Error: Call to a member function getId() on null
Closed, ResolvedPublicPRODUCTION ERROR
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Description

Error

mwversion: 1.38.0-wmf.13
reqId: cdc46e41-0799-462b-a86b-3428f7a3ce2f
Find reqId in Logstash

normalized_message

[{reqId}] {exception_url}   Error: Call to a member function getId() on null

exception.trace

from /srv/mediawiki/php-1.38.0-wmf.13/extensions/GrowthExperiments/includes/Mentorship/MentorPageMentorManager.php(335)
#0 /srv/mediawiki/php-1.38.0-wmf.13/extensions/GrowthExperiments/includes/Mentorship/MentorPageMentorManager.php(345): GrowthExperiments\Mentorship\MentorPageMentorManager->makeCacheKeyWeightedAutoAssignedMentors()
#1 /srv/mediawiki/php-1.38.0-wmf.13/extensions/GrowthExperiments/includes/Mentorship/MentorPageMentorManager.php(379): GrowthExperiments\Mentorship\MentorPageMentorManager->getWeightedAutoAssignedMentors()
#2 /srv/mediawiki/php-1.38.0-wmf.13/extensions/GrowthExperiments/includes/Mentorship/MentorPageMentorManager.php(201): GrowthExperiments\Mentorship\MentorPageMentorManager->getRandomAutoAssignedMentor(User, array)
#3 /srv/mediawiki/php-1.38.0-wmf.13/extensions/GrowthExperiments/includes/Mentorship/MentorPageMentorManager.php(156): GrowthExperiments\Mentorship\MentorPageMentorManager->getRandomAutoAssignedMentorForUserAndRole(User, string)
#4 /srv/mediawiki/php-1.38.0-wmf.13/extensions/GrowthExperiments/includes/Mentorship/MentorPageMentorManager.php(210): GrowthExperiments\Mentorship\MentorPageMentorManager->getMentorForUser(User, string)
#5 /srv/mediawiki/php-1.38.0-wmf.13/extensions/GrowthExperiments/includes/HelpPanelHooks.php(219): GrowthExperiments\Mentorship\MentorPageMentorManager->getMentorForUserSafe(User)
#6 /srv/mediawiki/php-1.38.0-wmf.13/extensions/GrowthExperiments/includes/HelpPanelHooks.php(147): GrowthExperiments\HelpPanelHooks->getMentorData(GrowthExperiments\Config\GrowthExperimentsMultiConfig, User, RequestContext)
#7 /srv/mediawiki/php-1.38.0-wmf.13/includes/HookContainer/HookContainer.php(160): GrowthExperiments\HelpPanelHooks->onBeforePageDisplay(OutputPage, SkinVector)
#8 /srv/mediawiki/php-1.38.0-wmf.13/includes/HookContainer/HookRunner.php(935): MediaWiki\HookContainer\HookContainer->run(string, array, array)
#9 /srv/mediawiki/php-1.38.0-wmf.13/includes/OutputPage.php(2695): MediaWiki\HookContainer\HookRunner->onBeforePageDisplay(OutputPage, SkinVector)
#10 /srv/mediawiki/php-1.38.0-wmf.13/includes/MediaWiki.php(917): OutputPage->output(boolean)
#11 /srv/mediawiki/php-1.38.0-wmf.13/includes/MediaWiki.php(930): MediaWiki::{closure}()
#12 /srv/mediawiki/php-1.38.0-wmf.13/includes/MediaWiki.php(563): MediaWiki->main()
#13 /srv/mediawiki/php-1.38.0-wmf.13/index.php(53): MediaWiki->run()
#14 /srv/mediawiki/php-1.38.0-wmf.13/index.php(46): wfIndexMain()
#15 /srv/mediawiki/w/index.php(3): require(string)
#16 {main}

Impact

Seems to happen solely on cawiki. I am guessing some feature is broken as a result?

