[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 denny vrandecic denny.vrande...@wikimedia.de changed: What|Removed |Added Status|RESOLVED|VERIFIED --- Comment #65 from denny vrandecic denny.vrande...@wikimedia.de --- Closed older resolved bugs as verified. -- You are receiving this mail because: You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 --- Comment #64 from Niklas Laxström niklas.laxst...@gmail.com --- I don't think so. Nevertheless it is soon irrelevant as remaining squids are being migrated to varnish (as far as I know). -- You are receiving this mail because: You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 Helder mybugs.m...@gmail.com changed: What|Removed |Added CC||mybugs.m...@gmail.com --- Comment #63 from Helder mybugs.m...@gmail.com --- (In reply to comment #62) (In reply to comment #61) Was this done? Ping. -- You are receiving this mail because: You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 Nemo federicol...@tiscali.it changed: What|Removed |Added CC||federicol...@tiscali.it --- Comment #62 from Nemo federicol...@tiscali.it --- (In reply to comment #61) The canonical home for Tim's X-Vary-Options patch is: https://gerrit.wikimedia.org/r/gitweb?p=operations/debs/squid.git;a=blob; f=debian/patches/26-vary_options.dpatch;hb=HEAD When Tim posted his patch to the squid-dev mailing list in 2008, there seem to have been interest in merging it to Squid-2.HEAD. Adrian Chadd, one of Squid's maintainers, wrote: I'm happy to commit this to Squid-2.HEAD as-is. Can you throw it in a Bugzilla report and spit me the number? http://www.squid-cache.org/mail-archive/squid-dev/200802/0282.html The idea of extending this patch to handle cookie names and values was floated later in the thread. One way to move this current ticket forward would be to do exactly as Adrian suggests and file a Bugzilla bug for this patch on Squid's bug tracker, provide a link to (and a summary of) this discussion, and then e-mail squid-dev about it. Was this done? Squid 2.7.9 is still the stable head of the 2.7 version and is widely used, so it is not implausible that someone with the requisite skill will step up. -- You are receiving this mail because: You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 --- Comment #61 from Ori Livneh o...@wikimedia.org 2012-11-16 18:11:24 UTC --- The canonical home for Tim's X-Vary-Options patch is: https://gerrit.wikimedia.org/r/gitweb?p=operations/debs/squid.git;a=blob;f=debian/patches/26-vary_options.dpatch;hb=HEAD When Tim posted his patch to the squid-dev mailing list in 2008, there seem to have been interest in merging it to Squid-2.HEAD. Adrian Chadd, one of Squid's maintainers, wrote: I'm happy to commit this to Squid-2.HEAD as-is. Can you throw it in a Bugzilla report and spit me the number? http://www.squid-cache.org/mail-archive/squid-dev/200802/0282.html The idea of extending this patch to handle cookie names and values was floated later in the thread. One way to move this current ticket forward would be to do exactly as Adrian suggests and file a Bugzilla bug for this patch on Squid's bug tracker, provide a link to (and a summary of) this discussion, and then e-mail squid-dev about it. Squid 2.7.9 is still the stable head of the 2.7 version and is widely used, so it is not implausible that someone with the requisite skill will step up. -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 --- Comment #59 from Daniel Kinzler daniel.kinz...@wikimedia.de 2012-11-15 19:57:38 UTC --- I have filed two feature requests to ULS for two possible solutions: * disable ULS for anons: bug 42157 * disable language detection (Eric's proposal): bug 42159 Perhaps this here report should be moved to the Wikimedia/wikidata component, because it's about a solution for wikidata.org that involves ULS and Squid configuration. -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 Tim Starling tstarl...@wikimedia.org changed: What|Removed |Added Status|NEW |RESOLVED Resolution||FIXED --- Comment #60 from Tim Starling tstarl...@wikimedia.org 2012-11-16 00:37:29 UTC --- (In reply to comment #59) I have filed two feature requests to ULS for two possible solutions: * disable ULS for anons: bug 42157 Implemented and deployed. -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 --- Comment #55 from Daniel Kinzler daniel.kinz...@wikimedia.de 2012-11-14 09:26:56 UTC --- (In reply to comment #53) Squid 2.x has a 'storeurl_rewrite_program' directive, which specifies an external program that Squid calls to rewrite / canonicalize URLs prior to performing cache operations: Squids are the front tier. They get hit about a hundred thousand times per second (perhaps a few hundred times each) on the wikimedia cluster. Are you sure this scales? -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 --- Comment #56 from Daniel Kinzler daniel.kinz...