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-rw-r--r--includes/db/LBFactory.php94
1 files changed, 16 insertions, 78 deletions
diff --git a/includes/db/LBFactory.php b/includes/db/LBFactory.php
index d469e867..16c43a00 100644
--- a/includes/db/LBFactory.php
+++ b/includes/db/LBFactory.php
@@ -134,7 +134,8 @@ abstract class LBFactory {
* Prepare all tracked load balancers for shutdown
* STUB
*/
- function shutdown() {}
+ function shutdown() {
+ }
/**
* Call a method of each tracked load balancer
@@ -201,7 +202,7 @@ class LBFactory_Simple extends LBFactory {
$flags |= DBO_COMPRESS;
}
- $servers = array(array(
+ $servers = array( array(
'host' => $wgDBserver,
'user' => $wgDBuser,
'password' => $wgDBpassword,
@@ -256,6 +257,7 @@ class LBFactory_Simple extends LBFactory {
if ( !isset( $this->extLBs[$cluster] ) ) {
$this->extLBs[$cluster] = $this->newExternalLB( $cluster, $wiki );
$this->extLBs[$cluster]->parentInfo( array( 'id' => "ext-$cluster" ) );
+ $this->chronProt->initLB( $this->extLBs[$cluster] );
}
return $this->extLBs[$cluster];
}
@@ -280,6 +282,9 @@ class LBFactory_Simple extends LBFactory {
if ( $this->mainLB ) {
$this->chronProt->shutdownLB( $this->mainLB );
}
+ foreach ( $this->extLBs as $extLB ) {
+ $this->chronProt->shutdownLB( $extLB );
+ }
$this->chronProt->shutdown();
$this->commitMasterChanges();
}
@@ -292,21 +297,27 @@ class LBFactory_Simple extends LBFactory {
* LBFactory::enableBackend() to return to normal behavior
*/
class LBFactory_Fake extends LBFactory {
- function __construct( $conf ) {}
+ function __construct( $conf ) {
+ }
- function newMainLB( $wiki = false) {
+ function newMainLB( $wiki = false ) {
throw new DBAccessError;
}
+
function getMainLB( $wiki = false ) {
throw new DBAccessError;
}
+
function newExternalLB( $cluster, $wiki = false ) {
throw new DBAccessError;
}
+
function &getExternalLB( $cluster, $wiki = false ) {
throw new DBAccessError;
}
- function forEachLB( $callback, $params = array() ) {}
+
+ function forEachLB( $callback, $params = array() ) {
+ }
}
/**
@@ -317,76 +328,3 @@ class DBAccessError extends MWException {
parent::__construct( "Mediawiki tried to access the database via wfGetDB(). This is not allowed." );
}
}
-
-/**
- * Class for ensuring a consistent ordering of events as seen by the user, despite replication.
- * Kind of like Hawking's [[Chronology Protection Agency]].
- */
-class ChronologyProtector {
- var $startupPos;
- var $shutdownPos = array();
-
- /**
- * Initialise a LoadBalancer to give it appropriate chronology protection.
- *
- * @param $lb LoadBalancer
- */
- function initLB( $lb ) {
- if ( $this->startupPos === null ) {
- if ( !empty( $_SESSION[__CLASS__] ) ) {
- $this->startupPos = $_SESSION[__CLASS__];
- }
- }
- if ( !$this->startupPos ) {
- return;
- }
- $masterName = $lb->getServerName( 0 );
-
- if ( $lb->getServerCount() > 1 && !empty( $this->startupPos[$masterName] ) ) {
- $info = $lb->parentInfo();
- $pos = $this->startupPos[$masterName];
- wfDebug( __METHOD__ . ": LB " . $info['id'] . " waiting for master pos $pos\n" );
- $lb->waitFor( $this->startupPos[$masterName] );
- }
- }
-
- /**
- * Notify the ChronologyProtector that the LoadBalancer is about to shut
- * down. Saves replication positions.
- *
- * @param $lb LoadBalancer
- */
- function shutdownLB( $lb ) {
- // Don't start a session, don't bother with non-replicated setups
- if ( strval( session_id() ) == '' || $lb->getServerCount() <= 1 ) {
- return;
- }
- $masterName = $lb->getServerName( 0 );
- if ( isset( $this->shutdownPos[$masterName] ) ) {
- // Already done
- return;
- }
- // Only save the position if writes have been done on the connection
- $db = $lb->getAnyOpenConnection( 0 );
- $info = $lb->parentInfo();
- if ( !$db || !$db->doneWrites() ) {
- wfDebug( __METHOD__ . ": LB {$info['id']}, no writes done\n" );
- return;
- }
- $pos = $db->getMasterPos();
- wfDebug( __METHOD__ . ": LB {$info['id']} has master pos $pos\n" );
- $this->shutdownPos[$masterName] = $pos;
- }
-
- /**
- * Notify the ChronologyProtector that the LBFactory is done calling shutdownLB() for now.
- * May commit chronology data to persistent storage.
- */
- function shutdown() {
- if ( session_id() != '' && count( $this->shutdownPos ) ) {
- wfDebug( __METHOD__ . ": saving master pos for " .
- count( $this->shutdownPos ) . " master(s)\n" );
- $_SESSION[__CLASS__] = $this->shutdownPos;
- }
- }
-}