环境说明：
本系统对数据安全性不高，TPS操作很低，主要是查询的环境。
本方案架构图如下：
应用服务器对只读的应用程序连接虚拟IP地址，连接到haproxy，然后通过haproxy将TCP协议转移到下面的3个数据库服务器中。
Haproxy在此做4层的TCP交换服务。keepalived为了防止haproxy单点故障。
为什么不用LVS？
我们的环境服务器少，haproxy和lvs相比性能差不多，且haproxy自带有mysql check，不需要额外的写mysql侦测脚本。
1.haproxy安装
下载地址：http://www.haproxy.org/download/1.5/src/haproxy-1.5.5.tar.gz
依赖包安装：
#yum install gcc gcc-c++ make zlib-devel bzip2-devel openssl-devel
安装pcre，自带的pcre-7.8-3.1.el6.x86_64貌似版本低了，导致无法安装proxy
#tar xzvf pcre-8.34.tar.gz
#cd pcre-8.34
#./configure --prefix=/usr \
--docdir=/usr/share/doc/pcre-8.34 \
--enable-utf --enable-unicode-properties \
--enable-pcregrep-libz --enable-pcregrep-libbz2
#make
#make check
#make install
haproxy安装：
#tar -xzvf haproxy-1.5.5.tar.gz
#cd haproxy-1.5.5
# make TARGET=linux26 USE_STATIC_PCRE=1 \
USE_REGPARM=1 USE_LINUX_TPROXY=1 USE_OPENSSL=1 USE_ZLIB=1 ARCH=x86_64
# make install
--编辑启动文件
# vi /etc/init.d/haproxy --添加以下内容
#!/bin/sh
#
# custom haproxy init.d script, by Mattias Geniar
#
# haproxy starting and stopping the haproxy load balancer
#
# chkconfig: 345 55 45
# description: haproxy is a TCP loadbalancer
# probe: true
# Source function library.
. /etc/rc.d/init.d/functions
# Source networking configuration.
. /etc/sysconfig/network
# Check that networking is up.
[ ${NETWORKING} = "no" ] && exit 0
[ -f /usr/local/sbin/haproxy ] || exit 0
[ -f /etc/haproxy/haproxy.conf ] || exit 0
# Define our actions
checkconfig() {
# Check the config file for errors
/usr/local/sbin/haproxy -c -q -f /etc/haproxy/haproxy.conf
if [ $? -ne 0 ]; then
echo "Errors found in configuration file."
return 1
fi
# We're OK!
return 0
}
start() {
# Check config
/usr/local/sbin/haproxy -c -q -f /etc/haproxy/haproxy.conf
if [ $? -ne 0 ]; then
echo "Errors found in configuration file."
return 1
fi
echo -n "Starting HAProxy: "
daemon /usr/local/sbin/haproxy -D -f /etc/haproxy/haproxy.conf -p /var/run/haproxy.pid
RETVAL=$?
echo
[ $RETVAL -eq 0 ] && touch /var/lock/subsys/haproxy
return $RETVAL
}
stop() {
echo -n "Shutting down HAProxy: "
killproc haproxy -USR1
RETVAL=$?
echo
[ $RETVAL -eq 0 ] && rm -f /var/lock/subsys/haproxy
[ $RETVAL -eq 0 ] && rm -f /var/run/haproxy.pid
return $RETVAL
}
restart() {
/usr/local/sbin/haproxy -c -q -f /etc/haproxy/haproxy.conf
if [ $? -ne 0 ]; then
echo "Errors found in configuration file."
return 1
fi
stop
start
}
check() {
/usr/local/sbin/haproxy -c -q -V -f /etc/haproxy/haproxy.conf
}
rhstatus() {
status haproxy
}
reload() {
/usr/local/sbin/haproxy -c -q -f /etc/haproxy/haproxy.conf
if [ $? -ne 0 ]; then
echo "Errors found in configuration file."