@wikimedia.de 2012-11-14 09:36:17 UTC --- (In reply to comment #53) I wrote a simple rewriter in Python that checks for the presence of a 'ULS' cookie and adds it to the URL as an additional query parameter (also attached). Does Squid consider that a variant, or a separate URL? If it's a separate URL, purging becomes a problem, because we then have to explicitly purge all 500 or so possible URL variations. -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 --- Comment #57 from Ori Livneh o...@wikimedia.org 2012-11-14 10:35:28 UTC --- Ok, so this too would screw with purging. Sorry for being daft. Following a discussion about this with Daniel and Tim on IRC, it appears that the right way to fix this is: 1) Disable the extension for now. 2) Amend Tim's X-Vary-Options patch (http://paste.ubuntu.com/1357630/) to also operate on cookies. -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 Siebrand s.mazel...@xs4all.nl changed: What|Removed |Added CC||prei...@wikimedia.org --- Comment #58 from Siebrand s.mazel...@xs4all.nl 2012-11-14 11:35:11 UTC --- AFAIK Patrick Reilly has some thoughts. I hope he can share them here. -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 --- Comment #48 from Niklas Laxström niklas.laxst...@gmail.com 2012-11-13 09:26:07 UTC --- It seems to be forgotten in this discussion that ULS will also set the default language for anon users based on the accept-language header even before they select any language explicitly. That feature would not work with the solution described in comment #47. -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 --- Comment #49 from Erik Moeller e...@wikimedia.org 2012-11-13 09:50:13 UTC --- Niklas, that feature could be disabled for now. If I'm understanding things correctly, implementing that feature reasonably well would require selection of cached language copies of a page based on the contents of the ULS cookie, and scalable implementation of purging across all cached copies. Is the description in comment 47 correct/workable? Is it preferable to a URL-based approach? If the answers are yes and yes, I suggest we iterate, and once we've got that solution implemented and deployed on small wikis that use ULS, focus on what the desired behavior will be in the glorious Varnish future. -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 --- Comment #50 from Erik Moeller e...@wikimedia.org 2012-11-13 10:02:41 UTC --- (In reply to comment #49) If I'm understanding things correctly, implementing that feature reasonably well would require selection of cached language copies of a page based on the contents of the ULS cookie To clarify, the Accept-Language feature would require selecting the correct variant from the cache based on Accept-Language, _and_ overriding that choice with the variant specified by the ULS cookie if set. Again, please limit the feature set to something that's feasible now and iterate from there. -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 --- Comment #51 from Ori Livneh o...@wikimedia.org 2012-11-13 23:55:15 UTC --- Created attachment 11354 -- https://bugzilla.wikimedia.org/attachment.cgi?id=11354 Patch for Squid to add cookie headers to output sent to storeurl_rewrite_program -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 --- Comment #52 from Ori Livneh o...@wikimedia.org 2012-11-13 23:56:50 UTC --- Created attachment 11355 -- https://bugzilla.wikimedia.org/attachment.cgi?id=11355 storeurl_rewrite_program in Python that adds value of ULS cookie as query param to URL. -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 --- Comment #53 from Ori Livneh o...@wikimedia.org 2012-11-13 23:57:26 UTC --- I wrote a patch for Squid that I hope would fix this issue. Squid 2.x has a 'storeurl_rewrite_program' directive, which specifies an external program that Squid calls to rewrite / canonicalize URLs prior to performing cache operations: http://www.squid-cache.org/Doc/config/storeurl_rewrite_program/ The rewriter is a simple program that reads a request log on standard input and writes URLs to standard output. The format of the request log that Squid sends the rewriter does not contain the cookie headers, but adding them requires the addition of just one line to store_rewrite.c. I've attached a patch made against the current stable tag (SQUID_2_7). I wrote a simple rewriter in Python that checks for the presence of a 'ULS' cookie and adds it to the URL as an additional query parameter (also attached). To state the obvious: making even a small change to Squid is a big deal, so this would need to be reviewed very carefully by ops to make sure it is correct. The effort required may or may not be worth it, depending on the practicality of other available workarounds. But I will note that there may be an additional benefit to using a storeurl rewrite program: we could apply some ordering rule on query parameters, which could plausibly improve cache performance. (Perhaps we're doing this already -- I'm not too familiar with our setup.) -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 Ori Livneh o...