Nginx本身就有缓存功能,能够缓存静态对象,比如图片、CSS、JS等内容直接缓存到本地,下次访问相同对象时,直接从缓存即可,无需访问后端静态服务器以及存储存储服务器,可以替代squid功能。1环境准备我们这里只测试nginx的proxy_cache...
Nginx本身就有缓存功能,能够缓存静态对象,比如图片、CSS、JS等内容直接缓存到本地,下次访问相同对象时,直接从缓存即可,无需访问后端静态服务器以及存储存储服务器,可以替代squid功能。
我们这里只测试nginx的proxy_cache的缓存功能,所以结构越简单越好,这里我们只需要准备一台nginx的虚拟机即可,如果没有nginx,那么我们可以使用epel源,yum安装一个即可:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 | #添加epel源 root@~>> wget -O /etc/yum .repos.d /epel .repohttp: //mirrors .aliyun.com /repo/epel-6 .repo #yum安装nginx root@~>> yum install nginx -y #rpm -ql查看主要配置文件位置 root@~>> rpm -ql nginx 这里为了简单,只使用简单的nginx.conf配置文件: root@nginx>> cat nginx.conf user nginx; worker_processes 1; error_log /var/log/nginx/error .log; 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]"$request" ' '$status $body_bytes_sent"$http_referer" ' '"$http_user_agent" "$http_x_forwarded_for"' ; sendfile on; keepalive_timeout 65; server { listen 80; location / { root /usr/share/nginx/html ; index index.html index.htm; } } } |
启动查看初始界面是否正常:
1 2 3 4 5 6 7 8 9 10 11 12 | root@nginx>> nginx root@nginx>> netstat -tupln|grepnginx tcp 0 0 0.0.0.0:80 0.0.0.0:* LISTEN 1043 /nginx root@nginx>> curl -I 192.168.16.199 HTTP /1 .1 200 OK Server: nginx /1 .0.15 Date: Mon, 14 Sep 2015 09:40:53 GMT Content-Type: text /html Content-Length: 3698 Last-Modified: Tue, 16 Jun 2015 21:34:15GMT Connection: keep-alive Accept-Ranges: bytes |
一切正常,首页有2张图片,正好用于实验:
1 2 3 4 5 6 7 | root@html>> tree /usr/share/nginx/html/ /usr/share/nginx/html/ |-- 404.html |-- 50x.html |-- index.html |-- nginx-logo.png `-- poweredby.png |
至此环境准备完毕。
nginx的proxy_cache是基于内存和磁盘的缓存,需要指定缓存目录和临时目录:
root@nginx>> mkdir /tmp/{ngx_tmp,ngx_cache}-p
缓存存放于磁盘,磁盘IO会影响缓存的速度,所以我们在将tmpfs挂载于ngx_cache目录上来加速缓存的读取和写入:
1 2 3 4 | root@nginx>> mount -t tmpfs -osize=100M tmpfs /tmp/ngx_cache root@nginx>> mount | grep tmpfs tmpfs on /dev/shm type tmpfs (rw) tmpfs on /tmp/ngx_cache type tmpfs (rw,size=100M) |
将下面配置放至http标签中:
root@nginx>> grep proxy_cache_pathnginx.conf
proxy_cache_path /tmp/ngx_cache levels=1:2 keys_zone=cache_one:100minactive=1d max_size=5g;
#指定缓存目录,缓存等级,键空间名,键空间大小,失效时间,以及磁盘最大缓存大小
首先配置upstream节点池:
1 2 3 | upstream server_pool { server 127.0.0.1:8080; } |
在server标签的location段中配置代理:
proxy_pass http://server_pool;
配置8080端口的标签:
1 2 3 4 5 6 7 8 | server { listen 8080; location / { root /usr/share/nginx/html ; index index.html index.htm; } access_log /var/log/nginx/access .log main; } |
配置proxy_cache相关参数启用缓存:
1 2 3 4 5 6 7 8 9 10 | proxy_pass http: //server_pool ; proxy_next_upstream http_502 http_504error timeout invalid_header; #出错尝试下一个节点 proxy_cache cache_one; #缓存键空间名 proxy_cache_valid 200 304 12h; #指定对应状态码的缓存时间 proxy_cache_valid 301 302 1m; proxy_cache_valid any 1m; proxy_cache_key $host$uri$is_args$args; #指定键key的格式 proxy_set_header Host $host; #传递主机名给后端节点 proxy_set_header X-Forwarded-For$remote_addr; #传递客户端IP给后端节点 expires 1d; #超期时间 |
