Fatal UnresolvedEntityRedirectException when viewing certain Wikidata item pages
Closed, ResolvedPublicPRODUCTION ERROR
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Authored By

	RolandUnger
	Jan 27 2020, 4:00 PM

Description

Error

If I call https://www.wikidata.org/w/index.php?title=Q28966042&redirect=no then I get a server error or an exception like [Xi8HgwpAADsAADteSMgAAACA] 2020-01-27 15:53:39: Fataler Ausnahmefehler des Typs „Wikibase\DataModel\Services\Lookup\UnresolvedEntityRedirectException“.

Wikimedia error message: "Error
Our servers are currently under maintenance or experiencing a technical problem. Please try again in a few minutes.
See the error message at the bottom of this page for more information."

2020-01-27 15:53:39 [Xi8HgwpAADsAADteSMgAAACA] mw1264 wikidatawiki 1.35.0-wmf.16 exception ERROR

Wikibase\DataModel\Services\Lookup\UnresolvedEntityRedirectException: Unresolved redirect from Q28966040 to Q28966039 

at /srv/mediawiki/php-1.35.0-wmf.16/extensions/Wikibase/lib/includes/Store/RevisionBasedEntityLookup.php:75

trace

#0 /srv/mediawiki/php-1.35.0-wmf.16/extensions/Wikibase/lib/includes/Store/LatestRevisionIdResult.php(157): Wikibase\Lib\Store\RevisionBasedEntityLookup->Wikibase\Lib\Store\{closure}(integer, Wikibase\DataModel\Entity\ItemId)
#1 /srv/mediawiki/php-1.35.0-wmf.16/extensions/Wikibase/lib/includes/Store/RevisionBasedEntityLookup.php(77): Wikibase\Lib\Store\LatestRevisionIdResult->map()
#2 /srv/mediawiki/php-1.35.0-wmf.16/vendor/wikibase/data-model-services/src/Lookup/RedirectResolvingEntityLookup.php(72): Wikibase\Lib\Store\RevisionBasedEntityLookup->hasEntity(Wikibase\DataModel\Entity\ItemId)
#3 /srv/mediawiki/php-1.35.0-wmf.16/extensions/Wikibase/repo/RepoHooks.php(960): Wikibase\DataModel\Services\Lookup\RedirectResolvingEntityLookup->hasEntity(Wikibase\DataModel\Entity\ItemId)
#4 /srv/mediawiki/php-1.35.0-wmf.16/includes/Hooks.php(174): Wikibase\RepoHooks::onSkinTemplateBuildNavUrlsNavUrlsAfterPermalink(SkinVector, array, integer, integer)
#5 /srv/mediawiki/php-1.35.0-wmf.16/includes/Hooks.php(202): Hooks::callHook(string, array, array, NULL)
#6 /srv/mediawiki/php-1.35.0-wmf.16/includes/skins/SkinTemplate.php(1332): Hooks::run(string, array)
#7 /srv/mediawiki/php-1.35.0-wmf.16/includes/skins/SkinTemplate.php(455): SkinTemplate->buildNavUrls()
#8 /srv/mediawiki/php-1.35.0-wmf.16/includes/skins/SkinTemplate.php(217): SkinTemplate->prepareQuickTemplate()
#9 /srv/mediawiki/php-1.35.0-wmf.16/includes/OutputPage.php(2593): SkinTemplate->outputPage()
#10 /srv/mediawiki/php-1.35.0-wmf.16/includes/MediaWiki.php(974): OutputPage->output(boolean)
#11 /srv/mediawiki/php-1.35.0-wmf.16/includes/MediaWiki.php(987): MediaWiki->{closure}()
#12 /srv/mediawiki/php-1.35.0-wmf.16/includes/MediaWiki.php(530): MediaWiki->main()
#13 /srv/mediawiki/php-1.35.0-wmf.16/index.php(46): MediaWiki->run()
#14 /srv/mediawiki/w/index.php(3): require(string)
#15 {main}

Impact

Users unable to read or edit part of the data.
User stranded with no clue or further interface (useless system error).
Raised MW exeption noise affecting (alerts and deploy abort).
Raised HTTP 500 levels from prod traffic (alerts)

TODO

In T243779#5865639, @Ladsgroup wrote:

After talking to @Lydia_Pintscher her idea is that anything that's easiest to implement given that this page is barely going to be visited.

Details

	Subject	Repo	Branch	Lines +/-
	Fatal UnresolvedEntityRedirectException when viewing certain Wikidata item pages	mediawiki/extensions/Wikibase	master	+326 -35

Customize query in gerrit

Related Objects

Mentioned In: T238014: Viewing history version of double redirect results in UnresolvedEntityRedirectException
Mentioned Here: T238014: Viewing history version of double redirect results in UnresolvedEntityRedirectException

Event Timeline

RolandUnger created this task.Jan 27 2020, 4:00 PM

Restricted Application added a subscriber: Aklapper. · View Herald TranscriptJan 27 2020, 4:00 PM

RolandUnger added a project: Wikibase-DataModel.Jan 27 2020, 4:06 PM

Addshore added a project: Wikidata-Campsite.Jan 27 2020, 4:29 PM

Addshore added a project: Wikimedia-production-error.

Addshore moved this task from Incoming to Needs Tech Work on the Wikidata-Campsite board.

Reedy changed the subtype of this task from "Task" to "Production Error".Jan 27 2020, 10:15 PM

Reedy edited Stack Trace. (Show Details)

Krinkle renamed this task from Wikidata internal error to Fatal UnresolvedEntityRedirectException when viewing certain Wikidata item pages.Jan 29 2020, 12:17 AM

Krinkle updated the task description. (Show Details)

Krinkle updated the task description. (Show Details)Jan 29 2020, 12:19 AM

Krinkle edited Stack Trace. (Show Details)

Krinkle moved this task from Untriaged to Jan2020/1.35-wmf.14 on the Wikimedia-production-error board.

