-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 13/11/2014 3:04 a.m., Hussam Al-Tayeb wrote: > On Thursday 13 November 2014 02:23:12 Amos Jeffries wrote: >> On 13/11/2014 1:55 a.m., Hussam Al-Tayeb wrote: >>> On Thursday 13 November 2014 01:39:27 Amos Jeffries wrote: >>>> On 13/11/2014 12:17 a.m., Hussam Al-Tayeb wrote: >>>>> Hello. I have a problem with 'squidclient -m PURGE' and >>>>> also the purge command. They won't purge urls from disk >>>>> that are not available online anymore or redirect to other >>>>> links. >>>> >>>> PURGE was designed for use in HTTP/1.0. It does not handle >>>> HTTP/1.1 negotiated content / variants at all well. >>>> >>>>> For example, >>>>> http://static.firedrive.com/dynamic/previews/75/27577be2d6d86af20265734b >>>>> >>>>> 64 >> >> e8d563.jpg >> >>>> which corresponds to /home/squid/00/BB/0000BBC0 >>>> >>>>> Even "purge -e "static.firedrive.com" -c >>>>> /etc/squid/squid.conf -P 0x01" reads it but will not really >>>>> remove it from disk. Are such files stuck on disk forever? >>>> >>>> No. Cache is a temporary storage location. Think of it as a >>>> buffer in the network. >>>> >>>> They will exist only until a) the storage space is needed >>>> for something else, or b) the timestamp in their Expires: >>>> header, or c) an origin server informs Squid they are no >>>> longer existing. >>>> >>>> PURGE method was a way to fake (c). >>>> >>>>> What would the correct way to clear them? >>>> >>>> By obeying HTTP protocol. HTTP has built-in mechanisms for >>>> doing that automatically. >>>> >>>> Or you can just delete the disk file. Squid will auto-detect >>>> the removal at some point when it needs to use or delete the >>>> object. Until then it will just under-count the amount of >>>> used disk. >>>> >>>> Amos >>>> >>>> _______________________________________________ squid-users >>>> mailing list squid-users@xxxxxxxxxxxxxxxxxxxxx >>>> http://lists.squid-cache.org/listinfo/squid-users >>> >>> head /home/squid/00/BB/0000BBC0 -n20 >>> >>> �u��(▒��,�|�S�| >>> �S��f7�P`Uhttp://static.firedrive.com/dynamic/previews/75/27577be2d6d86af2 >>> >>> 0265734b64e8d563.jpg >> R"accept-encoding="gzip,%20deflate"HTTP/1.1 200 OK >> >> ... notice and remember the accept-encoding=* value in quotes >> above. We shall get back to that later. >> >> Now for a little tale of woe... >> >> On this Date: >>> Date: Tue, 26 Aug 2014 12:25:13 GMT >> >> ... the >> >>> Server: cloudflare-nginx >> >> ... representing static.firedrive.com has expicitly with >> complete >> >> authority state that the: >>> Content-Type: image/jpeg >> >> ... otherwise known as: >>> ETag: "5090c137-2efb" >> >> ... should remain in cache until: >>> Expires: Fri, 23 Aug 2024 12:25:13 GMT >> >> ... should remain in cache until Aug 2024. >> >> Furthermore that: >>> Last-Modified: Wed, 31 Oct 2012 06:12:07 GMT Cache-Control: >>> public, max-age=315360000 >> >> ... there is no need for any recipient storing the object to >> even check for validity again until Oct 2022. >> >>> Access-Control-Allow-Origin: * Access-Control-Allow-Methods: >>> GET, POST, OPTIONS Access-Control-Allow-Headers: >>> Origin,Referer,Accept-Encoding,Accept- >>> Language,Accept,DNT,X-Mx-ReqToken,Keep-Alive,User-Agent,X-Requested-With,I >>> >>> f- >> Modified-Since,Cache-Control,Content-Type,X-Forwarded-For,X-Forwarded-Proto >> >>> >> CF-Cache-Status: HIT Vary: Accept-Encoding Accept-Ranges: bytes >>> CF-RAY: 160002c2e4730887-FRA Content-Length: 12027 Connection: >>> Keep-Alive Set-Cookie: >>> __cfduid=dfcf568ed46ef827243b3d6c342b3bdc41409055913424; >>> expires=Mon, 23-Dec-2019 23:50:00 GMT; path=/; >>> domain=.firedrive.com; HttpOnly >> >> ... and that the Cookies it served up shall remain on the users >> machine until Dec 2019. Thereafter this object shall be served >> without any Cookie. >> >>> The Expires header is in the past. >>> "http://static.firedrive.com/dynamic/previews/75/27577be2d6d86af20265734b6 >>> >>> 4e8d563.jpg" >> Sending HTTP request ... done. >> >>> HTTP/1.1 404 Not Found Server: squid Mime-Version: 1.0 Date: >>> Wed, 12 Nov 2014 12:54:13 GMT Content-Length: 0 X-Cache: MISS >>> from SERV1 X-Cache-Lookup: NONE from SERV1:3129 Via: 1.1 SERV1 >>> (squid) Connection: close >>> >>> Is that why squidclient -m PURGE -h 127.0.0.1 -p 3129 says >>> not found in cache? >> >> The Vary: header is why your PURGE is not doing anything. It >> means you have to find and send in the exactly right value for >> Accept-Encoding, in order for PURGE to find and erase the actual >> object. >> >> The request *not* having an Accept-Encoding header is one of the >> possible variations of values. In particular it is the one which >> is foudn to already be absent from your cache by your PURGE >> command. >> >> This is where that quoted string up top of the object file comes >> in. What is cached on disk is the object for: squidclient -m >> PURGE -p 3129 -H 'Accept-Encoding: gzip, deflate\n' >> >> The purge tool has not been updated in some years and does not >> support these types of variant commonly found in HTTP/1.1 >> traffic. >> >> Amos > > Ok, thank you for the explanation. seems wget and curl also say > "X-Cache: MISS from SERV1 X-Cache-Lookup: NONE from SERV1:3129" Expected. It's hard to set exactly the right header contents with those tools. Thus squidclient is recommended when manually doing fine-grained testing. > > So the current natural ways of purging the object is waiting till > squid runs out of space and rotates old objects or reaching the > Expire date of 2024, correct? Both options are ok. I just wanted to > make sure squid is self cleaning even if things take time. Yes, it is. To be more precise Squid currently will revalidate objects more than 1 year old if things actually stay in cache that long. Most times the traffic throughput is big enough to push objects out of cache after only a month or two even when configuring huge cache_dir spaces. Amos -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (MingW32) iQEcBAEBAgAGBQJUY3H3AAoJELJo5wb/XPRjr3sH/15KC9dV0VlqTdS6b/QKcBOM LhCcNOhod/qVibtX0j4W1R+FtPvW+ZZqrgl/d3+XA50PF65Bsp6UAG9Greq1Kwav cqu1tkhV/aokLgxxi9YdUcphLqq15hGdEusx/+XwwH59sPDqR9+PpIbRnWyLwBG9 b7TGgZFjNXvK4/8CLXcOPgjm0L5ML4mo0DPf4AYPCKo6kRJ7/AWNKBt93aanQcFx dA6UIjvdWf8T86uF5NJXSHQf4T75fTRiTAZSDIiN8Q8TogeEG1ys8IUa5XZi008d nst0I4EopqZalbh2e4yQ1taCNpR0wjIRdbwXzQVu1WxytnyrfRql/1gunTYGq8A= =vDUl -----END PGP SIGNATURE----- _______________________________________________ squid-users mailing list squid-users@xxxxxxxxxxxxxxxxxxxxx http://lists.squid-cache.org/listinfo/squid-users
