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keepalived+nginx高可用实现方法示例

1.keepalived介绍

keepalived最初是专为LVS负载均衡软件设计的,用来管理并监控LVS集群系统中各个服务节点的状态,后来又加入了实现高可用的VRRP功能。keepalived除了能够管理LVS软件外,还能支持其他服务的高可用解决方案。

keepalived通过VRRP协议实现高可用功能的。VRRP(Virtual Router Redundancy Protocol)虚拟路由冗余协议。VRRP出现的目的就是为了解决静态路由单点故障问题,它能保证当个别节点宕机时,整个网络可以不间断地运行。


2.keepalived高可用故障转移原理

keepalived高可用服务之间的故障转移,是通过VRRP来实现的。在keepalived服务工作时,主Master节点会不断地向备节点发送(多播的方式)心跳消息,用来告诉备Backup节点自己还活着。

  当主节点发生故障时,无法给备节点发送心跳消息,如果备节点无法继续检测到来自主节点的心跳。就会调用自身的接管程序,接管主节点的IP资源和服务。当主节点恢复时,备节点又会释放主节点故障时自身接管的IP资源和服务,恢复到原来的备用角色


3.安装nginx


3.1.主节点(192.168.80.22)

3.1.1.安装编译工具和库文件

yum -y install make zlib zlib-devel gcc-c++ libtool openssl openssl-devel3.1.2.安装pcre

#进入目录

cd /usr/local/develop/anginx

#上传安装文件并解压

tar -zxvf pcre-8.38.tar.gz

#进入安装目录

cd pcre-8.38

#检查配置

./configure

#编译、安装

make && make install

#查看pcre版本

pcre-config –version3.1.3.安装nginx

#进入目录

cd /usr/local/develop/anginx



#上传安装文件,并解压

tar -zxvf nginx-1.8.1.tar.gz



#进入安装目录

cd nginx-1.8.1



#检查配置

./configure –prefix=/usr/local/develop/anginx/webserver/nginx –with-http_stub_status_module –with-http_ssl_module –with-pcre=/usr/local/develop/anginx/pcre-8.38



#编译安装

make && make install



#查看nginx版本

/usr/local/develop/anginx/webserver/nginx/sbin/nginx -v

——————————————————–

[root@hadoop02 webserver]# /usr/local/develop/anginx/webserver/nginx/sbin/nginx -v

nginx version: nginx/1.8.1



#配置nginx(检查)

/usr/local/develop/anginx/webserver/nginx/sbin/nginx -t



#nginx管理命令

/usr/local/develop/anginx/webserver/nginx/sbin/nginx       # 启动 Nginx

/usr/local/develop/anginx/webserver/nginx/sbin/nginx -s stop       # 停止 Nginx

/usr/local/develop/anginx/webserver/nginx/sbin/nginx -s reload      # 重新载入配置文件

/usr/local/develop/anginx/webserver/nginx/sbin/nginx -s reopen      # 重启 Nginx3.1.4.nginx基础配置

vi nginx.conf

#user nobody;

worker_processes 1;



#error_log logs/error.log;

#error_log logs/error.log notice;

#error_log logs/error.log info;



pid    logs/nginx.pid;





events {

  worker_connections 1024;

}





http {

  include    mime.types;

  default_type APPlication/octet-stream;



  log_format main ‘$remote_addr – $remote_user [$time_local] “$request” ‘

           ‘$status $body_bytes_sent “$http_referer” ‘

           ‘”$http_user_agent” “$http_x_forwarded_for”‘;



  access_log logs/access.log main;



  sendfile    on;

  #tcp_nopush   on;



  #keepalive_timeout 0;

  keepalive_timeout 65;



  #gzip on;

  #添加tomcat列表,真实应用服务器都放在这

  upstream tomcat_pool{

    #server tomcat地址:端口号 weight表示权值,权值越大,被分配的几率越大;

    server 192.168.80.22:8080 weight=4 max_fails=2 fail_timeout=30s;

    server 192.168.80.22:8081 weight=4 max_fails=2 fail_timeout=30s;

  }



  server {

    listen    80;

    server_name tomcat_pool;



    #charset koi8-r;



    #access_log logs/host.access.log main;



    location / {

      #root  html;

