<?php
/**
- * Database load balancing.
+ * Database load balancing manager
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* @file
* @ingroup Database
*/
+use Psr\Log\LoggerInterface;
/**
- * Database load balancing object
+ * Database load balancing, tracking, and transaction management object
*
- * @todo document
* @ingroup Database
*/
-class LoadBalancer {
+class LoadBalancer implements ILoadBalancer {
/** @var array[] Map of (server index => server config array) */
private $mServers;
/** @var array[] Map of (local/foreignUsed/foreignFree => server index => DatabaseBase array) */
private $mAllowLagged;
/** @var integer Seconds to spend waiting on replica DB lag to resolve */
private $mWaitTimeout;
- /** @var array LBFactory information */
- private $mParentInfo;
-
/** @var string The LoadMonitor subclass name */
private $mLoadMonitorClass;
+
/** @var LoadMonitor */
private $mLoadMonitor;
/** @var BagOStuff */
private $wanCache;
/** @var TransactionProfiler */
protected $trxProfiler;
+ /** @var LoggerInterface */
+ protected $replLogger;
+ /** @var LoggerInterface */
+ protected $connLogger;
+ /** @var LoggerInterface */
+ protected $queryLogger;
+ /** @var LoggerInterface */
+ protected $perfLogger;
/** @var bool|DatabaseBase Database connection that caused a problem */
private $mErrorConnection;
private $trxRoundId = false;
/** @var array[] Map of (name => callable) */
private $trxRecurringCallbacks = [];
+ /** @var string Local Wiki ID and default for selectDB() calls */
+ private $localDomain;
+ /** @var callable Exception logger */
+ private $errorLogger;
+
+ /** @var boolean */
+ private $disabled = false;
/** @var integer Warn when this many connection are held */
const CONN_HELD_WARN_THRESHOLD = 10;
/** @var integer Seconds to cache master server read-only status */
const TTL_CACHE_READONLY = 5;
- /**
- * @var boolean
- */
- private $disabled = false;
-
- /**
- * @param array $params Array with keys:
- * - servers : Required. Array of server info structures.
- * - loadMonitor : Name of a class used to fetch server lag and load.
- * - readOnlyReason : Reason the master DB is read-only if so [optional]
- * - waitTimeout : Maximum time to wait for replicas for consistency [optional]
- * - srvCache : BagOStuff object [optional]
- * - wanCache : WANObjectCache object [optional]
- * @throws MWException
- */
public function __construct( array $params ) {
if ( !isset( $params['servers'] ) ) {
- throw new MWException( __CLASS__ . ': missing servers parameter' );
+ throw new InvalidArgumentException( __CLASS__ . ': missing servers parameter' );
}
$this->mServers = $params['servers'];
$this->mWaitTimeout = isset( $params['waitTimeout'] )
? $params['waitTimeout']
: self::POS_WAIT_TIMEOUT;
+ $this->localDomain = isset( $params['localDomain'] ) ? $params['localDomain'] : '';
$this->mReadIndex = -1;
- $this->mWriteIndex = -1;
$this->mConns = [
'local' => [],
'foreignUsed' => [],
} else {
$this->trxProfiler = new TransactionProfiler();
}
+
+ $this->errorLogger = isset( $params['errorLogger'] )
+ ? $params['errorLogger']
+ : function ( Exception $e ) {
+ trigger_error( E_WARNING, $e->getMessage() );
+ };
+
+ foreach ( [ 'replLogger', 'connLogger', 'queryLogger', 'perfLogger' ] as $key ) {
+ $this->$key = isset( $params[$key] ) ? $params[$key] : new \Psr\Log\NullLogger();
+ }
}
/**
if ( !isset( $this->mLoadMonitor ) ) {
$class = $this->mLoadMonitorClass;
$this->mLoadMonitor = new $class( $this );
+ $this->mLoadMonitor->setLogger( $this->replLogger );
}
return $this->mLoadMonitor;
}
- /**
- * Get or set arbitrary data used by the parent object, usually an LBFactory
- * @param mixed $x
- * @return mixed
- */
- public function parentInfo( $x = null ) {
- return wfSetVar( $this->mParentInfo, $x );
