Database connection, tracking, load balancing, and transaction manager for a cluster. More...

Inheritance diagram for Wikimedia\Rdbms\LoadBalancer:

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Collaboration diagram for Wikimedia\Rdbms\LoadBalancer:

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Public Member Functions
	__construct (array $params)
	Construct a manager of IDatabase connection objects.

	__destruct ()

	allowLagged ( $mode=null)
	Disables/enables lag checks.

	approveMasterChanges (array $options)
	Perform all pre-commit checks for things like replication safety.

	beginMasterChanges ( $fname=__METHOD__)
	Flush any master transaction snapshots and set DBO_TRX (if DBO_DEFAULT is set)

	closeAll ()
	Close all open connections.

	closeConnection (IDatabase $conn)
	Close a connection.

	commitAll ( $fname=__METHOD__)
	Commit transactions on all open connections.

	commitMasterChanges ( $fname=__METHOD__)
	Issue COMMIT on all master connections where writes where done.

	disable ()
	Disable this load balancer.

	finalizeMasterChanges ()
	Perform all pre-commit callbacks that remain part of the atomic transactions and disable any post-commit callbacks until runMasterPostTrxCallbacks()

	flushReplicaSnapshots ( $fname=__METHOD__)
	Commit all replica DB transactions so as to flush any REPEATABLE-READ or SSI snapshot.

	forEachOpenConnection ( $callback, array $params=[])
	Call a function with each open connection object.

	forEachOpenMasterConnection ( $callback, array $params=[])
	Call a function with each open connection object to a master.

	forEachOpenReplicaConnection ( $callback, array $params=[])
	Call a function with each open replica DB connection object.

	getAnyOpenConnection ( $i, $flags=0)
	Get any open connection to a given server index, local or foreign.

	getConnection ( $i, $groups=[], $domain=false, $flags=0)
	Get a connection handle by server index.

	getConnectionRef ( $db, $groups=[], $domain=false, $flags=0)
	Get a database connection handle reference.

	getLaggedReplicaMode ( $domain=false)

	getLaggedSlaveMode ( $domain=false)

	getLagTimes ( $domain=false)
	Get an estimate of replication lag (in seconds) for each server.

	getLazyConnectionRef ( $db, $groups=[], $domain=false, $flags=0)
	Get a database connection handle reference without connecting yet.

	getLocalDomainID ()
	Get the local (and default) database domain ID of connection handles.

	getMaintenanceConnectionRef ( $db, $groups=[], $domain=false, $flags=0)
	Get a maintenance database connection handle reference for migrations and schema changes.

	getMasterPos ()
	Get the current master position for chronology control purposes.

	getMaxLag ( $domain=false)
	Get the hostname and lag time of the most-lagged replica DB.

	getReaderIndex ( $group=false, $domain=false)
	Get the index of the reader connection, which may be a replica DB.

	getReadOnlyReason ( $domain=false, IDatabase $conn=null)

	getServerAttributes ( $i)

	getServerCount ()
	Get the number of defined servers (not the number of open connections)

	getServerInfo ( $i)
	Return the server info structure for a given index, or false if the index is invalid.

	getServerName ( $i)
	Get the host name or IP address of the server with the specified index.

	getServerType ( $i)
	Get DB type of the server with the specified index.

	getWriterIndex ()

	hasMasterChanges ()
	Determine if there are pending changes in a transaction by this thread.

	hasMasterConnection ()

	hasOrMadeRecentMasterChanges ( $age=null)
	Check if this load balancer object had any recent or still pending writes issued against it by this PHP thread.

	haveIndex ( $i)
	Returns true if the specified index is a valid server index.

	isNonZeroLoad ( $i)
	Returns true if the specified index is valid and has non-zero load.

	laggedReplicaUsed ()
	Checks whether the database for generic connections this request was both:

	laggedSlaveUsed ()

	lastMasterChangeTimestamp ()
	Get the timestamp of the latest write query done by this thread.

	openConnection ( $i, $domain=false, $flags=0)
	Open a connection to the server given by the specified index.

	pendingMasterChangeCallers ()
	Get the list of callers that have pending master changes.

	pingAll ()

	reuseConnection (IDatabase $conn)
	Mark a foreign connection as being available for reuse under a different DB domain.

	rollbackMasterChanges ( $fname=__METHOD__)
	Issue ROLLBACK only on master, only if queries were done on connection.

	runMasterPostTrxCallbacks ( $type)
	Issue all pending post-COMMIT/ROLLBACK callbacks.

	safeGetLag (IDatabase $conn)
	Get the lag in seconds for a given connection, or zero if this load balancer does not have replication enabled.

	safeWaitForMasterPos (IDatabase $conn, $pos=false, $timeout=null)

	setDomainPrefix ( $prefix)
	Set a new table prefix for the existing local domain ID for testing.

	setIndexAliases (array $aliases)
	Convert certain index names to alternative names before querying the DB.

	setTableAliases (array $aliases)
	Make certain table names use their own database, schema, and table prefix when passed into SQL queries pre-escaped and without a qualified database name.

	setTransactionListener ( $name, callable $callback=null)
	Set a callback via IDatabase::setTransactionListener() on all current and future master connections of this load balancer.

	suppressTransactionEndCallbacks ()
	Suppress all pending post-COMMIT/ROLLBACK callbacks.

	waitFor ( $pos)
	Set the master wait position.

	waitForAll ( $pos, $timeout=null)
	Set the master wait position and wait for ALL replica DBs to catch up to it.

	waitForOne ( $pos, $timeout=null)
	Set the master wait position and wait for a "generic" replica DB to catch up to it.