I guess the expected behaviour here would be the same as mediawiki which is:

First Page 1 ius a redirect then redirect to displaying page 2
If page 2 is a redirect, display the content of page 2 showing that it is a redirect. (see below)

Oh, interesting, the trace looks like it relates to something else though (not main content page render)

@Lydia_Pintscher I'm going to bounce this one over to you for a decision.
I created an example of this happening on test https://test.wikidata.org/w/index.php?title=Q211856&redirect=no

Currently when viewing the item ending 57 which redirects to the item ending 58 we see the following page (when having redirect=no):

Note that the concept URI appears in the toolbox with a link to the concept uri 57
The page content displays the fact the page is a redirect to 58.

If we take a step back in the chain we currently see this (see https://test.wikidata.org/w/index.php?title=Q211856&redirect=no)
we just appear to get a fatal.

This error is happening because of a lookup to do with the concept URI.

I guess the desired behaviour is that this page would render in the same way as the next entity down the chain and the concept URI would be there in the side bar?

Should be quite an easy fix from us either checking if the title is a redirect and not doing the hasEntity check, or just deciding we never need to do the hasEntity check perhaps?

Addshore triaged this task as Medium priority.Feb 6 2020, 9:34 AM

Addshore mentioned this in T238014: Viewing history version of double redirect results in UnresolvedEntityRedirectException.

Addshore merged a task: T238014: Viewing history version of double redirect results in UnresolvedEntityRedirectException.

Addshore added subscribers: Bugreporter, Krinkle.

Krinkle unsubscribed.Feb 6 2020, 2:44 PM

Moving back to match T238014.

After talking to @Lydia_Pintscher her idea is that anything that's easiest to implement given that this page is barely going to be visited.

Addshore moved this task from Needs Wikidata PM Work to Prioritized Wikidata Tech Backlog (prioritised from top to bottom) on the Wikidata-Campsite board.Feb 17 2020, 8:01 AM

Addshore updated the task description. (Show Details)Feb 20 2020, 10:40 AM

Addshore edited projects, added Wikidata-Campsite (Wikidata-Campsite-Iteration-∞ (On Hold)); removed Wikidata-Campsite.

Maintenance_bot moved this task from incoming to in progress on the Wikidata board.Feb 20 2020, 11:15 AM

Rosalie_WMDE claimed this task.Feb 21 2020, 9:51 AM

Rosalie_WMDE moved this task from To Do (prioritised from top to bottom) to Doing on the Wikidata-Campsite (Wikidata-Campsite-Iteration-∞ (On Hold)) board.

Rosalie_WMDE updated the task description. (Show Details)Feb 21 2020, 2:49 PM

In T243779#5839611, @Addshore wrote:

I created an example of this happening on test https://test.wikidata.org/w/index.php?title=Q211856&redirect=no

[…]
The page content displays the fact the page is a redirect to 58.

If we take a step back in the chain we currently see this (see https://test.wikidata.org/w/index.php?title=Q211856&redirect=no)
we just appear to get a fatal.

Fatal exception of type "Wikibase\DataModel\Services\Lookup\UnresolvedEntityRedirectException"

Still reproducible at that url, for the record :)

Change 574495 had a related patch set uploaded (by Rosalie Perside (WMDE); owner: Rosalie Perside (WMDE)):
[mediawiki/extensions/Wikibase@master] Fatal UnresolvedEntityRedirectException when viewing certain Wikidata item pages

https://gerrit.wikimedia.org/r/574495

gerritbot added a project: Patch-For-Review.Feb 24 2020, 3:33 PM

Rosalie_WMDE moved this task from Doing to Peer Review on the Wikidata-Campsite (Wikidata-Campsite-Iteration-∞ (On Hold)) board.Feb 24 2020, 4:01 PM

ItamarWMDE moved this task from Peer Review to Doing on the Wikidata-Campsite (Wikidata-Campsite-Iteration-∞ (On Hold)) board.Mar 2 2020, 10:17 AM

ItamarWMDE claimed this task.Mar 2 2020, 10:26 AM

ItamarWMDE added a subscriber: Rosalie_WMDE.

ItamarWMDE moved this task from Doing to Peer Review on the Wikidata-Campsite (Wikidata-Campsite-Iteration-∞ (On Hold)) board.Mar 4 2020, 11:39 AM

Krinkle merged a task: T246892: UnresolvedEntityRedirectException: Unresolved redirect from Q211857 to Q211858.Mar 12 2020, 1:24 AM

Krinkle added a subscriber: • LarsWirzenius.

Change 574495 merged by jenkins-bot:
[mediawiki/extensions/Wikibase@master] Fatal UnresolvedEntityRedirectException when viewing certain Wikidata item pages

https://gerrit.wikimedia.org/r/574495

ReleaseTaggerBot added a project: MW-1.35-notes (1.35.0-wmf.24; 2020-03-17).Mar 13 2020, 10:00 AM

Maintenance_bot removed a project: Patch-For-Review.Mar 13 2020, 10:11 AM

WMDE-leszek moved this task from Peer Review to Test (Verification) on the Wikidata-Campsite (Wikidata-Campsite-Iteration-∞ (On Hold)) board.Mar 13 2020, 10:20 AM

Addshore closed this task as Resolved.May 4 2020, 1:06 PM

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	Jan 30 2020, 8:44 AM

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Fatal UnresolvedEntityRedirectException when viewing certain Wikidata item pagesClosed, ResolvedPublicPRODUCTION ERRORActions