架构拓扑图如下：

haproxy
VIP：  192.168.1.150
Master：192.168.1.10
Slave： 192.168.1.11
之间用keepalived实现HA
webserver1：192.168.1.101
webserver2：192.168.1.102
webserver3：192.168.1.103
webserver4：192.168.1.104
1.下载：

#wget http://haproxy.1wt.eu/download/1.3/src/haproxy-1.3.14.4.tar.gz

2.解压安装

#tar  –zxvf  haproxy-1.3.14.4.tar.gz
#tar zxvf haproxy-1.3.14.4..tar.gz
#mv  haproxy-1.3.14.4  haproxy
#cd haproxy
#make TARGET=linux26

（2.4内核版本 make TARGET=linux24
freebsd  make  TARGET=freebsd
solaris系统  make TARGET=solaris CPU=ultrasparc REGEX=static-pcre）
然后增加一个haproxy用户
3.配置haproxy
vi /etc/haproxy/haproxy.cfg

global
chroot /var/chroot/haproxy
daemon
gid     501
log 127.0.0.1 local3
nbproc  2
pidfile /var/run/haproxy-private.pid
ulimit-n        65535
user    haproxy
maxconn         32000
spread-checks           4
tune.maxaccept          8
tune.maxpollevents      100
defaults askwan
log     global
mode    http
option  httplog
option  dontlognull
log 127.0.0.1 local3
retries 3
option redispatch
maxconn 32000
contimeout      5000
clitimeout      50000
srvtimeout      50000
listen  askwan  0.0.0.0:80
appsession JSESSIONID len 52 timeout 3h
cookie SRV insert indirect nocache
mode http
stats enable
stats hide-version
stats uri /haproxy-stats
stats realm Haproxy\ statistics
stats auth askwan:askwan
stats refresh 3s
monitor-uri /haproxy_test
balance roundrobin
option httpclose
option forwardfor
option httpchk HEAD /index.html HTTP/1.0
server server1 192.168.1.101:80 check inter 2000
server server2 192.168.1.102:80 check inter 2000
server server3 192.168.1.103:80 check inter 2000
server server4 192.168.1.104:80 check inter 2000

slave机器上同样配置如斯
下面是监控页面

附上haproxy启动脚本：

#!/bin/sh
#
# chkconfig: - 85 15
# description: HA-Proxy is a TCP/HTTP reverse proxy which is particularly suited \
#              for high availability environments.
# processname: haproxy
# config: /etc/haproxy/haproxy.cfg
# pidfile: /var/run/haproxy.pid
# Script Author: Simon Matter
# Version: 2004060600
# Source function library.
if [ -f /etc/init.d/functions ]; then
. /etc/init.d/functions
elif [ -f /etc/rc.d/init.d/functions ] ; then
. /etc/rc.d/init.d/functions
else
exit 0
fi
# Source networking configuration.
. /etc/sysconfig/network
# Check that networking is up.
[ ${NETWORKING} = "no" ] && exit 0
# This is our service name
BASENAME=`basename $0`
if [ -L $0 ]; then
BASENAME=`find $0 -name $BASENAME -printf %l`
BASENAME=`basename $BASENAME`
fi
[ -f /etc/$BASENAME/$BASENAME.cfg ] || exit 1
RETVAL=0
start() {
/usr/sbin/$BASENAME -c -q -f /etc/$BASENAME/$BASENAME.cfg
if [ $? -ne 0 ]; then
echo "Errors found in configuration file, check it with '$BASENAME check'."
return 1
fi
echo -n "Starting $BASENAME: "
daemon /usr/sbin/$BASENAME -D -f /etc/$BASENAME/$BASENAME.cfg -p /var/run/$BASENAME.pid
RETVAL=$?
echo
[ $RETVAL -eq 0 ] && touch /var/lock/subsys/$BASENAME
return $RETVAL
}
stop() {
echo -n "Shutting down $BASENAME: "
killproc $BASENAME -USR1
RETVAL=$?
echo
[ $RETVAL -eq 0 ] && rm -f /var/lock/subsys/$BASENAME
[ $RETVAL -eq 0 ] && rm -f /var/run/$BASENAME.pid
return $RETVAL
}
restart() {
/usr/sbin/$BASENAME -c -q -f /etc/$BASENAME/$BASENAME.cfg
if [ $? -ne 0 ]; then
echo "Errors found in configuration file, check it with '$BASENAME check'."
return 1
fi
stop
start
}
check() {
/usr/sbin/$BASENAME -c -q -V -f /etc/$BASENAME/$BASENAME.cfg
}
rhstatus() {
status $BASENAME
}
condrestart() {
[ -e /var/lock/subsys/$BASENAME ] && restart || :
}
# See how we were called.
case "$1" in
start)
start
;;
stop)
stop
;;
restart)
restart
;;
reload)
restart
;;
condrestart)
condrestart
;;
status)
rhstatus
;;
check)
check
;;
*)
echo $"Usage: $BASENAME {start|stop|restart|reload|condrestart|status|check}"
exit 1
esac
exit $?