- }
-
/**
* @param array $loads
* @param bool|string $wiki Wiki to get non-lagged for
$host = $this->getServerName( $i );
if ( $lag === false && !is_infinite( $maxServerLag ) ) {
- wfDebugLog( 'replication', "Server $host (#$i) is not replicating?" );
+ $this->replLogger->error( "Server $host (#$i) is not replicating?" );
unset( $loads[$i] );
} elseif ( $lag > $maxServerLag ) {
- wfDebugLog( 'replication', "Server $host (#$i) has >= $lag seconds of lag" );
+ $this->replLogger->warning( "Server $host (#$i) has >= $lag seconds of lag" );
unset( $loads[$i] );
}
}
return ArrayUtils::pickRandom( $loads );
}
- /**
- * Get the index of the reader connection, which may be a replica DB
- * This takes into account load ratios and lag times. It should
- * always return a consistent index during a given invocation
- *
- * Side effect: opens connections to databases
- * @param string|bool $group Query group, or false for the generic reader
- * @param string|bool $wiki Wiki ID, or false for the current wiki
- * @throws MWException
- * @return bool|int|string
- */
public function getReaderIndex( $group = false, $wiki = false ) {
- global $wgDBtype;
-
- # @todo FIXME: For now, only go through all this for mysql databases
- if ( $wgDBtype != 'mysql' ) {
- return $this->getWriterIndex();
- }
-
if ( count( $this->mServers ) == 1 ) {
# Skip the load balancing if there's only one server
- return 0;
+ return $this->getWriterIndex();
} elseif ( $group === false && $this->mReadIndex >= 0 ) {
# Shortcut if generic reader exists already
return $this->mReadIndex;
$nonErrorLoads = $this->mGroupLoads[$group];
} else {
# No loads for this group, return false and the caller can use some other group
- wfDebugLog( 'connect', __METHOD__ . ": no loads for group $group\n" );
+ $this->connLogger->info( __METHOD__ . ": no loads for group $group" );
return false;
}
}
if ( !count( $nonErrorLoads ) ) {
- throw new MWException( "Empty server array given to LoadBalancer" );
+ throw new InvalidArgumentException( "Empty server array given to LoadBalancer" );
}
- # Scale the configured load ratios according to the dynamic load (if the load monitor supports it)
+ # Scale the configured load ratios according to the dynamic load if supported
$this->getLoadMonitor()->scaleLoads( $nonErrorLoads, $group, $wiki );
$laggedReplicaMode = false;
}
if ( $i === false && count( $currentLoads ) != 0 ) {
# All replica DBs lagged. Switch to read-only mode
- wfDebugLog( 'replication', "All replica DBs lagged. Switch to read-only mode" );
+ $this->replLogger->error( "All replica DBs lagged. Switch to read-only mode" );
$i = ArrayUtils::pickRandom( $currentLoads );
$laggedReplicaMode = true;
}
# pickRandom() returned false
# This is permanent and means the configuration or the load monitor
# wants us to return false.
- wfDebugLog( 'connect', __METHOD__ . ": pickRandom() returned false" );
+ $this->connLogger->debug( __METHOD__ . ": pickRandom() returned false" );
return false;
}
$serverName = $this->getServerName( $i );
- wfDebugLog( 'connect', __METHOD__ . ": Using reader #$i: $serverName..." );
+ $this->connLogger->debug( __METHOD__ . ": Using reader #$i: $serverName..." );
$conn = $this->openConnection( $i, $wiki );
if ( !$conn ) {
- wfDebugLog( 'connect', __METHOD__ . ": Failed connecting to $i/$wiki" );
+ $this->connLogger->warning( __METHOD__ . ": Failed connecting to $i/$wiki" );
unset( $nonErrorLoads[$i] );
unset( $currentLoads[$i] );
$i = false;
# If all servers were down, quit now
if ( !count( $nonErrorLoads ) ) {
- wfDebugLog( 'connect', "All servers down" );
+ $this->connLogger->error( "All servers down" );
}
if ( $i !== false ) {
}
}
$serverName = $this->getServerName( $i );
- wfDebugLog( 'connect', __METHOD__ .
