From: Aaron Schulz <aschulz@wikimedia.org>
Date: Thu, 14 Jun 2018 00:14:23 +0000 (-0700)
Subject: rdbms: disable ChronologyProtector if EmptyBagOStuff is used
X-Git-Tag: 1.31.1~12
X-Git-Url: https://git.heureux-cyclage.org/?p=lhc%2Fweb%2Fwiklou.git;a=commitdiff_plain;h=b718b8926c061b9fa1253c24e9d094e039791ea7

rdbms: disable ChronologyProtector if EmptyBagOStuff is used

Bug: T197206
Change-Id: Ic07634224fac1ae72d1ba20176c028fdda5ba415
---

diff --git a/RELEASE-NOTES-1.31 b/RELEASE-NOTES-1.31
index 7872403e41..a67aca010c 100644
--- a/RELEASE-NOTES-1.31
+++ b/RELEASE-NOTES-1.31
@@ -13,6 +13,7 @@ This is a security and maintenance release of the MediaWiki 1.31 branch.
 * (T193829) Indicate when a Bot Password needs reset.
 * (T198037) GitInfo: Don't try shelling out if it's disabled.
 * (T151415) Log email changes.
+* (T197206) Fix performance regression when multiple DB used without caching.
 
 == MediaWiki 1.31 ==
 
diff --git a/includes/libs/rdbms/lbfactory/LBFactory.php b/includes/libs/rdbms/lbfactory/LBFactory.php
index c272147639..401e9b3627 100644
--- a/includes/libs/rdbms/lbfactory/LBFactory.php
+++ b/includes/libs/rdbms/lbfactory/LBFactory.php
@@ -466,6 +466,10 @@ abstract class LBFactory implements ILBFactory {
 			// Request opted out of using position wait logic. This is useful for requests
 			// done by the job queue or background ETL that do not have a meaningful session.
 			$this->chronProt->setWaitEnabled( false );
+		} elseif ( $this->memStash instanceof EmptyBagOStuff ) {
+			// No where to store any DB positions and wait for them to appear
+			$this->chronProt->setEnabled( false );
+			$this->replLogger->info( 'Cannot use ChronologyProtector with EmptyBagOStuff.' );
 		}
 
 		$this->replLogger->debug( __METHOD__ . ': using request info ' .