实现用keepalived将nginx高可用

文章目录

2.关于keepalived配置讲解
2.1定制主配置文件
3.环境说明
4.安装配置nginx和keepalived

4.1给master和backup两台服务器安装下载nginx和keepalive
4.2验证结果
4.3修改内核参数(如果不想做请看下一步)
4.4keepalived监控nginx负载均衡机(在master上用脚本监控)
4.5分别在主服务和备服务上配置脚本

2.关于keepalived配置讲解

keepalived 的主配置文件是 /etc/keepalived/keepalived.conf

[[email protected] ~]# cat /etc/keepalived/keepalived.conf
! Configuration File for keepalived

global_defs {       //全局配置
   notification_email {     //定义报警收件人邮件地址
     [email protected]
     [email protected]
     [email protected]
   }
   notification_email_from [email protected]    //定义报警发件人邮箱
   smtp_server 192.168.100.1    //邮箱服务器地址
   smtp_connect_timeout 30      //定义邮箱超时时间
   router_id LVS_DEVEL          //定义路由标识信息，同局域网内唯一
   vrrp_skip_check_adv_addr
   vrrp_strict
   vrrp_garp_interval 0
   vrrp_gna_interval 0
}

vrrp_instance VI_1 {        //定义实例
    state MASTER            //指定keepalived节点的初始状态，可选值为MASTER|BACKUP
    interface eth0          //VRRP实例绑定的网卡接口，用户发送VRRP包
    virtual_router_id 51    //虚拟路由的ID，同一集群要一致
    priority 100            //定义优先级，按优先级来决定主备角色，优先级越大越优先
    nopreempt               //设置不抢占
    advert_int 1            //主备通讯时间间隔
    authentication {        //配置认证
        auth_type PASS      //认证方式，此处为密码
        auth_pass 1111      //同一集群中的keepalived配置里的此处必须一致，推荐使用8位随机数
    }
    virtual_ipaddress {     //配置要使用的VIP地址
        192.168.200.16
    }
}

virtual_server 192.168.100.16{    //配置虚拟服务器,ip为vip
    delay_loop 6        //健康检查的时间间隔
    lb_algo rr          //lvs调度算法
    lb_kind NAT         //lvs模式
    persistence_timeout 50      //持久化超时时间，单位是秒
    protocol TCP        //4层协议

    sorry_server 192.168.200.200 1358   //定义备用服务器，当所有RS都故障时用sorry_server来响应客户端

    real_server 192.168.200.2 1358 {    //定义真实处理请求的服务器
        weight 1    //给服务器指定权重，默认为1
        HTTP_GET {
            url {
              path /testurl/test.jsp    //指定要检查的URL路径
              digest 640205b7b0fc66c1ea91c463fac6334d   //摘要信息
            }
            url {
              path /testurl2/test.jsp
              digest 640205b7b0fc66c1ea91c463fac6334d
            }
            url {
              path /testurl3/test.jsp
              digest 640205b7b0fc66c1ea91c463fac6334d
            }
            connect_timeout 3       //连接超时时间
            nb_get_retry 3          //get尝试次数
            delay_before_retry 3    //在尝试之前延迟多长时间
        }
    }

    real_server 192.168.200.3 1358 {
        weight 1
        HTTP_GET {
            url {
              path /testurl/test.jsp
              digest 640205b7b0fc66c1ea91c463fac6334c
            }
            url {
              path /testurl2/test.jsp
              digest 640205b7b0fc66c1ea91c463fac6334c
            }
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
        }
    }
}

2.1定制主配置文件

vrrp_instance段配置

nopreempt   //设置为不抢占。默认是抢占的，当高优先级的机器恢复后，会抢占低优先 \
级的机器成为MASTER，而不抢占，则允许低优先级的机器继续成为MASTER，即使高优先级 \
的机器已经上线。如果要使用这个功能，则初始化状态必须为BACKUP。

preempt_delay   //设置抢占延迟。单位是秒，范围是0---1000，默认是0.发现低优先 \
级的MASTER后多少秒开始抢占。

vrrp_script段配置

//作用：添加一个周期性执行的脚本。脚本的退出状态码会被调用它的所有的VRRP Instance记录。
//注意：至少有一个VRRP实例调用它并且优先级不能为0.优先级范围是1-254.

vrrp_script <SCRIPT_NAME> {
          ...
    }

//选项说明：
script "/path/to/somewhere"      //指定要执行的脚本的路径。
interval <INTEGER>              //指定脚本执行的间隔。单位是秒。默认为1s。
timeout <INTEGER>               //指定在多少秒后，脚本被认为执行失败。
weight <-254 --- 254>           //调整优先级。默认为2.
rise <INTEGER>                  //执行成功多少次才认为是成功。
fall <INTEGER>                  //执行失败多少次才认为失败。
user <USERNAME> [GROUPNAME]     //运行脚本的用户和组。
init_fail                       //假设脚本初始状态是失败状态。

