CentOS 6.5 安装 keeplived + nginx

负载均衡是个老生常谈的话题，之前很早就接触过LVS+keepalived ，对其原理也仔细学习过，这次温故而知新，巩固一下这方面的知识，本次试验在ESXI 上面完成，试验环境如下：
LB1(NGINX + keepalived)  //nginx 为前端负载调度器 ,keepalived 实现HA 为MASTER
LB2(NGINX + keepalived)  //nginx 为前端负载调度器 ,keepalived 实现HA 为BACKUP
NODE1   //REAL SERVER
NODE2   //REAL SERVER
192.168.1.241,192.168.1.242 // VIP，现在一般都是互为主备，资源合理利用，例如一些多线机房，不同的ip线路

安装步骤
1.MASTER 安装
#yum install keepalived    //现在直接用yum 安装
#yum install nginx  
#vim /etc/keepalived/keepalived.conf
内容如下：

! Configuration File for keepalived

global_defs {
   router_id LVS_DEVEL
}

vrrp_script chk_http_port {
    script "/usr/bin/killall -0 nginx"
    interval 2
    weight 2
}

vrrp_instance VI_1 {
    state MASTER
    interface eth0
    virtual_router_id 51
    priority 101    //备份机 优先级数字要比这个小
    advert_int 5
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    track_script {
        chk_http_port
    }
    virtual_ipaddress {
        192.168.1.241
    }
}

vrrp_instance VI_2 {
    state BACKUP
    interface eth0
    virtual_router_id 52
    priority 100
    advert_int 5
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    track_script {
        chk_http_port
    }

    virtual_ipaddress {
        192.168.1.242
    }
}

编辑nginx配置文件，内容如下

user  nobody;
worker_processes  2;

#error_log  logs/error.log;
#error_log  logs/error.log  notice;
#error_log  logs/error.log  info;

#pid        logs/nginx.pid;


events {
    worker_connections  65535;
}


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;
    #proxy_cache_path /app/nginx/cache keys_zone=one:10m inactive=1d max_size=1g;
    #proxy_cache_key "$host$request_uri$cookie_user";
    #proxy_cache_min_uses 5;
    #proxy_cache_valid 200 302 10m;
    #proxy_cache_valid 404      1m;

    upstream backend {
        server 192.168.1.64  weight=5;
        server 192.168.1.139  weight=15;
        server 192.168.1.70  backup;
    }

    include vhosts/*.conf;
}

default 虚拟机配置如下

server {
        listen       80;
        root /app/nginx/html/;
        access_log /app/nginx/logs/test.log ;
        error_log /app/nginx/logs/error.log;
        index index.html;

        location ~ \.php$ {
                fastcgi_pass 127.0.0.1:9000;
                fastcgi_index index.php;
                fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
                include fastcgi_params;
        }

        location /status {
                stub_status on;
                access_log /app/nginx/logs/status.log;
                auth_basic "mypass";
                allow 127.0.0.1;
                deny all;
        }

        #这段是我编译安装的淘宝开发的footer 模块，当时为了方便看测试结果
        #location /test {
        #        #footer "";
        #        #footer "/* host: $server_name - $date_local */";
        #        footer "/* host: $hostname - $date_local */";
        #}

        location  / {
                #proxy_redirect off;
                proxy_set_header Host $host;
                proxy_set_header X-Real-IP $remote_addr;
                proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
                proxy_pass http://backend;
        }
}

BACKUP 安装雷同，只需要注意keepalived的优先级，测试过程很简单，注意查看/var/log/messages ,看虚拟ip 的浮动情况

总结：我只用keepalived的VRRP 协议机制保障服务的可用性，real server 健康检查机制由nginx自己完成，具体请参考