@wikimedia.org changed: What|Removed |Added Attachment #11354|0 |1 is obsolete|| --- Comment #54 from Ori Livneh o...@wikimedia.org 2012-11-14 00:02:20 UTC --- Created attachment 11356 -- https://bugzilla.wikimedia.org/attachment.cgi?id=11356 Patch for Squid to add cookie headers to output sent to storeurl_rewrite_program -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 --- Comment #43 from Daniel Kinzler daniel.kinz...@wikimedia.de 2012-11-12 09:01:03 UTC --- My understanding is that in the near term the ULS folks are only deploying ULS to small wikis (Wikidata is probably one of the biggest ones). So would disabling or splitting the cache if the ULS cookie is present be a) acceptable, and b) feasible using one of the available methods, e.g. X-Vary-Options? I suppose Mark and Tim are the authorities on the subject, but let me reiterate my understanding: ad a) Splitting the cache by language in the ULS cookie is actually not the issue - it would rather be a solution to the issue. As far as I understand, it would be fine at least for small wikis. ad b) It's not possible with Squid (but probably is with Varnish). We could vary on the entire cookie header - but that would be unique per client, not splitting but exploding the cache and making it useless. Or we could use XVO, but that only lets us vary on the *presence* of a cookie - all anons with the ULS cookie set (no matter to which value) would hit the same cached version, which would not improve the situation at all. Or we could hack squid to make this possible. I don't know how complex this is, or who could do it, or how long it would take to roll this out. There's an option c): use different URLs for different language versions of each page. There are two problems with this: 1) whenever the page changes, *all* the (potential) URLs have to be purged explicitly, increasing the number of purged by two orders of magnitude (and we'd need to hack core to do it). And we need to rewrite *all* links in the interface to the language specific version (needs lots of changes in core and messes with internal caching). The StickToThatLanguage extension uses URL parameters and rewrites the links using JavaScript. It does not work without JS. Because it uses the uselang=xx parameter, it bypasses all caches. Maybe squid can be made to vary on the uselang parameter, but then we again have the purging problem. Even though, STTL might actually be the best option we have right now. -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 --- Comment #44 from Liangent liang...@gmail.com 2012-11-12 09:30:44 UTC --- (In reply to comment #43) Or we could use XVO, but that only lets us vary on the *presence* of a cookie - all anons with the ULS cookie set (no matter to which value) would hit the same cached version, which would not improve the situation at all. IIRC the language converter varies on the presence of every supported variant code in Accept-Language. Maybe we can vary on the presence of mw_uls_langcode in cookies here (however the list will be much longer than the language converter one)? -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 --- Comment #45 from Mark Bergsma m...@nedworks.org 2012-11-12 11:21:20 UTC --- (In reply to comment #40) Please help me better understand our options here. My understanding is that in the near term the ULS folks are only deploying ULS to small wikis (Wikidata is probably one of the biggest ones). So would disabling or splitting the cache if the ULS cookie is present be a) acceptable, and b) feasible using one of the available methods, e.g. X-Vary-Options? (Does ULS have to set a cookie if the user does not change the language? It seems to do so regardless of whether I change the language or not right now.) If that's feasible, then I would suggest going for that path, limiting ULS deployments for logged out users to small wikis until the Varnish migration, and working with someone in ops until then to explore the best option to scale caching of UI language variants of the same page properly via Varnish. Does that make sense? That seems reasonable, yes. It takes care of the slashdot problem, since first time visitors don't have a cookie set and get the cached default language page. When there's a cookie set, we better not cache it at all since the cache hit rate would be extremely low anyways, and it would just inflate the cache. As Faidon indicates, we'll have to send Vary: cookie headers anyway, for other caching proxies out there. That will destroy their cache hit rate on this as well, but there's not much we can do about that. -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 --- Comment #46 from Mark Bergsma m...