      #index index.html index.htm;

      proxy_pass http://tomcat_pool;  #转向tomcat处理

      proxy_set_header  Host       $host;

      proxy_set_header  X-Real-IP    $remote_addr;

      proxy_set_header  X-Forwarded-For $proxy_add_x_forwarded_for;

    }



    #error_page 404       /404.html;



    # redirect server error pages to the static page /50x.html

    #

    error_page  500 502 503 504 /50x.html;

    location = /50x.html {

      root  html;

    }





}
3.2.备节点(192.168.80.21)

说明:安装方式同nginx主节点。


4.安装keepalived


4.1.主节点(192.168.80.22)

#安装keepalived

yum install keepalived -y



#启动keepalived服务

/etc/init.d/keepalived start

——————————————-

[root@hadoop02 anginx]# /etc/init.d/keepalived start

正在启动 keepalived:                   [确定]

[root@hadoop02 anginx]# ps -ef |grep keepalived

root   15723   1 0 00:59 ?    00:00:00 /usr/sbin/keepalived -D

root   15724 15723 0 00:59 ?    00:00:00 /usr/sbin/keepalived -D

root   15725 15723 0 00:59 ?    00:00:00 /usr/sbin/keepalived -D

root   15731 15622 0 00:59 pts/1  00:00:00 grep keepalived

[root@hadoop02 anginx]#



#设置开机自启动

echo “/etc/init.d/keepalived start” >>/etc/rc.local



#关闭keepalived服务

/etc/init.d/keepalived stop



#编辑keepalived配置文件

vi /etc/keepalived/keepalived.conf



———————————————————–

! Configuration File for keepalived



global_defs {

  notification_email {

   acassen@firewall.loc

   failover@firewall.loc

   sysadmin@firewall.loc

  }

  notification_email_from Alexandre.Cassen@firewall.loc

  smtp_server 192.168.200.1

  smtp_connect_timeout 30

  router_id lb01

}



vrrp_instance VI_1 {

  state MASTER

  interface eth1

  virtual_router_id 55

  priority 150

  advert_int 1

  authentication {

    auth_type PASS

    auth_pass server123

  }

  virtual_ipaddress {

    192.168.80.100 dev eth1 label eth1:1

  }

}

…………………………………………………..关于配置说明:

  • 【router_id】 是路由标识,在一个X里面应该是唯一的
      【vrrp_instance VI_1】{…}这是一个VRRP实例,里面定义了keepalived的主备状态、接口、优先级、认证和IP信息【state】 定义了VRRP的角色【interface】定义使用的接口,这里我的服务器用的网卡都是eth1【virtual_router_id】是虚拟路由ID标识,一组的keepalived配置中主备都是设置一致【priority】是优先级,数字越大,优先级越大,【auth_type】是认证方式【auth_pass】是认证的密码

    【virtual_ipaddress】 {…}定义虚拟IP地址,可以配置多个IP地址,这里我定义为192.168.80.100,绑定了eth1的网络接口,虚拟接口eth1:1

4.2.备节点(192.168.80.21)

#安装keepalived

yum install keepalived -y



#启动keepalived服务

/etc/init.d/keepalived start

——————————————-

[root@hadoop02 anginx]# /etc/init.d/keepalived start

正在启动 keepalived:                   [确定]

[root@hadoop02 anginx]# ps -ef |grep keepalived

root   15723   1 0 00:59 ?    00:00:00 /usr/sbin/keepalived -D

root   15724 15723 0 00:59 ?    00:00:00 /usr/sbin/keepalived -D

root   15725 15723 0 00:59 ?    00:00:00 /usr/sbin/keepalived -D

root   15731 15622 0 00:59 pts/1  00:00:00 grep keepalived

[root@hadoop02 anginx]#



#设置开机自启动

echo “/etc/init.d/keepalived start” >>/etc/rc.local



#关闭keepalived服务

/etc/init.d/keepalived stop



#编辑keepalived配置文件

vi /etc/keepalived/keepalived.conf



—————————————————————–

! Configuration File for keepalived



global_defs {

  notification_email {

   acassen@firewall.loc

   failover@firewall.loc

   sysadmin@firewall.loc

  }

  notification_email_from Alexandre.Cassen@firewall.loc

  smtp_server 192.168.200.1

  smtp_connect_timeout 30

  router_id lb02

}



vrrp_instance VI_1 {

  state BACKUP

  interface eth1

  virtual_router_id 55

  priority 100

  advert_int 1

  authentication {

    auth_type PASS

    auth_pass server123

  }

  virtual_ipaddress {

    192.168.80.100 dev eth1 label eth1:1

  }

}

…………………………………………………….