4.在两台haproxy机器上安装配置好keepalived
Keepalived配置
VIP 192.168.1.150
Realserver  192.168.1.10 （MASTER）
RealServer  192.168.1.11 （SLAVER）
分别在两台机器上配置keepalived.conf文件

global_defs {
notification_email {
askwan@yahoo.com
}
notification_email_from askwan@askwan.com
smtp_server 192.168.1.3
smtp_connect_timeout 30
router_id LVS_DEVEL
}
vrrp_instance VI_1 {
state MASTER
interface eth0
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass askwan
}
virtual_ipaddress {
192.168.1.150
}

5调试
这个是Master机keepalived调试信息：

Apr 22 08:32:22 db1 Keepalived: Starting Keepalived v1.1.15 (04/22,2008)
Apr 22 08:32:22 db1 Keepalived: daemon is already running
Apr 22 08:32:24 db1 Keepalived: Starting Keepalived v1.1.15 (04/22,2008)
Apr 22 08:32:24 db1 Keepalived: daemon is already running
Apr 22 08:32:46 db1 Keepalived: Starting Keepalived v1.1.15 (04/22,2008)
Apr 22 08:32:46 db1 Keepalived: daemon is already running
Apr 22 08:37:42 db1 Keepalived: Starting Keepalived v1.1.15 (04/22,2008)
Apr 22 08:37:42 db1 Keepalived: daemon is already running
Apr 22 08:39:34 db1 Keepalived: Starting Keepalived v1.1.15 (04/22,2008)
Apr 22 08:39:34 db1 Keepalived: daemon is already running
Apr 22 08:41:20 db1 sshd(pam_unix)[6317]: session opened for user root by root(uid=0)
Apr 22 08:41:32 db1 Keepalived: Terminating on signal
Apr 22 08:41:32 db1 Keepalived_vrrp: Terminating VRRP child process on signal
Apr 22 08:41:32 db1 Keepalived: Stopping Keepalived v1.1.15 (04/22,2008)
Apr 22 08:42:03 db1 Keepalived: Starting Keepalived v1.1.15 (04/22,2008)
Apr 22 08:42:03 db1 Keepalived_vrrp: Using MII-BMSR NIC polling thread...
Apr 22 08:42:03 db1 Keepalived_vrrp: Registering Kernel netlink reflector
Apr 22 08:42:03 db1 Keepalived_vrrp: Registering Kernel netlink command channel
Apr 22 08:42:03 db1 Keepalived_vrrp: Registering gratutious ARP shared channel
Apr 22 08:42:03 db1 Keepalived: Starting VRRP child process, pid=6358
Apr 22 08:42:03 db1 Keepalived_vrrp: Opening file '/usr/local/keepalived/etc/keepalived/keepalived.conf'.
Apr 22 08:42:03 db1 Keepalived_vrrp: Configuration is using : 33290 Bytes
Apr 22 08:42:03 db1 Keepalived_vrrp: VRRP sockpool: [ifindex(2), proto(112), fd(7,8)]
Apr 22 08:42:04 db1 Keepalived_vrrp: VRRP_Instance(VI_1) Transition to MASTER STATE
Apr 22 08:42:05 db1 Keepalived_vrrp: VRRP_Instance(VI_1) Entering MASTER STATE
Apr 22 08:42:05 db1 Keepalived_vrrp: VRRP_Instance(VI_1) setting protocol VIPs.
Apr 22 08:42:05 db1 Keepalived_vrrp: VRRP_Instance(VI_1) Sending gratuitous ARPs on eth0 for 192.168.1.150
Apr 22 08:42:10 db1 Keepalived_vrrp: VRRP_Instance(VI_1) Sending gratuitous ARPs on eth0 for 192.168.1.150

可以看到此机此时处于MASTER状态
slave机调试信息

Apr 20 08:43:28 db2 Keepalived: Starting Keepalived v1.1.15 (04/22,2008)
Apr 22 08:43:28 db2 Keepalived_vrrp: Using MII-BMSR NIC polling thread...
Apr 22 08:43:28 db2 Keepalived_vrrp: Registering Kernel netlink reflector
Apr 22 08:43:28 db2 Keepalived_vrrp: Registering Kernel netlink command channel
Apr 22 08:43:28 db2 Keepalived_vrrp: Registering gratutious ARP shared channel
Apr 22 08:43:28 db2 Keepalived: Starting VRRP child process, pid=5857
Apr 22 08:43:28 db2 Keepalived_vrrp: Opening file '/usr/local/keepalived/etc/keepalived/keepalived.conf'.
Apr 22 08:43:28 db2 Keepalived_vrrp: Configuration is using : 36052 Bytes
Apr 22 08:43:28 db2 Keepalived_vrrp: VRRP_Instance(VI_1) Entering BACKUP STATE
Apr 22 08:43:28 db2 Keepalived_vrrp: VRRP sockpool: [ifindex(2), proto(112), fd(7,8)]

可以看到此机此时处于BACKUP状态
5.测试
地址已经分配完成后，可以开始做测试 测试过程简单 省略了
在HA的测试过程说一下
192.168.1.10宕机后192.168.1.11接管
192.168.1.10恢复后 192.168.1.11移交服务权限10
本方案经过我多次测试基本达到了架构拓扑图中的需求。这样一个简单高可用集群方案搭建完成。
如果文章中有什么不对，你有更好的建议，请联系我 askwan （at）yahoo.cn
更过信息请参阅：

http://haproxy.1wt.eu/

http://www.keepalived.org /