From: Aaron Schulz <aschulz@wikimedia.org>
Date: Wed, 15 Jan 2014 04:14:17 +0000 (-0800)
Subject: Use regular slaves for user contribs parent revision queries
X-Git-Tag: 1.31.0-rc.0~17075^2
X-Git-Url: https://git.cyclocoop.org/%28%28?a=commitdiff_plain;h=f7d9a8b74c1e4e59eab68084183c2fd216bf8646;p=lhc%2Fweb%2Fwiklou.git

Use regular slaves for user contribs parent revision queries

Follows-up I65d8eb14c7ea1, I790f5b303fa2.

Bug: 59987
Change-Id: I2265dc81835ccef5d74a043cb85400140b4160c2
---

diff --git a/includes/specials/SpecialContributions.php b/includes/specials/SpecialContributions.php
index 6b56c2fa2a..1e79a11ebb 100644
--- a/includes/specials/SpecialContributions.php
+++ b/includes/specials/SpecialContributions.php
@@ -601,6 +601,9 @@ class ContribsPager extends ReverseChronologicalPager {
 	public $mDb;
 	public $preventClickjacking = false;
 
+	/** @var DatabaseBase */
+	public $mDbSecondary;
+
 	/**
 	 * @var array
 	 */
@@ -637,6 +640,10 @@ class ContribsPager extends ReverseChronologicalPager {
 		$month = isset( $options['month'] ) ? $options['month'] : false;
 		$this->getDateCond( $year, $month );
 
+		// Most of this code will use the 'contributions' group DB, which can map to slaves
+		// with extra user based indexes or partioning by user. The additional metadata
+		// queries should use a regular slave since the lookup pattern is not all by user.
+		$this->mDbSecondary = wfGetDB( DB_SLAVE ); // any random slave
 		$this->mDb = wfGetDB( DB_SLAVE, 'contributions' );
 	}
 
@@ -856,7 +863,7 @@ class ContribsPager extends ReverseChronologicalPager {
 				$batch->add( $row->page_namespace, $row->page_title );
 			}
 		}
-		$this->mParentLens = Revision::getParentLengths( $this->getDatabase(), $revIds );
+		$this->mParentLens = Revision::getParentLengths( $this->mDbSecondary, $revIds );
 		$batch->execute();
 		$this->mResult->seek( 0 );
 	}