- ": using server $serverName for group '$group'\n" );
+ $this->connLogger->debug(
+ __METHOD__ . ": using server $serverName for group '$group'\n" );
}
return $i;
}
- /**
- * Set the master wait position
- * If a DB_REPLICA connection has been opened already, waits
- * Otherwise sets a variable telling it to wait if such a connection is opened
- * @param DBMasterPos $pos
- */
public function waitFor( $pos ) {
$this->mWaitForPos = $pos;
$i = $this->mReadIndex;
return $ok;
}
- /**
- * Set the master wait position and wait for ALL replica DBs to catch up to it
- * @param DBMasterPos $pos
- * @param int $timeout Max seconds to wait; default is mWaitTimeout
- * @return bool Success (able to connect and no timeouts reached)
- */
public function waitForAll( $pos, $timeout = null ) {
$this->mWaitForPos = $pos;
$serverCount = count( $this->mServers );
return $ok;
}
- /**
- * Get any open connection to a given server index, local or foreign
- * Returns false if there is no connection open
- *
- * @param int $i
- * @return DatabaseBase|bool False on failure
- */
public function getAnyOpenConnection( $i ) {
- foreach ( $this->mConns as $conns ) {
- if ( !empty( $conns[$i] ) ) {
- return reset( $conns[$i] );
+ foreach ( $this->mConns as $connsByServer ) {
+ if ( !empty( $connsByServer[$i] ) ) {
+ return reset( $connsByServer[$i] );
}
}
/** @var DBMasterPos $knownReachedPos */
$knownReachedPos = $this->srvCache->get( $key );
if ( $knownReachedPos && $knownReachedPos->hasReached( $this->mWaitForPos ) ) {
- wfDebugLog( 'replication', __METHOD__ .
+ $this->replLogger->debug( __METHOD__ .
": replica DB $server known to be caught up (pos >= $knownReachedPos).\n" );
return true;
}
$conn = $this->getAnyOpenConnection( $index );
if ( !$conn ) {
if ( !$open ) {
- wfDebugLog( 'replication', __METHOD__ . ": no connection open for $server\n" );
+ $this->replLogger->debug( __METHOD__ . ": no connection open for $server\n" );
return false;
} else {
$conn = $this->openConnection( $index, '' );
if ( !$conn ) {
- wfDebugLog( 'replication', __METHOD__ . ": failed to connect to $server\n" );
+ $this->replLogger->warning( __METHOD__ . ": failed to connect to $server\n" );
return false;
}
}
}
- wfDebugLog( 'replication', __METHOD__ . ": Waiting for replica DB $server to catch up...\n" );
+ $this->replLogger->info( __METHOD__ . ": Waiting for replica DB $server to catch up...\n" );
$timeout = $timeout ?: $this->mWaitTimeout;
$result = $conn->masterPosWait( $this->mWaitForPos, $timeout );
if ( $result == -1 || is_null( $result ) ) {
// Timed out waiting for replica DB, use master instead
$msg = __METHOD__ . ": Timed out waiting on $server pos {$this->mWaitForPos}";
- wfDebugLog( 'replication', "$msg\n" );
- wfDebugLog( 'DBPerformance', "$msg:\n" . wfBacktrace( true ) );
+ $this->replLogger->warning( "$msg\n" );
+ $this->perfLogger->warning( "$msg:\n" . wfBacktrace( true ) );
$ok = false;
} else {
- wfDebugLog( 'replication', __METHOD__ . ": Done\n" );
+ $this->replLogger->info( __METHOD__ . ": Done\n" );
$ok = true;
// Remember that the DB reached this point
$this->srvCache->set( $key, $this->mWaitForPos, BagOStuff::TTL_DAY );
return $ok;
}
- /**
- * Get a connection by index
- * This is the main entry point for this class.
- *
- * @param int $i Server index
- * @param array|string|bool $groups Query group(s), or false for the generic reader
- * @param string|bool $wiki Wiki ID, or false for the current wiki
- *
- * @throws MWException
- * @return DatabaseBase
- */
public function getConnection( $i, $groups = [], $wiki = false ) {
if ( $i === null || $i === false ) {
- throw new MWException( 'Attempt to call ' . __METHOD__ .