最终的nginx.conf配置文件如下:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 | root@nginx>> cat nginx.conf user nginx; worker_processes 1; error_log /var/log/nginx/error .log; 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]"$request" ' '$status $body_bytes_sent"$http_referer" ' '"$http_user_agent" "$http_x_forwarded_for"' '"addr:$upstream_addr-status:$upstream_status-cachestatus:$upstream_cache_status"' ; sendfile on; keepalive_timeout 65; proxy_cache_path /tmp/ngx_cache levels=1:2 keys_zone=cache_one:100m inactive=1dmax_size=5g; upstream server_pool { server 127.0.0.1:8080; } server { listen 80; location / { proxy_passhttp: //server_pool ; proxy_next_upstreamhttp_502 http_504 error timeout invalid_header; proxy_cache cache_one; proxy_cache_valid 200304 12h; proxy_cache_valid 301302 1m; proxy_cache_valid any 1m; proxy_cache_key$host$uri$is_args$args; proxy_set_header Host$host; proxy_set_headerX-Forwarded-For $remote_addr; expires 1d; } access_log /var/log/nginx/cache_access .log main; } server { listen 8080; location / { root /usr/share/nginx/html ; index index.htmlindex.htm; } } } |
为了观察缓存的命中状态,我们可以将缓存相关的变量记录在日志中。
定义日志格式:
1 2 3 4 | log_format main '$remote_addr - $remote_user[$time_local] "$request" ' '$status $body_bytes_sent"$http_referer" ' '"$http_user_agent""$http_x_forwarded_for"' '"addr:$upstream_addr-status:$upstream_status-cachestatus:$upstream_cache_status"' ; |
#其中upstream_addr记录分发的后端节点IP;upstream_status记录后端节点返回的状态码;upstream_cache_status记录缓存的命中情况。
在反向代理标签中引用日志:
access_log /var/log/nginx/cache_access.log main;
nginx重新加载配置:
root@nginx>> nginx -s reload
监测缓存文件的事件
浏览网站:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 | root@ngx_cache>> inotifywait -mrq /tmp/ngx_cache/ /tmp/ngx_cache/ CREATE,ISDIR 6 /tmp/ngx_cache/ OPEN,ISDIR 6 /tmp/ngx_cache/ CLOSE_NOWRITE,CLOSE,ISDIR6 /tmp/ngx_cache/ CREATE,ISDIR 1 /tmp/ngx_cache/ OPEN,ISDIR 1 /tmp/ngx_cache/ CLOSE_NOWRITE,CLOSE,ISDIR1 /tmp/ngx_cache/ CREATE,ISDIR 3 /tmp/ngx_cache/ OPEN,ISDIR 3 /tmp/ngx_cache/ CLOSE_NOWRITE,CLOSE,ISDIR3 /tmp/ngx_cache/3/ CREATE,ISDIR fd /tmp/ngx_cache/3/ OPEN,ISDIR fd /tmp/ngx_cache/3/CLOSE_NOWRITE ,CLOSE,ISDIR fd /tmp/ngx_cache/3/fd/ CREATEdd404cd351f6b9efb072e5806dc2efd3.0000000026 /tmp/ngx_cache/3/fd/ OPENdd404cd351f6b9efb072e5806dc2efd3.0000000026 /tmp/ngx_cache/3/fd/ MODIFYdd404cd351f6b9efb072e5806dc2efd3.0000000026 /tmp/ngx_cache/3/fd/ CLOSE_WRITE,CLOSEdd404cd351f6b9efb072e5806dc2efd3.0000000026 /tmp/ngx_cache/3/fd/ MOVED_FROMdd404cd351f6b9efb072e5806dc2efd3.0000000026 /tmp/ngx_cache/3/fd/ MOVED_TOdd404cd351f6b9efb072e5806dc2efd3 |
说明:有最后几行可知,图片缓存到目录中。
全文详见:http://xpxw.com/?id=26