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Nginx负载均衡(主备)+Keepalived

时间:2016-03-20 03:51来源:linux.it.net.cn 作者:IT

Nginx负载均衡器的优点:

实现看弹性化操作的架构,压力增大的时候可以临时添加后端Web服务器;

upstream具有负载均衡能力(默认使用轮询),可以自动判断下面的机器,并且自动踢出不能正常提供服务的机器;

Keepalvied加Nginx监测脚本可保证单个nginx负载均衡器的有效性,避免单点故障

系统

 

两台Nginx:

CentOS6.7 x86_64

两台Web:

Ubuntu15.04 desktop

拓扑

IP地址

nginx(主LB):192.168.15.132

nginx(备LB):192.168.15.133

VIP地址:192.168.15.135

Real1IP:192.168.15.128

Real2的IP:192.168.15.130

部署整个环境用到的软件为:

nginx-1.6.3.tar.gz  
prce-8.38.tar.gz 

zlib-1.2.8.tar.gz

2Web主机(Ubuntu)上部署Nginx+PHP-FPM+MySQL,此处省略。

分别在二台Nginx负载均衡器上安装Nginx,配置

 

安装GCC编译器等工具:

 

yum install -y gcc gcc-c++ autoconf automake libtool make openssl openssl-devel

安装Nginx:

wget http://exim.mirror.fr/pcre/pcre-8.38.tar.gz

tar -zxvf pcre-8.38.tar.gz

cd pcre-8.38

./configure

make && make install

wget http://zlib.net/zlib-1.2.8.tar.gz

tar -zxvf zlib-1.2.8.tar.gz

cd zlib-1.2.8

./configure

make && make install

wget http://nginx.org/download/nginx-1.6.3.tar.gz

tar -zxvf nginx-1.6.3.tar.gz 
cd nginx-1.6.3/  

./configure --prefix=/usr/local/nginx

--sbin-path=/usr/local/nginx/sbin/nginx

--conf-path=/usr/local/nginx/conf/nginx.conf

 

--pid-path=/usr/local/nginx/logs/nginx.pid \

--with-http_ssl_module \

--with-http_stub_status_module \

--with-http_gzip_static_module \ 

make && make install 

注:查询"./configure --help"相关模块,按需求指定启用

Nginx.conf配置文件二个nginx负载均衡器的文件一样

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user  www-data www-data;
worker_processes  1;
error_log  /usr/local/nginx/logs/error.log notice;
pid        /usr/local/nginx/logs/nginx.pid;
worker_rlimit_nofile 51200;
events {
    use epoll;
    worker_connections  51200;
}
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;
    server_names_hash_bucket_size 128;
    client_header_buffer_size 32k;
    large_client_header_buffers 4 32k;
    client_max_body_size 8m;
    sendfile        on;
    tcp_nopush     on;
    server_tokens off;
    keepalive_timeout  60;
    fastcgi_connect_timeout 300;
    fastcgi_send_timeout 300;
    fastcgi_read_timeout 300;
    fastcgi_buffer_size 64k;
    fastcgi_buffers 4 64k;
    fastcgi_busy_buffers_size 128k;
    fastcgi_temp_file_write_size 128k;
    gzip  on;
    upstream backend
    {
    server 192.168.15.128;
    server 192.168.15.130;
    }
    server {
        listen       80;
        server_name  192.168.15.135;
        location / {
            root   html;
            index  index.php index.html index.htm;
            proxy_redirect off;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            #后端的Web服务器可以通过X-Forwarded-For获取用户真实IP
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_pass http://backend;
        }
        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   html;
        }
        
        location /nginx_status {
            stub_status on; 
            auth_basic "NginxStatus";
            auth_basic_user_file /usr/local/nginx/htpasswd;
            #allow 127.0.0.1;
            #deny all;
        }
        location ~* \.(ini|docx|txt|doc|pdf)$ {
        #禁止访问文档性文件
        root /usr/share/nginx/html;
        deny all;
        }
        location ~ .*\.(gif|jpg|jpeg|png|bmp|swf|js|html|htm|css)$ {
        root /home/image;
        proxy_store on;
        proxy_store_access user:rw group:rw all:rw;
        proxy_temp_path /home/image;
        if ( !-e $request_filename) {
           proxy_pass  http://backend;
        }
    }
}
}

在二台Nginx上安装及配置keepalived:

 

 

wget http://www.keepalived.org/software/keepalived-1.2.15.tar.gz

tar -zxvf keepalived-1.2.15.tar.gz

cd keepalived-1.2.15

./configure --sysconf=/etc/  --with-kernel-dir=/usr/src/kernels/2.6.32-573.8.1.el6.x86_64

make && make install

ln -s /usr/local/sbin/keepalived  /sbin/  

#这一步很重要,不执行ln -s会报错“Starting keepalived: /bin/bash: keepalived: command not found”

service keepalived start

 

二台Nginxkeepalived.conf配置文件如下配置完成后分别service keepalived start启动检验keepalived配置是否成功

主:

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global_defs {
   notification_email {
     test@163.com
   }
   notification_email_from keepalived@localhost 
   smtp_server 127.0.0.1
   smtp_connect_timeout 30
   router_id LVS_MASTER
}
vrrp_script chk_http_port {
script "/usr/local/src/check_nginx_pid.sh"
interval 2                           #(检测脚本执行的间隔)
weight 2
}
vrrp_instance VI_1 {
   #state MASTER
    state BACKUP
    nopreempt                       
    #设置非抢占模式时,需修改“state MASTER”为“state BACKUP”,添加“nopreempt“
    interface bond0
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
}
track_script {
chk_http_port            #(调用检测脚本)
}
    virtual_ipaddress {
        192.168.15.135/24 broadcast 192.168.15.255 dev bond0 label bond0:1
    }
}

 

备: 

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global_defs {
   notification_email {
     test@163.com
   }
   notification_email_from keepalived@localhost 
   smtp_server 127.0.0.1
   smtp_connect_timeout 30
   router_id LVS_BACKUP
}
vrrp_script chk_http_port {
script "/usr/local/src/check_nginx_pid.sh"
interval 2                           #(检测脚本执行的间隔)
weight 2
}
vrrp_instance VI_1 {
    state BACKUP
    interface bond0
    virtual_router_id 51
    priority 66
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
}
track_script {
chk_http_port            #(调用检测脚本)
}
    virtual_ipaddress {
        192.168.15.135/24 broadcast 192.168.15.255 dev bond0 label bond0:1
    }
}

以下是针对nginx状态进行检测的脚本,第一次nginx服务死掉时,会重新启动,如果Nginx服务无法正常启动,则杀掉keepalived进程

vim  /usr/local/src/check_nginx_pid.sh

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#!/bin/bash
A=`ps -C nginx --no-header |wc -l`        
if [ $A -eq 0 ];then                            
      /usr/local/nginx/sbin/nginx        
      if [ `ps -C nginx --no-header |wc -l` -eq 0 ];then  
              killall keepalived                    
      fi
fi

 

Ok,开始nginx负载均衡测试,停掉其中一台的任何服务,不影响整个系统的运作

注:两台LBServer也可分别添加一个VIP①②(Keepalived心跳监控,服务不可用或者宕机,VIP①被备LBServer接管),外部使用智能DNS轮询两个VIP①②,提高硬件资源利用率




(责任编辑:IT)
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