nginx+keepalived高可用配置

linux

服务器IP:

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server_ip
    172.16.88.179
    172.16.88.180
vip
    172.16.88.178

软件版本及下载

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http://tengine.taobao.org/download/tengine-2.1.2.tar.gz
http://www.keepalived.org/software/keepalived-1.3.2.tar.gz

nginx安装

参加nginx的安装文档

keepalived安装

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tar zxvf keepalived-1.3.2.tar.gz
cd keepalived-1.3.2
./configure --sysconf=/etc
make && make install 
ln -s /usr/local/sbin/keepalived /sbin/keepalived
cp  keepalived/etc/init.d/keepalived /etc/init.d/
chkconfig --add keepalived
chkconfig keepalived on

配置nginx+keepalived

在172.16.88.179上

创建nginx服务监测脚本

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vim /etc/keepalived/chk_nginx.sh
#!/bin/bash
# description:
# 查看nginx进程是否存在，如果不存在则启动nginx
# 如果启动失败，则停止keepalived
status=$(ps -C nginx --no-heading|wc -l)
if [ "${status}" = "0" ]; then
        /usr/sbin/nginx
        status2=$(ps -C nginx --no-heading|wc -l)
        if [ "${status2}" = "0"  ]; then
                service keepalived stop
        fi
fi

添加可执行权限

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chmod +x /etc/keepalived/chk_nginx.sh
配置keepalived.conf
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mv /etc/keepalived/keepalived.conf{,.bak}
 
vim /etc/keepalived/keepalived.conf
#主配置文件
#定义监控脚本
vrrp_script chk_nginx {
        script "/etc/keepalived/chk_nginx.sh"   #脚本位置
        interval 2  #检查时间间隔,单位秒
        weight 2    #定义失败时对应的权重减少值
        fall 3      #定义多少次失败则判定失败(检测3次失败,就认为失败)
        rise 2      #判定成功检测次数(检测二次成功,就认为在线)
}
 
 
vrrp_instance VI_1 {
    state MASTER    #角色
    interface eth0  #监听的网卡
    virtual_router_id 51    #虚拟路由标志
    priority 100    #优先级
    advert_int 1    #检查时间间隔，单位秒
    authentication {
        auth_type PASS  #验证类型
        auth_pass 1111  #验证密码
    }
 
    track_script {
        chk_nginx
    }
 
    virtual_ipaddress {
        172.16.88.178   #vip
    }
}
拷贝配置文件到172.16.88.180
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scp /etc/keepalived/keepalived.conf root@172.16.88.180:/etc/keepalived/
scp /etc/keepalived/chk_nginx.sh root@172.16.88.180:/etc/keepalived/
在172.16.88.180上

修改从172.16.88.179拷贝过来的配置文件/etc/keepalived/keepalived.conf

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vim /etc/keepalived/keepalived.conf
 
#主配置文件
global_defs {
   notification_email {     #设置管理员的email邮箱信息
     acassen@firewall.loc
     failover@firewall.loc
     sysadmin@firewall.loc
   }
   notification_email_from Alexandre.Cassen@firewall.loc    #通知邮件来源
   smtp_server 127.0.0.1    #设置邮件服务器地址为本地
   smtp_connect_timeout 30  #设置连接超时时间
   router_id LVS_DEVEL      #设置本keepalived的ID名称
   vrrp_skip_check_adv_addr
#   vrrp_strict             ##严格遵守vrrp协议，下面这些功能将会禁止：1.VIP;2.unicast(单播) peers;3.vrrp 版本2的ipv6功能,开启此选项会开启防火墙并DROP所以VIP请求
#   vrrp_garp_interval 0
#   vrrp_gna_interval 0
}
 
vrrp_script chk_nginx {
        script "/etc/keepalived/chk_nginx.sh"
        interval 2
        weight 2
        fall 3
        rise 2
}
 
 
vrrp_instance VI_1 {
    state SLAVE     #修改角色
    interface eth0
    virtual_router_id 51
    priority 90     #修改优先级
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
 
    track_script {
        chk_nginx
    }
 
    virtual_ipaddress {
        172.16.88.178
    }
}

测试

启动nginx+keepalived服务(两台均启动)

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/usr/sbin/ngix  #启动nginx
service keepalived start    #启动keepalived

在优先级较高的这条查看ip

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ip addr
eth0:mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 52:54:00:0c:47:79 brd ff:ff:ff:ff:ff:ff
inet 172.16.88.179/23 brd 172.16.89.255 scope global eth0
inet 172.16.88.178/23 scope global secondary eth0   #发现多了一个虚拟ip
inet6 fe80::5054:ff:fe0c:4779/64 scope link 
   valid\_lft forever preferred\_lft forever

注意:此时在优先级低的服务器上是看不到这个虚拟ip的

模拟master(172.16.88.179)宕机，关闭keepalived

此时查看ip,发现虚拟IP漂移到SLAVE(172.16.88.180)上了