1，keepalived 高可用的安装配置

Keeplived 正常工作时，主节点会不断的向备机广播心跳消息，用以告诉备节点自己还活着。

当主节点down了的话，备节点无法继续检测到主节点的心跳，那么备机就自动接管主节点的IP资源及服务。当主节点恢复，备节点自动恢复为原先的备机状态。

VRRP 的出现就是为了解决静态路由的单点故障。

主备的配置文件里面都指明了VIP地址。

 

1 解压安装keepalived

http://www.keepalived.org/software/keepalived-1.2.16.tar.gz

tar xf  keepalived-1.2.16.tar.gz

cd  keepalived-1.2.16.tar.gz

ln -s /usr/src/kernels/2.6.32-504.e16.x86_64/     /usr/src/linux   (不同的内核版本根据实际情况)

./configure

make && make install

2 规范启动

/bin/cp /usr/local/etc/rc.d/init.d/keepalived     /etc/init.d/     ====è生成启动脚本命令 
/bin/cp /usr/local/etc/sysconfig/keepalived     /etc/sysconfig/       ====è配置启动脚本的参数

mkdir  /etc/keepalived   ===è创建默认的keepalived配置文件路径。

/bin/cp /usr/local/etc/keepalived/keepalived.conf /etc/keepalived/   ==è把keeplived.conf 模板拷贝到/etc/keepalived 下。

/bin/cp /usr/local/sbin/keepalived /usr/sbin/

/etc/init.d/ keepalived start

3.接下来看配置文件

 

4 主机的的keep alived.conf 的配置

[root@lb01 keepalived]# cat keepalived.conf
global_defs {
   notification_email {
    49000448-@qq.com
   }
   notification_email_from Alexandre.Cassen@firewall.loc
   smtp_server 192.168.200.1
   smtp_connect_timeout 30
   router_id LVS_01
}

vrrp_instance VI_1 {
    state MASTER
    interface eth0
    virtual_router_id 51
    priority 150
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
     10.0.0.17/24
    }
}

5 如下方式添加VIP

[root@moban ~]# ip addr add 10.0.0.18/24 dev eth0
[root@moban ~]# ip add
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 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: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:0c:29:ab:06:1c brd ff:ff:ff:ff:ff:ff
    inet 192.168.132.131/24 brd 192.168.132.255 scope global eth0
    inet 10.0.0.18/24 scope global eth0
    inet6 fe80::20c:29ff:feab:61c/64 scope link 
       valid_lft forever preferred_lft forever
[root@moban ~]#

VIP删除的话，就这样

[root@moban ~]# ip addr del 10.0.0.18/24 dev eth0

[root@moban ~]# ip add
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 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: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:0c:29:ab:06:1c brd ff:ff:ff:ff:ff:ff
    inet 192.168.132.131/24 brd 192.168.132.255 scope global eth0
    inet6 fe80::20c:29ff:feab:61c/64 scope link 
       valid_lft forever preferred_lft forever
[root@moban ~]#

6.备机的keepalived.conf 配置如下

 [root@lb02 keepalived]# cat keepalived.conf 
global_defs {
   notification_email {
    49000448-@qq.com
   }
   notification_email_from Alexandre.Cassen@firewall.loc
   smtp_server 192.168.200.1
   smtp_connect_timeout 30
   router_id LVS_02
}

vrrp_instance VI_1 {
    state BACKUP
    interface eth0
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
     10.0.0.17/24
    }
}

7

Keepalived +nginx :

说白了就是给nginx提供了一个VIP,域名解析到VIP,vip对应2个真实机器IP(2个真实机器的配置文件里面配置了VIP)，然后只要nginx有一台活着，域名就可以正常访问。Keepalive down了一台，VIP自动会飘到备机的keepalived。