+ throw new InvalidArgumentException( 'Attempt to call ' . __METHOD__ .
' with invalid server index' );
}
- if ( $wiki === wfWikiID() ) {
+ if ( $wiki === $this->localDomain ) {
$wiki = false;
}
if ( $this->connsOpened > $oldConnsOpened ) {
$host = $conn->getServer();
$dbname = $conn->getDBname();
- $trxProf = Profiler::instance()->getTransactionProfiler();
- $trxProf->recordConnection( $host, $dbname, $masterOnly );
+ $this->trxProfiler->recordConnection( $host, $dbname, $masterOnly );
}
if ( $masterOnly ) {
return $conn;
}
- /**
- * Mark a foreign connection as being available for reuse under a different
- * DB name or prefix. This mechanism is reference-counted, and must be called
- * the same number of times as getConnection() to work.
- *
- * @param DatabaseBase $conn
- * @throws MWException
- */
public function reuseConnection( $conn ) {
$serverIndex = $conn->getLBInfo( 'serverIndex' );
$refCount = $conn->getLBInfo( 'foreignPoolRefCount' );
$wiki = $dbName;
}
if ( $this->mConns['foreignUsed'][$serverIndex][$wiki] !== $conn ) {
- throw new MWException( __METHOD__ . ": connection not found, has " .
+ throw new InvalidArgumentException( __METHOD__ . ": connection not found, has " .
"the connection been freed already?" );
}
$conn->setLBInfo( 'foreignPoolRefCount', --$refCount );
* @param array|string|bool $groups Query group(s), or false for the generic reader
* @param string|bool $wiki Wiki ID, or false for the current wiki
* @return DBConnRef
+ * @since 1.22
*/
public function getConnectionRef( $db, $groups = [], $wiki = false ) {
return new DBConnRef( $this, $this->getConnection( $db, $groups, $wiki ) );
* @param array|string|bool $groups Query group(s), or false for the generic reader
* @param string|bool $wiki Wiki ID, or false for the current wiki
* @return DBConnRef
+ * @since 1.22
*/
public function getLazyConnectionRef( $db, $groups = [], $wiki = false ) {
+ $wiki = ( $wiki !== false ) ? $wiki : $this->localDomain;
+
return new DBConnRef( $this, [ $db, $groups, $wiki ] );
}
- /**
- * Open a connection to the server given by the specified index
- * Index must be an actual index into the array.
- * If the server is already open, returns it.
- *
- * On error, returns false, and the connection which caused the
- * error will be available via $this->mErrorConnection.
- *
- * @note If disable() was called on this LoadBalancer, this method will throw a DBAccessError.
- *
- * @param int $i Server index
- * @param string|bool $wiki Wiki ID, or false for the current wiki
- * @return DatabaseBase|bool Returns false on errors
- */
public function openConnection( $i, $wiki = false ) {
if ( $wiki !== false ) {
$conn = $this->openForeignConnection( $i, $wiki );
$conn = $this->reallyOpenConnection( $server, false );
$serverName = $this->getServerName( $i );
if ( $conn->isOpen() ) {
- wfDebugLog( 'connect', "Connected to database $i at $serverName\n" );
+ $this->connLogger->debug( "Connected to database $i at '$serverName'." );
$this->mConns['local'][$i][0] = $conn;
} else {
- wfDebugLog( 'connect', "Failed to connect to database $i at $serverName\n" );
+ $this->connLogger->warning( "Failed to connect to database $i at '$serverName'." );
$this->mErrorConnection = $conn;
$conn = false;
}
* @return DatabaseBase
*/
private function openForeignConnection( $i, $wiki ) {
- list( $dbName, $prefix ) = wfSplitWikiID( $wiki );
+ list( $dbName, $prefix ) = explode( '-', $wiki, 2 ) + [ '', '' ];
+
if ( isset( $this->mConns['foreignUsed'][$i][$wiki] ) ) {
// Reuse an already-used connection
$conn = $this->mConns['foreignUsed'][$i][$wiki];
}
if ( !is_array( $server ) ) {
- throw new MWException( 'You must update your load-balancing configuration. ' .
+ throw new InvalidArgumentException( 'You must update your load-balancing configuration. ' .
