From 420c0e0f42509be4b404c74efeb6f77e93bf9599 Mon Sep 17 00:00:00 2001
From: =?utf8?q?M=C3=A1t=C3=A9=20Szab=C3=B3?= <mszabo@wikia-inc.com>
Date: Wed, 22 May 2019 18:03:50 +0200
Subject: [PATCH] Configure LoadBalancer with $wgSharedTables after WAN cache
 autodetection

Currently, $wgSharedTables - if configured - is injected into the LoadBalancer
before the WAN cache autodetection runs. As such, if $wgSharedTables is set
but $wgMainWANCache was not explicitly given, the LoadBalancer will force
a premature instantion of the WAN cache with an EmptyBagOStuff backend,
preventing the autodetection logic from setting a correct backend.
This change moves $wgSharedTables initialization after the WAN cache
autodetection to accunt for this scenario.

Change-Id: I59bb52f42905cda1c2aa47bc589a2f0b36b2a28f
---
 includes/Setup.php | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/includes/Setup.php b/includes/Setup.php
index 071b7c6feb..a51cb83c19 100644
--- a/includes/Setup.php
+++ b/includes/Setup.php
@@ -605,20 +605,6 @@ if ( $wgDebugToolbar && !$wgCommandLineMode ) {
 // re-created while taking into account any custom settings and extensions.
 MediaWikiServices::resetGlobalInstance( new GlobalVarConfig(), 'quick' );
 
-if ( $wgSharedDB && $wgSharedTables ) {
-	// Apply $wgSharedDB table aliases for the local LB (all non-foreign DB connections)
-	MediaWikiServices::getInstance()->getDBLoadBalancer()->setTableAliases(
-		array_fill_keys(
-			$wgSharedTables,
-			[
-				'dbname' => $wgSharedDB,
-				'schema' => $wgSharedSchema,
-				'prefix' => $wgSharedPrefix
-			]
-		)
-	);
-}
-
 // Define a constant that indicates that the bootstrapping of the service locator
 // is complete.
 define( 'MW_SERVICE_BOOTSTRAP_COMPLETE', 1 );
@@ -694,6 +680,20 @@ if ( $wgMainWANCache === false ) {
 	];
 }
 
+if ( $wgSharedDB && $wgSharedTables ) {
+	// Apply $wgSharedDB table aliases for the local LB (all non-foreign DB connections)
+	MediaWikiServices::getInstance()->getDBLoadBalancer()->setTableAliases(
+		array_fill_keys(
+			$wgSharedTables,
+			[
+				'dbname' => $wgSharedDB,
+				'schema' => $wgSharedSchema,
+				'prefix' => $wgSharedPrefix
+			]
+		)
+	);
+}
+
 Profiler::instance()->scopedProfileOut( $ps_default2 );
 
 $ps_misc = Profiler::instance()->scopedProfileIn( $fname . '-misc' );
-- 
2.20.1