From 3b13196c8a4d77617438e37f9ca29e8eee416317 Mon Sep 17 00:00:00 2001
From: Tim Starling <tstarling@users.mediawiki.org>
Date: Thu, 28 Sep 2006 09:05:28 +0000
Subject: [PATCH] various improvements

---
 maintenance/fixSlaveDesync.php | 133 ++++++++++++++++++++++++++++-----
 1 file changed, 114 insertions(+), 19 deletions(-)

diff --git a/maintenance/fixSlaveDesync.php b/maintenance/fixSlaveDesync.php
index e97f96c9a8..d2dffe543f 100644
--- a/maintenance/fixSlaveDesync.php
+++ b/maintenance/fixSlaveDesync.php
@@ -22,12 +22,50 @@ if ( isset( $args[0] ) ) {
 } else {
 	$dbw =& wfGetDB( DB_MASTER );
 	$maxPage = $dbw->selectField( 'page', 'MAX(page_id)', false, 'fixDesync.php' );
+	$corrupt = findPageLatestCorruption();
+	foreach ( $corrupt as $id => $dummy ) {
+		desyncFixPage( $id );
+	}
+		/*
 	for ( $i=1; $i <= $maxPage; $i++ ) {
 		desyncFixPage( $i );
 		if ( !($i % $reportingInterval) ) {
 			print "$i\n";
 		}
+	}*/
+}
+
+function findPageLatestCorruption() {
+	$desync = array();
+	$n = 0;
+	$dbw =& wfGetDB( DB_MASTER );
+	$masterIDs = array();
+	$res = $dbw->select( 'page', array( 'page_id', 'page_latest' ), array( 'page_id<6054123' ), __METHOD__ );
+	print "Number of pages: " . $dbw->numRows( $res ) . "\n";
+	while ( $row = $dbw->fetchObject( $res ) ) {
+		$masterIDs[$row->page_id] = $row->page_latest;
+		if ( !( ++$n % 10000 ) ) {
+			print "$n\r";
+		}
 	}
+	print "\n";
+	$dbw->freeResult( $res );
+	
+	global $slaveIndexes;
+	foreach ( $slaveIndexes as $i ) {
+		$slaveIDs = array();
+		$db =& wfGetDB( $i );
+		$res = $db->select( 'page', array( 'page_id', 'page_latest' ), array( 'page_id<6054123' ), __METHOD__ );
+		while ( $row = $db->fetchObject( $res ) ) {
+			if ( isset( $masterIDs[$row->page_id] ) && $masterIDs[$row->page_id] != $row->page_latest ) {
+				$desync[$row->page_id] = true;
+				print $row->page_id . "\t";
+			}
+		}
+		$db->freeResult( $res );
+	}
+	print "\n";
+	return $desync;
 }
 
 function desyncFixPage( $pageID ) {
@@ -36,10 +74,20 @@ function desyncFixPage( $pageID ) {
 
 	# Check for a corrupted page_latest
 	$dbw =& wfGetDB( DB_MASTER );
-	$realLatest = $dbw->selectField( 'page', 'page_latest', array( 'page_id' => $pageID ), $fname );
+	$dbw->begin();
+	$realLatest = $dbw->selectField( 'page', 'page_latest', array( 'page_id' => $pageID ), 
+		$fname, 'FOR UPDATE' );
+	#list( $masterFile, $masterPos ) = $dbw->getMasterPos();
 	$found = false;
 	foreach ( $slaveIndexes as $i ) {
 		$db =& wfGetDB( $i );
+		/*
+		if ( !$db->masterPosWait( $masterFile, $masterPos, 10 ) ) {
+		       echo "Slave is too lagged, aborting\n";
+		       $dbw->commit();
+		       sleep(10);
+		       return;
+		}*/	       
 		$latest = $db->selectField( 'page', 'page_latest', array( 'page_id' => $pageID ), $fname );
 		$max = $db->selectField( 'revision', 'MAX(rev_id)', false, $fname );
 		if ( $latest != $realLatest && $realLatest < $max ) {
@@ -49,11 +97,14 @@ function desyncFixPage( $pageID ) {
 		}
 	}
 	if ( !$found ) {
+		print "page_id $pageID seems fine\n";
+		$dbw->commit();
 		return;
 	}
 
