[squid-users] Whis this dosn't cache??

From: Eliezer Croitoru <eliezer_at_ngtech.co.il>
Date: Wed, 03 Jul 2013 10:21:44 +0300

I am working on a nice CDN thingy and it seems like squid dosn't like to
cache a specific file which I am unsure what the source of the situation.

http://image.slidesharecdn.com/rhintrotoglusterfsoct11final-111028123627-phpapp01/95/slide-1-728.jpg

The above picture should be valid for a very long time.
but still it wont be "cached" by squid.
it shows a tcp_miss but with 304 in some cases.

let see the headers:
http://image.slidesharecdn.com/rhintrotoglusterfsoct11final-111028123627-phpapp01/95/slide-1-728.jpg
    HTTP/1.1 200 OK
     x-amz-id-2:
JtJw8v5lPSefAEEDVApzLOWPF/Lmy7ttRT/HgRdKuLl5JAX9Rbb1pygmP8pQeuEv
     x-amz-request-id: 9FA9F1E86159EA13
     Last-Modified: Tue, 22 May 2012 21:39:05 GMT
     x-amz-version-id: G2WGsAhVccve.RJClMGhTihNIt1KLDFw
     ETag: "3393a72a72e345fc4e4a376cccc19b8a"
     Accept-Ranges: bytes
     Content-Type: image/jpeg
     Server: AmazonS3
     Vary: Accept-Encoding
     Content-Encoding: gzip
     Content-Length: 41835
     Cache-Control: max-age=31536000
     Date: Wed, 03 Jul 2013 07:11:19 GMT
     Connection: keep-alive

Which should be cachable for at-least very very long time on all caches.
the local browser indeed caches this response but squid that I am using
is not caching.
I am trying to debug it and findout if the reason is ETAG, VARY or any
other logical reason.
in storelog I get:
1372835768.497 RELEASE -1 FFFFFFFF 3CD80312CC879BF0B4A6BC9C4961EC58 200
1372835768 -1 1372935768 x-squid-internal/vary -1/0 GET
http://image.slidesharecdn.com/rhintrotoglusterfsoct11final-111028123627-phpapp01/95/slide-1-728.jpg?1319823416
1372835768.498 RELEASE 00 00052434 1CB505B7CCAB884A87D43FDE53B6CD28 200
1372835445 1337722745 1404371445 image/jpeg 41835/41835 GET
http://image.slidesharecdn.com/rhintrotoglusterfsoct11final-111028123627-phpapp01/95/slide-1-728.jpg?1319823416
1372835768.537 SWAPOUT 00 0005243D 14024A1A79441DDDD53A39CD5A2A954B 200
1372835787 1337722745 1404371787 image/jpeg 41835/41835 GET
http://image.slidesharecdn.com/rhintrotoglusterfsoct11final-111028123627-phpapp01/95/slide-1-728.jpg?1319823416
1372835768.991 RELEASE 00 0005243C 4A81AD074E34431EAFBB0029E93C0EDF 200
1372835698 1372835698 1372835758 application/javascript 205/205 GET
http://syndication.twimg.com/widgets/timelines/paged/345198371184709633?domain=www.linuxuser.co.uk&lang=en&since_id=352154234759823361&callback=twttr.tfw.callbacks.tlPoll_345198371184709633_1_352154234759823361&suppress_response_codes=true

Which I am unsure on how to read now.

in squid access.log I see that:
1372835884.106 127 192.168.10.124 TCP_MISS/200 42410 GET
http://image.slidesharecdn.com/rhintrotoglusterfsoct11final-111028123627-phpapp01/95/slide-1-728.jpg
- HIER_DIRECT/88.221.156.163 image/jpeg
1372835893.774 72 192.168.10.124 TCP_MISS/200 42410 GET
http://image.slidesharecdn.com/rhintrotoglusterfsoct11final-111028123627-phpapp01/95/slide-1-728.jpg
- HIER_DIRECT/88.221.156.163 image/jpeg

there is no revalidation which is preferred and should be done in a case
of reload using refresh_patttern

I also tried another thing:
1372835980.822 155 192.168.10.124 TCP_MISS/200 42410 GET
http://image.slidesharecdn.com/rhintrotoglusterfsoct11final-111028123627-phpapp01/95/slide-1-728.jpg?1319823415
- HIER_DIRECT/88.221.156.163 image/jpeg
1372835983.651 74 192.168.10.124 TCP_MISS/200 42410 GET
http://image.slidesharecdn.com/rhintrotoglusterfsoct11final-111028123627-phpapp01/95/slide-1-728.jpg?1319823415
- HIER_DIRECT/88.221.156.163 image/jpeg

Which uses StoreID and it seems like the internals of StoreID do the
trick for most sites but in this case there is another issue which I am
unable to identify myself yet.

Any points to findout what is going on and why squid wouldn't cache a
response that firefox explorer and chrome would do???

Thanks,
Eliezer
Received on Wed Jul 03 2013 - 07:22:09 MDT

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