."
	    ret=1
	fi
	if [ $ret -eq 0 ]; then
	    action $"Starting $prog: " /bin/true
	    chmod o+r $mypidfile >/dev/null 2>&1
	    touch $lockfile
	else
	    action $"Starting $prog: " /bin/false
	fi
    fi
    return $ret
}

stop(){
	if [ ! -f "$mypidfile" ]; then
	    # not running; per LSB standards this is "ok"
	    action $"Stopping $prog: " /bin/true
	    return 0
	fi
	MYSQLPID=`cat "$mypidfile" 2>/dev/null`
	if [ -n "$MYSQLPID" ]; then
	    /bin/kill "$MYSQLPID" >/dev/null 2>&1
	    ret=$?
	    if [ $ret -eq 0 ]; then
		TIMEOUT="$STOPTIMEOUT"
		while [ $TIMEOUT -gt 0 ]; do
		    /bin/kill -0 "$MYSQLPID" >/dev/null 2>&1 || break
		    sleep 1
		    let TIMEOUT=${TIMEOUT}-1
		done
		if [ $TIMEOUT -eq 0 ]; then
		    echo "Timeout error occurred trying to stop MySQL Daemon."
		    ret=1
		    action $"Stopping $prog: " /bin/false
		else
		    rm -f $lockfile
		    rm -f "$socketfile"
		    action $"Stopping $prog: " /bin/true
		fi
	    else
		action $"Stopping $prog: " /bin/false
	    fi
	else
	    # failed to read pidfile, probably insufficient permissions
	    action $"Stopping $prog: " /bin/false
	    ret=4
	fi
	return $ret
}
 
restart(){
    stop
    start
}

condrestart(){
    [ -e $lockfile ] && restart || :
}


# See how we were called.
case "$1" in
  start)
    start
    ;;
  stop)
    stop
    ;;
  status)
    status -p "$mypidfile" $prog
    ;;
  restart)
    restart
    ;;
  condrestart|try-restart)
    condrestart
    ;;
  reload)
    exit 3
    ;;
  force-reload)
    restart
    ;;
  *)
    echo $"Usage: $0 {start|stop|status|restart|condrestart|try-restart|reload|force-reload}"
    exit 2
esac

exit $?

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