Public Attributes
const	KEY_FOREIGN_FREE = 'foreignFree'

const	KEY_FOREIGN_FREE_NOROUND = 'foreignFreeAutoCommit'

const	KEY_FOREIGN_INUSE = 'foreignInUse'

const	KEY_FOREIGN_INUSE_NOROUND = 'foreignInUseAutoCommit'

const	KEY_LOCAL = 'local'

const	KEY_LOCAL_NOROUND = 'localAutoCommit'

Public Attributes inherited from Wikimedia\Rdbms\ILoadBalancer
const	DB_MASTER = self::DB_PRIMARY
	Request a primary, write-enabled DB connection.

const	DB_PRIMARY = -2
	Request a primary, write-enabled DB connection.

Protected Member Functions
	doWait ( $index, $open=false, $timeout=null)
	Wait for a given replica DB to catch up to the master pos stored in $this.

	getScopedPHPBehaviorForCommit ()
	Make PHP ignore user aborts/disconnects until the returned value leaves scope.

	reallyOpenConnection (array $server, DatabaseDomain $domainOverride)
	Open a new network connection to a server (uncached)

Protected Attributes
string	$agent
	Agent name for query profiling.

bool	$cliMode
	Whether this PHP instance is for a CLI script.

LoggerInterface	$connLogger

LoggerInterface	$perfLogger

object string	$profiler
	Class name or object With profileIn/profileOut methods.

LoggerInterface	$queryLogger

LoggerInterface	$replLogger

TransactionProfiler	$trxProfiler

Private Member Functions
	applyTransactionRoundFlags (IDatabase $conn)
	Make all DB servers with DBO_DEFAULT/DBO_TRX set join the transaction round.

	getLoadMonitor ()
	Get a LoadMonitor instance.

	getRandomNonLagged (array $loads, $domain=false, $maxLag=INF)

	isOpen ( $index)
	Test if the specified index represents an open connection.

	masterRunningReadOnly ( $domain, IDatabase $conn=null)

	openForeignConnection ( $i, $domain, $flags=0)
	Open a connection to a foreign DB, or return one if it is already open.

	pickReaderIndex (array $loads, $domain=false)

	reportConnectionError ()

	setLocalDomain (DatabaseDomain $domain)

	setWaitForPositionIfHigher ( $pos)

	undoTransactionRoundFlags (IDatabase $conn)

Private Attributes
bool	$allowLagged
	Whether to disregard replica DB lag as a factor in replica DB selection.

bool	$allReplicasDownMode = false
	Whether the generic reader fell back to a lagged replica DB.

callable null	$chronologyCallback
	Callback to run before the first connection attempt.

bool	$connectionAttempted = false
	Whether any connection has been attempted yet.

Database[][][]	$conns
	Map of (connection category => server index => IDatabase[])

int	$connsOpened = 0
	Total connections opened.

callable	$deprecationLogger
	Deprecation logger.

bool	$disabled = false

Database	$errorConnection
	DB connection object that caused a problem.

callable	$errorLogger
	Exception logger.

array[]	$groupLoads
	Map of (group => server index => weight)

string	$host
	Current server name.

string[]	$indexAliases = []
	Map of (index alias => index)

bool	$laggedReplicaMode = false
	Whether the generic reader fell back to a lagged replica DB.

string	$lastError = 'Unknown error'
	The last DB selection or connection error.

ILoadMonitor	$loadMonitor

array	$loadMonitorConfig
	The LoadMonitor configuration.

float[]	$loads
	Map of (server index => weight)

DatabaseDomain	$localDomain
	Local Domain ID and default for selectDB() calls.

string	$localDomainIdAlias
	Alternate ID string for the domain instead of DatabaseDomain::getId()

int	$maxLag = self::MAX_LAG_DEFAULT

int	$readIndex
	The generic (not query grouped) replica DB index (of $mServers)

string bool	$readOnlyReason = false
	Reason the LB is read-only or false if not.

array[]	$servers
	Map of (server index => server config array)

BagOStuff	$srvCache

	$tableAliases = []

array[]	$trxRecurringCallbacks = []
	Map of (name => callable)

string bool	$trxRoundId = false
	String if a requested DBO_TRX transaction round is active.

bool DBMasterPos	$waitForPos
	False if not set.

int	$waitTimeout
	Seconds to spend waiting on replica DB lag to resolve.

WANObjectCache	$wanCache

Detailed Description

Database connection, tracking, load balancing, and transaction manager for a cluster.

Definition at line 41 of file LoadBalancer.php.

Constructor & Destructor Documentation

◆ __construct()

Wikimedia\Rdbms\LoadBalancer::__construct ( array $params )

Construct a manager of IDatabase connection objects.

