From: Tim Starling <tstarling@users.mediawiki.org>
Date: Sat, 20 Sep 2008 15:00:53 +0000 (+0000)
Subject: Don't run hour-long, unlimited row-count DB queries with set_time_limit(0) in respons... 
X-Git-Tag: 1.31.0-rc.0~45193
X-Git-Url: https://git.cyclocoop.org/%7B%24admin_url%7Dmembres/fiche.php?a=commitdiff_plain;h=9b8782aaa8d8a8d20e95217c16d50a13178de724;p=lhc%2Fweb%2Fwiklou.git

Don't run hour-long, unlimited row-count DB queries with set_time_limit(0) in response to unauthenticated web requests on the  Run them on the slave instead. Maybe we can crash the whole cluster instead of just a master or two.

Don't use DB_LAST, ever again.
---

diff --git a/RELEASE-NOTES b/RELEASE-NOTES
index 1024ecfb3c..6d40652e81 100644
--- a/RELEASE-NOTES
+++ b/RELEASE-NOTES
@@ -212,6 +212,7 @@ it from source control: http://www.mediawiki.org/wiki/Download_from_SVN
 * (bug 14638) Special:Blockip now provides a link to the block log if the user
   has been blocked more than 10 times. Patch by Matt Johnston.
 * (bug 12678) Skins don't show Upload link if the user isn't allowed to upload.
+* Fixed incorrect usage of DB_LAST in Special:Export. Deprecated DB_LAST.
 
 === API changes in 1.14 ===
 
diff --git a/includes/GlobalFunctions.php b/includes/GlobalFunctions.php
index 44d35120da..5733c957a5 100644
--- a/includes/GlobalFunctions.php
+++ b/includes/GlobalFunctions.php
@@ -2644,7 +2644,7 @@ function wfSplitWikiID( $wiki ) {
  * will always return the same object, unless the underlying connection or load
  * balancer is manually destroyed.
  */
-function &wfGetDB( $db = DB_LAST, $groups = array(), $wiki = false ) {
+function &wfGetDB( $db, $groups = array(), $wiki = false ) {
 	return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
 }
 
diff --git a/includes/db/Database.php b/includes/db/Database.php
index ed5c05c1bc..476260dc32 100644
--- a/includes/db/Database.php
+++ b/includes/db/Database.php
@@ -372,7 +372,7 @@ class Database {
 			if ( !$error ) {
 				$error = $phpError;
 			}
-			wfLogDBError( "Connection error: $error\n" );
+			wfLogDBError( "Error connecting to {$this->mServer}: $error\n" );
 		}
 		
 		wfProfileOut("dbconnect-$server");
diff --git a/includes/db/LoadBalancer.php b/includes/db/LoadBalancer.php
index dd0c66b562..733ee5ee38 100644
--- a/includes/db/LoadBalancer.php
+++ b/includes/db/LoadBalancer.php
@@ -15,7 +15,7 @@ class LoadBalancer {
 
 	/* private */ var $mServers, $mConns, $mLoads, $mGroupLoads;
 	/* private */ var $mFailFunction, $mErrorConnection;
-	/* private */ var $mReadIndex, $mLastIndex, $mAllowLagged;
+	/* private */ var $mReadIndex, $mAllowLagged;
 	/* private */ var $mWaitForPos, $mWaitTimeout;
 	/* private */ var $mLaggedSlaveMode, $mLastError = 'Unknown error';
 	/* private */ var $mParentInfo, $mLagTimes;
@@ -52,7 +52,6 @@ class LoadBalancer {
 			'local' => array(),
 			'foreignUsed' => array(),
 			'foreignFree' => array() );
-		$this->mLastIndex = -1;
 		$this->mLoads = array();
 		$this->mWaitForPos = false;
 		$this->mLaggedSlaveMode = false;
@@ -441,13 +440,7 @@ class LoadBalancer {
 		if ( $i == DB_SLAVE ) {
 			$i = $this->getReaderIndex( false, $wiki, $attempts );
 		} elseif ( $i == DB_LAST ) {
-			# Just use $this->mLastIndex, which should already be set
-			$i = $this->mLastIndex;
-			if ( $i === -1 ) {
-				# Oh dear, not set, best to use the writer for safety
-				wfDebug( "Warning: DB_LAST used when there was no previous index\n" );
-				$i = $this->getWriterIndex();
-			}
+			throw new MWException( 'Attempt to call ' . __METHOD__ . ' with deprecated server index DB_LAST' );
 		}
 		# Couldn't find a working server in getReaderIndex()?
 		if ( $i === false ) {
@@ -545,7 +538,6 @@ class LoadBalancer {
 				$conn = false;
 			}
 		}
-		$this->mLastIndex = $i;
 		wfProfileOut( __METHOD__ );
 		return $conn;
 	}
diff --git a/includes/specials/SpecialExport.php b/includes/specials/SpecialExport.php
index 5021e96fc3..32a43ec0a5 100644
--- a/includes/specials/SpecialExport.php
+++ b/includes/specials/SpecialExport.php
@@ -230,7 +230,7 @@ function wfSpecialExport( $page = '' ) {
 		} else {
 			// Use an unbuffered query; histories may be very long!
 			$lb = wfGetLBFactory()->newMainLB();
-			$db = $lb->getConnection( DB_LAST );
+			$db = $lb->getConnection( DB_SLAVE );
 			$buffer = WikiExporter::STREAM;
 			
 			// This might take a while... :D