'See DefaultSettings.php entry for $wgDBservers.' );
}
}
// Let the handle know what the cluster master is (e.g. "db1052")
- $masterName = $this->getServerName( 0 );
+ $masterName = $this->getServerName( $this->getWriterIndex() );
$server['clusterMasterHost'] = $masterName;
// Log when many connection are made on requests
if ( ++$this->connsOpened >= self::CONN_HELD_WARN_THRESHOLD ) {
- wfDebugLog( 'DBPerformance', __METHOD__ . ": " .
+ $this->perfLogger->warning( __METHOD__ . ": " .
"{$this->connsOpened}+ connections made (master=$masterName)\n" .
wfBacktrace( true ) );
}
- # Create object
+ // Set loggers
+ $server['connLogger'] = $this->connLogger;
+ $server['queryLogger'] = $this->queryLogger;
+
+ // Create a live connection object
try {
$db = DatabaseBase::factory( $server['type'], $server );
} catch ( DBConnectionError $e ) {
return false; /* not reached */
}
- /**
- * @return int
- * @since 1.26
- */
public function getWriterIndex() {
return 0;
}
- /**
- * Returns true if the specified index is a valid server index
- *
- * @param string $i
- * @return bool
- */
public function haveIndex( $i ) {
return array_key_exists( $i, $this->mServers );
}
- /**
- * Returns true if the specified index is valid and has non-zero load
- *
- * @param string $i
- * @return bool
- */
public function isNonZeroLoad( $i ) {
return array_key_exists( $i, $this->mServers ) && $this->mLoads[$i] != 0;
}
- /**
- * Get the number of defined servers (not the number of open connections)
- *
- * @return int
- */
public function getServerCount() {
return count( $this->mServers );
}
- /**
- * Get the host name or IP address of the server with the specified index
- * Prefer a readable name if available.
- * @param string $i
- * @return string
- */
public function getServerName( $i ) {
if ( isset( $this->mServers[$i]['hostName'] ) ) {
$name = $this->mServers[$i]['hostName'];
return ( $name != '' ) ? $name : 'localhost';
}
- /**
- * Return the server info structure for a given index, or false if the index is invalid.
- * @param int $i
- * @return array|bool
- */
public function getServerInfo( $i ) {
if ( isset( $this->mServers[$i] ) ) {
return $this->mServers[$i];
}
}
- /**
- * Sets the server info structure for the given index. Entry at index $i
- * is created if it doesn't exist
- * @param int $i
- * @param array $serverInfo
- */
public function setServerInfo( $i, array $serverInfo ) {
$this->mServers[$i] = $serverInfo;
}
- /**
- * Get the current master position for chronology control purposes
- * @return mixed
- */
public function getMasterPos() {
# If this entire request was served from a replica DB without opening a connection to the
# master (however unlikely that may be), then we can fetch the position from the replica DB.
- $masterConn = $this->getAnyOpenConnection( 0 );
+ $masterConn = $this->getAnyOpenConnection( $this->getWriterIndex() );
if ( !$masterConn ) {
$serverCount = count( $this->mServers );
for ( $i = 1; $i < $serverCount; $i++ ) {
$this->disabled = true;
}
- /**
- * Close all open connections
- */
public function closeAll() {
$this->forEachOpenConnection( function ( DatabaseBase $conn ) {
$conn->close();
$this->connsOpened = 0;
}
- /**
- * Close a connection
- * Using this function makes sure the LoadBalancer knows the connection is closed.
- * If you use $conn->close() directly, the load balancer won't update its state.
