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Joerg
Asked: 2021-02-12 05:38:25 +0800 CST

Which response headers are making Squid's refresh_pattern ineffective?

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I cannot get Squid to cache anything with the following origin response headers.

When I use curl repeatedly, I get the following response

> curl -s -D - -o /dev/null -x "http://localhost:3128" http://my-domain.com/test.jpeg
HTTP/1.1 200 OK
x-powered-by: Express
access-control-allow-origin: undefined
Vary: Accept
Content-Type: image/jpeg
Cache-Control: private, no-transform, max-age=0
Date: Thu, 11 Feb 2021 12:44:00 GMT
Server: Google Frontend
X-Cache: MISS from b6cf67dac785
X-Cache-Lookup: HIT from b6cf67dac785:3128
Transfer-Encoding: chunked
Via: 1.1 google, 1.1 b6cf67dac785 (squid/4.13)
Connection: keep-alive

It looks like it finds the image in its cache, but revalidates with the server and then gets a fresh copy from the server?

I don't want it to revalidate first - it needs to serve it straight out of the cache. I am the only client of Squid - and I want to force every single image to be cached regardless of the headers of the origin server. I know this breaks HTTP accepted protocols - but I still want to force Squid to cache absolutely everything. (it will only ever fetch images)

This is my refresh_pattern directive I am using

refresh_pattern . 525600 100% 525600 override-expire override-lastmod ignore-reload ignore-no-cache ignore-no-store reload-into-ims ignore-must-revalidate ignore-private ignore-auth store-stale

I can't see which of the response headers are rendering my refresh_pattern ineffective?

I have also the following two directives set. With or without them - there is no difference.

minimum_expiry_time 1 year
max_stale 1 year

For reference, I also attach response headers that do cache well with my current refresh_pattern.

HTTP/1.1 200 OK
x-goog-generation: 1613049999992692
x-goog-metageneration: 3
x-goog-stored-content-encoding: identity
x-goog-stored-content-length: 159962
x-goog-meta-: 
x-goog-custom-time: 1970-01-01T00:00:00Z
Content-Type: image/jpeg
x-goog-hash: crc32c=6EwUgA==
x-goog-hash: md5=OGlL99uyN7kr4j0umpn5pw==
x-goog-storage-class: STANDARD
Accept-Ranges: bytes
X-GUploader-UploadID: ABg5-UwYGdi405Mc_A1_ppi6O7NIXd3UKOpqbzcj1WvMzVN-N3U1hb-O_FdSGdBt5ZPDWU63egT-kwi4lrx8RVu4k_0
Date: Thu, 11 Feb 2021 13:27:47 GMT
Cache-Control: private, no-transform, max-age=0
Expires: Thu, 11 Feb 2021 13:27:47 GMT
Last-Modified: Thu, 11 Feb 2021 13:26:40 GMT
ETag: "38694bf7dbb237b92be23d2e9a99f9a7"
Content-Length: 0
Server: UploadServer
Age: 0
X-Cache: HIT from b6cf67dac785
X-Cache-Lookup: HIT from b6cf67dac785:3128
Via: 1.1 b6cf67dac785 (squid/4.13)
Connection: keep-alive
cache squid

0 Answers