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Attempt to add a query cache to DPL

Description

Attempt to add a query cache to DPL

DPL has some expensive queries. When an expensive query is used
in a template used on a lot of pages, and they all get refreshed
at once (or in this specific case, a bot edited 100,000 such pages
in very short time frame), this can cause a bit of a stampede to
the db to recalculate the same value over and over again, potentially
causing query pile ups.

This adds support for having a cache of the query results. The idea
being that a short cache should help reduce repetitive load on the db.
Using "lowTTL" should help ensure that not all application servers
attempt to requery the DPL at the same time.

By default this cache is disabled, I would suggest setting
$wgDLPQueryCacheTime to be 120 on Wikimedia wikis to begin with,
and see how that works.

Bug: T262391
Bug: T262240
Bug: T263220
Change-Id: I92197f93d67342f9c4e7550ed5760f512d2416b9

Details

Provenance
BawolffAuthored on Sep 10 2020, 6:37 AM
UrbanecmCommitted on Oct 29 2020, 1:37 PM
Parents
rEANDa55482365884: build: Updating mediawiki/mediawiki-phan-config to 0.10.3
Branches
Unknown
Tags
Unknown
References
wmf/1.36.0-wmf.16, refs/changes/68/626268/14
ChangeId
I92197f93d67342f9c4e7550ed5760f512d2416b9

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