Parameters

array

$params

Parameter map with keys:

servers : Required. Array of server info structures.
localDomain: A DatabaseDomain or domain ID string.
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]
maxLag: Avoid replica DB servers with more lag than this [optional]
srvCache : BagOStuff object for server cache [optional]
wanCache : WANObjectCache object [optional]
chronologyCallback: Callback to run before the first connection attempt [optional]
hostname : The name of the current server [optional]
cliMode: Whether the execution context is a CLI script. [optional]
profiler : Class name or instance with profileIn()/profileOut() methods. [optional]
trxProfiler: TransactionProfiler instance. [optional]
replLogger: PSR-3 logger instance. [optional]
connLogger: PSR-3 logger instance. [optional]
queryLogger: PSR-3 logger instance. [optional]
perfLogger: PSR-3 logger instance. [optional]
errorLogger : Callback that takes an Exception and logs it. [optional]
deprecationLogger: Callback to log a deprecation warning. [optional]

Exceptions

InvalidArgumentException

Implements Wikimedia\Rdbms\ILoadBalancer.

Reimplemented in Wikimedia\Rdbms\LoadBalancerSingle.

Definition at line 143 of file LoadBalancer.php.

References $e, Wikimedia\Rdbms\LoadBalancer\$localDomain, Wikimedia\Rdbms\LoadBalancer\$maxLag, $params, Wikimedia\Rdbms\LoadBalancer\allowLagged(), Wikimedia\Rdbms\DatabaseDomain\newFromId(), Wikimedia\Rdbms\DatabaseDomain\newUnspecified(), servers, and Wikimedia\Rdbms\LoadBalancer\setLocalDomain().

◆ __destruct()

Wikimedia\Rdbms\LoadBalancer::__destruct ( )

Definition at line 1864 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\disable().

Member Function Documentation

◆ allowLagged()

Wikimedia\Rdbms\LoadBalancer::allowLagged ( $mode = null )

Disables/enables lag checks.

Parameters

null | bool $mode

Returns: bool

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1621 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$allowLagged, and Wikimedia\Rdbms\LoadBalancer\allowLagged().

Referenced by Wikimedia\Rdbms\LoadBalancer\__construct(), Wikimedia\Rdbms\LoadBalancer\allowLagged(), and Wikimedia\Rdbms\LoadBalancer\pickReaderIndex().

◆ applyTransactionRoundFlags()

Wikimedia\Rdbms\LoadBalancer::applyTransactionRoundFlags ( IDatabase $conn )

private

Make all DB servers with DBO_DEFAULT/DBO_TRX set join the transaction round.

Some servers may have neither flag enabled, meaning that they opt out of such transaction rounds and remain in auto-commit mode. Such behavior might be desired when a DB server is used for something like simple key/value storage.

Parameters

IDatabase $conn

Definition at line 1457 of file LoadBalancer.php.

References Wikimedia\Rdbms\IDatabase\getFlag(), Wikimedia\Rdbms\IDatabase\getLBInfo(), Wikimedia\Rdbms\IDatabase\setFlag(), and Wikimedia\Rdbms\IDatabase\setLBInfo().

Referenced by Wikimedia\Rdbms\LoadBalancer\beginMasterChanges(), and Wikimedia\Rdbms\LoadBalancer\reallyOpenConnection().

◆ approveMasterChanges()

Wikimedia\Rdbms\LoadBalancer::approveMasterChanges ( array $options )

Perform all pre-commit checks for things like replication safety.

Use this only for mutli-database commits

Parameters

array

$options

Includes:

maxWriteDuration : max write query duration time in seconds

Exceptions

DBTransactionError

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1296 of file LoadBalancer.php.

References $options, $time, Wikimedia\Rdbms\IDatabase\explicitTrxActive(), Wikimedia\Rdbms\LoadBalancer\forEachOpenMasterConnection(), Wikimedia\Rdbms\IDatabase\pendingWriteQueryDuration(), Wikimedia\Rdbms\IDatabase\ping(), and Wikimedia\Rdbms\IDatabase\writesOrCallbacksPending().

◆ beginMasterChanges()

Wikimedia\Rdbms\LoadBalancer::beginMasterChanges ( $fname = __METHOD__ )

Flush any master transaction snapshots and set DBO_TRX (if DBO_DEFAULT is set)

The DBO_TRX setting will be reverted to the default in each of these methods:

commitMasterChanges()
rollbackMasterChanges()
commitAll() This allows for custom transaction rounds from any outer transaction scope.

Parameters

string $fname

Exceptions

DBExpectedError

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1329 of file LoadBalancer.php.

References $e, $fname, Wikimedia\Rdbms\LoadBalancer\applyTransactionRoundFlags(), Wikimedia\Rdbms\Database\flushSnapshot(), Wikimedia\Rdbms\LoadBalancer\forEachOpenMasterConnection(), and Wikimedia\Rdbms\Database\setTrxEndCallbackSuppression().

◆ closeAll()

Wikimedia\Rdbms\LoadBalancer::closeAll ( )

Close all open connections.

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1218 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$host, Wikimedia\Rdbms\IDatabase\close(), Wikimedia\Rdbms\LoadBalancer\forEachOpenConnection(), and Wikimedia\Rdbms\IDatabase\getServer().

