Nginx 是什么？
Nginx™ [engine x] is an HTTP and reverse proxy server, a mail proxy server, and a generic TCP/UDP proxy server
环境搭建
下载
在 Nginx Archive 下载页面，下载 nginx-1.13.12.tar.gz 安装包
安装依赖
$ yum -y install openssl openssl-devel
$ yum -y install pcre-devel复制
编译安装
$ tar zxvf nginx-1.13.12.tar.gz
# 必须要跳转到 nginx 安装目录下
$ cd nginx-1.13.12
$ ./configure --prefix=/usr/local/nginx --conf-path=/usr/local/nginx/nginx.conf
$ make -j4 && make -j4 install复制
启动
$ cd /usr/local/nginx/
$ sbin/nginx -c /usr/local/nginx/nginx.conf复制
$ ps -ef | grep nginx复制
root 107034 1 0 Oct31 ? 00:00:00 nginx: master process sbin/nginx
nobody 107036 107034 0 Oct31 ? 00:00:00 nginx: worker process
nobody 107266 107265 0 Oct31 ? 00:00:00 tsar --check --apache --cpu --mem --load --io --traffic --tcp --partition --nginx --swap
root 107270 97588 0 Oct31 pts/1 00:00:00 grep nginx复制
停止
$ sbin/nginx -s stop复制
校验
$ curl localhost复制
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
body {
width: 35em;
margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif;
}
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and working. Further configuration is required.</p>
<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>
<p><em>Thank you for using nginx.</em></p>
</body>
</html>复制
修改配置文件
$ vim nginx.conf复制
重新加载配置文件
$ sbin/nginx -s reload复制
查看日志
# 查看流量详情
$ tail -f logs/access.log
# 查看异常日志
$ tail -f logs/error.log复制
流量镜像
Upstream 模块
通过 upstream
模块，可以将源地址（当前集群）和镜像地址（目标集群）分组
upstream curr {
server 192.168.0.101:8080;
server 192.168.0.102:8080;
keepalive 64;
}
upstream dest {
server 192.168.0.103:8080;
server 192.168.0.104:8080;
keepalive 64;
}复制
Server 模块
如下定义了当前 Nginx 进程（ localhost
）监听的端口（ 80
）
server {
listen 80;
server_name localhost;
# ...
}复制
注意观察 logs/error.log 日志，检查是否出现端口冲突的日志，以调整这里面的端口号
Location 模块
server
模块下的 location
模块，可以定义流量转发的规则， location/
会接受所有 Nginx 进来的流量，而 mirror/mirror;
会将流量转发到镜像地址，而 location/mirror
则定义了转发的规则
location / {
root html;
index index.html index.htm;
mirror /mirror;
mirror_request_body on;
proxy_pass http://curr;
}
location /mirror {
internal;
proxy_pass http://dest$request_uri;
proxy_set_header X-Original-URI $request_uri;
}复制
完整示例
本地转发
#user nginx;
worker_processes auto;
#error_log logs/error.log;
#error_log logs/error.log notice;
#error_log logs/error.log info;
#pid logs/nginx.pid;
events {
worker_connections 1024;
}
http {
include mime.types;
default_type application/octet-stream;
log_format main '$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;
keepalive_timeout 65;
upstream curr {
server localhost:8080;
keepalive 64;
}
server {
listen 80;
server_name localhost;
#charset koi8-r;
#access_log logs/host.access.log main;
location / {
root html;
index index.html index.htm;
mirror_request_body on;
proxy_pass http://curr;
}
error_page 500 502 503 504 /50x.html;
location = /50x.html {
root html;
}
}
}复制
集群间转发
#user nginx;
worker_processes auto;
#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;
keepalive_timeout 65;
upstream curr {
server 192.168.0.101:8080;
server 192.168.0.102:8080;
keepalive 64;
}
upstream dest {
server 192.168.0.103:8080;
server 192.168.0.104:8080;
keepalive 64;
}
server {
listen 80;
server_name localhost;
#charset koi8-r;
#access_log logs/host.access.log main;
location / {
root html;
index index.html index.htm;
mirror /mirror;
mirror_request_body on;
proxy_pass http://curr;
}
location /mirror {
internal;
proxy_pass http://dest$request_uri;
proxy_set_header X-Original-URI $request_uri;
}
error_page 500 502 503 504 /50x.html;
location = /50x.html {
root html;
}
}
}复制
轮询策略
RR
按时间顺序逐一将请求发送到不同的服务器，并且服务器故障后，会被自动剔除
upstream yuzhouwan {
server 192.168.0.101:80 max_fails=3 fail_timeout=3s weight=9;
server 192.168.0.102:80 max_fails=3 fail_timeout=3s weight=9;
}复制
Nginx 默认会采用 RR（round-robin）简单轮询策略
balance
支持指定轮询的几率，参数 weight
的数值和访问几率成正比，常用于集群中服务器资源不均的场景
upstream yuzhouwan {
server 192.168.0.101:80 weight=6;
server 192.168.0.102:80 weight=1;
}复制
ip_hash
按访问 ip 的 hash 结果将请求发送到不同的服务器，这样每个访客固定访问一个后端服务器。可以在 Session 有状态情况下，避免请求被转发到不同的服务器后，需要重复登录的问题
upstream yuzhouwan {
ip_hash;
server 192.168.0.101:80;
server 192.168.0.102:80;
}复制
fair
按服务器的响应时间来分配请求，响应时间短的优先分配
upstream yuzhouwan {
fair;
server 192.168.0.101:80;
server 192.168.0.102:80;
}复制
url_hash
按访问 url 的 hash 结果来分配请求，可以充分发挥服务器上缓存的作用
bash
upstream yuzhouwan{hash $request_uri;hash_method crc32;server192.168.0.101:80;server192.168.0.102:80;}
踩过的坑
client intended to send too large body
分析
Nginx 默认不允许发送超过 1MB 的请求体，由 client_max_body_size
参数控制
解决
$ vim nginx.conf复制
http {
client_max_body_size 10M;
# ...
}复制
$ sbin/nginx -s reload复制
补充
| 参数名 | 含义 | 默认值 | 作用域 |
|---|---|---|---|
chunked_transfer_encoding | 是否开启 HTTP/1.1 下的 chunked 编码 | on | http, server, location |
client_header_buffer_size | 请求头的大小限制 | 1k | http, server |
client_body_timeout | 读取请求体的超时限制 | 60s | http, server, location |
