Hi Eliezer, Yes, Jaap is my first name :) I might have not mentioned this before, but I'm using Squid as a reverse proxy / in acceleration mode. So as far as I know your comments are not applicable. Thanks for your thoughts though!
Jaap 2016-06-19 7:16 GMT+02:00 Eliezer Croitoru <elie...@ngtech.co.il>: > Hey Jaap, (not sure if it's the first name) > > The issue is that there are consequences for cached objects not being > revalidated. > Also if there are sites which needs to be targeted it would be a different > story. > Some might not understand the difference between a cache and an archive or > want it to act as one. > A cache is meant to be temporary while archive should last longer. > One example is Windows Updates which might needs to be archived since it's > always needed. > > If you have a specific targeted site, let me know and I will try to see if > something can be done. > > Eliezer > > ---- > Eliezer Croitoru > Linux System Administrator > Mobile: +972-5-28704261 > Email: elie...@ngtech.co.il > > > -----Original Message----- > From: squid-users [mailto:squid-users-boun...@lists.squid-cache.org] On > Behalf Of Alex Rousskov > Sent: Friday, June 17, 2016 6:22 PM > To: Jaap Dam > Cc: squid-users@lists.squid-cache.org > Subject: Re: [squid-users] Queue incoming requests when fetching from > origin > > On 06/17/2016 05:33 AM, Jaap Dam wrote: > > > From what I > > understand, re-validation is useful when done with If-Modified-Since > > or If-None-Match. > > To revalidate stale objects, Squid uses conditional requests. That is not > the only way to revalidate, but that is what Squid does. > > > > However my responses do not provide the E-Tag header nor the > > Last-Modified header. > > IIRC, the If-Modified-Since field in a conditional request may use the > response Date header when Last-Modified is not available. If the origin > server supports checking resource modification times (without disclosing > them in responses for some reason), revalidation would still work as > intended. > > > > Is it possible for Squid to never revalidate but always to assume > > 'pure cache-miss' when a resource is stale? > > I am not sure. Others may be able to answer this question authoritatively. > If you force me to guess, I would say "no". > > Alex. > > > > > 2016-06-16 17:20 GMT+02:00 Alex Rousskov > > <rouss...@measurement-factory.com > > <mailto:rouss...@measurement-factory.com>>: > > > > On 06/16/2016 01:45 AM, Jaap Dam wrote: > > > > > Thanks for the information. Could you elaborate on when collapsed > > > forwarding does apply? > > > > Squid is currently able to collapse HTTP client [miss] requests (but > not > > internally generated HTTP requests triggered by HTTP client > requests). > > Furthermore, to be collapsable, the request must have no markings > that > > make the future response uncachable. > > > > > > > With your extra information, my assumption would > > > be that it only applies on requests of a resource that has never > been > > > cached before. > > > > I would not phrase it like that because Squid does not remember was > has > > been cached before, only what is still cached at the query time. > There > > are three primary cases for an HTTP client request to consider here: > > > > * pure cache hit: Collapsing is inapplicable because Squid does not > send > > any requests (there is nothing to collapse). Each HTTP client > request is > > satisfied from the Squid cache. > > > > * pure cache miss: Multiple requests for the same missing object can > be > > collapsed if collapsed_forwarding is enabled. Collapsable requests > have > > no markings that make the future response uncachable. > > > > * revalidation: The requested object was found in the cache but it > was > > stale. Squid sends an internal "revalidation" request to the origin > > server or peer. These internal requests are currently not collapsed. > We > > are working on collapsing them as well. > > > > > > > Secondly would you have a suggestion for solving the issue I'm > facing? > > > > > > I have not studied the issue you are facing, but if you think > collapsing > > revalidation requests would solve your problem, then either wait for > us > > to finish initial collapsed revalidation support (and then see if it > > solves your problem) or co-sponsor that ongoing development (to make > > sure it solves your problem). > > > > > > HTH, > > > > Alex. > > > > > > > > > 2016-06-15 17:19 GMT+02:00 Alex Rousskov: > > > > > > On 06/14/2016 02:51 AM, Jaap Dam wrote: > > > > > > > I've part of the logging as an attachment. I'm requesting a > > single URL > > > > in this log. The log starts with a stale cache of the item. > > > > > > Collapsed forwarding does not apply to cache revalidation > > requests yet. > > > Factory is working on implementing collapsed revalidations (in > > some > > > environments), but I cannot promise a specific delivery date > > or that > > > your particular environment will be covered. > > > > > > Alex. > > > > > > > > > > > > > > > > 2016-06-13 15:34 GMT+02:00 Amos Jeffries: > > > > > > > > On 14/06/2016 12:29 a.m., Jaap Dam wrote: > > > > > Is the collapsed_forwarding directive the correct one > > to use > > > for my > > > > > use-case or am i missing something? > > > > > > > > Yes it is correct so far as I am understanding your need. > > > > > > > > For further debugging about what is going on you will > > need the > > > HTTP > > > > messages involved. Add the directive "debug_options 11,2 > > 20,3" > > > to your > > > > config to get them logged in cache.log. > > > > > > > > > > > > _______________________________________________ > squid-users mailing list > squid-users@lists.squid-cache.org > http://lists.squid-cache.org/listinfo/squid-users > >
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