@nedworks.org 2012-11-12 11:33:34 UTC --- (In reply to comment #45) As Faidon indicates, we'll have to send Vary: cookie headers anyway, for other caching proxies out there. That will destroy their cache hit rate on this as well, but there's not much we can do about that. Actually, they have to revalidate every time anyway, so that doesn't matter. :) -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 --- Comment #47 from Erik Moeller e...@wikimedia.org 2012-11-13 07:32:07 UTC --- (In reply to comment #45) That seems reasonable, yes. It takes care of the slashdot problem, since first time visitors don't have a cookie set and get the cached default language page. When there's a cookie set, we better not cache it at all since the cache hit rate would be extremely low anyways, and it would just inflate the cache. So how would this work in practice? Scenario A: 1) Client requests https://wikidata.org/ _without_ ULS cookies present and without being logged in. 2) Say we get a cache MISS. Page is returned with XVO including the ULS cookie name, and with Vary: cookie for other caches not supporting XVO. 3) Page is now cached server-side. 4) ULS is loaded client-side. It does not set any cookies because the user does not change her default language. 5) User continues to browse as normal. 6) User gets cache HITs or MISSes as normal in the default language. Scenario B: 1) Client requests https://wikidata.org/ with ULS cookie present due to a previous language change via ULS. 2) We get a cache MISS because page hasn't been previously cached in variant with ULS cookie present. 3) MediaWiki checks for ULS cookie and sends Cache-Control: no-cache, no-store, must-revalidate header alongside the requested page. 4) Squid therefore does not cache the page. 5) The same is true for subsequent pageviews, including pageviews by other users with the ULS cookie present. The user now consistently gets cache MISSes, including from intermediate caches. Would this approach more or less work for small wikis or am I fundamentally misunderstanding something? -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 Erik Moeller e...@wikimedia.org changed: What|Removed |Added CC||e...@wikimedia.org --- Comment #40 from Erik Moeller e...@wikimedia.org 2012-11-10 13:11:12 UTC --- Please help me better understand our options here. My understanding is that in the near term the ULS folks are only deploying ULS to small wikis (Wikidata is probably one of the biggest ones). So would disabling or splitting the cache if the ULS cookie is present be a) acceptable, and b) feasible using one of the available methods, e.g. X-Vary-Options? (Does ULS have to set a cookie if the user does not change the language? It seems to do so regardless of whether I change the language or not right now.) If that's feasible, then I would suggest going for that path, limiting ULS deployments for logged out users to small wikis until the Varnish migration, and working with someone in ops until then to explore the best option to scale caching of UI language variants of the same page properly via Varnish. Does that make sense? -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 --- Comment #41 from Niklas Laxström niklas.laxst...@gmail.com 2012-11-11 05:05:32 UTC --- (In reply to comment #40) (Does ULS have to set a cookie if the user does not change the language? It seems to do so regardless of whether I change the language or not right now.) We can change it to not add* cookie if the user interface language === wiki content language. * and remove if already existing -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 --- Comment #42 from Patrick Reilly prei...@wikimedia.org 2012-11-11 06:19:11 UTC --- I'm going to talk to Siebrand Mazeland about this issue today and see if we can figure something out short-term. — Patrick -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451
--- Comment #32 from Siebrand s.mazel...@xs4all.nl 2012-11-09 09:37:23 UTC ---
(In reply to comment #31)
(In reply to comment #30)
Copy-pasting what I said on wikitech-l:
I don't know about Squid, but there are all manner of ways you could
attack
this problem with Varnish. Overriding vcl_hash lets you customize how a
cache key is constructed from a request. It's usually just hostname +
URL,
but you can add any string to the hash:
sub vcl_hash {
if (req.http.Cookie ~ language) {
hash_data(regsub(req.http.Cookie, ^.*(language=[^;]+).*$,
\1));
}
}
You've just broken purging.
Mark, you being the expert here, at least to me knowledge, can you please help
and work towards a solution? From what I can see, your expertise hasn't been
used yet on this issue, except for pointing out what's wrong with proposed
solutions.
