在使用srcache过程中遇到的cache命中的情况下继续访问后端服务情况

xidianwlc · 2013-02-02T09:49:35+00:00

Hello! 2013/2/1 307413083: > 在使用lua-resty-mysql 的时候，应用压力比&#x8F83...

在使用srcache过程中遇到的cache命中的情况下继续访问后端服务情况

xidianwlc

在使用srcache过程中遇到的cache命中的情况下继续访问后端fastcig服务情况，具体情况是通过

set $key '$uri';

srcache_fetch GET /memc $key;

srcache_store PUT /memc $key;

写入cache一个key后再次访问的时候虽然memcached中已经存在这个key的value但是还是会调用upstream的fastcgi去处理。测试的nginx的配置如下：

user lichaowang;

worker_processes 12;

error_log /home/lichaowang/test/openresty/nginx/logs/error.log debug;

pid /home/lichaowang/test/openresty/nginx/logs/nginx.pid;

events {

use epoll;

worker_connections 12;

}

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" $request_time';

access_log /home/lichaowang/test/openresty/nginx/logs/access.log main;

sendfile off;

tcp_nodelay on;

keepalive_timeout 2;

gzip on;

gzip_types text/plain text/css application/x-_javascript_ text/xml application/xml application/xml+rss text/_javascript_;

client_header_buffer_size 256k;

large_client_header_buffers 4 256k;

client_max_body_size 50m;

client_body_buffer_size 256k;

client_header_timeout 3m;

client_body_timeout 3m;

proxy_buffers 128 256k;

#log_not_found off;

upstream fastcgi {

server 127.0.0.1:8778;

}

#Memcache服务upstream

upstream memcache {

server localhost:11211;

keepalive 1024;

}

server {

open_file_cache max=102400 inactive=20s;

open_file_cache_valid 30s;

open_file_cache_min_uses 1;

client_header_buffer_size 4096;

listen 8080;

server_name localhost;

charset utf-8;

root /home/lichaowang/service/image_webroot/program;

#memc-nginx-module

location = /memc {

internal;

no_error_pages;

set $memc_key $query_string;

memc_pass memcache;

}

location ~* ^/(pic|ap|tmp|img|glogo|mix).*\.(jpg|png|jpeg|gif)$ {

srcache_fetch GET /memc $key;

srcache_store PUT /memc $key;

rewrite ^(.*)$ /index.php break;

root /home/lichaowang/service/image_webroot/program;

fastcgi_pass fastcgi;

fastcgi_index index.php;

include fastcgi_params;

fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;

}

location /nginx_status {

stub_status on;

access_log off;

#设置为可访问该状态信息的ip

allow 127.0.0.1;

deny all;

}

error_page 500 502 503 504 /50x.html;

location = /50x.html {

root html;

}

agentzh

Hello!

On Fri, Feb 1, 2013 at 4:53 PM, Lichao Wang wrote:
>
> 在使用srcache过程中遇到的cache命中的情况下继续访问后端fastcig服务情况，具体情况是通过
>             set $key '$uri';
>             srcache_fetch GET /memc $key;
>             srcache_store PUT /memc $key;
> 写入cache一个key后再次访问的时候虽然memcached中已经存在这个key的value但是还是会调用upstream的fastcgi去处理。

请提供问题请求相对应的 Nginx 调试日志，见这里的文档：

    http://wiki.nginx.org/HttpSRCacheModule#Trouble_Shooting

Best regards,
-agentzh

xidianwlc

配置：

location ~* ^/(pic|ap|tmp|img|glogo|mix).*\.(jpg|png|jpeg|gif)$ {

charset utf-8;

default_type text/html;

#srcache-nginx-module

set $key '$uri';

#set $key '/img/_o/44/56/8e99bbe907d20d1f7f687993b543_200_200.jpg';

#set_md5 $key $uri;

srcache_fetch GET /memc $key;

srcache_store PUT /memc $key;

rewrite ^/(.*?)$ /index.php break;

root /home/lichaowang/service/image_webroot/program;

fastcgi_pass fastcgi;

include fastcgi_params;

fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;

}

请求：http://127.0.0.1:8080/pic/r/9f/19/f2723a951f08b38a468ddad30221_481_768.jpg

nginx的debug的日志：

2013/02/03 20:05:06 [debug] 4226#0: *4 http script set $key

2013/02/03 20:05:06 [debug] 4226#0: *4 http script set $memc_key

2013/02/03 20:05:06 [debug] 4226#0: *4 http output filter "/memc?/pic/r/9f/19/f2723a951f08b38a468ddad30221_481_768.jpg"

2013/02/03 20:05:06 [debug] 4226#0: *4 http output filter "/index.php?"