5.测试


5.1.启动主备节点的keepalived服务

#在节点一执行(192.168.80.22)

/etc/init.d/keepalived start

————————————-

[root@hadoop02 anginx]# ps -ef |grep keepalived

root   15788   1 0 01:09 ?    00:00:00 /usr/sbin/keepalived -D

root   15790 15788 0 01:09 ?    00:00:00 /usr/sbin/keepalived -D

root   15791 15788 0 01:09 ?    00:00:00 /usr/sbin/keepalived -D

root   15807 15622 0 01:33 pts/1  00:00:00 grep keepalived

[root@hadoop02 anginx]#





#在节点二执行(192.168.80.21)

/etc/init.d/keepalived start

—————————————

[root@hadoop01 ~]# ps -ef |grep keepalived

root   11542   1 0 01:30 ?    00:00:00 /usr/sbin/keepalived -D

root   11544 11542 0 01:30 ?    00:00:00 /usr/sbin/keepalived -D

root   11545 11542 0 01:30 ?    00:00:00 /usr/sbin/keepalived -D

root   11550 11512 0 01:33 pts/1  00:00:00 grep keepalived

[root@hadoop01 ~]#
5.2.通过虚ip访问服务

http://192.168.80.100/session-redis-demo/

5.3.停止主节点keepalived服务

#在节点一执行(192.168.80.22)

/etc/init.d/keepalived stop



#观察备节点变化

ip addr

——————————————-

[root@hadoop01 ~]# ip addr

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: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000

  link/ether 00:50:56:38:e5:46 brd ff:ff:ff:ff:ff:ff

  inet 192.168.80.21/24 brd 192.168.80.255 scope global eth1

  inet 192.168.80.100/32 scope global eth1:1

  inet6 fe80::250:56ff:fe38:e546/64 scope link

    valid_lft forever preferred_lft forever

[root@hadoop01 ~]#
5.4.继续通过虚ip访问服务

http://192.168.80.100/session-redis-demo/


6.keepalived+nginx整合

说明:编写nginx守护脚本,如果nginx服务出现故障,则停止当前节点的keepalived服务。自动切换到备用节点。


6.1.编写nginx守护脚本

vi nginx_check.sh



————————————–

#!/bin/bash

while true

do

if [ $(netstat -tlnp|grep nginx|wc -l) -ne 1 ]

then

  /etc/init.d/keepalived stop

fi

sleep 2

done



#给脚本授权

chmod u+x nginx_check.sh



#执行脚本

nohup /usr/local/develop/anginx/shell/nginx_check.sh &
6.2.停止主节点nginx服务

#停止主节点nginx服务

/usr/local/develop/anginx/webserver/nginx/sbin/nginx -s stop



#查找进程

[root@hadoop02 ~]# ps -ef |grep nginx

root   15915   1 0 01:51 ?    00:00:00 /bin/bash /usr/local/develop/anginx/shell/nginx_check.sh

root   16516 15753 0 01:54 pts/5  00:00:00 grep nginx

[root@hadoop02 ~]#



#观察备用节点变化【服务正常】

ip addr

————————————–

[root@hadoop01 shell]# ip addr

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: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000

  link/ether 00:50:56:38:e5:46 brd ff:ff:ff:ff:ff:ff

  inet 192.168.80.21/24 brd 192.168.80.255 scope global eth1

  inet 192.168.80.100/32 scope global eth1:1

  inet6 fe80::250:56ff:fe38:e546/64 scope link

    valid_lft forever preferred_lft forever

[root@hadoop01 shell]#



#再次重新启动主节点nginx和keepalived服务

/usr/local/develop/anginx/webserver/nginx/sbin/nginx



/etc/init.d/keepalived start以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持软件技术网。

原创文章,作者:starterknow,如若转载,请注明出处:https://www.starterknow.com/109229.html

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