From: Aaron Schulz <aschulz@wikimedia.org>
Date: Mon, 15 Jun 2015 23:58:54 +0000 (-0700)
Subject: Reduce RC table contention for file deletion
X-Git-Tag: 1.31.0-rc.0~11074^2
X-Git-Url: http://git.cyclocoop.org/%24href?a=commitdiff_plain;h=4a3002063c941e79a48d4903126993a94158e827;p=lhc%2Fweb%2Fwiklou.git

Reduce RC table contention for file deletion

Bug: T98706
Change-Id: I13f12b93abccb348c7093c77c363a54a65b59142
---

diff --git a/includes/deferred/LinksUpdate.php b/includes/deferred/LinksUpdate.php
index eeadd16451..e9ec7ffa2b 100644
--- a/includes/deferred/LinksUpdate.php
+++ b/includes/deferred/LinksUpdate.php
@@ -995,15 +995,27 @@ class LinksDeletionUpdate extends SqlDataUpdate {
 
 		# If using cleanup triggers, we can skip some manual deletes
 		if ( !$this->mDb->cleanupTriggers() ) {
-			# Clean up recentchanges entries...
-			$this->mDb->delete( 'recentchanges',
-				array( 'rc_type != ' . RC_LOG,
+			# Find recentchanges entries to clean up...
+			$rcIdsForTitle = $this->mDb->selectFieldValues( 'recentchanges',
+				'rc_id',
+				array(
+					'rc_type != ' . RC_LOG,
 					'rc_namespace' => $title->getNamespace(),
-					'rc_title' => $title->getDBkey() ),
-				__METHOD__ );
-			$this->mDb->delete( 'recentchanges',
+					'rc_title' => $title->getDBkey()
+				),
+				__METHOD__
+			);
+			$rcIdsForPage = $this->mDb->selectFieldValues( 'recentchanges',
+				'rc_id',
 				array( 'rc_type != ' . RC_LOG, 'rc_cur_id' => $id ),
-				__METHOD__ );
+				__METHOD__
+			);
+
+			# T98706: delete PK to avoid lock contention with RC delete log insertions
+			$rcIds = array_merge( $rcIdsForTitle, $rcIdsForPage );
+			if ( $rcIds ) {
+				$this->mDb->delete( 'recentchanges', array( 'rc_id' => $rcIds ), __METHOD__ );
+			}
 		}
 	}