Haproxy+Keepalived+apache實現高可用

Haproxy通過結合Keepalived實現負載均衡器節點的高可用

環境介紹：CentOS 6.5平臺
Haproxy1：10.10.10.128/24
Haproxy2：10.10.10.129/24
web1：10.10.10.130/24
web2：10.10.10.131/24
VIP：10.10.10.100/24

部署前準備：
1、時間同步：
ntpdate ntp1.aliyun.com
2、防火牆策略：
service iptables stop
chkconfig iptables off
3、SELinux策略：
sed -i 's#SELINUX=enforcing#SELINUX=disabled#' /etc/selinux/config
4、更換國內yum源：
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-6.repo
yum clean all
yum makecache
5、重啓服務器
reboot

web服務器配置：
1、安裝httpd服務
    yum install httpd -y
2、修改配置文件：/etc/httpd/conf/httpd.conf
    .....
    Listen 8080
    ServerName 10.10.10.130:8080  #web1
    ServerName 10.10.10.131:8080  #web2
3、修改web主頁：/var/www/html/index.html
    echo "web1" >/var/www/html/index.html     #web1
    echo "web2" >/var/www/html/index.html     #web2
4、啓動web服務：
    service httpd start
    chkconfig httpd on
5、驗證服務是否正常：
    lsof -i:8080
    curl 10.10.10.130:8080  #返回web1
    curl 10.10.10.131:8080  #返回web2

Haproxy服務器配置：
1、安裝Haproxy服務
    yum install haproxy -y
2、修改配置文件：/etc/haproxy/haproxy.cfg
    cp /etc/haproxy/haproxy /etc/haproxy/haproxy.cfg.bak
    vim /etc/haproxy/haproxy.cfg
  .........
  .........
#---------------------------------------------------------------------
# main frontend which proxys to the backends
#---------------------------------------------------------------------
frontend  main
    bind 0.0.0.0:80
    acl url_static       path_beg       -i /static /images /javascript /stylesheets
    acl url_static       path_end       -i .jpg .gif .png .css .js

    use_backend static          if url_static
    default_backend             dynamic

#---------------------------------------------------------------------
# static backend for serving up images, stylesheets and such
#---------------------------------------------------------------------
backend static
    balance     roundrobin
    server      static 127.0.0.1:80 check

#---------------------------------------------------------------------
# round robin balancing between the various backends
#---------------------------------------------------------------------
backend dynamic
    balance     roundrobin
    server  web1 10.10.10.130:8080 check maxconn 2000
    server  web2 10.10.10.131:8080 check maxconn 2000

3、檢測配置文件是否正確：
    haproxy -c -f /etc/haproxy/haproxy.cfg

4、啓動Haproxy
    service haproxy start
    chkconfig haproxy on
5、驗證是否正常解析：
    curl 10.10.10.128  //重複兩次，分別顯示web1和web2
    curl 10.10.10.129  //重複兩次，分別顯示web1和web2

Keepalived配置：
1、安裝keepalived服務：
    yum -y install keepalived
2、修改配置文件：
#MASTER端：
! Configuration File for keepalived
#定義檢查腳本
vrrp_script check_haproxy {
        script "/etc/keepalived/check_haproxy.sh"
        interval 2
        weight 2
}
global_defs {
   notification_email {
        root@localhost
   }
   notification_email_from keepalived@localhost
   smtp_server 127.0.0.1
   smtp_connect_timeout 30
   router_id haproxy1
}

vrrp_instance ha1 {
    state MASTER
    interface eth0
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        10.10.10.100/24 dev eth0
    }
    track_script{
         check_haproxy
    }
}

#BACKUP端：
.........
router_id haproxy2   #修改虛擬路由的ID
state BACKUP   #修改角色
priority 80     #修改優先級

重啓各服務：
service keepalived restart
service haproxy restart

驗證：
ip addr
發現虛擬ip：10.10.10.100在MASTER端
訪問10.10.10.100正常

/etc/keepalived/check_haproxy.sh

#!/bin/bash
A=`ps -C haproxy --no-header |wc -l`
if [ $A -eq 0 ];then
/etc/init.d/keepalived stop
fi

驗證Haproxy+Keepalived服務的可靠性：

web端：關閉web1的httpd服務，service httpd stop
curl 10.10.10.100  #正常返回web2
Haproxy端：關閉haproxy1的keepalived服務，service keepalived stop
curl 10.10.10.100 #正常輪詢返回web1/web2
通過ip addr 可以查看 VIP漂移到Haproxy2中