Hi, We have squid as reverse proxy that caches files. There are two types of cacheable files. I see in the log that one type always gets TCP_HIT:NONE (response from disk cache) and the other type always gets TCP_MEM_HIT:NONE (response from memory cache). What is the reason that one file type is not cached in memory, but still cached on disk? If I ask this file a few times in a row it should be in memory, but it is always on disk. If squid caches it with LRU, shouldn't it be in the memory cache if it's the last file accessed? Response headers for files that are cached always on DISK: HTTP/1.x 200 OK Expires: Tue, 14 Jul 2009 07:39:15 GMT Cache-Control: max-age=600 Content-Type: text/xml;charset=UTF-8 Content-Length: 7963 Date: Tue, 14 Jul 2009 07:29:15 GMT Age: 18 X-Cache: HIT from www.foo.com Via: 1.1 www.foo.com (squid/2.7.STABLE6) Connection: keep-alive Headers for files that are cached always in MEMORY: HTTP/1.x 200 OK Etag: W/"7624-1237327990000" Last-Modified: Tue, 17 Mar 2009 22:13:10 GMT Content-Type: image/gif Content-Length: 7624 Expires: Thu, 13 Aug 2009 05:10:48 GMT Cache-Control: max-age=2592001 Date: Tue, 14 Jul 2009 07:08:58 GMT Age: 187 X-Cache: HIT from www.foo.com Via: 1.1 www.foo.com (squid/2.7.STABLE6) Connection: keep-alive This is consistent. One file is always on disk, the other always in memory. No matter how many times I refresh. Is there any http header that I can add to the first file to get it into memory cache? Etag? Relevant squid conf: cache_dir aufs /usr/local/squid/var/cache 200 16 256 The rest is the default config file with reverse proxy configuration (should be cache_replacement_policy lru). There is also an ACL that blocks certain folders, this should not affect the LRU policy. Thanks