-	# Find the missing revision
-	$res = $dbw->select( 'revision', array( 'rev_id' ), array( 'rev_page' => $pageID ), $fname );
+	# Find the missing revisions
+	$res = $dbw->select( 'revision', array( 'rev_id' ), array( 'rev_page' => $pageID ), 
+		$fname, 'FOR UPDATE' );
 	$masterIDs = array();
 	while ( $row = $dbw->fetchObject( $res ) ) {
 		$masterIDs[] = $row->rev_id;
@@ -66,35 +117,79 @@ function desyncFixPage( $pageID ) {
 		$slaveIDs[] = $row->rev_id;
 	}
 	$db->freeResult( $res );
-	$missingIDs = array_diff( $masterIDs, $slaveIDs );
+	if ( count( $masterIDs ) < count( $slaveIDs ) ) {
+		$missingIDs = array_diff( $slaveIDs, $masterIDs );
+		if ( count( $missingIDs ) ) {
+			print "Found " . count( $missingIDs ) . " lost in master, copying from slave... ";
+			$dbFrom = $db;
+			$dbTo = $dbw;
+			$found = true;
+			$toMaster = true;
+		} else {
+			$found = false;
+		}
+	} else {
+		$missingIDs = array_diff( $masterIDs, $slaveIDs );
+		if ( count( $missingIDs ) ) {
+			print "Found " . count( $missingIDs ) . " missing revision(s), copying from master... ";
+			$dbFrom = $dbw;
+			$dbTo = $db;
+			$found = true;
+			$toMaster = false;
+		} else {
+			$found = false;
+		}
+	}
 
-	if ( count( $missingIDs ) ) {
-		print "Found " . count( $missingIDs ) . " missing revision(s), copying from master... ";
+	if ( $found ) {
 		foreach ( $missingIDs as $rid ) {
 			print "$rid ";
 			# Revision
-			$row = $dbw->selectRow( 'revision', '*', array( 'rev_id' => $rid ), $fname );
-			foreach ( $slaveIndexes as $i ) {
-				$db =& wfGetDB( $i );
-				$db->insert( 'revision', get_object_vars( $row ), $fname, 'IGNORE' );
+			$row = $dbFrom->selectRow( 'revision', '*', array( 'rev_id' => $rid ), $fname );
+			if ( $toMaster ) {
+				$id = $dbw->selectField( 'revision', 'rev_id', array( 'rev_id' => $rid ), 
+					$fname,	'FOR UPDATE' );
+				if ( $id ) {
+					echo "Revision already exists\n";
+					$found = false;
+					break;
+				} else {
+					$dbw->insert( 'revision', get_object_vars( $row ), $fname, 'IGNORE' );
+				}
+			} else {
+				foreach ( $slaveIndexes as $i ) {
+					$db =& wfGetDB( $i );
+					$db->insert( 'revision', get_object_vars( $row ), $fname, 'IGNORE' );
+				}
 			}
 
 			# Text
-			$row = $dbw->selectRow( 'text', '*', array( 'old_id' => $row->rev_text_id ), $fname );
-			foreach ( $slaveIndexes as $i ) {
-				$db =& wfGetDB( $i );
-				$db->insert( 'text', get_object_vars( $row ), $fname, 'IGNORE' );
+			$row = $dbFrom->selectRow( 'text', '*', array( 'old_id' => $row->rev_text_id ), $fname );
+			if ( $toMaster ) {
+				$dbw->insert( 'text', get_object_vars( $row ), $fname, 'IGNORE' );
+			} else {
+				foreach ( $slaveIndexes as $i ) {
+					$db =& wfGetDB( $i );
+					$db->insert( 'text', get_object_vars( $row ), $fname, 'IGNORE' );
+				}
 			}
 		}
 		print "done\n";
 	}
 
-	print "Fixing page_latest... ";
-	foreach ( $slaveIndexes as $i ) {
-		$db =& wfGetDB( $i );
-		$db->update( 'page', array( 'page_latest' => $realLatest ), array( 'page_id' => $pageID ), $fname );
+	if ( $found ) {
+		print "Fixing page_latest... ";
+		if ( $toMaster ) {
+			#$dbw->update( 'page', array( 'page_latest' => $realLatest ), array( 'page_id' => $pageID ), $fname );
+		} else {
+			foreach ( $slaveIndexes as $i ) {
+				$db =& wfGetDB( $i );
+				$db->update( 'page', array( 'page_latest' => $realLatest ), array( 'page_id' => $pageID ), $fname );
+			}
+		}
+		print "done\n";
 	}
-	print "done\n";
+	$dbw->commit();
 }
 
 ?>
-- 
2.20.1