Day 59 应用工具_nginx高可用

nginx高可用

高可用介绍

分发器宕机怎么办
数据服务器宕机怎么办

Keepalived

Keepalived的作用是检测服务器的状态，如果有一台web服务器宕机，或工作出现故障，Keepalived将检测到，并将有故障的服务器从系统中剔除，同时使用其他服务器代
替该服务器的工作，当服务器工作正常后Keepalived自动将服务器加入到服务器群中，这些工作全部自动完成，不需要人工干涉，需要人工做的只是修复故障的服务器。
一个监控+自愈的软件

Keepalived获得

http://www.keepalived.org/download.html
wget http://www.keepalived.org/software/keepalived-2.0.8.tar.gz

Keepalived 安装

#cat keepalived_install.sh
#!/bin/bash
pkg=keepalived-2.0.8.tar.gz
tar xf $pkg
yum -y install kernel-devel
ln -s /usr/src/kernels/3.10.0-862.14.4.el7.x86_64/ /usr/src/linux
cd keepalived-2.0.8/
yum install openssl-* -y
./configure --prefix=/usr/local/keepalived
make
make install
mkdir -pv /etc/keepalived
cp  /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/
ln -s /usr/local/keepalived/sbin/keepalived /sbin/

构建高可用Nginx集群

声明?
•  实验机器: Vmware 虚拟机 2核4G
•  ⽹网卡:桥接
•  系统:centos7.5
•  防火墙:关闭
•  Selinux：关闭
•  网段:192.168.10.0/24
主机名                          IP                     角色                 软件
Master.ayitula.com 192.168.10.40 主分发器器          Nginx+keepalived
Backup.ayitula.com 192.168.10.41 备分发器器         Nginx+keepalived
Web01.ayitula.com 192.168.10.42 数据服务器器1    nginx
Web02.ayitula.com 192.168.10.43 数据服务器器2    nginx

部署步骤

软件环境部署
1)分发器 nginx+keepalived
2)数据服务器 Nginx
3) 配置Nginx分发器
4)配置数据服务器页面（web01 web02）
5)配置keepalived.conf
6)测试

配置Nginx集群

upstream web {
    server 192.168.10.42 max_fails=2 fail_timeout=3;
    server 192.168.10.43 max_fails=2 fail_timeout=3；
    server {
        listen 80;
        server_name localhost;
        location / {
            proxy_pass http://web;
    }
}

配置keepalived

#cat /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
    router_id NGINX_DEVEL
}
vrrp_script check_nginx {
    script "/etc/keepalived/nginx_pid.sh"
    interval 2
    fall 1
}
vrrp_instance nginx {
    state MASTER
    interface ens33
    mcast_src_ip 192.168.10.40
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    track_script {
        check_nginx
    }
    virtual_ipaddress {
        192.168.10.213/24
    }
}

关联脚本 nginx_pid.sh

#chmod 755 /etc/keepalived/nginx_pid.sh
#cat /etc/keepalived/nginx_pid.sh
#!/bin/bash
nginx_kp_check () {
    nginxpid=`ps -C nginx --no-header |wc -l`
    if [ $nginxpid -eq 0 ];then
    /usr/local/nginx/sbin/nginx
    sleep 1
    nginxpid=`ps -C nginx --no-header |wc -l`
    if [ $nginxpid -eq 0 ];then
    systemctl stop keepalived
    fi
    fi
}

启动keepalived

systemctl start keepalived

配置备份Nginx分发器

backuo.ayitula.com
#cat /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
    router_id NGINX_DEVEL
}
vrrp_script check_nginx {
    script "/etc/keepalived/nginx_pid.sh"
    interval 2
    fall 1
}
vrrp_instance nginx {
    state BACKUP
    interface ens33
    mcast_src_ip 192.168.10.41
    virtual_router_id 51
    priority 90
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    track_script {
        check_nginx
    }
    virtual_ipaddress {
        192.168.10.213/24
    }
}

测试高可用

模拟故障

数据服务器器宕机测试
分发器器宕机测试