From ad183cc875c1c44835e733bd2949d464b012d1c1 Mon Sep 17 00:00:00 2001 From: Aaron Date: Wed, 15 Aug 2012 16:24:08 -0700 Subject: [PATCH] Catch exceptions in SqlBagOStuff and cache connection failures. Change-Id: I443f1bed3f9ccb40c444dd01ec446b677caf9d03 --- includes/objectcache/SqlBagOStuff.php | 223 +++++++++++++++----------- 1 file changed, 127 insertions(+), 96 deletions(-) diff --git a/includes/objectcache/SqlBagOStuff.php b/includes/objectcache/SqlBagOStuff.php index 5ad7020fbf..a3d2d8904a 100644 --- a/includes/objectcache/SqlBagOStuff.php +++ b/includes/objectcache/SqlBagOStuff.php @@ -27,7 +27,6 @@ * @ingroup Cache */ class SqlBagOStuff extends BagOStuff { - /** * @var LoadBalancer */ @@ -43,6 +42,9 @@ class SqlBagOStuff extends BagOStuff { var $shards = 1; var $tableName = 'objectcache'; + protected $connFailureTime = 0; // UNIX timestamp + protected $connFailureError; // exception + /** * Constructor. Parameters are: * - server: A server info structure in the format required by each @@ -88,6 +90,12 @@ class SqlBagOStuff extends BagOStuff { */ protected function getDB() { global $wgDebugDBTransactions; + + # Don't keep timing out trying to connect for each call if the DB is down + if ( $this->connFailureError && ( time() - $this->connFailureTime ) < 60 ) { + throw $this->connFailureError; + } + if ( !isset( $this->db ) ) { # If server connection info was given, use that if ( $this->serverInfo ) { @@ -107,7 +115,7 @@ class SqlBagOStuff extends BagOStuff { if ( wfGetDB( DB_MASTER )->getType() == 'mysql' ) { $this->lb = wfGetLBFactory()->newMainLB(); $this->db = $this->lb->getConnection( DB_MASTER ); - $this->db->clearFlag( DBO_TRX ); + $this->db->clearFlag( DBO_TRX ); // auto-commit mode } else { $this->db = wfGetDB( DB_MASTER ); } @@ -165,55 +173,59 @@ class SqlBagOStuff extends BagOStuff { public function getMulti( array $keys ) { $values = array(); // array of (key => value) - $keysByTableName = array(); - foreach ( $keys as $key ) { - $tableName = $this->getTableByKey( $key ); - if ( !isset( $keysByTableName[$tableName] ) ) { - $keysByTableName[$tableName] = array(); + try { + $db = $this->getDB(); + $keysByTableName = array(); + foreach ( $keys as $key ) { + $tableName = $this->getTableByKey( $key ); + if ( !isset( $keysByTableName[$tableName] ) ) { + $keysByTableName[$tableName] = array(); + } + $keysByTableName[$tableName][] = $key; } - $keysByTableName[$tableName][] = $key; - } - $db = $this->getDB(); - $this->garbageCollect(); // expire old entries if any + $this->garbageCollect(); // expire old entries if any - $dataRows = array(); - foreach ( $keysByTableName as $tableName => $tableKeys ) { - $res = $db->select( $tableName, - array( 'keyname', 'value', 'exptime' ), - array( 'keyname' => $tableKeys ), - __METHOD__ ); - foreach ( $res as $row ) { - $dataRows[$row->keyname] = $row; + $dataRows = array(); + foreach ( $keysByTableName as $tableName => $tableKeys ) { + $res = $db->select( $tableName, + array( 'keyname', 'value', 'exptime' ), + array( 'keyname' => $tableKeys ), + __METHOD__ ); + foreach ( $res as $row ) { + $dataRows[$row->keyname] = $row; + } } - } - foreach ( $keys as $key ) { - if ( isset( $dataRows[$key] ) ) { // HIT? - $row = $dataRows[$key]; - $this->debug( "get: retrieved data; expiry time is " . $row->exptime ); - if ( $this->isExpired( $row->exptime ) ) { // MISS - $this->debug( "get: key has expired, deleting" ); - try { - $db->begin( __METHOD__ ); - # Put the expiry