//weight说明： 
1. 如果脚本执行成功(退出状态码为0)，weight大于0，则priority增加。
2. 如果脚本执行失败(退出状态码为非0)，weight小于0，则priority减少。
3. 其他情况下，priority不变。

real_server段配置

weight <INT>            //给服务器指定权重。默认是1
inhibit_on_failure      //当服务器健康检查失败时，将其weight设置为0， \
                        而不是从Virtual Server中移除
notify_up <STRING>      //当服务器健康检查成功时，执行的脚本
notify_down <STRING>    //当服务器健康检查失败时，执行的脚本
uthreshold <INT>        //到这台服务器的最大连接数
lthreshold <INT>        //到这台服务器的最小连接

tcp_check段配置

connect_ip <IP ADDRESS>     //连接的IP地址。默认是real server的ip地址
connect_port <PORT>         //连接的端口。默认是real server的端口
bindto <IP ADDRESS>         //发起连接的接口的地址。
bind_port <PORT>            //发起连接的源端口。
connect_timeout <INT>       //连接超时时间。默认是5s。
fwmark <INTEGER>            //使用fwmark对所有出去的检查数据包进行标记。
warmup <INT>    //指定一个随机延迟，最大为N秒。可防止网络阻塞。如果为0，则关闭该功能。
retry <INIT>                //重试次数。默认是1次。
delay_before_retry <INT>    //默认是1秒。在重试之前延迟多少秒。

3.环境说明

服务名称	ip	vip
master	192.168.69.130	192.168.69.132
backup	192.168.69.134	192.168.69.132

关闭三台服务器防火墙和setLinux安装仓库源

[[email protected] ~]# systemctl stop firewalld
[[email protected] ~]# setenforce 0
[[email protected] ~]# cd /etc/yum.repos.d/
[[email protected] yum.repos.d]# yum -y install epel-release
[[email protected] yum.repos.d]# curl -o /etc/yum.repos.d/CentOS7-Base-163.repo http://mirrors.163.com/.help/CentOS7-Base-163.repo
[[email protected] yum.repos.d]# sed -i 's/\$releasever/7/g' /etc/yum.repos.d/CentOS7-Base-163.repo
[[email protected] yum.repos.d]# sed -i 's/^enabled=.*/enabled=1/g' /etc/yum.repos.d/CentOS7-Base-163.repo
[[email protected] yum.repos.d]# yum -y install epel-release

4.安装配置nginx和keepalived

4.1给master和backup两台服务器安装下载nginx和keepalive

启动nginx和keepalived

[[email protected] yum.repos.d]# yum -y install nginx
[[email protected] ~]# yum -y install keepalived
[[email protected] ~]# systemctl start keepalived    \\如果报错参照下面一步

如果启动不了keepalived

[[email protected] ~]# cd /usr/sbin/
[[email protected] sbin]# rm -f keepalived
[[email protected] sbin]# cp /usr/local/keepalived/sbin/keepalived  /usr/sbin/
[[email protected] sbin]# systemctl start keepalived

修改master配置

[[email protected] ~]# cd /etc/keepalived/
[[email protected] keepalived]# vim keepalived.conf 
    }   
! Configuration File for keepalived

global_defs {
   router_id master
}

vrrp_instance VI_1 {
    state MASTER
    interface ens33
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.69.100
    }
}

virtual_server 192.168.69.100 80 {
    delay_loop 6
    lb_algo rr
    lb_kind NAT
    persistence_timeout 50
    protocol TCP

    real_server 192.168.69.130 80 {
        weight 1
        TCP_CHECK {
            connect_port 80_
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
        }
    }
}

    real_server 192.168.69.134 80 {
        weight 1
        TCP_CHECK {
            connect_port 80_
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
        }
    }
}
[[email protected] html]# echo "hello master" > index.html 
[[email protected] html]# systemctl start keepalived
[[email protected] html]# systemctl start nginx

修改backup配置

[[email protected] keepalived]# cd
[[email protected] ~]# vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived

global_defs {
   router_id backup
}

vrrp_instance VI_1 {
    state BACKUP
    interface ens33
    virtual_router_id 51
    priority 90
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.69.100
    }
}

virtual_server 192.168.69.100 80 {
    delay_loop 6
    lb_algo rr
    lb_kind DR
    persistence_timeout 50
    protocol TCP
    
    real_server 192.168.69.130 80 {
        weight 1
        TCP_CHECK {
            connect_port 80 
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
        }
    }
}   
    
    real_server 192.168.69.134 80 {
        weight 1
        TCP_CHECK {
            connect_port 80 
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
        }
    }
}
[[email protected] ~]# cd /usr/share/nginx/html/
[[email protected] html]# echo "helo backup" > index.html
[[email protected] html]# systemctl start keepalived

