实验目的
通过nginx实现反向代理的功能，类似apache反向代理和haproxy反向代理
工作中用nginx做反向代理和负载均衡的也越来越多了
有些公司从web服务器到反向代理，都使用nginx。nginx在1.9版本加入了tcp的反向代理功能
甚至安全策略：nginx+lua 完全可以搞定。
打开nginx官网
nginx做反向代理，安装命令如下，使用www用户运行nginx
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useradd -s /sbin/noglogin -M wwwwget http://nginx.org/download/nginx-1.9.12.tar.gztar zxf nginx-1.9.12.tar.gzcd nginx-1.9.12./configure --prefix=/usr/local/nginx-1.9.12 \--user=www --group=www --with-http_ssl_module \--with-http_stub_status_module --with-file-aiomake && make installln -s /usr/local/nginx-1.9.12/ /usr/local/nginx |
检查语法
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[root@linux-node2 nginx-1.9.12]# /usr/local/nginx/sbin/nginx -tnginx: the configuration file /usr/local/nginx-1.9.12/conf/nginx.conf syntax is oknginx: configuration file /usr/local/nginx-1.9.12/conf/nginx.conf test is successful[root@linux-node2 nginx-1.9.12]# |
检查服务器有无其它服务占用80端口，可以关闭了。
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[root@linux-node1 ~]# /usr/local/httpd/bin/apachectl -k stop |
配置nginx反向代理，修改主配置文件
gzip是默认关闭的
长连接默认打开的
sendfile 默认打开的
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[root@linux-node1 conf]# cat nginx.conf#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 10240;}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 backend { server 10.0.1.105:8080 weight=1 max_fails=3 fail_timeout=30s; server 10.0.1.106:8080 weight=2 max_fails=3 fail_timeout=30s; } server { listen 80; server_name www.nginx-nmap.com; #charset koi8-r; #access_log logs/host.access.log main; location / { root html; index index.html index.htm; proxy_pass http://backend; } #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; # } #}}[root@linux-node1 conf]# |
上面设置虚拟主机名www.nginx-nmap.com，以及后端集群组backend，设置了location把任何请求都发给后端backend
上面配置文件里也设置了后端web集群
负载均衡配置时的2个参数：fail_timeout和max_fails
这2个参数一起配合，来控制nginx怎样认为upstream中的某个server是失效的当在fail_timeout的时间内，某个server连接失败了max_fails次，则nginx会认为该server不工作了。
同时，在接下来的 fail_timeout时间内，nginx不再将请求分发给失效的server。
比如失败3次，那么接下来10秒不会之内不会把请求发个这个认为失败的机器。然后过了30秒后，这个机器继续收到探测请求.一般生产中设置为30秒
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upstream backend { server 10.0.1.105:8080 weight=1 max_fails=3 fail_timeout=30s; server 10.0.1.106:8080 weight=2 max_fails=3 fail_timeout=30s; } |
关于nginx反向代理功能由下面模块提供
可以参照下官方个的配置例子
官方文档做的挺好
检测语法，启动或者reload。查看监听状态
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[root@linux-node1 conf]# /usr/local/nginx/sbin/nginx -tnginx: the configuration file /usr/local/nginx-1.9.12/conf/nginx.conf syntax is oknginx: configuration file /usr/local/nginx-1.9.12/conf/nginx.conf test is successful[root@linux-node1 conf]# /usr/local/nginx/sbin/nginx -s reload[root@linux-node1 conf]# netstat -lntp | grep 80tcp 0 0 0.0.0.0:80 0.0.0.0:* LISTEN 27141/nginx: master tcp6 0 0 :::8080 :::* LISTEN 20130/httpd [root@linux-node1 conf]# |
客户端windows的hosts文件里配置如下
10.0.1.105 www.nginx-nmap.com
浏览器测试
停止node2的httpd。nginx会自动把请求发送给node1，前端无感知
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[root@linux-node2 nginx-1.9.12]# systemctl stop httpd[root@linux-node2 nginx-1.9.12]# systemctl start httpd[root@linux-node2 nginx-1.9.12]# |
启动node2的httpd之后，刷30秒，node2才出现，也就是我们设置的fail_timeout=30的缘故
关于会话保持
会话保持，有基于ip的有ip_hash
直接添加这一行即可
重启
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[root@linux-node1 conf]# /usr/local/nginx/sbin/nginx -tnginx: the configuration file /usr/local/nginx-1.9.12/conf/nginx.conf syntax is oknginx: configuration file /usr/local/nginx-1.9.12/conf/nginx.conf test is successful[root@linux-node1 conf]# /usr/local/nginx/sbin/nginx -s reload[root@linux-node1 conf]# |
再次访问就只有node2了
关于nginx的负载均衡算法有很多，自行百度
