JavaWeb 使用nginx负载均衡

Nginx是什么

Nginx是一个轻量级、高性能、稳定性高、并发性好的HTTP和反向代理服务器。

核心功能

· 负载均衡

多在高并发情况下需要使用。其原理就是将数据流量分摊到多个服务器执行，减轻每台服务器的压力，多台服务器(集群)共同完成工作任务，从而提高了数据的吞吐量。

· 反向代理

代理我们要访问的目标服务器。代理服务器接受请求，然后将请求转发给内部网络的服务器(集群化)，此时代理服务器对外就表现为一个服务器。

· 动静分离

Nginx提供的动静分离是指把动态请求和静态请求分离开，合适的服务器处理相应的请求，使整个服务器系统的性能、效率更高。

Centos下搭建Nginx

接下来要实现的是两台服务器上装tomcat，一台服务器装Nginx，由Nginx接受请求并将请求转发到相应的服务器.

· gcc 安装

yum install gcc-c++

· PCRE pcre-devel 安装

yum install -y pcre pcre-devel

· zlib

yum install -y zlib zlib-devel

· OpenSSL

yum install -y openssl openssl-devel

Nginx 下载地址

· 解压 nginx-1.8.1.tar.gz

tar -zxvf nginx-1.8.1.tar.gz

cd nginx-1.8.1

· 编译、安装nginx

./configure

make

make install

· 启动 nginx

cd /usr/local/nginx/

./sbin/nginx

·访问ID端口默认是80，出现如下界面，代表Nignx安装成功

cd /usr/local/nginx/conf/

vim nginx.conf

我的配置文件如下

#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;

  upstream testsite.com{
server 174.137.63.58:8080 weight=1;
server 94.191.14.127:8080 weight=2;
}


server {
    listen       80;
    server_name  localhost;

    #charset koi8-r;

    #access_log  logs/host.access.log  main;

    location / {
        root   html;
        index  index.html index.htm;
    }
     
location /myweb/ {
        proxy_pass http://testsite.com/;
    proxy_redirect default;
}

    #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;
    }

    # proxy the PHP scripts to Apache listening on 127.0.0.1:80
    #
    #location ~ .php$ {
    #    proxy_pass   http://127.0.0.1;
    #}

    # pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
    #
    #location ~ .php$ {
    #    root           html;
    #    fastcgi_pass   127.0.0.1:9000;
    #    fastcgi_index  index.php;
    #    fastcgi_param  SCRIPT_FILENAME  /scripts$fastcgi_script_name;
    #    include        fastcgi_params;
    #}

    # deny access to .htaccess files, if Apache's document root
    # concurs with nginx's one
    #
    #location ~ /.ht {
    #    deny  all;
    #}
}


# another virtual host using mix of IP-, name-, and port-based configuration
#
#server {
#    listen       8000;
#    listen       somename:8080;
#    server_name  somename  alias  another.alias;

#    location / {
#        root   html;
#        index  index.html index.htm;
#    }
#}


# HTTPS server
#
#server {
#    listen       443 ssl;
#    server_name  localhost;

#    ssl_certificate      cert.pem;
#    ssl_certificate_key  cert.key;

#    ssl_session_cache    shared:SSL:1m;
#    ssl_session_timeout  5m;

#    ssl_ciphers  HIGH:!aNULL:!MD5;
#    ssl_prefer_server_ciphers  on;

#    location / {
#        root   html;
#        index  index.html index.htm;
#    }
#}
复制代码

}

· 改完配置文件之后重启nginx

/usr/local/nginx/sbin/nginx -s reload

接下来我们使用http://自己的IP/myweb/访问，结果如下