Referenced by Wikimedia\Rdbms\LoadBalancer\disable().

◆ closeConnection()

Wikimedia\Rdbms\LoadBalancer::closeConnection ( IDatabase $conn )

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.

Parameters

IDatabase $conn

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1237 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$connsOpened, Wikimedia\Rdbms\LoadBalancer\$host, $type, Wikimedia\Rdbms\IDatabase\close(), Wikimedia\Rdbms\IDatabase\getLBInfo(), and Wikimedia\Rdbms\LoadBalancer\getServerName().

Referenced by Wikimedia\Rdbms\LoadBalancer\doWait(), and Wikimedia\Rdbms\LoadBalancer\safeWaitForMasterPos().

◆ commitAll()

Wikimedia\Rdbms\LoadBalancer::commitAll ( $fname = __METHOD__ )

Commit transactions on all open connections.

Parameters

string $fname Caller name

Exceptions

DBExpectedError

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1259 of file LoadBalancer.php.

References $e, $fname, Wikimedia\Rdbms\IDatabase\commit(), false, Wikimedia\Rdbms\LoadBalancer\forEachOpenConnection(), Wikimedia\Rdbms\IDatabase\getLBInfo(), and Wikimedia\Rdbms\LoadBalancer\undoTransactionRoundFlags().

◆ commitMasterChanges()

Wikimedia\Rdbms\LoadBalancer::commitMasterChanges ( $fname = __METHOD__ )

Issue COMMIT on all master connections where writes where done.

Parameters

string $fname Caller name

Exceptions

DBExpectedError

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1361 of file LoadBalancer.php.

References $e, $fname, false, Wikimedia\Rdbms\IDatabase\flushSnapshot(), Wikimedia\Rdbms\LoadBalancer\forEachOpenMasterConnection(), Wikimedia\Rdbms\LoadBalancer\getScopedPHPBehaviorForCommit(), Wikimedia\Rdbms\LoadBalancer\undoTransactionRoundFlags(), and Wikimedia\Rdbms\IDatabase\writesOrCallbacksPending().

◆ disable()

Wikimedia\Rdbms\LoadBalancer::disable ( )

Disable this load balancer.

All connections are closed, and any attempt to open a new connection will result in a DBAccessError.

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1213 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\closeAll().

Referenced by Wikimedia\Rdbms\LoadBalancer\__destruct().

◆ doWait()

Wikimedia\Rdbms\LoadBalancer::doWait	(	$index,
		$open = false,
		$timeout = null )

protected

Wait for a given replica DB to catch up to the master pos stored in $this.

Parameters

int	$index	Server index
bool	$open	Check the server even if a new connection has to be made
int	$timeout	Max seconds to wait; default is "waitTimeout" given to __construct()

Returns: bool

Definition at line 594 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$waitTimeout, Wikimedia\Rdbms\LoadBalancer\closeConnection(), Wikimedia\Rdbms\LoadBalancer\getAnyOpenConnection(), Wikimedia\Rdbms\LoadBalancer\getServerName(), Wikimedia\Rdbms\DBMasterPos\hasReached(), and Wikimedia\Rdbms\LoadBalancer\openConnection().

Referenced by Wikimedia\Rdbms\LoadBalancer\getReaderIndex(), Wikimedia\Rdbms\LoadBalancer\waitFor(), Wikimedia\Rdbms\LoadBalancer\waitForAll(), and Wikimedia\Rdbms\LoadBalancer\waitForOne().

◆ finalizeMasterChanges()

Wikimedia\Rdbms\LoadBalancer::finalizeMasterChanges ( )

Perform all pre-commit callbacks that remain part of the atomic transactions and disable any post-commit callbacks until runMasterPostTrxCallbacks()

Use this only for mutli-database commits

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1286 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\forEachOpenMasterConnection(), Wikimedia\Rdbms\Database\runOnTransactionPreCommitCallbacks(), and Wikimedia\Rdbms\Database\setTrxEndCallbackSuppression().

◆ flushReplicaSnapshots()

Wikimedia\Rdbms\LoadBalancer::flushReplicaSnapshots ( $fname = __METHOD__ )

Commit all replica DB transactions so as to flush any REPEATABLE-READ or SSI snapshot.

Parameters

string $fname Caller name

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1490 of file LoadBalancer.php.

References Wikimedia\Rdbms\IDatabase\flushSnapshot(), and Wikimedia\Rdbms\LoadBalancer\forEachOpenReplicaConnection().

◆ forEachOpenConnection()

Wikimedia\Rdbms\LoadBalancer::forEachOpenConnection	(		$callback,
		array	$params = [] )

Call a function with each open connection object.

Parameters

callable	$callback
array	$params

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1641 of file LoadBalancer.php.

References $params.

Referenced by Wikimedia\Rdbms\LoadBalancer\closeAll(), Wikimedia\Rdbms\LoadBalancer\commitAll(), Wikimedia\Rdbms\LoadBalancer\pingAll(), and Wikimedia\Rdbms\LoadBalancer\setDomainPrefix().

