Nginx基础

1.缓存配置语法

1）proxy_cache配置语法

Syntax: proxy_cache zone | off;
Default: proxy_cache off;
Context: http, server, location

2）缓存路径

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

3）缓存过期周期

Syntax: proxy_cache_valid [code ...] time;
Default: —
Context: http, server, location

#示例
proxy_cache_valid 200 302 10m;
proxy_cache_valid 404 1m;

4）缓存的维度

Syntax: proxy_cache_key string;
Default: proxy_cache_key $scheme$proxy_host$request_uri;
Context: http, server, location

#示例
proxy_cache_key "$host$request_uri $cookie_user";
proxy_cache_key $scheme$proxy_host$uri$is_args$args;

2.代理配置缓存

[root@localhost ~]# mkdir /var/cache/nginx
[root@localhost ~]# vim /etc/nginx/conf.d/proxy_cache.conf
upstream cache {
server 10.0.0.12:80;
server 10.0.0.13:80;
server 10.0.0.14:80;
}

#proxy_cache_path 存放缓存临时文件
#levels 按照两层目录分级
#keys_zone 开辟空间名, 10m:开辟空间大小, 1m可存放8000key
#max_size 控制最大大小, 超过后Nginx会启用淘汰规则
#inactive 60分钟没有被访问缓存会被清理
#use_temp_path 临时文件, 会影响性能, 建议关闭
proxy_cache_path /var/cache/nginx levels=1:2 keys_zone=code_cache:10m max_size=10g inactive=60m use_temp_path=off;

server {
listen 80;
server_name 127.0.0.1;

#proxy_cache 开启缓存
#proxy_cache_valid 状态码200|304的过期为12h, 其余状态码10分钟过期
#proxy_cache_key 缓存key
#add_header 增加头信息, 观察客户端respoce是否命中
#proxy_next_upstream 出现502-504或错误, 会跳过此台服务器访问下台
location / {
proxy_pass http://cache;
proxy_cache code_cache;
proxy_cache_valid 200 304 12h;
proxy_cache_valid any 10m;
add_header Nginx-Cache "$upstream_cache_status";
proxy_next_upstream error timeout invalid_header http_500 http_502 http_503 http_504;
include proxy_params;
}
}

3.客户端测试

[root@localhost ~]# curl -s -I http://127.0.0.1/index.html | grep "Nginx-Cache"
Nginx-Cache: MISS

[root@localhost ~]# curl -s -I http://127.0.0.1/index.html | grep "Nginx-Cache"
Nginx-Cache: HIT

4.缓存清理

1）删除已缓存数据

[root@proxy ~]# rm -rf /var/cache/nginx/*
[root@localhost ~]# curl -s -I http://127.0.0.1/index.html | grep "Nginx-Cache"
Nginx-Cache: MISS

2）使用ngx_cache_purge扩展模块清理，需要编译安装nginx（安装过程略）

修改配置文件

[root@localhost ~]# vim /usr/local/nginx/conf/nginx.conf
...
upstream cache {
server 10.0.0.12:80;
server 10.0.0.13:80;
server 10.0.0.14:80; 
}

proxy_cache_path /var/cache/nginx levels=1:2 keys_zone=code_cache:10m max_size=10g inactive=60m use_temp_path=off;

server {
listen 80;
server_name 127.0.0.1;

location / {
proxy_pass http://cache;
proxy_cache code_cache;
proxy_cache_valid 200 304 12h;
proxy_cache_valid any 10m;
add_header Nginx-Cache "$upstream_cache_status";
proxy_next_upstream error timeout invalid_header http_500 http_502 http_503 http_504;
include proxy_params;
}
location ~ /purge(/.*) {
allow 127.0.0.1;
deny all;
proxy_cache_purge code_cache $host$1$is_args$args;
}
}
...

清理缓存

[root@localhost ~]# curl http://127.0.0.1/purge/index.html

5.部分页面不缓存
1）指定部分页面不进行proxy_Cache缓存

[root@localhost conf.d]# vim proxy_cache.conf 
upstream cache{
server 10.0.0.12:80;
server 10.0.0.13:80;
server 10.0.0.14:80; 
}

proxy_cache_path /soft/cache levels=1:2 keys_zone=code_cache:10m max_size=10g inactive=60m use_temp_path=off;

server {
listen 80;
server_name 127.0.0.1;
if ($request_uri ~ ^/(login |register|password)) {
set $cookie_nocache 1;
}

location / {
proxy_pass http://cache;
proxy_cache code_cache;
proxy_cache_valid 200 304 12h;
proxy_cache_valid any 10m;
proxy_cache_key $host$uri$is_args$args;
proxy_no_cache $cookie_nocache $arg_nocache $arg_comment;
proxy_no_cache $http_pargma $http_authorization;
add_header Nginx-Cache "$upstream_cache_status";
proxy_next_upstream error timeout invalid_header http_500 http_502 http_503 http_504;
include proxy_params;
}
}

2）清理原先的缓存

[root@localhost ~]# rm -rf /var/cache/nginx/*

3）请求测试

[root@localhost ~]# curl -s -I http://127.0.0.1/login | grep "Nginx-Cache" 
Nginx-Cache: MISS
[root@localhost ~]# curl -s -I http://127.0.0.1/login | grep "Nginx-Cache"
Nginx-Cache: MISS
[root@localhost ~]# curl -s -I http://127.0.0.1/login | grep "Nginx-Cache"
Nginx-Cache: MISS

6.缓存日志记录统计
通过日志记录proxy_cache命中情况与对应url

1）修改/etc/nginx/nginx.conf中log_format格式

log_format main '$http_user_agent' '$request_uri' '$remote_addr - $remote_user [$time_local] "$request" '
'$status $body_bytes_sent "$http_referer" '
'"$http_user_agent" "$http_x_forwarded_for"' '"$upstream_cache_status"';

2）查看访问日志（略）