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[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 --- Comment #33 from Daniel Kinzler daniel.kinz...@wikimedia.de 2012-11-09 11:04:10 UTC --- Going by what I heard from Mark, Tim Starling and others, the situation seems to be like this: * there is no way to do this with the current Squid caches. Varying con Accept-Language and Cookie got vetoed by Tim. * Bypassing Squids would make it work, but opens a DoS vector. Mark does *not* like it. * there are probably ways to do this with the new Varnish caches. * Migration to Varnish is at least 6 months away. * ULS can still be used as a convenient way to switch UI language for logged in users. At least for Wikidata, that would still be helpful. I'd be happy if someone could tell me this assessment is wrong... -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 --- Comment #34 from Mark Bergsma m...@nedworks.org 2012-11-09 11:20:02 UTC --- (In reply to comment #33) Going by what I heard from Mark, Tim Starling and others, the situation seems to be like this: * there is no way to do this with the current Squid caches. Varying con Accept-Language and Cookie got vetoed by Tim. * Bypassing Squids would make it work, but opens a DoS vector. Mark does *not* like it. * there are probably ways to do this with the new Varnish caches. * Migration to Varnish is at least 6 months away. * ULS can still be used as a convenient way to switch UI language for logged in users. At least for Wikidata, that would still be helpful. Correct. There isn't really any solution right now. I think ULS should only be enabled for logged in users until we have Varnish in place. -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 --- Comment #35 from Liangent liang...@gmail.com 2012-11-09 11:54:57 UTC --- I think I'm now confused about X-Vary-Options: http://www.squid-cache.org/mail-archive/squid-dev/200802/0085.html Does it mean things are cached with those test results appended as key or things are not cached at all if any test whether the XXX header contains the string YYY succeed? -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 --- Comment #36 from Siebrand s.mazel...@xs4all.nl 2012-11-09 12:51:05 UTC --- (In reply to comment #33) Going by what I heard from Mark, Tim Starling and others, the situation seems to be like this: * Bypassing Squids would make it work, but opens a DoS vector. Mark does *not* like it. * there are probably ways to do this with the new Varnish caches. * Migration to Varnish is at least 6 months away. I'm confused. See below. (In reply to comment #21) Aren't we using Varnish already? Snippet from wikidata.org: Server:Apache Vary:Accept-Encoding Via:1.1 varnish Via:1.1 varnish X-Varnish:1326947601 X-Varnish:3373410970 X-Vary-Options:Accept-Encoding;list-contains=gzip This remained unanswered. So I'm asking again: Aren't we using Varnish already? -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 --- Comment #37 from Mark Bergsma m...@nedworks.org 2012-11-09 13:04:33 UTC --- (In reply to comment #36) I'm confused. See below. (In reply to comment #21) Aren't we using Varnish already? Snippet from wikidata.org: Server:Apache Vary:Accept-Encoding Via:1.1 varnish Via:1.1 varnish X-Varnish:1326947601 X-Varnish:3373410970 X-Vary-Options:Accept-Encoding;list-contains=gzip This remained unanswered. So I'm asking again: Aren't we using Varnish already? No we're not. Elsewhere, but not on the text cluster, which is what's relevant here. I'm not sure where the snippet above comes from, but not from the text caching cluster. -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 --- Comment #38 from Aude aude.w...@gmail.com 2012-11-09 15:07:14 UTC --- I assume the varnish is coming from the bits, which includes images and also resource loader stuff (e.g. javascript). I think what matters for the use-case here is the actual html page, which still comes from squid. -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 Faidon Liambotis fai...@wikimedia.org changed: What|Removed |Added CC||fai...@wikimedia.org --- Comment #39 from Faidon Liambotis fai...@wikimedia.org 2012-11-09 16:14:19 UTC --- As I've noted elsewhere, do note that there are intermediate (forward) caches around in the world, and you have to take those into account too when setting HTTP cache headers. -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451
--- Comment #31 from Mark Bergsma m...@nedworks.org 2012-11-07 11:44:50 UTC
---
(In reply to comment #30)
Copy-pasting what I said on wikitech-l:
I don't know about Squid, but there are all manner of ways you could attack
this problem with Varnish. Overriding vcl_hash lets you customize how a
cache key is constructed from a request. It's usually just hostname + URL,
but you can add any string to the hash:
sub vcl_hash {
if (req.http.Cookie ~ language) {
hash_data(regsub(req.http.Cookie, ^.*(language=[^;]+).*$,
\1));
}
}
You've just broken purging.