- * @param DatabaseBase $conn
- */
- public function closeConnection( $conn ) {
- $done = false;
- foreach ( $this->mConns as $i1 => $conns2 ) {
- foreach ( $conns2 as $i2 => $conns3 ) {
- foreach ( $conns3 as $i3 => $candidateConn ) {
- if ( $conn === $candidateConn ) {
- $conn->close();
- unset( $this->mConns[$i1][$i2][$i3] );
- --$this->connsOpened;
- $done = true;
- break;
- }
+ public function closeConnection( IDatabase $conn ) {
+ $serverIndex = $conn->getLBInfo( 'serverIndex' ); // second index level of mConns
+ foreach ( $this->mConns as $type => $connsByServer ) {
+ if ( !isset( $connsByServer[$serverIndex] ) ) {
+ continue;
+ }
+
+ foreach ( $connsByServer[$serverIndex] as $i => $trackedConn ) {
+ if ( $conn === $trackedConn ) {
+ unset( $this->mConns[$type][$serverIndex][$i] );
+ --$this->connsOpened;
+ break 2;
}
}
}
- if ( !$done ) {
- $conn->close();
- }
+
+ $conn->close();
}
- /**
- * Commit transactions on all open connections
- * @param string $fname Caller name
- * @throws DBExpectedError
- */
public function commitAll( $fname = __METHOD__ ) {
$failures = [];
try {
$conn->commit( $fname, $conn::FLUSHING_ALL_PEERS );
} catch ( DBError $e ) {
- MWExceptionHandler::logException( $e );
+ call_user_func( $this->errorLogger, $e );
$failures[] = "{$conn->getServer()}: {$e->getMessage()}";
}
if ( $restore && $conn->getLBInfo( 'master' ) ) {
function ( DatabaseBase $conn ) use ( $fname, &$failures ) {
$conn->setTrxEndCallbackSuppression( true );
try {
- $conn->clearSnapshot( $fname );
+ $conn->flushSnapshot( $fname );
} catch ( DBError $e ) {
- MWExceptionHandler::logException( $e );
+ call_user_func( $this->errorLogger, $e );
$failures[] = "{$conn->getServer()}: {$e->getMessage()}";
}
$conn->setTrxEndCallbackSuppression( false );
}
}
- /**
- * Issue COMMIT on all master connections where writes where done
- * @param string $fname Caller name
- * @throws DBExpectedError
- */
public function commitMasterChanges( $fname = __METHOD__ ) {
$failures = [];
if ( $conn->writesOrCallbacksPending() ) {
$conn->commit( $fname, $conn::FLUSHING_ALL_PEERS );
} elseif ( $restore ) {
- $conn->clearSnapshot( $fname );
+ $conn->flushSnapshot( $fname );
}
} catch ( DBError $e ) {
- MWExceptionHandler::logException( $e );
+ call_user_func( $this->errorLogger, $e );
$failures[] = "{$conn->getServer()}: {$e->getMessage()}";
}
if ( $restore ) {
public function runMasterPostTrxCallbacks( $type ) {
$e = null; // first exception
$this->forEachOpenMasterConnection( function ( DatabaseBase $conn ) use ( $type, &$e ) {
- $conn->clearSnapshot( __METHOD__ ); // clear no-op transactions
-
$conn->setTrxEndCallbackSuppression( false );
+ if ( $conn->writesOrCallbacksPending() ) {
+ // This happens if onTransactionIdle() callbacks leave callbacks on *another* DB
+ // (which finished its callbacks already). Warn and recover in this case. Let the
+ // callbacks run in the final commitMasterChanges() in LBFactory::shutdown().
+ wfWarn( __METHOD__ . ": did not expect writes/callbacks pending." );
+ return;
+ } elseif ( $conn->trxLevel() ) {
+ // This happens for single-DB setups where DB_REPLICA uses the master DB,
+ // thus leaving an implicit read-only transaction open at this point. It
+ // also happens if onTransactionIdle() callbacks leave implicit transactions
+ // open on *other* DBs (which is slightly improper). Let these COMMIT on the
+ // next call to commitMasterChanges(), possibly in LBFactory::shutdown().
+ return;
+ }
try {
$conn->runOnTransactionIdleCallbacks( $type );
} catch ( Exception $ex ) {
}
/**
- * @param DatabaseBase $conn
+ * @param IDatabase $conn
*/
- private function applyTransactionRoundFlags( DatabaseBase $conn ) {
+ private function applyTransactionRoundFlags( IDatabase $conn ) {
if ( $conn->getFlag( DBO_DEFAULT ) ) {
// DBO_TRX is controlled entirely by CLI mode presence with DBO_DEFAULT.
// Force DBO_TRX even in CLI mode since a commit round is expected soon.
