nginx的负载均衡配置

1.下载nginx的压缩包，可以去官网下载

2.解压缩，可以看到其中有个conf的文件夹，在该目录中，nginx.conf配置文件就是核心配置文件

3.默认配置

#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;
 
    server {
        listen       80;
        server_name  localhost;
 
        #charset koi8-r;
 
        #access_log  logs/host.access.log  main;
 
        location / {
            root   html;
            index  index.html index.htm;
        }
 
        #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;
    #    }
    #}
 
}

4.配置负载后的配置文件

#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 cluster {
        #server 192.168.0.15:8080 weight=1;
        #server 192.168.0.12:8080 weight=2;
        server 192.168.1.107:8080 weight=1;
    }
 
    server {
        listen       8001;
        server_name  192.168.0.15;
 
        #charset koi8-r;
 
        #access_log  logs/host.access.log  main;
 
        location / {
            root   html;
            index  index.html index.htm;
            proxy_pass http://cluster/;
            #proxy_redirect  default;
            proxy_set_header Host $http_host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $scheme;
        }
 
        #location ~ .*\.(html|htm|gif|jpg|jpeg|bmp|png|ico|txt|js|css)$
        #{
            #proxy_pass http://cluster/;
        #}
 
        #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;
    #    }
    #}
 
}

5.配置解释

1）upstream 用来配置上游负载均衡的真实服务器

2）location：

proxy_pass：用来配置代理转发的请求目标地址

以下部分的配置是防止在nginx的代理转发之后，web界面无法加载js和css

proxy_set_header Host $http_host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto $scheme;

root 、alias指令区别

location /img/ {
    alias /var/www/image/;
}

#若按照上述配置的话，则访问/img/目录里面的文件时，ningx会自动去/var/www/image/目录找文件

location /img/ {
    root /var/www/image;
}

#若按照这种配置的话，则访问/img/目录下的文件时，nginx会去/var/www/image/img/目录下找文件。] 

alias是一个目录别名的定义，root则是最上层目录的定义。

还有一个重要的区别是alias后面必须要用“/”结束，否则会找不到文件的。。。而root则可有可无~~

上述路径针对的是nginx的目录，而不是负载后的服务器中的目录