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Maniphest T242871

wbterms: Add a cache for PrefetchingPropertyTermLookup::prefetchTerms()
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Description

Graphs show us that PrefetchingPropertyTermLookup::prefetchTerms() is being called around 70K times every minute. This is clearly too much for something like properties. I suggest adding a layer of APCu cache with TTL of ten seconds to keep the hot data in the servers for long period of time without drowning it.

Details

SubjectRepoBranchLines +/-
Wrap PrefetchingPropertyTermLookup cache to emit metricsmediawiki/extensions/Wikibasemaster+10 -0
Wire up caching around PrefetchingPropertyTermLookupmediawiki/extensions/Wikibasemaster+47 -2
LatestRevisionAndRedirectResolverTest: avoid repeated lookupsmediawiki/extensions/Wikibasemaster+36 -4
Add CachingPrefetchingTermLookupmediawiki/extensions/Wikibasemaster+618 -0
Add RedirectResolvingLatestRevisionLookupmediawiki/extensions/Wikibasemaster+196 -126
Add TermCacheKeyBuildermediawiki/extensions/Wikibasemaster+58 -22
Customize query in gerrit

Related Objects

Event Timeline

Ladsgroup created this task.Jan 15 2020, 3:35 PM
Restricted Application added a subscriber: Aklapper. · View Herald TranscriptJan 15 2020, 3:35 PM
Addshore added a comment.Jan 15 2020, 4:11 PM

As noted in mattermost this might relate to T241050 and before we add any cache we should make sure we need to.
What exactly is causing all of these calls to prefetchTerms ?

Addshore triaged this task as Medium priority.Jan 15 2020, 4:11 PM
Maintenance_bot moved this task from incoming to in progress on the Wikidata board.Jan 15 2020, 4:15 PM
WMDE-leszek changed the task status from Open to Stalled.Jan 16 2020, 1:10 PM

To check next: why prefetching happens, and whether it is needed - if not, should stop happening.

WMDE-leszek changed the task status from Stalled to Open.Jan 16 2020, 1:10 PM
Addshore renamed this task from Add a cache for PrefetchingPropertyTermLookup::prefetchTerms() to wbterms: Add a cache for PrefetchingPropertyTermLookup::prefetchTerms().Jan 16 2020, 4:34 PM
Ladsgroup added a comment.Jan 16 2020, 4:47 PM

It should use the formatter cache.

Jakob_WMDE claimed this task.Jan 20 2020, 12:00 PM
Jakob_WMDE moved this task from To Do (prioritised from top to bottom) to Doing on the Wikidata-Campsite (Wikidata-Campsite-Iteration-∞ (On Hold)) board.
Addshore added a comment.Jan 22 2020, 11:03 AM

We dove a bit deeper into all of the things that are happening surrounding the prefetching, term buffers, lookups, fallbacks and caching and decided that to do this properly we should probably aim for something like this:

image.png (606×1 px, 831 KB)

This doesnt really account for just wanting to retrieve raw terms (rarther than term fallbacks yet), but that could also be worked in, even with its own cache.
This topic area might be a good candidate for a Wikidata-Trailblazing-Exploration

gerritbot added a comment.Jan 23 2020, 4:03 PM

Change 566779 had a related patch set uploaded (by Jakob; owner: Jakob):
[mediawiki/extensions/Wikibase@master] Add TermCache

https://gerrit.wikimedia.org/r/566779

gerritbot added a project: Patch-For-Review.Jan 23 2020, 4:03 PM
gerritbot added a comment.Jan 24 2020, 12:34 PM

Change 567020 had a related patch set uploaded (by Jakob; owner: Jakob):
[mediawiki/extensions/Wikibase@master] Add LatestRevisionResolvingTermCache

https://gerrit.wikimedia.org/r/567020

gerritbot added a comment.Jan 28 2020, 4:52 PM

Change 567487 had a related patch set uploaded (by Jakob; owner: Jakob):
[mediawiki/extensions/Wikibase@master] Add CachingPrefetchingTermLookup

https://gerrit.wikimedia.org/r/567487

gerritbot added a comment.Jan 29 2020, 12:50 PM

Change 566779 merged by jenkins-bot:
[mediawiki/extensions/Wikibase@master] Add TermCacheKeyBuilder

https://gerrit.wikimedia.org/r/566779

ReleaseTaggerBot added a project: MW-1.35-notes (1.35.0-wmf.18; 2020-02-04).Jan 29 2020, 1:01 PM
gerritbot added a comment.Jan 29 2020, 1:59 PM

