[squid-users] offline mode not working for me

[Robin Carlisle]

Thanks for the explanations Amos, much appreciated.

On Thu, 18 Jan 2024 at 16:24, Amos Jeffries <squid3 at 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 at lists.squid-cache.org
> https://lists.squid-cache.org/listinfo/squid-users
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.squid-cache.org/pipermail/squid-users/attachments/20240119/a42920d9/attachment.htm>