}
/**
- * @param DatabaseBase $conn
+ * @param IDatabase $conn
*/
- private function undoTransactionRoundFlags( DatabaseBase $conn ) {
+ private function undoTransactionRoundFlags( IDatabase $conn ) {
if ( $conn->getFlag( DBO_DEFAULT ) ) {
$conn->restoreFlags( $conn::RESTORE_PRIOR );
}
*/
public function flushReplicaSnapshots( $fname = __METHOD__ ) {
$this->forEachOpenReplicaConnection( function ( DatabaseBase $conn ) {
- $conn->clearSnapshot( __METHOD__ );
+ $conn->flushSnapshot( __METHOD__ );
} );
}
* @return bool
*/
public function hasMasterChanges() {
- $masterIndex = $this->getWriterIndex();
- foreach ( $this->mConns as $conns2 ) {
- if ( empty( $conns2[$masterIndex] ) ) {
- continue;
- }
- /** @var DatabaseBase $conn */
- foreach ( $conns2[$masterIndex] as $conn ) {
- if ( $conn->trxLevel() && $conn->writesOrCallbacksPending() ) {
- return true;
- }
- }
- }
- return false;
+ $pending = 0;
+ $this->forEachOpenMasterConnection( function ( DatabaseBase $conn ) use ( &$pending ) {
+ $pending |= $conn->writesOrCallbacksPending();
+ } );
+
+ return (bool)$pending;
}
/**
*/
public function lastMasterChangeTimestamp() {
$lastTime = false;
- $masterIndex = $this->getWriterIndex();
- foreach ( $this->mConns as $conns2 ) {
- if ( empty( $conns2[$masterIndex] ) ) {
- continue;
- }
- /** @var DatabaseBase $conn */
- foreach ( $conns2[$masterIndex] as $conn ) {
- $lastTime = max( $lastTime, $conn->lastDoneWrites() );
- }
- }
+ $this->forEachOpenMasterConnection( function ( DatabaseBase $conn ) use ( &$lastTime ) {
+ $lastTime = max( $lastTime, $conn->lastDoneWrites() );
+ } );
+
return $lastTime;
}
/**
* Get the list of callers that have pending master changes
*
- * @return array
+ * @return string[] List of method names
* @since 1.27
*/
public function pendingMasterChangeCallers() {
$fnames = [];
-
- $masterIndex = $this->getWriterIndex();
- foreach ( $this->mConns as $conns2 ) {
- if ( empty( $conns2[$masterIndex] ) ) {
- continue;
- }
- /** @var DatabaseBase $conn */
- foreach ( $conns2[$masterIndex] as $conn ) {
- $fnames = array_merge( $fnames, $conn->pendingWriteCallers() );
- }
- }
+ $this->forEachOpenMasterConnection( function ( DatabaseBase $conn ) use ( &$fnames ) {
+ $fnames = array_merge( $fnames, $conn->pendingWriteCallers() );
+ } );
return $fnames;
}
- /**
- * @note This method will trigger a DB connection if not yet done
- * @param string|bool $wiki Wiki ID, or false for the current wiki
- * @return bool Whether the generic connection for reads is highly "lagged"
- */
public function getLaggedReplicaMode( $wiki = false ) {
// No-op if there is only one DB (also avoids recursion)
if ( !$this->laggedReplicaMode && $this->getServerCount() > 1 ) {
/**
* @note This method may trigger a DB connection if not yet done
* @param string|bool $wiki Wiki ID, or false for the current wiki
- * @param DatabaseBase|null DB master connection; used to avoid loops [optional]
+ * @param IDatabase|null DB master connection; used to avoid loops [optional]
* @return string|bool Reason the master is read-only or false if it is not
* @since 1.27
*/
- public function getReadOnlyReason( $wiki = false, DatabaseBase $conn = null ) {
+ public function getReadOnlyReason( $wiki = false, IDatabase $conn = null ) {
if ( $this->readOnlyReason !== false ) {
return $this->readOnlyReason;
} elseif ( $this->getLaggedReplicaMode( $wiki ) ) {
/**
* @param string $wiki Wiki ID, or false for the current wiki
- * @param DatabaseBase|null DB master connectionl used to avoid loops [optional]
+ * @param IDatabase|null DB master connectionl used to avoid loops [optional]
* @return bool
*/
- private function masterRunningReadOnly( $wiki, DatabaseBase $conn = null ) {
+ private function masterRunningReadOnly( $wiki, IDatabase $conn = null ) {
$cache = $this->wanCache;
$masterServer = $this->getServerName( $this->getWriterIndex() );
);
}
- /**
- * Disables/enables lag checks
- * @param null|bool $mode
- * @return bool
- */
public function allowLagged( $mode = null ) {
if ( $mode === null ) {
return $this->mAllowLagged;
return $this->mAllowLagged;
}
- /**
- * @return bool
- */
public function pingAll() {
$success = true;
$this->forEachOpenConnection( function ( DatabaseBase $conn ) use ( &$success ) {
return $success;
}
- /**
- * Call a function with each open connection object
- * @param callable $callback
- * @param array $params
- */
public function forEachOpenConnection( $callback, array $params = [] ) {
foreach ( $this->mConns as $connsByServer ) {
foreach ( $connsByServer as $serverConns ) {
}
}
- /**
- * Get the hostname and lag time of the most-lagged replica DB
- *
- * This is useful for maintenance scripts that need to throttle their updates.
