Thanks for the explanations Amos, much appreciated. On Thu, 18 Jan 2024 at 16:24, Amos Jeffries <squ...@treenet.co.nz> wrote:
> On 19/01/24 03:53, Robin Carlisle wrote: > > Hi, Hoping someone can help me with this issue that I have been > > struggling with for days now. I am setting up squid on an ubuntu PC to > > forward HTTPS requests to an API and an s3 bucket under my control on > > amazon AWS. The reason I am setting up the proxy is two-fold... > > > > 1) To reduce costs from AWS. > > 2) To provide content to the client on the ubuntu PC if there is a > > networking issue somewhere in between the ubuntu PC and AWS. > > > > Item 1 is going well so far. Item 2 is not going well. Setup details > ... > > > ... > > > > > When network connectivity is BAD, I get errors and a cache MISS. In > > this test case I unplugged the ethernet cable from the back on the > > ubuntu-pc ... > > > > *# /var/log/squid/access.log* > > 1705588717.420 11 127.0.0.1 NONE_NONE/200 0 CONNECT > > stuff.amazonaws.com:443 <http://stuff.amazonaws.com:443> - > > HIER_DIRECT/3.135.162.228 <http://3.135.162.228> - > > 1705588717.420 0 127.0.0.1 NONE_NONE/503 4087 GET > > https://stuff.amazonaws.com/api/v1/stuff/stuff.json > > <https://stuff.amazonaws.com/api/v1/stuff/stuff.json> - HIER_NONE/- > > text/html > > > > *# extract from /usr/bin/proxy-test output* > > < HTTP/1.1 503 Service Unavailable > > < Server: squid/5.7 > > < Mime-Version: 1.0 > > < Date: Thu, 18 Jan 2024 14:38:37 GMT > > < Content-Type: text/html;charset=utf-8 > > < Content-Length: 3692 > > < X-Squid-Error: ERR_CONNECT_FAIL 101 > > < Vary: Accept-Language > > < Content-Language: en > > < X-Cache: MISS from ubuntu-pc > > < X-Cache-Lookup: NONE from ubuntu-pc:3129 > > < Via: 1.1 ubuntu-pc (squid/5.7) > > < Connection: close > > > > I have also seen it error in a different way with a 502 but with the > > same ultimate result. > > > > My expectation/hope is that squid would return the cached object on any > > network failure in between ubuntu-pc and the AWS endpoint - and continue > > to return this cached object forever. Is this something squid can do? > > It would seem that offline_mode should do this? > > > > > FYI, offline_mode is not a guarantee that a URL will always HIT. It is > simply a form of "greedy" caching - where Squid will take actions to > ensure that full-size objects are fetched whenever it lacks one, and > serve things as stale HITs when a) it is not specifically prohibited, > and b) a refresh/fetch is not working. > > > The URL you are testing with should meet your expected behaviour due to > the "Cache-Control: public, stale-of-error" header alone. > Regardless of offline_mode configuration. > > > That said, getting a 5xx response when there is an object already in > cache seems like something is buggy to me. > > A high level cache.log will be needed to figure out what is going on > (see https://wiki.squid-cache.org/SquidFaq/BugReporting#full-debug-output > ). > Be aware this list does not permit large posts so please provide a link > to download in your reply not attachment. > > > Cheers > Amos > _______________________________________________ > squid-users mailing list > squid-users@lists.squid-cache.org > https://lists.squid-cache.org/listinfo/squid-users >
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