time in the WHERE condition to avoid deleting a - # newly-inserted value - $db->delete( $this->getTableByKey( $key ), - array( 'keyname' => $key, 'exptime' => $row->exptime ), - __METHOD__ ); - $db->commit( __METHOD__ ); - } catch ( DBQueryError $e ) { - $this->handleWriteError( $e ); + foreach ( $keys as $key ) { + if ( isset( $dataRows[$key] ) ) { // HIT? + $row = $dataRows[$key]; + $this->debug( "get: retrieved data; expiry time is " . $row->exptime ); + if ( $this->isExpired( $row->exptime ) ) { // MISS + $this->debug( "get: key has expired, deleting" ); + try { + $db->begin( __METHOD__ ); + # Put the expiry time in the WHERE condition to avoid deleting a + # newly-inserted value + $db->delete( $this->getTableByKey( $key ), + array( 'keyname' => $key, 'exptime' => $row->exptime ), + __METHOD__ ); + $db->commit( __METHOD__ ); + } catch ( DBQueryError $e ) { + $this->handleWriteError( $e ); + } + $values[$key] = false; + } else { // HIT + $values[$key] = $this->unserialize( $db->decodeBlob( $row->value ) ); } + } else { // MISS $values[$key] = false; - } else { // HIT - $values[$key] = $this->unserialize( $db->decodeBlob( $row->value ) ); + $this->debug( 'get: no matching rows' ); } - } else { // MISS - $values[$key] = false; - $this->debug( 'get: no matching rows' ); } - } + } catch ( DBError $e ) { + $this->handleReadError( $e ); + }; return $values; } @@ -225,23 +237,23 @@ class SqlBagOStuff extends BagOStuff { * @return bool */ public function set( $key, $value, $exptime = 0 ) { - $db = $this->getDB(); - $exptime = intval( $exptime ); - - if ( $exptime < 0 ) { - $exptime = 0; - } + try { + $db = $this->getDB(); + $exptime = intval( $exptime ); - if ( $exptime == 0 ) { - $encExpiry = $this->getMaxDateTime(); - } else { - if ( $exptime < 3.16e8 ) { # ~10 years - $exptime += time(); + if ( $exptime < 0 ) { + $exptime = 0; } - $encExpiry = $db->timestamp( $exptime ); - } - try { + if ( $exptime == 0 ) { + $encExpiry = $this->getMaxDateTime(); + } else { + if ( $exptime < 3.16e8 ) { # ~10 years + $exptime += time(); + } + + $encExpiry = $db->timestamp( $exptime ); + } $db->begin( __METHOD__ ); // (bug 24425) use a replace if the db supports it instead of // delete/insert to avoid clashes with conflicting keynames @@ -254,9 +266,8 @@ class SqlBagOStuff extends BagOStuff { 'exptime' => $encExpiry ), __METHOD__ ); $db->commit( __METHOD__ ); - } catch ( DBQueryError $e ) { + } catch ( DBError $e ) { $this->handleWriteError( $e ); - return false; } @@ -269,18 +280,16 @@ class SqlBagOStuff extends BagOStuff { * @return bool */ public function delete( $key, $time = 0 ) { - $db = $this->getDB(); - try { + $db = $this->getDB(); $db->begin( __METHOD__ ); $db->delete( $this->getTableByKey( $key ), array( 'keyname' => $key ), __METHOD__ ); $db->commit( __METHOD__ ); - } catch ( DBQueryError $e ) { + } catch ( DBError $e ) { $this->handleWriteError( $e ); - return false; } @@ -293,11 +302,10 @@ class SqlBagOStuff extends BagOStuff { * @return int|null */ public function incr( $key, $step = 1 ) { - $db = $this->getDB(); - $tableName = $this->getTableByKey( $key ); - $step = intval( $step ); - try { + $db = $this->getDB(); + $tableName = $this->getTableByKey( $key ); + $step = intval( $step ); $db->begin( __METHOD__ ); $row = $db->selectRow( $tableName, @@ -333,9 +341,8 @@ class SqlBagOStuff extends BagOStuff { $newValue = null; } $db->commit( __METHOD__ ); - } catch ( DBQueryError $e ) { + } catch ( DBError $e ) { $this->handleWriteError( $e ); - return null; } @@ -346,15 +353,19 @@ class SqlBagOStuff extends BagOStuff { * @return Array */ public function keys() { - $db = $this->getDB(); $result = array(); - for ( $i = 0; $i < $this->shards; $i++ ) { - $res = $db->select( $this->getTableByShard( $i ), - array( 'keyname' ), false, __METHOD__ ); - foreach ( $res as $row ) { - $result[] = $row->keyname; + try { + $db = $this->getDB(); + for ( $i = 0; $i < $this->shards; $i++ ) { + $res = $db->select( $this->getTableByShard( $i ), + array( 'keyname' ), false, __METHOD__ ); + foreach ( $res as $row ) { + $result[] = $row->keyname; + } } + } catch ( DBError $e ) { + $this->handleReadError( $e ); } return $result; @@ -407,12 +418,11 @@ class SqlBagOStuff extends BagOStuff { * @return bool */ public function deleteObjectsExpiringBefore( $timestamp, $progressCallback = false ) { - $db = $this->getDB(); - $dbTimestamp = $db->timestamp( $timestamp ); - $totalSeconds = false; - $baseConds = array( 'exptime < ' . $db->addQuotes( $dbTimestamp ) ); - try { + $db = $this->getDB(); + $dbTimestamp = $db->timestamp( $timestamp ); + $totalSeconds = false; + $baseConds = array( 'exptime < ' . $db->addQuotes( $dbTimestamp ) ); for ( $i = 0; $i < $this->shards; $i++ ) { $maxExpTime = false; while ( true ) { @@ -468,24 +478,28 @@ class SqlBagOStuff extends BagOStuff { } } } - } catch ( DBQueryError $e ) { + } catch ( DBError $e ) { $this->handleWriteError( $e ); + return false; } + return true; } public function deleteAll() { - $db = $this->getDB(); - try { + $db = $this->getDB(); for ( $i = 0; $i < $this->shards; $i++ ) { $db->begin( __METHOD__ ); $db->delete( $this->getTableByShard( $i ), '*', __METHOD__ ); $db->commit( __METHOD__ ); } - } catch ( DBQueryError $e ) { + } catch ( DBError $e ) { $this->handleWriteError( $e ); + return false; } + + return true; } /** @@ -528,23 +542,40 @@ class SqlBagOStuff extends BagOStuff { } /** - * Handle a DBQueryError which occurred during a write operation. - * Ignore errors which are due to a read-only database, rethrow others. + * Handle a DBError which occurred during a read operation. */ - protected function handleWriteError( $exception ) { - $db = $this->getDB(); - - if ( !$db->wasReadOnlyError() ) { - throw $exception; + protected function handleReadError( DBError $exception ) { + if ( $exception instanceof DBConnectionError ) { + $this->connFailureTime = time(); + $this->connFailureError = $exception; } - - try { - $db->rollback( __METHOD__ ); - } catch ( DBQueryError $e ) { + wfDebugLog( 'SQLBagOStuff', "DBError: {$exception->getMessage()}" ); + if ( $this->db ) { + wfDebug( __METHOD__ . ": ignoring query error\n" ); + } else { + wfDebug( __METHOD__ . ": ignoring connection error\n" ); } + } - wfDebug( __METHOD__ . ": ignoring query error\n" ); - $db->ignoreErrors( false ); + /** + * Handle a DBQueryError which occurred during a write operation. + */ + protected function handleWriteError( DBError $exception ) { + if ( $exception instanceof DBConnectionError ) { + $this->connFailureTime = time(); + $this->connFailureError = $exception; + } + if ( $this->db && $this->db->wasReadOnlyError() ) { + try { + $this->db->rollback( __METHOD__ ); + } catch ( DBError $e ) {} + } + wfDebugLog( 'SQLBagOStuff', "DBError: {$exception->getMessage()}" ); + if ( $this->db ) { + wfDebug( __METHOD__ . ": ignoring query error\n" ); + } else { + wfDebug( __METHOD__ . ": ignoring connection error\n" ); + } } /** -- 2.20.1