◆ forEachOpenMasterConnection()

Wikimedia\Rdbms\LoadBalancer::forEachOpenMasterConnection	(		$callback,
		array	$params = [] )

Call a function with each open connection object to a master.

Parameters

callable	$callback
array	$params

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1652 of file LoadBalancer.php.

References $params, and Wikimedia\Rdbms\LoadBalancer\getWriterIndex().

◆ forEachOpenReplicaConnection()

Wikimedia\Rdbms\LoadBalancer::forEachOpenReplicaConnection	(		$callback,
		array	$params = [] )

Call a function with each open replica DB connection object.

Parameters

callable	$callback
array	$params

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1665 of file LoadBalancer.php.

References $params, and Wikimedia\Rdbms\LoadBalancer\getWriterIndex().

Referenced by Wikimedia\Rdbms\LoadBalancer\flushReplicaSnapshots().

◆ getAnyOpenConnection()

Wikimedia\Rdbms\LoadBalancer::getAnyOpenConnection	(		$i,
			$flags = 0 )

Get any open connection to a given server index, local or foreign.

Use CONN_TRX_AUTOCOMMIT to only look for connections opened with that flag

Parameters

int	$i	Server index or DB_MASTER/DB_REPLICA
int	$flags	Bitfield of CONN_* class constants

Returns: Database|bool False if no such connection is open

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 570 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\doWait(), Wikimedia\Rdbms\LoadBalancer\getMasterPos(), Wikimedia\Rdbms\LoadBalancer\isOpen(), and Wikimedia\Rdbms\LoadBalancer\safeWaitForMasterPos().

◆ getConnection()

Wikimedia\Rdbms\LoadBalancer::getConnection	(	$i,
		$groups = [],
		$domain = false,
		$flags = 0 )

Get a connection handle by server index.

The CONN_TRX_AUTOCOMMIT flag is ignored for databases with ATTR_DB_LEVEL_LOCKING (e.g. sqlite) in order to avoid deadlocks. ILoadBalancer::getServerAttributes() can be used to check such flags beforehand.

If the caller uses $domain or sets CONN_TRX_AUTOCOMMIT in $flags, then it must also call ILoadBalancer::reuseConnection() on the handle when finished using it. In all other cases, this is not necessary, though not harmful either.

Parameters

int	$i	Server index (overrides $groups) or DB_MASTER/DB_REPLICA
array \| string \| bool	$groups	Query group(s), or false for the generic reader
string \| bool	$domain	Domain ID, or false for the current domain
int	$flags	Bitfield of CONN_* class constants

Note: This method throws DBAccessError if ILoadBalancer::disable() was called

Exceptions

DBError

Returns: Database

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 683 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$connsOpened, Wikimedia\Rdbms\LoadBalancer\$host, Wikimedia\Rdbms\LoadBalancer\$lastError, array(), false, Wikimedia\Rdbms\LoadBalancer\getReaderIndex(), Wikimedia\Rdbms\LoadBalancer\getReadOnlyReason(), Wikimedia\Rdbms\LoadBalancer\getServerAttributes(), Wikimedia\Rdbms\LoadBalancer\getWriterIndex(), Wikimedia\Rdbms\LoadBalancer\openConnection(), and Wikimedia\Rdbms\LoadBalancer\reportConnectionError().

Referenced by Wikimedia\Rdbms\LoadBalancer\getConnectionRef(), Wikimedia\Rdbms\LoadBalancer\getLaggedReplicaMode(), Wikimedia\Rdbms\LoadBalancer\getMaintenanceConnectionRef(), and Wikimedia\Rdbms\LoadBalancer\masterRunningReadOnly().

◆ getConnectionRef()

Wikimedia\Rdbms\LoadBalancer::getConnectionRef	(	$i,
		$groups = [],
		$domain = false,
		$flags = 0 )

Get a database connection handle reference.

The handle's methods simply wrap those of a Database handle

The CONN_TRX_AUTOCOMMIT flag is ignored for databases with ATTR_DB_LEVEL_LOCKING (e.g. sqlite) in order to avoid deadlocks. ILoadBalancer::getServerAttributes() can be used to check such flags beforehand.

See also: ILoadBalancer::getConnection() for parameter information

Parameters

int	$i	Server index or DB_MASTER/DB_REPLICA
array \| string \| bool	$groups	Query group(s), or false for the generic reader
string \| bool	$domain	Domain ID, or false for the current domain
int	$flags	Bitfield of CONN_* class constants (e.g. CONN_TRX_AUTOCOMMIT)

Returns: DBConnRef

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 829 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$localDomain, false, and Wikimedia\Rdbms\LoadBalancer\getConnection().

Referenced by ImportableOldRevisionImporter\import().

◆ getLaggedReplicaMode()

Wikimedia\Rdbms\LoadBalancer::getLaggedReplicaMode ( $domain = false )

Note: This method will trigger a DB connection if not yet done

Parameters

string | bool $domain Domain ID, or false for the current domain

Returns: bool Whether the database for generic connections this request is highly "lagged"

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1534 of file LoadBalancer.php.