Notes

Details

Request URL: https://ca.wikipedia.org/wiki/Viquiprojecte:Tecnologia_de_l%27audiovisual

Subject	Repo	Branch	Lines +/-
Harden MentorPageMentorManager a bit more	mediawiki/extensions/GrowthExperiments	master	+19 -13
MentorManager: Only invalidate cache when mentor list exists	mediawiki/extensions/GrowthExperiments	master	+5 -3
MentorManager: Only invalidate cache when mentor list exists	mediawiki/extensions/GrowthExperiments	wmf/1.38.0-wmf.13	+5 -3
MentorPageMentorManager: Do not fail hard with no mentor list configured	mediawiki/extensions/GrowthExperiments	wmf/1.38.0-wmf.13	+4 -0
MentorPageMentorManager: Do not fail hard with no mentor list configured	mediawiki/extensions/GrowthExperiments	master	+4 -0
Revert "group1 wikis to 1.38.0-wmf.13 refs T293954"	operations/mediawiki-config	master	+528 -528

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		Status	Subtype	Assigned	Task
		Resolved	Release	hashar	T293954 1.38.0-wmf.13 deployment blockers
		Resolved	PRODUCTION ERROR	Urbanecm_WMF	T297827 Error: Call to a member function getId() on null

Event Timeline

hashar triaged this task as Unbreak Now! priority.Dec 15 2021, 8:21 PM

hashar created this task.

Restricted Application added a project: Growth-Team. · View Herald TranscriptDec 15 2021, 8:21 PM

Restricted Application added a subscriber: Aklapper. · View Herald Transcript

hashar added a parent task: T293954: 1.38.0-wmf.13 deployment blockers.Dec 15 2021, 8:21 PM

Seems to be caused by https://gerrit.wikimedia.org/r/c/mediawiki/extensions/GrowthExperiments/+/742269.

@Zabe is right, that's the cause. I asked releng to rollback train because this stops majority of cawiki newcomers from using cawiki.

I'll come up with a patch to fix the error ASAP.

Restricted Application added a project: User-Urbanecm_WMF. · View Herald TranscriptDec 15 2021, 8:43 PM

Change 747606 had a related patch set uploaded (by Hashar; author: Hashar):

[operations/mediawiki-config@master] Revert \"group1 wikis to 1.38.0-wmf.13 refs T293954\"

https://gerrit.wikimedia.org/r/747606

Change 747606 merged by jenkins-bot:

[operations/mediawiki-config@master] Revert \"group1 wikis to 1.38.0-wmf.13 refs T293954\"

https://gerrit.wikimedia.org/r/747606

MediaWiki has been rolled back from group 1 wiki since newcomers were unable to login on cawiki.

hashar mentioned this in T293954: 1.38.0-wmf.13 deployment blockers.Dec 15 2021, 8:52 PM

Maintenance_bot removed a project: Patch-For-Review.Dec 15 2021, 9:10 PM

• kostajh moved this task from Incoming to Ready for Development on the Growth-Team (Sprint 0 (Growth Team)) board.Dec 15 2021, 10:31 PM

Change 747621 had a related patch set uploaded (by Urbanecm; author: Urbanecm):

[mediawiki/extensions/GrowthExperiments@master] MentorPageMentorManager: Do not fail hard with no mentor list configured

https://gerrit.wikimedia.org/r/747621

gerritbot added a project: Patch-For-Review.Dec 15 2021, 10:34 PM

Change 747484 had a related patch set uploaded (by Urbanecm; author: Urbanecm):

[mediawiki/extensions/GrowthExperiments@wmf/1.38.0-wmf.13] MentorPageMentorManager: Do not fail hard with no mentor list configured

https://gerrit.wikimedia.org/r/747484

Both 'getWeightedAutoAssignedMentors' (line 343) and 'invalidateCache' (line 320) call 'makeCacheKeyWeightedAutoAssignedMentors'. The last one calls the getId function of the function getMentorsPage directly( $this->getMentorsPage()->getId(), line 335 ), without checking whether the MentorsPage exists. This could be unsafe.
In getWeightedAutoAssignedMentors there is a check included to see if $this->getMentorsPage() does not return null, that check is NOT made in invalidateCache. I think it is save to have it checked there as well. Or better, make makeCacheKeyWeightedAutoAssignedMentors save by testing there whether $this->getMentorsPage() does not equal null.