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[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 Daniel Kinzler daniel.kinz...@wikimedia.de changed: What|Removed |Added Summary|Assumes Dutch on first |ULS causes pages to be |visit, then switches to |cached with random user |English |language -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 --- Comment #24 from Mark Bergsma m...@nedworks.org 2012-11-06 14:11:21 UTC --- (In reply to comment #20) Oh, to add one more problem: purging. When a page changes, all variants (languages) of that page need to be purged. I don't think we currently have a mechanism for this at all. All variants of a URL are purged by Squid and Varnish, so that in itself is not a problem. -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 --- Comment #25 from Mark Bergsma m...@nedworks.org 2012-11-06 14:18:17 UTC --- (In reply to comment #14) I dug up Tim's original mail containing the patch that introduces X-Vary-Options into Squid: http://www.squid-cache.org/mail-archive/squid-dev/200802/0085.html. There seems to be very li8ttle documentation beyond that. From what I see, the best we can do with that is something like: X-Vary-Options: Cookie; string-contains=language; But that would just split the cache into two: requests with the language cookie set, and those without the language cookie set. It does not very on the value of the cookie. Also - is it still true that X-Vary-Options is a custom patch, and never got into the Squids main line? if not, please fix http://wiki.squid-cache.org/Features/XvaryOptions :) I believe it did enter Squid main line. But that doesn't help much; other caches (like Varnish) don't have it. Anyway - what we would actually need is something like X-Vary-Cookie: language ...that would vary on the value of the language cookie. Or maybe X-Vary-Options could be extended to cover this: X-Vary-Options: Cookie; string-extract=language=([^;]*); But this is messy, and I don't think anyone is up to patching Squid further. So... other options? Could we vary on the ETAg header, and generate it depending on the user language? No, since the client doesn't know the E-Tag header of course, and isn't sending it. PS: I'm also a bit surprised that this issue comes at a surprise. Allowing anons to set the interface language is requested about once a year, and this problem is the reason it got shot down time and time again. With regards to Wikidata, I discussed this problem with several staffers at the Berlin hackathon and at Wikimania. Essentially I was told wait for ULS, they'll take care of that stuff. Hm. I am too. It's not exactly a new problem. Of course exploding the cache is not a big problem for a small wiki like wikidata, but we can't even think about deploying this on any larger wikis until we've solved this properly... -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 --- Comment #26 from Mark Bergsma m...@nedworks.org 2012-11-06 14:20:20 UTC --- So eventually we'll move the text cluster to Varnish as well, which would make this problem slightly easier as we can influence request headers in VCL. ULS would need to be adapted for efficient use of that. But the migration of the Text caching cluster to Varnish is at least another 6 months out still. -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 --- Comment #27 from Daniel Kinzler daniel.kinz...@wikimedia.de 2012-11-06 15:30:58 UTC --- @mark: so how about ULS just send out Cache-Control: no-cache for now? That would cause all pages to just bypass the proxies, right? Better than a vary on cookie and accept-language, and probably acceptable for Wikidata, where we expect few anon visitors. -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 --- Comment #28 from Mark Bergsma m...@nedworks.org 2012-11-06 16:03:51 UTC --- I think neither disabling all caching, nor fragmenting the cache are acceptable solutions for any wiki getting more than a tiny amount of traffic. But if I absolutely had to pick one, it would be fragmenting the cache, along with a lowish (5 mins?) cache ttl. Because that would still protect the backend infrastructure a bit in case of spikes/slashdotting/etc. But again, we really need a better solution than either of those two. If not, we'd probably be forced to turn ULS off entirely when hitting problems/spikes. -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451 --- Comment #29 from Daniel Kinzler daniel.kinz...@wikimedia.de 2012-11-06 16:09:45 UTC --- For the record: I'm told that with varnish, we could vary on the value of a given cookie. That would solve the problem. But migration to varnish is at least 6 months away. I think ULS should have an option for working with that kind of varnish setup efficiently. -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 41451] ULS causes pages to be cached with random user language
https://bugzilla.wikimedia.org/show_bug.cgi?id=41451
Ori Livneh o...@wikimedia.org changed:
What|Removed |Added
CC||o...@wikimedia.org
--- Comment #30 from Ori Livneh o...@wikimedia.org 2012-11-07 06:19:13 UTC ---
(In reply to comment #29)
For the record: I'm told that with varnish, we could vary on the value of a
given cookie. That would solve the problem. But migration to varnish is at
least 6 months away.
I think ULS should have an option for working with that kind of varnish setup
efficiently.
Copy-pasting what I said on wikitech-l:
I don't know about Squid, but there are all manner of ways you could attack
this problem with Varnish. Overriding vcl_hash lets you customize how a
cache key is constructed from a request. It's usually just hostname + URL,
but you can add any string to the hash:
sub vcl_hash {
if (req.http.Cookie ~ language) {
hash_data(regsub(req.http.Cookie, ^.*(language=[^;]+).*$, \1));
}
}
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