写在前面：由于mysql master 主机上的xinet传给Haproxy的状态不稳定，haproxy会不停的切换mysql主机，造成网站应用反应慢，建议做mysql主从服务器者谨用（用mysql-proxy读写分离代替），mysql cluster方案可以用。
1. 添加监控MySQL状态的端口
在db服务器上(每台都一样)
安装xinetd
# yum
install xinetd
# vi /etc/services
================================================
mysqlcheck
6033/tcp
# MySQL status check
2. 使用xinetd守护进程运行MySQL状态检测
在db服务器上
# 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
only_from
= 192.168.3.0/24 # recommended to put the IPs that need
# to connect exclusively (security purposes)
}
3. 状态检测脚本
在db服务器上
# vi /usr/local/haproxy/sbin/mysqlchk_status.sh
================================================
#/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;”
ERROR_MSG=`ps -e | grep mysqld |wc -l`
if [ “$ERROR_MSG” != “0” ]
then
# mysql is fine, return http 200
/bin/echo -e “HTTP/1.1 200 OK\r\n”
/bin/echo -e “Content-Type: Content-Type: text/plain\r\n”
/bin/echo -e “\r\n”
/bin/echo -e “MySQL is running.\r\n”
/bin/echo -e “\r\n”
else
# mysql is fine, return http 503
/bin/echo -e “HTTP/1.1 503 Service Unavailable\r\n”
/bin/echo -e “Content-Type: Content-Type: text/plain\r\n”
/bin/echo -e “\r\n”
/bin/echo -e “MySQL is *down*.\r\n”
/bin/echo -e “\r\n”
fi
==================================================================
# chmod +x
/usr/local/haproxy/sbin/mysqlchk_status.sh
# service xinetd stop
# service xinetd start
# chown haproxy.haproxy /usr/local/haproxy/sbin/mysqlchk_status.sh
4. HAproxy日志
# touch /var/log/haproxy.log
# chown haproxy.haproxy /var/log/haproxy.log
编辑/etc/syslog.conf文件，添加如下语句
local0.*
/var/log/haproxy.log
5. HAProxy配置文件
在均衡服务器上
[root@localhost htdocs]# cat /usr/local/haproxy/conf/haproxy.conf
================================================================
global
maxconn 4096
daemon
pidfile /usr/local/haproxy/run/haproxy.pid
#debug
#quiet
user haproxy
group haproxy
defaults
log
global
mode
http
option
httplog
option
dontlognull
log 127.0.0.1 local0
retries 3
option redispatch
maxconn 2000
contimeout
5000
clitimeout
50000
#如果程序执行时间很长，把这个值调大一些 我在后面多加两个0改成5000000 毫秒
srvtimeout
50000
listen
admin_stats 192.168.0.1:80
mode
http
stats uri
/dbs
stats realm
Global\ statistics
stats auth
test:123456
listen
proxy-mysql 0.0.0.0:23306
mode tcp
balance roundrobin
option httpchk OPTIONS * HTTP/1.1\r\nHost:\ www
server db01 192.168.0.1:3306 weight 1 check port 6033 inter 1s rise 2 fall 2
server db02 192.168.0.2:3306 weight 1 check port 6033 inter 1s rise 2 fall 2
option tcpka
===================================================
6. HAProxy启动脚本
在均衡服务器上
# cat /etc/init.d/haproxy
===================================================
#! /bin/sh
set -e
PATH=/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/haproxy/sbin
PROGDIR=/usr/local/haproxy
PROGNAME=haproxy
DAEMON=$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