Change 747621 merged by jenkins-bot:

[mediawiki/extensions/GrowthExperiments@master] MentorPageMentorManager: Do not fail hard with no mentor list configured

https://gerrit.wikimedia.org/r/747621

ReleaseTaggerBot added a project: MW-1.38-notes (1.38.0-wmf.16; 2022-01-03).Dec 16 2021, 12:00 AM

Change 747791 had a related patch set uploaded (by Urbanecm; author: Urbanecm):

[mediawiki/extensions/GrowthExperiments@master] MentorManager: Only invalidate cache when mentor list exists

https://gerrit.wikimedia.org/r/747791

Change 747484 merged by jenkins-bot:

[mediawiki/extensions/GrowthExperiments@wmf/1.38.0-wmf.13] MentorPageMentorManager: Do not fail hard with no mentor list configured

https://gerrit.wikimedia.org/r/747484

Mentioned in SAL (#wikimedia-operations) [2021-12-16T08:31:56Z] <urbanecm@deploy1002> Synchronized php-1.38.0-wmf.13/extensions/GrowthExperiments/: 35c055cead3d240625b76d21aa4e685525ca0d4b: MentorPageMentorManager: Do not fail hard with no mentor list configured (T297827) (duration: 01m 09s)

Hopefully, this should be fixed with the backport deployed. Note I temporarily disabled mentorship at cawiki, so purely pushing the train forward will not be enough to test this by traffic. I will hopefully test with certainity very soon.

Change 747795 had a related patch set uploaded (by Thiemo Kreuz (WMDE); author: Thiemo Kreuz (WMDE)):

[mediawiki/extensions/GrowthExperiments@master] Harden MentorPageMentorManager a bit more

https://gerrit.wikimedia.org/r/747795

ReleaseTaggerBot edited projects, added MW-1.38-notes (1.38.0-wmf.13; 2021-12-13); removed MW-1.38-notes (1.38.0-wmf.16; 2022-01-03).Dec 16 2021, 9:00 AM

Change 747791 merged by jenkins-bot:

[mediawiki/extensions/GrowthExperiments@master] MentorManager: Only invalidate cache when mentor list exists

https://gerrit.wikimedia.org/r/747791

ReleaseTaggerBot edited projects, added MW-1.38-notes (1.38.0-wmf.16; 2022-01-03); removed MW-1.38-notes (1.38.0-wmf.13; 2021-12-13).Dec 16 2021, 10:00 AM

In T297827#7574050, @RonnieV wrote:

Both 'getWeightedAutoAssignedMentors' (line 343) and 'invalidateCache' (line 320) call 'makeCacheKeyWeightedAutoAssignedMentors'. The last one calls the getId function of the function getMentorsPage directly( $this->getMentorsPage()->getId(), line 335 ), without checking whether the MentorsPage exists. This could be unsafe.
In getWeightedAutoAssignedMentors there is a check included to see if $this->getMentorsPage() does not return null, that check is NOT made in invalidateCache. I think it is save to have it checked there as well. Or better, make makeCacheKeyWeightedAutoAssignedMentors save by testing there whether $this->getMentorsPage() does not equal null.

Thanks for noticing that @RonnieV! This is definitely likely to cause a similar issue in the future. Fortunately, the patch that makes use of the invalidation method is not merged as of now, so this is not as serious as the other issue (for now).

Either way, I uploaded a patch to harden the invalidation patch too, see https://gerrit.wikimedia.org/r/c/mediawiki/extensions/GrowthExperiments/+/747791/.

This is resolved (verified at cawiki, manually promoting it to wmf.13).

Change 747908 had a related patch set uploaded (by Urbanecm; author: Urbanecm):

[mediawiki/extensions/GrowthExperiments@wmf/1.38.0-wmf.13] MentorManager: Only invalidate cache when mentor list exists

https://gerrit.wikimedia.org/r/747908

Change 747908 merged by jenkins-bot:

[mediawiki/extensions/GrowthExperiments@wmf/1.38.0-wmf.13] MentorManager: Only invalidate cache when mentor list exists

https://gerrit.wikimedia.org/r/747908

Mentioned in SAL (#wikimedia-operations) [2021-12-16T19:58:21Z] <urbanecm@deploy1002> Synchronized php-1.38.0-wmf.13/extensions/GrowthExperiments/includes/Mentorship/MentorPageMentorManager.php: b8e64fe189a6a447e68e342ce23cedad6f542df0: MentorManager: Only invalidate cache when mentor list exists (T297827) (duration: 01m 06s)