- * May attempt to open connections to replica DBs on the default DB. If there is
- * no lag, the maximum lag will be reported as -1.
- *
- * @param bool|string $wiki Wiki ID, or false for the default database
- * @return array ( host, max lag, index of max lagged host )
- */
public function getMaxLag( $wiki = false ) {
$maxLag = -1;
$host = '';
return [ $host, $maxLag, $maxIndex ];
}
- /**
- * Get an estimate of replication lag (in seconds) for each server
- *
- * Results are cached for a short time in memcached/process cache
- *
- * Values may be "false" if replication is too broken to estimate
- *
- * @param string|bool $wiki
- * @return int[] Map of (server index => float|int|bool)
- */
public function getLagTimes( $wiki = false ) {
if ( $this->getServerCount() <= 1 ) {
return [ 0 => 0 ]; // no replication = no lag
return $this->getLoadMonitor()->getLagTimes( array_keys( $this->mServers ), $wiki );
}
- /**
- * Get the lag in seconds for a given connection, or zero if this load
- * balancer does not have replication enabled.
- *
- * This should be used in preference to Database::getLag() in cases where
- * replication may not be in use, since there is no way to determine if
- * replication is in use at the connection level without running
- * potentially restricted queries such as SHOW SLAVE STATUS. Using this
- * function instead of Database::getLag() avoids a fatal error in this
- * case on many installations.
- *
- * @param IDatabase $conn
- * @return int|bool Returns false on error
- */
public function safeGetLag( IDatabase $conn ) {
if ( $this->getServerCount() == 1 ) {
return 0;
$result = $conn->masterPosWait( $pos, $timeout );
if ( $result == -1 || is_null( $result ) ) {
$msg = __METHOD__ . ": Timed out waiting on {$conn->getServer()} pos {$pos}";
- wfDebugLog( 'replication', "$msg\n" );
- wfDebugLog( 'DBPerformance', "$msg:\n" . wfBacktrace( true ) );
+ $this->replLogger->warning( "$msg\n" );
+ $this->perfLogger->warning( "$msg:\n" . wfBacktrace( true ) );
$ok = false;
} else {
- wfDebugLog( 'replication', __METHOD__ . ": Done\n" );
+ $this->replLogger->info( __METHOD__ . ": Done\n" );
$ok = true;
}
* Clear the cache for slag lag delay times
*
* This is only used for testing
+ * @since 1.26
*/
public function clearLagTimeCache() {
$this->getLoadMonitor()->clearCaches();
}
);
}
+
+ /**
+ * Set a new table prefix for the existing local wiki ID for testing
+ *
+ * @param string $prefix
+ * @since 1.28
+ */
+ public function setDomainPrefix( $prefix ) {
+ list( $dbName, ) = explode( '-', $this->localDomain, 2 );
+
+ $this->localDomain = "{$dbName}-{$prefix}";
+ }
}
dépôts / lhc / web / wiklou.git / blobdiff