References $e, Wikimedia\Rdbms\LoadBalancer\$laggedReplicaMode, Wikimedia\Rdbms\LoadBalancer\getConnection(), Wikimedia\Rdbms\LoadBalancer\getServerCount(), and Wikimedia\Rdbms\LoadBalancer\reuseConnection().

Referenced by Wikimedia\Rdbms\LoadBalancer\getLaggedSlaveMode(), and Wikimedia\Rdbms\LoadBalancer\getReadOnlyReason().

◆ getLaggedSlaveMode()

Wikimedia\Rdbms\LoadBalancer::getLaggedSlaveMode ( $domain = false )

Parameters

bool $domain

Returns: bool

Deprecated: 1.28; use getLaggedReplicaMode()

Definition at line 1556 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\getLaggedReplicaMode().

◆ getLagTimes()

Wikimedia\Rdbms\LoadBalancer::getLagTimes ( $domain = false )

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

Parameters

string | bool $domain

Returns: int[] Map of (server index => float|int|bool)

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1700 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\getLoadMonitor(), Wikimedia\Rdbms\LoadBalancer\getServerCount(), Wikimedia\Rdbms\LoadBalancer\getWriterIndex(), and servers.

Referenced by Wikimedia\Rdbms\LoadBalancer\getMaxLag(), and Wikimedia\Rdbms\LoadBalancer\getRandomNonLagged().

◆ getLazyConnectionRef()

Wikimedia\Rdbms\LoadBalancer::getLazyConnectionRef	(	$i,
		$groups = [],
		$domain = false,
		$flags = 0 )

Get a database connection handle reference without connecting yet.

The handle's methods simply wrap those of a Database handle

The CONN_TRX_AUTOCOMMIT flag is ignored for databases with ATTR_DB_LEVEL_LOCKING (e.g. sqlite) in order to avoid deadlocks. ILoadBalancer::getServerAttributes() can be used to check such flags beforehand.

See also: ILoadBalancer::getConnection() for parameter information

Parameters

int	$i	Server index or DB_MASTER/DB_REPLICA
array \| string \| bool	$groups	Query group(s), or false for the generic reader
string \| bool	$domain	Domain ID, or false for the current domain
int	$flags	Bitfield of CONN_* class constants (e.g. CONN_TRX_AUTOCOMMIT)

Returns: DBConnRef

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 835 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$localDomain, and false.

Referenced by Wikimedia\Rdbms\LoadBalancer\reallyOpenConnection().

◆ getLoadMonitor()

Wikimedia\Rdbms\LoadBalancer::getLoadMonitor ( )

private

Get a LoadMonitor instance.

Returns: ILoadMonitor

Definition at line 268 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$loadMonitor.

Referenced by Wikimedia\Rdbms\LoadBalancer\getLagTimes(), and Wikimedia\Rdbms\LoadBalancer\getReaderIndex().

◆ getLocalDomainID()

Wikimedia\Rdbms\LoadBalancer::getLocalDomainID ( )

Get the local (and default) database domain ID of connection handles.

See also: DatabaseDomain

Returns: string Database domain ID; this specifies DB name, schema, and table prefix

Since: 1.31

Definition at line 259 of file LoadBalancer.php.

◆ getMaintenanceConnectionRef()

Wikimedia\Rdbms\LoadBalancer::getMaintenanceConnectionRef	(	$db,
		$groups = [],
		$domain = false,
		$flags = 0 )

Get a maintenance database connection handle reference for migrations and schema changes.

The handle's methods simply wrap those of a Database handle

The CONN_TRX_AUTOCOMMIT flag is ignored for databases with ATTR_DB_LEVEL_LOCKING (e.g. sqlite) in order to avoid deadlocks. ILoadBalancer::getServerAttributes() can be used to check such flags beforehand.

See also: ILoadBalancer::getConnection() for parameter information

Parameters

int	$db	Server index or DB_MASTER/DB_REPLICA
array \| string \| bool	$groups	Query group(s), or false for the generic reader
string \| bool	$domain	Domain ID, or false for the current domain
int	$flags	Bitfield of CONN_* class constants (e.g. CONN_TRX_AUTOCOMMIT)

Returns: MaintainableDBConnRef

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 841 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$localDomain, false, and Wikimedia\Rdbms\LoadBalancer\getConnection().

◆ getMasterPos()

Wikimedia\Rdbms\LoadBalancer::getMasterPos ( )

Get the current master position for chronology control purposes.

Returns: DBMasterPos|bool Returns false if not applicable

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1194 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\getAnyOpenConnection(), Wikimedia\Rdbms\LoadBalancer\getWriterIndex(), and servers.

◆ getMaxLag()

Wikimedia\Rdbms\LoadBalancer::getMaxLag ( $domain = false )

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.

Parameters

bool | string $domain Domain ID, or false for the default database

Returns: array ( host, max lag, index of max lagged host )

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1679 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$host, Wikimedia\Rdbms\LoadBalancer\$maxLag, Wikimedia\Rdbms\LoadBalancer\getLagTimes(), Wikimedia\Rdbms\LoadBalancer\getServerCount(), and servers.