在 2013年2月2日星期六UTC+8上午9时52分32秒，agentzh写道：

Hello!

On Fri, Feb 1, 2013 at 4:53 PM, Lichao Wang wrote:
>
> 在使用srcache过程中遇到的cache命中的情况下继续访问后端fastcig服务情况，具体情况是通过
> set $key '$uri';
> srcache_fetch GET /memc $key;
> srcache_store PUT /memc $key;
> 写入cache一个key后再次访问的时候虽然memcached中已经存在这个key的value但是还是会调用upstream的fastcgi去处理。

请提供问题请求相对应的 Nginx 调试日志，见这里的文档：

http://wiki.nginx.org/HttpSRCacheModule#Trouble_Shooting

Best regards,
-agentzh

agentzh

Hello!

2013/2/3 Lichao Wang:
> 配置：
>         location ~* ^/(pic|ap|tmp|img|glogo|mix).*\.(jpg|png|jpeg|gif)$ {
>             charset        utf-8;
>             default_type   text/html;
>             #srcache-nginx-module
>             set $key '$uri';
>             #set $key
> '/img/_o/44/56/8e99bbe907d20d1f7f687993b543_200_200.jpg';
>             #set_md5 $key $uri;
>             srcache_fetch GET /memc $key;
>             srcache_store PUT /memc $key;
>
>             rewrite ^/(.*?)$ /index.php break;
>             root     /home/lichaowang/service/image_webroot/program;
>             fastcgi_pass   fastcgi;
>             include        fastcgi_params;
>             fastcgi_param  SCRIPT_FILENAME
> $document_root$fastcgi_script_name;
>         }
> 请求：http://127.0.0.1:8080/pic/r/9f/19/f2723a951f08b38a468ddad30221_481_768.jpg
> nginx的debug的日志：
> 2013/02/03 20:05:06 [debug] 4226#0: *4 http script set $key
> 2013/02/03 20:05:06 [debug] 4226#0: *4 http script set $memc_key
> 2013/02/03 20:05:06 [debug] 4226#0: *4 http output filter
> "/memc?/pic/r/9f/19/f2723a951f08b38a468ddad30221_481_768.jpg"
> 2013/02/03 20:05:06 [debug] 4226#0: *4 http output filter
> "/memc?/pic/r/9f/19/f2723a951f08b38a468ddad30221_481_768.jpg"
> 2013/02/03 20:05:06 [debug] 4226#0: *4 http output filter
> "/memc?/pic/r/9f/19/f2723a951f08b38a468ddad30221_481_768.jpg"
> 2013/02/03 20:05:06 [debug] 4226#0: *4 http output filter
> "/memc?/pic/r/9f/19/f2723a951f08b38a468ddad30221_481_768.jpg"
> 2013/02/03 20:05:06 [debug] 4226#0: *4 http output filter
> "/memc?/pic/r/9f/19/f2723a951f08b38a468ddad30221_481_768.jpg"
> 2013/02/03 20:05:06 [debug] 4226#0: *4 http output filter
> "/memc?/pic/r/9f/19/f2723a951f08b38a468ddad30221_481_768.jpg"
> 2013/02/03 20:05:06 [debug] 4226#0: *4 http output filter
> "/memc?/pic/r/9f/19/f2723a951f08b38a468ddad30221_481_768.jpg"
> 2013/02/03 20:05:06 [debug] 4226#0: *4 http output filter "/index.php?"
>

你给出的该请求的调试日志不完整，一个请求开始时对应的调试日志一般类似下面这两行：

    [debug] 11964#0: *1 http process request line
    [debug] 11964#0: *1 http request line: "GET /pic/r/9f/19 HTTP/1.1"

请求结束时一般会有类似下面这几行调试日志：

    [debug] 11964#0: *1 http close request
    [debug] 11964#0: *1 http log handler
    [debug] 11964#0: *1 close http connection: 7

你提供问题请求的调试日志时，应当提供开头和结尾以及中间所有的调试日志。

而且其中没有任何 srcache 模块输出的日志。一般地，如果用户仔细阅读 srcache 模块输出的错误日志（或者调试日志）就可以自己诊断问题。

另外，请确认你使用的是最新版本的 ngx_srcache :)

Regards,
-agentzh