From: Brad Jorsch <bjorsch@wikimedia.org>
Date: Thu, 21 Feb 2019 15:47:07 +0000 (-0500)
Subject: ApiQueryUserContribs: Only use 'contributions' replica if querying by user ID
X-Git-Tag: 1.34.0-rc.0~2751^2
X-Git-Url: http://git.cyclocoop.org/?a=commitdiff_plain;h=fe65f68588638d9f067580a341f8de3d3a85394f;hp=1900a8a12e8e1445fa8b9cca46a89354fcc88f1d;p=lhc%2Fweb%2Fwiklou.git

ApiQueryUserContribs: Only use 'contributions' replica if querying by user ID

When querying by user name or actor ID, the partitioning on the
'contributions' replicas makes things worse rather than better.

Bug: T216656
Change-Id: Ib4caf19d8fad64c527dee99667e425fd3e4b1a16
---

diff --git a/includes/api/ApiQueryUserContribs.php b/includes/api/ApiQueryUserContribs.php
index 60826178b4..ae1be0d4ef 100644
--- a/includes/api/ApiQueryUserContribs.php
+++ b/includes/api/ApiQueryUserContribs.php
@@ -61,14 +61,11 @@ class ApiQueryUserContribs extends ApiQueryBase {
 		$this->fld_patrolled = isset( $prop['patrolled'] );
 		$this->fld_tags = isset( $prop['tags'] );
 
-		// Most of this code will use the 'contributions' group DB, which can map to replica DBs
+		// The main query may use the 'contributions' group DB, which can map to replica DBs
 		// with extra user based indexes or partioning by user. The additional metadata
 		// queries should use a regular replica DB since the lookup pattern is not all by user.
 		$dbSecondary = $this->getDB(); // any random replica DB
 
-		// TODO: if the query is going only against the revision table, should this be done?
-		$this->selectNamedDB( 'contributions', DB_REPLICA, 'contributions' );
-
 		$sort = ( $this->params['dir'] == 'newer' ? '' : ' DESC' );
 		$op = ( $this->params['dir'] == 'older' ? '<' : '>' );
 
@@ -269,6 +266,13 @@ class ApiQueryUserContribs extends ApiQueryBase {
 			$this->orderBy = 'actor';
 		}
 
+		// Use the 'contributions' replica, but only if we're querying by user ID (T216656).
+		if ( $this->orderBy === 'id' &&
+			!( $wgActorTableSchemaMigrationStage & SCHEMA_COMPAT_READ_NEW )
+		) {
+			$this->selectNamedDB( 'contributions', DB_REPLICA, 'contributions' );
+		}
+
 		$count = 0;
 		$limit = $this->params['limit'];
 		$userIter->rewind();