Nginx配置使用upstream负载均衡和proxy_cache缓存

ngx_http_upstream_module模块：Nginx负载均衡模块

Syntax:      upstreamname { ... }

Default:     —

Context:    http

Defines a group of servers. Servers can listen ondifferent ports. In addition, servers listening on TCP and UNIX-domain socketscan be mixed.

简单示例:

    upstream backend {

        server backend1.example.com weight=5;

        server 127.0.0.1:8080       max_fails=3 fail_timeout=30s;

        server unix:/tmp/backend3;

        server backup1.example.com  backup;

    }

配置示例：

    upstream backend {

        server backend1.example.com       weight=5;

        server backend2.example.com:8080;

        server unix:/tmp/backend3;

 

        server backup1.example.com:8080   backup;

        server backup2.example.com:8080   backup;

    }

    server {

        location / {

            proxy_pass http://backend;

        }

    }

 

前置条件，编辑后端web 服务器测试页面

nginx作为后端web服务器：192.168.88.130:8080  test.field.com

[root@testhtml]# pwd

/usr/share/nginx/html

[root@testhtml]# cat  index.html

<h1>Welcometo Nginx on test.field.com!!</h1>

<p><em>If you see this page,test OK! </em></p>

<p>Thank you!</p>

[root@test html]#

Http作为后端web服务器：192.168.88.129:80  web2.field.com

[root@web2html]# pwd

/var/www/html

[root@web2html]# cat index.html

<h1>Welcometo Http on web2.field.com!!</h1>

<p>If yousee this page,test ok. </p>

<p><em>Thank you!</em></p>

 

案例1、负载均衡基础应用

编辑nginx.conf，添加如下内容：

   upstreamupservers {

        server  192.168.88.129;

        server  192.168.88.130:8080;

    }

编辑conf.d/default.conf，添加如下内容：

    location/field/ {

     proxy_pass  http://upservers/;

    }

    location ~*\.(jpg|png|gif)$ {

     proxy_pass  http://upservers;

}

[root@wwwnginx]# vi nginx.conf

user  nginx;

worker_processes  1;

error_log   /var/log/nginx/error.log warn;

pid        /var/run/nginx.pid;

events {

    worker_connections  1024;

}

http {

    include       /etc/nginx/mime.types;

    default_type   application/octet-stream;

    log_format main  '$remote_addr - $remote_user[$time_local] "$request" $http_host '

                      '$status $body_bytes_sent"$http_referer" '

                      '"$http_user_agent""$http_x_forwarded_for"';

    access_log /var/log/nginx/access.log  main;

    proxy_cache_path  /cache/nginx/ levels=1:1keys_zone=mycache:32m;   

    upstream  upservers {

        server  192.168.88.129;

        server  192.168.88.130:8080;

    }

    sendfile        on;

    #tcp_nopush     on;

    keepalive_timeout  65;

    #gzip on;

    include /etc/nginx/conf.d/*.conf;

}

[root@wwwconf.d]# vi default.conf

server {

    listen      8080;

    server_name localhost;

    #charset koi8-r;

    #access_log /var/log/nginx/log/host.access.log main;

    location / {

       root  /usr/share/nginx/html;

       # proxy_pass http://192.168.88.130/;

       index index.html index.php index.htm;

    }

    location /field/ {

     proxy_pass  http://upservers/;

     proxy_set_header Host      $host;

     proxy_set_header X-Real-IP $remote_addr;

    }

    location ~* \.(jpg|png|gif)$ {

     proxy_pass   http://upservers;

     proxy_set_header X-Real-IP $remote_addr;

    }

    error_page  500 502 503 504  /50x.html;

    location = /50x.html {

        root   /usr/share/nginx/html;

    }

}

[root@wwwconf.d]# service nginx restart

停止 nginx：[确定]

正在启动 nginx：[确定]

[root@wwwconf.d]#

wind7访问 http://192.168.88.131:8080/field/

刷新页面，页面内容会在【Welcome to Http on web2.field.com!!!】和【Welcome to Nginx on test.field.com!!】上跳转

案例2、负载均衡定义加权轮询

定义加权轮询，默认为轮询

    upstream  upservers {

        server  192.168.88.129  weight=n;

        server  192.168.88.130  weight=m;

    }

[root@wwwnginx]# vim nginx.conf

    upstream  upservers {

        server  192.168.88.129  weight=2;

        server  192.168.88.130:8080  weight=1;

    }                                  

[root@wwwnginx]# service nginx reload

重新载入 nginx：[确定]

Win7访问http://www.field.com/field/

依次刷新页面，页面内容会在【Welcome to Http on web2.field.com!!!】和【Welcome to Nginx on test.field.com!!】上以2:1跳转

 

案例3、负载均衡定义根据客户端IP进行调度

ip_hash:根据客户端IP进行调度：

每一个客户端访问时都生成一个hash码，来自同一客户端的定向到同一服务器

    upstream  upservers {

        ip_hash;

    }

[root@wwwnginx]# vim nginx.conf

    upstream  upservers {

               ip_hash;

        server  192.168.88.129  weight=2;

        server  192.168.88.130:8080  weight=1;