◆ getRandomNonLagged()

Wikimedia\Rdbms\LoadBalancer::getRandomNonLagged	(	array	$loads,
			$domain = false,
			$maxLag = INF )

private

Parameters

array	$loads
bool \| string	$domain	Domain to get non-lagged for
int	$maxLag	Restrict the maximum allowed lag to this many seconds

Returns: bool|int|string

Definition at line 295 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$host, Wikimedia\Rdbms\LoadBalancer\$loads, Wikimedia\Rdbms\LoadBalancer\$maxLag, Wikimedia\Rdbms\LoadBalancer\getLagTimes(), Wikimedia\Rdbms\LoadBalancer\getServerName(), ArrayUtils\pickRandom(), and servers.

Referenced by Wikimedia\Rdbms\LoadBalancer\pickReaderIndex().

◆ getReaderIndex()

Wikimedia\Rdbms\LoadBalancer::getReaderIndex	(		$group = false,
			$domain = false )

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

Parameters

string \| bool	$group	Query group, or false for the generic reader
string \| bool	$domain	Domain ID, or false for the current domain

Exceptions

DBError

Returns: bool|int|string

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 346 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$laggedReplicaMode, Wikimedia\Rdbms\LoadBalancer\$loads, Wikimedia\Rdbms\LoadBalancer\$readIndex, Wikimedia\Rdbms\LoadBalancer\doWait(), Wikimedia\Rdbms\LoadBalancer\getLoadMonitor(), Wikimedia\Rdbms\LoadBalancer\getServerName(), Wikimedia\Rdbms\LoadBalancer\getWriterIndex(), list, Wikimedia\Rdbms\LoadBalancer\pickReaderIndex(), and servers.

Referenced by Wikimedia\Rdbms\LoadBalancer\getConnection().

◆ getReadOnlyReason()

Wikimedia\Rdbms\LoadBalancer::getReadOnlyReason	(		$domain = false,
		IDatabase	$conn = null )

Note: This method may trigger a DB connection if not yet done

Parameters

string \| bool	$domain	Domain ID, or false for the current domain
IDatabase \| null	$conn	DB master connection; used to avoid loops [optional]

Returns: string|bool Reason the master is read-only or false if it is not

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1573 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$readOnlyReason, Wikimedia\Rdbms\LoadBalancer\getLaggedReplicaMode(), and Wikimedia\Rdbms\LoadBalancer\masterRunningReadOnly().

Referenced by Wikimedia\Rdbms\LoadBalancer\getConnection().

◆ getScopedPHPBehaviorForCommit()

Wikimedia\Rdbms\LoadBalancer::getScopedPHPBehaviorForCommit ( )

finalprotected

Make PHP ignore user aborts/disconnects until the returned value leaves scope.

This returns null and does nothing in CLI mode.

Returns: ScopedCallback|null

Definition at line 1853 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\commitMasterChanges().

◆ getServerAttributes()

Wikimedia\Rdbms\LoadBalancer::getServerAttributes ( $i )

Parameters

int $i Server index

Returns: array (Database::ATTRIBUTE_* constant => value) for all such constants

Since: 1.31

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1016 of file LoadBalancer.php.

References Wikimedia\Rdbms\Database\attributesFromType(), Wikimedia\Rdbms\LoadBalancer\getServerType(), and servers.

Referenced by Wikimedia\Rdbms\LoadBalancer\getConnection().

◆ getServerCount()

Wikimedia\Rdbms\LoadBalancer::getServerCount ( )

Get the number of defined servers (not the number of open connections)

Returns: int

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1166 of file LoadBalancer.php.

References servers.

Referenced by Wikimedia\Rdbms\LoadBalancer\getLaggedReplicaMode(), Wikimedia\Rdbms\LoadBalancer\getLagTimes(), Wikimedia\Rdbms\LoadBalancer\getMaxLag(), Wikimedia\Rdbms\LoadBalancer\safeGetLag(), and Wikimedia\Rdbms\LoadBalancer\safeWaitForMasterPos().

◆ getServerInfo()

Wikimedia\Rdbms\LoadBalancer::getServerInfo ( $i )

Return the server info structure for a given index, or false if the index is invalid.

Parameters

int $i

Returns: array|bool

Since: 1.31

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1182 of file LoadBalancer.php.

References servers.

◆ getServerName()

Wikimedia\Rdbms\LoadBalancer::getServerName ( $i )

Get the host name or IP address of the server with the specified index.

Parameters

int $i

Returns: string Readable name if available or IP/host otherwise

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1170 of file LoadBalancer.php.

References $name, and servers.

Referenced by Wikimedia\Rdbms\LoadBalancer\closeConnection(), Wikimedia\Rdbms\LoadBalancer\doWait(), Wikimedia\Rdbms\LoadBalancer\getRandomNonLagged(), Wikimedia\Rdbms\LoadBalancer\getReaderIndex(), Wikimedia\Rdbms\LoadBalancer\masterRunningReadOnly(), Wikimedia\Rdbms\LoadBalancer\openConnection(), Wikimedia\Rdbms\LoadBalancer\pickReaderIndex(), and Wikimedia\Rdbms\LoadBalancer\reallyOpenConnection().

◆ getServerType()

Wikimedia\Rdbms\LoadBalancer::getServerType ( $i )

Get DB type of the server with the specified index.

