SpecialVersion calls same Memcached get() four times for CentralAuth
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	Krinkle
	Feb 1 2018, 12:09 AM

Description

level=WARNING
channel=memcached
message=
Duplicate get(): "enwiki:specialversion-ext-version-text:/srv/mediawiki/php-1.31.0-wmf.17/extensions/CentralAuth/includes/../CentralAuth.php:d8c8c316b30f6ad6a9b18abd8792818ea78fbc7b" fetched 4 times

This might be related to CentralAuth registering 5 entries in the extension registry:

CentralAuth
GlobalRenameQueue
GlobalRenameRequest
Renameuser for CentralAuth
AntiSpoof for CentralAuth

Might be something we can avoid internally. Either by blindly process-caching (not preferred) or by deduplicating these entries internally for the purposes of SpecialVersion/GitInfo, so that when it goes about its batch to get this information, it only asks for it once and uses it four times. This is essentially process-caching, but within the application domain, instead of generically within WANObject/BagOStuff, and means that can be freed much sooner, as well.

Details

Related Changes in Gerrit:

	Subject	Repo	Branch	Lines +/-
	Hooks: Consolidate CentralAuth credits entries for subextensions	mediawiki/extensions/CentralAuth	master	+1 -47

Customize query in gerrit

Event Timeline

Krinkle created this task.Feb 1 2018, 12:09 AM

Restricted Application added a subscriber: Aklapper. · View Herald TranscriptFeb 1 2018, 12:09 AM

DannyS712 moved this task from To triage to Special:Version on the MediaWiki-Special-pages board.Oct 10 2019, 6:00 AM

Krinkle edited projects, added Performance-Team (Radar); removed Performance Issue.Jun 7 2022, 4:00 PM

Krinkle moved this task from Limbo to Perf recommendation on the Performance-Team (Radar) board.

Still seen today, though interestingly when reproducing it, the entry shows up only for CentralAuth, not for other extensions. This suggests something more specific to that rather than something general in SpecialVersion - unless there's a version information "feature" that only CA utilizes, perhaps?

channel: memcached
WARNING
Duplicate get(): "nlwikinews:specialversion-ext-version-text:/srv/mediawiki/php-1.39.0-wmf.14/extensions/CentralAuth/includes/../extension.json:d160b616f3dc19833e3d0a70bedbe453219cab2f" fetched 4 times

Krinkle edited projects, added MediaWiki-extensions-CentralAuth; removed MediaWiki-Special-pages.Jun 7 2022, 4:58 PM

I imagine CA is the only extension in production that dynamically adds values to $wgExtensionCredits on an extension function. I'm fine removing those and just having the main entry on Special:Version.

Change 829323 had a related patch set uploaded (by Zabe; author: Zabe):

[mediawiki/extensions/CentralAuth@master] Only add one credits entry for CentralAuth

https://gerrit.wikimedia.org/r/829323

gerritbot added a project: Patch-For-Review.Sep 5 2022, 12:40 AM

Change 829323 merged by jenkins-bot:

[mediawiki/extensions/CentralAuth@master] Hooks: Consolidate CentralAuth credits entries for subextensions

https://gerrit.wikimedia.org/r/829323

Maintenance_bot removed a project: Patch-For-Review.Sep 6 2022, 4:31 PM

ReleaseTaggerBot added a project: MW-1.40-notes (1.40.0-wmf.1; 2022-09-12).Sep 6 2022, 5:00 PM

Krinkle closed this task as Resolved.Sep 17 2022, 3:05 PM

Krinkle claimed this task.

Krinkle reassigned this task from Krinkle to Zabe.

SpecialVersion calls same Memcached get() four times for CentralAuthClosed, ResolvedPublicActions

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SpecialVersion calls same Memcached get() four times for CentralAuth
Closed, ResolvedPublic
Actions