    }

[root@wwwnginx]# service nginx configtest

nginx: theconfiguration file /etc/nginx/nginx.conf syntax is ok

nginx:configuration file /etc/nginx/nginx.conf test is successful

[root@wwwnginx]# service nginx reload

重新载入 nginx：[确定]

win7访问http://192.168.88.131:8080/field/

始终定位到【Welcome to Http on web2.field.com!!!】页面

130主机用curl访问http://192.168.88.131:8080/field/

始终定位到【Welcome to Nginx on test.field.com!!】页面

[root@testconf.d]# curl  http://192.168.88.131:8080/field/

<h1>Welcometo Nginx on test.field.com!!</h1>

<p><em>If you see this page,test OK! </em></p>

<p>Thankyou!</p>

[root@testconf.d]#

 

案例4、后端服务器健康状态检测：

max_fails=number 检查number次失败时定义为真实失败；

fail_timeout=time 每次检查失败的超时时间；

[root@wwwnginx]# vim  nginx.conf

    upstream  upservers {

        server  192.168.88.129  weight=2  max_fails=2  fail_timeout=1;

        server  192.168.88.130:8080  weight=1  max_fails=2  fail_timeout=1;

    }

[root@wwwnginx]# service  nginx  reload

重新载入 nginx：[确定]

wind7访问 http://www.field.com:8080/field/

刷新页面，页面内容会在【Welcome to Http on web2.field.com!!!】和【Welcome to Nginx on test.field.com!!】上以2:1跳转

测试：

1).关闭后端httpd服务

[root@web2html]# service  httpd  stop

停止 httpd：[确定]

[root@web2html]#

wind7访问 http://www.field.com:8080/field/

页面只显示【Welcome to Nginx on test.field.com!!】

2).关闭后端Nginx服务

[root@testconf.d]# service  nginx  stop

停止 nginx：[确定]

[root@testconf.d]#

wind7访问 http://www.field.com:8080/field/，

无法访问，页面显示【An error occurred.】

3).依次开启后端httpd、Nginx服务，访问恢复。

 

案例5、手动标记状态

backup:备用

down：下线

[root@wwwnginx]# vim nginx.conf

   upstream upservers {

        server  192.168.88.129  max_fails=2  fail_timeout=1;

        server  192.168.88.130:8080  max_fails=2  fail_timeout=1 backup;

    }

[root@wwwnginx]# service  nginx configtest

nginx: theconfiguration file /etc/nginx/nginx.conf syntax is ok

nginx:configuration file /etc/nginx/nginx.conf test is successful

[root@wwwnginx]# service nginx reload

重新载入 nginx：[确定]

测试：

1).服务器正常，只上线129主机的http服务

win7访问http://192.168.88.131:8080/field/，刷新页面，始终定位到【Welcome to Http onweb2.field.com!!!】页面

130主机用curl访问http://192.168.88.131:8080/field/，始终定位到【Welcome to Http on web2.field.com!!!】页面

[root@testconf.d]# curl  http://192.168.88.131:8080/field/

<h1>Welcometo Http on web2.field.com!!</h1>

<p>If yousee this page,test ok. </p>

<p><em>Thankyou!</em></p>

[root@testconf.d]#

2).关闭后端httpd服务，备用的130主机会上线。

[root@web2html]# service  httpd  stop

停止 httpd：[确定]

win7访问http://192.168.88.131:8080/field/，刷新页面，始终定位到【Welcome to Nginx ontest.field.com!!】页面

129主机用curl访问http://192.168.88.131:8080/field/，始终定位到【Welcome to Nginx on test.field.com!!】页面

[root@web2html]# curl  http://192.168.88.131:8080/field/

<h1>Welcometo Nginx on test.field.com!!</h1>

<p><em>If you see this page,test OK! </em></p>

<p>Thankyou!</p>

3).开启129主主机后端httpd服务，备用的130主机会下线，129主机上线。

[root@web2html]# service httpd start

正在启动 httpd：[确定]

win7访问http://192.168.88.131:8080/field/，刷新页面，始终定位到【Welcome to Http on web2.field.com!!!】页面

 

案例6、自定义相应报文首部： 

编辑default.conf，添加如下内容：

add_header X-Via $server_addr;

add_header X-Cache $upstream_cache_status;

[root@wwwconf.d]# vi  default.conf

server {

    listen      8080;

    server_name localhost;

    add_headerX-Via $server_addr;

    add_headerX-Cache $upstream_cache_status;

    #charset koi8-r;

    #access_log  /var/log/nginx/log/host.access.log main;

    location / {

       root  /usr/share/nginx/html;

       # proxy_pass  http://192.168.88.130/;

       index  index.html  index.php  index.htm;

    }

    location  /field/ {

     proxy_pass  http://upservers/;

     proxy_set_header  Host      $host;

     proxy_set_header  X-Real-IP  $remote_addr;

proxy_set_header        X-Forwarded-For  $proxy_add_x_forwarded_for;

    }

    location  ~* \.(jpg|png|gif)$  {

     proxy_pass  http://upservers;

     proxy_set_header  X-Real-IP  $remote_addr;