Change 568494 had a related patch set uploaded (by Jakob; owner: Jakob):
[mediawiki/extensions/Wikibase@master] LatestRevisionAndRedirectResolverTest: avoid repeated lookups

https://gerrit.wikimedia.org/r/568494

Ladsgroup mentioned this in T243912: The new PrefetchingTermLookup doesn't "prefetch".Jan 29 2020, 6:14 PM
Jakob_WMDE moved this task from Doing to Peer Review on the Wikidata-Campsite (Wikidata-Campsite-Iteration-∞ (On Hold)) board.Jan 30 2020, 10:17 AM
gerritbot added a comment.Jan 31 2020, 11:55 AM

Change 569210 had a related patch set uploaded (by Jakob; owner: Jakob):
[mediawiki/extensions/Wikibase@master] Wire up caching around PrefetchingPropertyTermLookup

https://gerrit.wikimedia.org/r/569210

gerritbot added a comment.Jan 31 2020, 3:45 PM

Change 567020 merged by jenkins-bot:
[mediawiki/extensions/Wikibase@master] Add RedirectResolvingLatestRevisionLookup

https://gerrit.wikimedia.org/r/567020

gerritbot added a comment.Feb 3 2020, 7:59 PM

Change 567487 merged by jenkins-bot:
[mediawiki/extensions/Wikibase@master] Add CachingPrefetchingTermLookup

https://gerrit.wikimedia.org/r/567487

gerritbot added a comment.Feb 3 2020, 7:59 PM

Change 568494 merged by jenkins-bot:
[mediawiki/extensions/Wikibase@master] LatestRevisionAndRedirectResolverTest: avoid repeated lookups

https://gerrit.wikimedia.org/r/568494

Addshore moved this task from Peer Review to Test (Verification) on the Wikidata-Campsite (Wikidata-Campsite-Iteration-∞ (On Hold)) board.Feb 6 2020, 9:27 AM
gerritbot added a comment.Feb 6 2020, 9:52 AM

Change 569210 merged by jenkins-bot:
[mediawiki/extensions/Wikibase@master] Wire up caching around PrefetchingPropertyTermLookup

https://gerrit.wikimedia.org/r/569210

ReleaseTaggerBot edited projects, added MW-1.35-notes (1.35.0-wmf.19; 2020-02-11); removed MW-1.35-notes (1.35.0-wmf.18; 2020-02-04).Feb 6 2020, 10:00 AM
Maintenance_bot removed a project: Patch-For-Review.Feb 6 2020, 10:11 AM
WMDE-leszek closed this task as Resolved.Feb 10 2020, 9:39 AM
WMDE-leszek moved this task from Test (Verification) to Done on the Wikidata-Campsite (Wikidata-Campsite-Iteration-∞ (On Hold)) board.

I think we're good with this one. Should there be some work left, please re-open.

gerritbot added a comment.Feb 13 2020, 1:02 PM

Change 571964 had a related patch set uploaded (by Jakob; owner: Jakob):
[mediawiki/extensions/Wikibase@master] Wrap PrefetchingPropertyTermLookup cache to emit metrics

https://gerrit.wikimedia.org/r/571964

gerritbot added a project: Patch-For-Review.Feb 13 2020, 1:02 PM
Ladsgroup added a comment.Feb 13 2020, 1:14 PM

This: https://grafana.wikimedia.org/d/000000548/wikibase-wb_terms?orgId=1&from=1581517070153&to=1581560270153&fullscreen&panelId=6

image.png (863×1 px, 274 KB)

gerritbot added a comment.Feb 13 2020, 2:03 PM

Change 571964 merged by jenkins-bot:
[mediawiki/extensions/Wikibase@master] Wrap PrefetchingPropertyTermLookup cache to emit metrics

https://gerrit.wikimedia.org/r/571964

Maintenance_bot removed a project: Patch-For-Review.Feb 13 2020, 2:10 PM
ReleaseTaggerBot edited projects, added MW-1.35-notes (1.35.0-wmf.20; 2020-02-18); removed MW-1.35-notes (1.35.0-wmf.19; 2020-02-11).Feb 13 2020, 3:00 PM
Addshore added a comment.Nov 16 2020, 7:09 PM

So I noticed that this change can now be seen in some other metrics now too (once I finally narrowed 12th 13th 14th of feb 2020 down to 1.35.0-wmf.19 and finally this ticket and these commits.

Below is the grafana dashboard showing the time it takes to generate parser output for Wikibase items.

image.png (803×1 px, 196 KB)

At the time this change was deploy we saw median "parse" time (and also p75 parse time) for Wikibase item halfed (~200ms -> ~100ms)
(which is awesome)

Lucas_Werkmeister_WMDE mentioned this in T324202: Remove use of utf8_encode and utf8_decode in Wikibase.Dec 21 2023, 11:58 AM
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