return 1
fi
echo -n "Reloading HAProxy config: "
/usr/local/sbin/haproxy -f /etc/haproxy/haproxy.conf -p /var/run/haproxy.pid -sf $(cat /var/run/haproxy.pid)
success $"Reloading HAProxy config: "
echo
}
# Possible parameters
case "$1" in
start)
start
;;
stop)
stop
;;
status)
rhstatus
;;
restart)
restart
;;
reload)
reload
;;
checkconfig)
check
;;
*)
echo "Usage: haproxy {start|stop|status|restart|reload|checkconfig}"
exit 1
esac
exit 0
授权：
#chmod +x /etc/init.d/haproxy
编辑haproxy配置文件：
可以参考说明：http://www.cnblogs.com/dkblog/archive/2012/03/13/2393321.html
#mkdir /etc/haproxy
#vi /etc/haproxy/haproxy.conf
defaults
log global
mode http
retries 3
option redispatch
maxconn 4096
timeout connect 50000
timeout client 50000
timeout server 50000
listen mysql_proxy 0.0.0.0:3307
mode tcp
balance roundrobin
option tcpka
option httpchk
option mysql-check user haproxy #在mysql中创建无任何权限用户haproxy，且无密码
server mysqldb1 192.168.231.8:3306 weight 1
server mysqldb2 192.168.231.9:3306 weight 3
server mysqldb3 192.168.231.11:3306 weight 3
listen stats *:8080
mode http
option httpclose
balance roundrobin
stats uri /
stats realm Haproxy\ Statistics
stats auth admin:admin
启动并检查：
#service haproxy start
# netstat -plantu | grep 3307
tcp 0 0 0.0.0.0:3307 0.0.0.0:* LISTEN 23626/haproxy
创建100次短连接测试：
其中db2和db3路由了43次，db1路由了14次
2.keepalived安装
下载地址：http://www.keepalived.org/software/
#tar zxvf keepalived-1.2.13.tar.gz
#cd keepalived-1.2.13
# ln -s /usr/src/kernels/2.6.32-220.el6.x86_64 /usr/src/linux
#./configure --prefix=/ --mandir=/usr/local/share/man/ --with-kernel-dir=/usr/src/kernels/2.6.32-220.el6.x86_64
#make
#make install
# cd /etc/keepalived/
配置参数文件：
# mv keepalived.conf keepalived.conf.default
#vi keepalived.conf
! Configuration File for keepalived
vrrp_script chk_http_port {
script "/etc/keepalived/check_haproxy.sh"
interval 2
weight 2
global_defs {
router_id LVS_DEVEL
}
vrrp_instance VI_1 {
state MASTER
interface bond0
virtual_router_id 51
priority 150
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
track_script {
chk_http_port
}
virtual_ipaddress {
192.168.231.18
}
}
}
配置侦测haproxy状态脚本：
#vi /etc/keepalived/check_haproxy.sh
#!/bin/bash
A=`ps -C haproxy --no-header |wc -l`
if [ $A -eq 0 ];then
/usr/local/sbin/haproxy -f /etc/haproxy/haproxy.conf
sleep 3
if [ `ps -C haproxy --no-header |wc -l` -eq 0 ];then
/etc/init.d/keepalived stop
fi
fi
启动keepalived服务：
# /etc/init.d/keepalived start
添加新的协议地址：
#ip add
[root@mss-dn03 ~]# ip add
1: lo: mtu 16436 qdisc noqueue state UNKNOWN
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth0: mtu 1500 qdisc mq state DOWN qlen 1000
link/ether 90:e2:ba:23:87:04 brd ff:ff:ff:ff:ff:ff
3: eth1: mtu 1500 qdisc mq state DOWN qlen 1000
link/ether 90:e2:ba:23:87:05 brd ff:ff:ff:ff:ff:ff
9: bond0: mtu 1500 qdisc noqueue state UP
link/ether 6c:ae:8b:26:52:3b brd ff:ff:ff:ff:ff:ff
inet 192.168.231.7/24 brd 192.168.231.255 scope global bond0
inet6 fe80::6eae:8bff:fe26:523b/64 scope link tentative dadfailed
valid_lft forever preferred_lft forever
设置开启自启动：
# chkconfig --level 0123456 keepalived on
# chkconfig --list keepalived
测试过程中发现，master宕机后，VIP需要几十秒才能ping通，切换很慢：
arping -I bond0 -c 5 -s VIP GATEWAY
# arping -I bond0 -c 5 -s 192.168.231.18 192.168.231.254
Getting started with HAProxy and MySQL replication（能实现读写路由）：
http://blog.yannickjaquier.com/linux/getting-started-with-haproxy-and-mysql-replication.html
Haproxy配置日志：
http://www.linuxidc.com/Linux/2012-06/63585.htm