    }

}

[root@wwwconf.d]# service nginx reload

重新载入 nginx：[确定]

[root@wwwconf.d]#

win7访问http://192.168.88.131:8080/field/，F12打开控制台

可以看到报文首部：

X-Via:192.168.88.131

 

案例7、负载均衡加入缓存机制

 Syntax:    proxy_cache_path path [levels=levels][use_temp_path=on|off] keys_zone=name:size [inactive=time] [max_size=size][manager_files=number] [manager_sleep=time] [manager_threshold=time][loader_files=number] [loader_sleep=time] [loader_threshold=time][purger=on|off] [purger_files=number] [purger_sleep=time][purger_threshold=time];

Default:     —

Context:    http

缓存文件路径定义levels=1:2，一级子目录一个字符表示，2级子目录两个字符表示

总共有62*62*62个文件

   proxy_cache_path /data/nginx/cache levels=1:2 keys_zone=one:10m;

file names in a cache will look like this:

   /data/nginx/cache/c/29/b7f54b2df7773722d382f4809d65029c  

$upstream_cache_status 包含以下几种状态：

MISS：未命中，请求被传送到后端

HIT：缓存命中

EXPIRED：缓存已经过期请求被传送到后端

UPDATING：正在更新缓存，将使用旧的应答

STALE：后端将得到过期的应答

简单配置如下： 

配置缓存：nginx.conf

 proxy_cache_path   /cache/nginx/ levels=1:1keys_zone=mycache:32m;

加入头信息：default.conf

    add_header  X-Via  $server_addr;

    add_header  X-Cache  $upstream_cache_status;

启用缓存：

     proxy_cache  mycache;

     proxy_cache_valid  200  1d;

#200 1d 表示这个zone中返回200的缓存文件如果在1天内没有被访问，那么文件会被cache manager进程删除掉    

     proxy_cache_valid  301  302  10m;

     proxy_cache_valid  any  1m;

     proxy_cache_use_stale  error  http_500  http_502  http_503  http_504     

[root@www nginx]#vi  nginx.conf

   proxy_cache_path  /cache/nginx/levels=1:2 keys_zone=mycache:32m;

    upstream upservers {

        server  192.168.88.129  max_fails=2  fail_timeout=1;

        server  192.168.88.130:8080  max_fails=2  fail_timeout=1  backup;

    }

[root@wwwconf.d]# vi default.conf

server {

    listen      8080;

    server_name  localhost;

    add_headerX-Via  $server_addr;

    add_headerX-Cache  $upstream_cache_status;

    #charset koi8-r;

    #access_log  /var/log/nginx/log/host.access.log  main;

    location / {

       root   /usr/share/nginx/html;

       # proxy_pass http://192.168.88.130/;

       index  index.html  index.php  index.htm;

    }

    location /field/ {

     proxy_cache  mycache;

    proxy_cache_valid  200  1d;

     proxy_cache_valid  301  302  10m;

    proxy_cache_valid  any  1m;

    proxy_cache_use_stale  error  http_500 http_502  http_503  http_504;

     proxy_pass  http://upservers/;

     proxy_set_header  Host      $host;

     proxy_set_header  X-Real-IP  $remote_addr;

     proxy_set_header        X-Forwarded-For $proxy_add_x_forwarded_for;

    } 

    location  ~* \.(jpg|png|gif)$ {

      proxy_cache  mycache;

     proxy_cache_valid  200  1d;

     proxy_cache_valid  301  302  10m;

     proxy_cache_valid  any  1m;

      proxy_cache_use_stale  error  http_500  http_502  http_503  http_504;

     proxy_pass  http://upservers;

     proxy_set_header  X-Real-IP  $remote_addr;

    }

    error_page   500  502  503  504  /50x.html;

    location = /50x.html {

        root   /usr/share/nginx/html;

    }

}

访问http://www.field.com:8080/field/，F12打开控制台

可以看到

X-Cache:MISS

X-Via:192.168.88.131

#MISS：缓存未命中，请求被传送到后端

此时已经在Nginx代理服务器形成缓存文件

[root@www ba]#pwd

/cache/nginx/5/ba

[root@www ba]#ll

总用量 4

-rw-------. 1nginx nginx 546 4月  20 16:43141b735b7bb97cf9c8914596bd253ba5

[root@www ba]#cat 141b735b7bb97cf9c8914596bd253ba5

KEY:http://upservers/

HTTP/1.1 200 OK

Date: Fri, 20Apr 2018 08:43:20 GMT

Server:Apache/2.2.15 (CentOS)

Last-Modified:Fri, 20 Apr 2018 07:28:38 GMT

ETag:"dbec8-6e-56a42a2f67580"

Accept-Ranges:bytes

Content-Length:110

Connection:close

Content-Type:text/html; charset=UTF-8

 

<h1>Welcometo Http on web2.field.com!!</h1>

<p>If yousee this page,test ok. </p>

<p><em>Thankyou!</em></p>

再刷新一次页面，可以看到：

X-Cache:HIT

X-Via:192.168.88.131

缓存命中，此时请求不会被传送到后端。