4.2验证结果

实现用keepalived将nginx高可用

4.3修改内核参数(如果不想做请看下一步)

不要重启backup的nginx
修改内核参数可不做

[[email protected] ~]# echo 'net.ipv4.ip_nonlocal_bind = 1' >>/etc/sysctl.conf
[[email protected] ~]# sysctl -p
net.ipv4.ip_nonlocal_bind = 1
[[email protected] ~]# cat /proc/sys/net/ipv4/ip_nonlocal_bind

修改backup参数

[[email protected] ~]# echo 'net.ipv4.ip_nonlocal_bind = 1' >>/etc/sysctl.conf
[[email protected] ~]# sysctl -p
net.ipv4.ip_nonlocal_bind = 1
[[email protected] ~]# cat /proc/sys/net/ipv4/ip_nonlocal_bind
1

4.4keepalived监控nginx负载均衡机(在master上用脚本监控)

keepalived通过脚本来监控nginx负载均衡机的状态

[[email protected] ~]# mkdir /scripts
[[email protected] ~]# cd /scripts/
[[email protected] scripts]# vim check_n.sh
[[email protected] scripts]# cat check_n.sh 
#!/bin/bash
nx_status=$(ps -ef|grep -Ev "grep|$0"|grep '\bnginx\b'|wc -l)
if [ $nginx_status -lt 1 ];then
    systemctl stop keepalived
fi

[[email protected] scripts]# chmod +x check_n.sh 
[[email protected] scripts]# vim notify.sh
[[email protected] scripts]# cat notify.sh 
#!/bin/bash/
VIP=$2
sendmail (){
        subject="${VIP}'s server keepalived state is translate"
        content="`date +'%F %T'`: `hostname`'s state change to master"
        echo $content | mail -s "$subject" [email protected]
}
case "$1" in
  master)
        nginx_status=$(ps -ef|grep -Ev "grep|$0"|grep '\bnginx\b'|wc -l)
        if [ $nginx_status -lt 1 ];then
            systemctl start nginx
        fi
        sendmail
  ;;
  backup)
        nginx_status=$(ps -ef|grep -Ev "grep|$0"|grep '\bnginx\b'|wc -l)
        if [ $nginx_status -gt 0 ];then
            systemctl stop nginx
        fi
  ;;
  *)
        echo "Usage:$0 master|backup VIP"
  ;;
esac
[[email protected] scripts]# chmod +x notify.sh

在backup上编写脚本

[[email protected] html]# mkdir /scripts
[[email protected] html]# cd /scripts/
[[email protected] scripts]# vim notify.sh
[[email protected] scripts]# cat notify.sh 
#!/bin/bash
VIP=$2
sendmail (){
        subject="${VIP}'s server keepalived state is translate"
        content="`date +'%F %T'`: `hostname`'s state change to master"
        echo $content | mail -s "$subject" [email protected]
}
case "$1" in
  master)
        nginx_status=$(ps -ef|grep -Ev "grep|$0"|grep '\bnginx\b'|wc -l)
        if [ $nginx_status -lt 1 ];then
            systemctl start nginx
        fi
        sendmail
  ;;
  backup)
        nginx_status=$(ps -ef|grep -Ev "grep|$0"|grep '\bnginx\b'|wc -l)
        if [ $nginx_status -gt 0 ];then
            systemctl stop nginx
        fi
  ;;
  *)
        echo "Usage:$0 master|backup VIP"
  ;;
[[email protected] scripts]# chmod +x notify.sh

4.5分别在主服务和备服务上配置脚本

配置主keepalived配置脚本

[[email protected] ~]# vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived

global_defs {
}  
vrrp_script nginx_check {
    script "/scripts/check_n.sh"
    interval 1
    weight -20
}   
vrrp_instance VI_1 {
    state MASTER
    interface ens33
    virtual_router_id 51
    priority 100
    advert_int 1
    interface ens33
    script "/scripts/check_n.sh"
    interval 1
    weight -20
}
vrrp_instance VI_1 {
    state MASTER
    interface ens33
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.69.100
    }
     track_script {
        nginx_check
    }
    notify_master "/scripts/notify.sh master 192.168.69.100"
    notify_backup "/scripts/notify.sh backup 192.168.69.100"
}

配置备keepalived配置脚本
backup无需检测nginx是否正常，当升级为MASTER时启动nginx，当降级为BACKUP时关闭

[[email protected] ~]# vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived

global_defs {
   router_id backup
}

vrrp_instance VI_1 {
    state BACKUP
    interface ens33
    virtual_router_id 51
    priority 90
    state BACKUP
    interface ens33
    virtual_router_id 51
    priority 90
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.69.100
    }
    notify_master "/scripts/notify.sh master 192.168.69.100"
    notify_backup "/scripts/notify.sh backup 192.168.69.100"
}
[[email protected] ~]# systemctl restart keepalived