基于Haproxy+Keepalived构建高可用负载均衡集群

1、在Nginx1/2上编译安装nginx服务
1.1 首先安装Nginx1

[root@Nginx-1 ~]# yum -y install gcc gcc-c++ make pcre-devel zlib-devel
[root@Nginx-1 ~]# useradd -M -s /sbin/nologin  nginx
[root@Nginx-1 ~]# tar xf nginx-1.6.2.tar.gz -C /usr/src
[root@Nginx-1 ~]# cd /usr/src/nginx-1.6.2
[root@Nginx-1 nginx-1.6.2]# ./configure --prefix=/usr/local/nginx --user=nginx --group=nginx && make && make install
[root@Nginx-1 nginx-1.6.2]# cd /usr/local/nginx/html/
[root@Nginx-1 html]# echo "server 192.168.200.103" > index.html
[root@Nginx-1 html]# /usr/local/nginx/sbin/nginx 
[root@Nginx-1 html]# netstat -anpt |grep nginx
tcp        0      0 0.0.0.0:80                  0.0.0.0:*                   LISTEN      4503/nginx 

1.2 安装Nginx2，同Nginx1搭建方式是一样的。
与Nginx1唯一不同的是：

[root@Nginx-2 html]# echo "server 192.168.200.104" > index.html

2、安装Haproxy-1与Haproxy-2 两台机器配置一致：

[root@Haproxy-1 ~]# yum -y install gcc gcc-c++ make pcre-devel bzip2-devel
[root@Haproxy-1 ~]# tar xf haproxy-1.4.24.tar.gz -C /usr/src/
[root@Haproxy-1 ~]# cd /usr/src/haproxy-1.4.24/
[root@Haproxy-1 haproxy-1.4.24]# make TARGET=linux26 && make install

2.1 Haproxy服务器配置
建立haproxy的配置目录及文件

[root@Haproxy-1 haproxy-1.4.24]# mkdir /etc/haproxy
[root@Haproxy-1 haproxy-1.4.24]# cp examples/haproxy.cfg /etc/haproxy/

2.2 haproxy配置项的介绍
haproxy的配置文件通常分为三部分: global（全局配置部分） defaults（默认配置部分） listen(应用组件部分)

[root@Haproxy-1 ~]# vim /etc/haproxy/haproxy.cfg
# this config needs haproxy-1.1.28 or haproxy-1.2.1
 
global
    log 127.0.0.1   local0
    log 127.0.0.1   local1 notice
    #log loghost    local0 info
    maxconn 4096
    #chroot /usr/share/haproxy
    uid 99
    gid 99
    daemon
    #debug
    #quiet
 
defaults
    log global
    mode    http
    option  httplog
    option  dontlognull
    retries 3
    #redispatch
    maxconn 2000
    contimeout  5000
    clitimeout  50000
    srvtimeout  50000
 
listen  web-cluster 0.0.0.0:80
    option httpchk GET /index.html
    balance roundrobin
    server  inst1 192.168.200.103:80 check inter 2000 fall 3
    server  inst2 192.168.200.104:80 check inter 2000 fall 3

2.3 创建自启动脚本

[root@Haproxy-1 ~]# cp /usr/src/haproxy-1.4.24/examples/haproxy.init /etc/init.d/haproxy
[root@Haproxy-1 ~]# ln -s /usr/local/sbin/haproxy /usr/sbin/haproxy
[root@Haproxy-1 ~]# chmod +x /etc/init.d/haproxy 
[root@Haproxy-1 ~]# /etc/init.d/haproxy start
Starting haproxy:                                          [确定]

2.4 客户端访问测试：

用浏览器打开 http://192.168.200.101 打开一个新的浏览器再次访问 http://192.168.200.101

用浏览器打开 http://192.168.200.102 打开一个新的浏览器再次访问 http://192.168.200.102

可以验证两次访问到的结果分别为：

server 192.168.200.103

server 192.168.200.104

3、编译安装keepalived服务

[root@Haproxy-1 ~]# yum -y install kernel-devel openssl-devel popt-devel
[root@Haproxy-1 ~]# tar xf keepalived-1.2.13.tar.gz 
[root@Haproxy-1 ~]# cd keepalived-1.2.13
[root@Haproxy-1 keepalived-1.2.13]# ./configure --prefix=/ --with-kernel-dir=/usr/src/kernels/2.6.18-194.el5-i686 && make && make install

3.1 配置keepalibed 开机启动脚本

[root@Haproxy-1 ~]# chkconfig --add keepalived
[root@Haproxy-1 ~]# chkconfig keepalived on
[root@Haproxy-1 ~]# chkconfig --list keepalived

3.2.1 配置keepalibed 主配置文件

[root@Haproxy-1 ~]# vim /etc/keepalived/keepalived.conf 
! Configuration File for keepalived
 
vrrp_script chk_http_port {
script "/etc/keepalived/check_haproxy.sh"
interval 2
 
global_defs {
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 1111
}
 
track_script {
chk_http_port
}
 
virtual_ipaddress {
192.168.200.254 
}
}
}

3.2.2 第二台Haproxy配置keepalibed 主配置文件

[root@Haproxy-2 ~]# cat /etc/keepalived/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 BACKUP 
interface eth0
virtual_router_id 51 
priority 50
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
 
track_script {
chk_http_port
}
 
virtual_ipaddress {
192.168.200.254 
}
}
}

4、两台机器上都配置haproxy检测脚本

[root@Haproxy-1 ~]# cat /etc/keepalived/check_haproxy.sh 
#!/bin/bash
num=`ps -C haproxy --no-header |wc -l`
if [ $num -eq 0 ]
then
    /usr/local/haproxy/sbin/haproxy -f /usr/local/haproxy/conf/haproxy.cfg
    sleep 3
    if [ `ps -C haproxy --no-header |wc -l` -eq 0 ]
    then
        /etc/init.d/keepalived stop
    fi
fi
 
[root@Haproxy-1 ~]# chmod +x /etc/keepalived/check_haproxy.sh
[root@Haproxy-1 ~]# service keepalived start
[root@Haproxy-2 ~]# service keepalived start

5.1、测试VIP地址

[root@Haproxy-1 ~]# ip addr show dev eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:0c:29:cc:18:a2 brd ff:ff:ff:ff:ff:ff
    inet 192.168.200.101/24 brd 192.168.200.255 scope global eth0
    inet 192.168.200.254/32 scope global eth0
    inet6 fe80::20c:29ff:fecc:18a2/64 scope link 
       valid_lft forever preferred_lft forever
 
[root@Haproxy-1 ~]# /etc/init.d/keepalived stop
停止 keepalived：                                          [确定]
 
[root@Haproxy-2 ~]# ip addr show dev eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:0c:29:fd:8a:4e brd ff:ff:ff:ff:ff:ff
    inet 192.168.200.102/24 brd 192.168.200.255 scope global eth0
    inet 192.168.200.254/32 scope global eth0
    inet6 fe80::20c:29ff:fefd:8a4e/64 scope link 
       valid_lft forever preferred_lft forever

5.2、测试Haproxy健康检查

[root@Haproxy-1 ~]# service haproxy stop
Shutting down haproxy:                                     [确定]
[root@Haproxy-1 ~]# service haproxy status
haproxy (pid 59717) 正在运行...

5.3 网页测试：
用浏览器打开 http://192.168.200.254
再次打开一个新的浏览器再次访问 http://192.168.200.254

可以验证两次访问到的结果分别为：
server 192.168.200.103
server 192.168.200.104