Hello,

I'm using nginx 1.4.0 to proxy a website, and I cache responses. I haven't noticed any problems on the front end, but the error log has unlink() errors.

2013/05/03 12:53:42 [crit] 16665#0: unlink() "/usr/local/nginx/cache/8/9f/42da8f2662887b05cbb46fd5c9dac9f8" failed (2: No such file or directory)
2013/05/03 12:53:42 [crit] 16665#0: unlink() "/usr/local/nginx/cache/8/7d/f16e1a9cee13b3a9852fff331491d7d8" failed (2: No such file or directory)
2013/05/03 12:53:42 [crit] 16665#0: unlink() "/usr/local/nginx/cache/d/96/2b1e341ee2ccd315643dcad397b9796d" failed (2: No such file or directory)
2013/05/03 12:53:42 [crit] 16665#0: unlink() "/usr/local/nginx/cache/6/87/c3324c5f79272b6fff64ac19be2d0876" failed (2: No such file or directory)
2013/05/03 12:53:42 [crit] 16665#0: unlink() "/usr/local/nginx/cache/c/ae/aa5ee91c36f7ab931251dd125a200aec" failed (2: No such file or directory)
2013/05/03 12:53:42 [crit] 16665#0: unlink() "/usr/local/nginx/cache/c/d8/2ac585aa18ec25e3a8eab19b096dcd8c" failed (2: No such file or directory)
2013/05/03 12:53:42 [crit] 16665#0: unlink() "/usr/local/nginx/cache/2/94/77170f4b850dcc5bae0e93bdf0f07942" failed (2: No such file or directory)
2013/05/03 12:53:42 [crit] 16665#0: unlink() "/usr/local/nginx/cache/3/cd/f92020ab245f9be3bab04cf8bf93acd3" failed (2: No such file or directory)

The list goes on.

Is this something to be concerned of?

My configuration is psuedo but here is the main parts:

#reverse ssl (usage not shown in examples)
proxy_cache_path /usr/local/nginx/cache levels=1:2 keys_zone=static-files:10m inactive=24h max_size=1g;

#main site cache
proxy_cache_path /usr/local/nginx/cache levels=1:2 keys_zone=page-cache:10m inactive=24h max_size=1g;

#main site
location / {
proxy_http_version 1.0;
proxy_set_header Accept-Encoding "";
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header Host *********;
proxy_ignore_headers Set-Cookie;
proxy_ignore_headers Cache-Control;
proxy_cache page-cache;
proxy_cache_key $scheme$proxy_host$request_uri;
proxy_cache_valid 200 30m;
proxy_cache_valid 404 1m;
proxy_intercept_errors on;
proxy_cache_use_stale error timeout invalid_header updating http_502 http_500 http_503 http_504;
add_header X-Cache $upstream_cache_status;
proxy_pass *********;
}

#sub domain
location / {
proxy_http_version 1.0;
proxy_set_header Accept-Encoding "";
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header Host *********;
proxy_ignore_headers Set-Cookie;
proxy_ignore_headers Cache-Control;
proxy_cache page-cache;
proxy_cache_key $scheme$proxy_host$request_uri;
proxy_cache_valid 200 30m;
proxy_cache_valid 404 1m;
proxy_intercept_errors on;
proxy_cache_use_stale error timeout invalid_header updating http_502 http_500 http_503 http_504;
add_header X-Cache $upstream_cache_status;
proxy_pass *********;
}


Is this bad practice to share caches among subdomains? Is sharing the cache the reason why I'm getting unlink() errors?