基于Haproxy + keepalived构建高可用负载集群

准备4台机器

两台Haproxy   两台Hginx

1，在Nginx机上安装

 yum -y install gcc gcc-c++ make pcre-devel zlib-devel
 useradd -M -s /sbin/nologin  nginx
 tar xf nginx-1.6.2.tar.gz -C /usr/src
 cd /usr/src/nginx-1.6.2
 ./configure --prefix=/usr/local/nginx --user=nginx --group=nginx && make && make install
cd /usr/local/nginx/html/
echo "server 192.168.200.103" > index.html
 /usr/local/nginx/sbin/nginx
[netstat -anpt |grep nginxnginx

2，安装Haproxy在另外两台机器上

yum -y install gcc gcc-c++ make pcre-devel bzip2-devel
 tar xf haproxy-1.4.24.tar.gz -C /usr/src/
 cd /usr/src/haproxy-1.4.24/
 make TARGET=linux26 && make install

3，创建一个Haproxy目录及文件

 mkdir /etc/haproxy
 cp examples/haproxy.cfg /etc/haproxy/

4，修改Haproxy主配置   /etc/haproxy/haproxy.cfg

------------------------------------------------修改Ip 指向另外两台nginx机ip

# 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

---------------------------------------------------------------------------------------------

5，在haproxy 机 上分别安装keepalived

yum  -y install  keepalived

6,  编辑Keepalived 主配置文件     /etc/keepalived/keepalived.conf

修改红色字地方--------------------------------------------------------------------

! Configuration File for keepalived
 
vrrp_script chk_http_port {
script "/etc/keepalived/check_haproxy.sh"     // 加上脚本
interval 2
 weight 2

global_defs {
router_id LVS_DEVEL
}
vrrp_instance VI_1 {
state MASTER（BACKUP） 
interface eth0    (..)
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
 
track_script {
chk_http_port                           //指定脚本
}
 
virtual_ipaddress {
192.168.200.254                      //虚拟网IP  （访问的网） 
}
}
}

-------------------------------------------------------------------------------

第二台keepalived   同上

修改权重为上面蓝字

7,创建对应的脚本  (两台keepalived)

vim    /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

8，给脚本相应的权限

chmod  +x  /etc/keepalived/check_haroxy.sh

systemctl    start    keepalived        //   启动

service  keepalived  start             //  另一种方法启动

9，进行测试即可

在浏览器上输入  IP  

可以模拟一台keepalived 机 出错，看看vip 会不会转向另一台haproxy 机