MySQL负载均衡

1. 添加监控MySQL状态的端口
# vi /etc/services

mysqlcheck      6033
/
tcp                        # MySQL status check

2. 使用xinetd守护进程运行MySQL状态检测
# cat /etc/xinetd.d/mysqlchk

service mysqlcheck
{

        disable         = no
        flags           = REUSE
        socket_type     = stream
        port            = 6033

        wait
            = no
        user            = root
        server          = /
usr/
local/
haproxy/
sbin/
mysqlchk_status.sh
        log_on_failure  += USERID
}

3. 状态检测脚本
# vi /usr/local/haproxy/sbin/mysqlchk_status.sh

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#/bin/bash MYSQL_HOST ="localhost" MYSQL_PORT ="3306" MYSQL_USERNAME ="root" MYSQL_PASSWORD ="123456"   ERROR_MSG =/ usr/ bin/ mysql --host =$MYSQL_HOST --port =$MYSQL_PORT --user =$MYSQL_USERNAME --password =$MYSQL_PASSWORD -e "show databases;"   if [ "$ERROR_MSG " ! = "" ] then # mysql is fine, return http 200 / bin/ echo -e "HTTP/1.1 200 OK\r \n " / bin/ echo -e "Content-Type: Content-Type: text/plain\r \n " / bin/ echo -e "\r \n " / bin/ echo -e "MySQL is running.\r \n " / bin/ echo -e "\r \n " else # mysql is fine, return http 503 / bin/ echo -e "HTTP/1.1 503 Service Unavailable\r \n " / bin/ echo -e "Content-Type: Content-Type: text/plain\r \n " / bin/ echo -e "\r \n " / bin/ echo -e "MySQL is *down*.\r \n " / bin/ echo -e "\r \n " fi

# chown haproxy.haproxy /usr/local/haproxy/sbin/mysqlchk_status.sh

4. HAproxy日志
# touch /var/log/haproxy.log
# chown haproxy.haproxy /var/log/haproxy.log
编辑/etc/syslog.conf文件，添加如下语句

local0.*
                                                /
var/
log/
haproxy.log

5. HAProxy配置文件
[root@localhost htdocs]# cat /usr/local/haproxy/conf/haproxy.conf

global
        maxconn 4096

        daemon
        pidfile /
usr/
local/
haproxy/
run/
haproxy.pid
        #debug

        #quiet

        user haproxy
        group haproxy
 
defaults
        log     global
        mode    http
        option  httplog
        option  dontlognull
        log 127.0.0.1 local0
        retries 3

        option redispatch
        maxconn 2000

        contimeout      5000

        clitimeout      50000

        srvtimeout      50000

 
listen  admin_stats 192.168.0.1:80

        mode        http
        stats uri   /
dbs
        stats realm     Global\ statistics
        stats auth  test
:123456

 
listen  proxy-mysql 0.0.0.0:23306

        mode tcp
        balance roundrobin
        option httpchk OPTIONS *
 HTTP/
1.1
\r\nHost:\ www
        server db01 192.168.0.1:3306
 weight 1
 check port 6033
 inter 1s rise 2
 fall 2

        server db02 192.168.0.2:3306
 weight 1
 check port 6033
 inter 1s rise 2
 fall 2

        option tcpka

6. HAProxy启动脚本
# cat /etc/init.d/haproxy

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#! /bin/sh set -e   PATH =/ sbin:/ bin:/ usr/ sbin:/ usr/ bin:/ usr/ local/ haproxy/ sbin PROGDIR =/ usr/ local/ haproxy PROGNAME =haproxy DAEMON =$PROGDIR / sbin/ $PROGNAME CONFIG =$PROGDIR / conf/ $PROGNAME .conf PIDFILE =$PROGDIR / run/ $PROGNAME .pid DESC ="HAProxy daemon" SCRIPTNAME =/ etc/ init.d/ $PROGNAME   # Gracefully exit if the package has been removed. test -x $DAEMON || exit 0   start( ) { echo -n "Starting $DESC : $PROGNAME " $DAEMON -f $CONFIG echo "." }   stop( ) { echo -n "Stopping $DESC : $PROGNAME " haproxy_pid =cat $PIDFILE kill $haproxy_pid echo "." }   restart( ) { echo -n "Restarting $DESC : $PROGNAME " $DAEMON -f $CONFIG -p $PIDFILE -sf $( cat $PIDFILE ) echo "." }   case "$1" in start) start ;; stop) stop ;; restart) restart ;; * ) echo "Usage: $SCRIPTNAME {start|stop|restart}" >& 2 exit 1 ;; esac   exit 0