Thanks for the info. One more question about this: If I use store_rewrite to trim the GUID from the path and only use the relative path to the file (data/foo.txt, for example), and I do another deployment of the same file path (but a different MD5), will squid actually store two copies of this file, or will it dirty the cache copy right away because it uses the URL in the lookup? -----Original Message----- From: Amos Jeffries [mailto:squid3@xxxxxxxxxxxxx] Sent: Friday, December 10, 2010 7:49 PM To: squid-users@xxxxxxxxxxxxxxx Subject: Re: Caching identical items from a dynamic URL On 11/12/10 10:59, Volker-Yoblick, Adam wrote: > Greetings, > > I've got a fairly unique problem that maybe someone can assist with. > > I'm sending files to a machine through my cache, but part of the URL > is dynamic, even if the file is exactly the same. For example, the > lines in my access.log all look like this: > > GET http://1.2.3.4/foo/<GUID>/bar/abc.txt > > Where GUID is different for every single deploy, even if the file is > exactly the same. This is done by creating a virtual directory that > points to a fixed location, but the name of the virtual directory is a > GUID, and changes on every run. This system is already in place, and > cannot be changed. > > I have found that the files are NEVER served from the cache when the > GUID is different, even if the file MD5 is exactly the same. Every > single fill is a cache miss, every time. (I've verified that I DO get > cache hits across multiple deploys when the GUID is the same) > > I imagine this is because squid is using the full URL to determine > whether or not the file is cached, either by including it in the MD5 > hash, or using it as the lookup, or something similar. It is. That is how HTTP works. You can work around such broken server software internally with storeurl_rewrite, but this does nothing to reduce the external bandwidth costs added unnecessarily by your nasty backend. If the client software is capable of handing 30x redirects I recommend performing one from all those GUID paths back to the actual data URI: acl guidBounce urlpath_regex ^/foo/[^/]+/bar/abc.txt$ deny_info http://1.2.3.4/foo/bar/abc.txt guidBounce http_access deny guidBounce Amos -- Please be using Current Stable Squid 2.7.STABLE9 or 3.1.9 Beta testers wanted for 3.2.0.3
