欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页  >  网络运营

keepalived+nginx高可用实现方法示例

程序员文章站 2022-07-02 11:17:25
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...

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-devel

3.1.2.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 --version

3.1.3.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 nginx

3.1.4.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,在一个局域网里面应该是唯一的
    • 【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/

keepalived+nginx高可用实现方法示例

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/

keepalived+nginx高可用实现方法示例

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。