Parameters

int $i

Returns: string One of (mysql,postgres,sqlite,...) or "unknown" for bad indexes

Since: 1.30

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1190 of file LoadBalancer.php.

References servers.

Referenced by Wikimedia\Rdbms\LoadBalancer\getServerAttributes().

◆ getWriterIndex()

Wikimedia\Rdbms\LoadBalancer::getWriterIndex ( )

Returns: int

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1154 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\forEachOpenMasterConnection(), Wikimedia\Rdbms\LoadBalancer\forEachOpenReplicaConnection(), Wikimedia\Rdbms\LoadBalancer\getConnection(), Wikimedia\Rdbms\LoadBalancer\getLagTimes(), Wikimedia\Rdbms\LoadBalancer\getMasterPos(), Wikimedia\Rdbms\LoadBalancer\getReaderIndex(), Wikimedia\Rdbms\LoadBalancer\hasMasterConnection(), Wikimedia\Rdbms\LoadBalancer\masterRunningReadOnly(), Wikimedia\Rdbms\LoadBalancer\reallyOpenConnection(), Wikimedia\Rdbms\LoadBalancer\safeWaitForMasterPos(), and Wikimedia\Rdbms\LoadBalancer\waitForOne().

◆ hasMasterChanges()

Wikimedia\Rdbms\LoadBalancer::hasMasterChanges ( )

Determine if there are pending changes in a transaction by this thread.

Returns: bool

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1500 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\forEachOpenMasterConnection(), and Wikimedia\Rdbms\IDatabase\writesOrCallbacksPending().

Referenced by Wikimedia\Rdbms\LoadBalancer\hasOrMadeRecentMasterChanges().

◆ hasMasterConnection()

Wikimedia\Rdbms\LoadBalancer::hasMasterConnection ( )

Returns: bool Whether a master connection is already open

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1496 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\getWriterIndex(), and Wikimedia\Rdbms\LoadBalancer\isOpen().

◆ hasOrMadeRecentMasterChanges()

Wikimedia\Rdbms\LoadBalancer::hasOrMadeRecentMasterChanges ( $age = null )

Check if this load balancer object had any recent or still pending writes issued against it by this PHP thread.

Parameters

float $age How many seconds ago is "recent" [defaults to mWaitTimeout]

Returns: bool

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1518 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\hasMasterChanges(), and Wikimedia\Rdbms\LoadBalancer\lastMasterChangeTimestamp().

◆ haveIndex()

Wikimedia\Rdbms\LoadBalancer::haveIndex ( $i )

Returns true if the specified index is a valid server index.

Parameters

int $i

Returns: bool

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1158 of file LoadBalancer.php.

References servers.

◆ isNonZeroLoad()

Wikimedia\Rdbms\LoadBalancer::isNonZeroLoad ( $i )

Returns true if the specified index is valid and has non-zero load.

Parameters

int $i

Returns: bool

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1162 of file LoadBalancer.php.

References servers.

◆ isOpen()

Wikimedia\Rdbms\LoadBalancer::isOpen ( $index )

private

Test if the specified index represents an open connection.

Parameters

int $index Server index

Access:\n private

Returns: bool

Definition at line 1030 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\getAnyOpenConnection().

Referenced by Wikimedia\Rdbms\LoadBalancer\hasMasterConnection().

◆ laggedReplicaUsed()

Wikimedia\Rdbms\LoadBalancer::laggedReplicaUsed ( )

Checks whether the database for generic connections this request was both:

a) Already choosen due to a prior connection attempt
b) Considered highly "lagged"

Note: This method will never cause a new DB connection

Returns: bool

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1560 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$laggedReplicaMode.

Referenced by Wikimedia\Rdbms\LoadBalancer\laggedSlaveUsed().

◆ laggedSlaveUsed()

Wikimedia\Rdbms\LoadBalancer::laggedSlaveUsed ( )

Returns: bool

Since: 1.27

Deprecated: Since 1.28; use laggedReplicaUsed()

Definition at line 1569 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\laggedReplicaUsed().

◆ lastMasterChangeTimestamp()

Wikimedia\Rdbms\LoadBalancer::lastMasterChangeTimestamp ( )

Get the timestamp of the latest write query done by this thread.

Returns: float|bool UNIX timestamp or false

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1509 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\forEachOpenMasterConnection(), and Wikimedia\Rdbms\IDatabase\lastDoneWrites().

Referenced by Wikimedia\Rdbms\LoadBalancer\hasOrMadeRecentMasterChanges().

◆ masterRunningReadOnly()

Wikimedia\Rdbms\LoadBalancer::masterRunningReadOnly	(		$domain,
		IDatabase	$conn = null )

private

Parameters

string	$domain	Domain ID, or false for the current domain
IDatabase \| null	$conn	DB master connectionl used to avoid loops [optional]

Returns: bool

Definition at line 1596 of file LoadBalancer.php.

References $cache, $e, Wikimedia\Rdbms\LoadBalancer\$wanCache, function, Wikimedia\Rdbms\LoadBalancer\getConnection(), Wikimedia\Rdbms\LoadBalancer\getServerName(), Wikimedia\Rdbms\LoadBalancer\getWriterIndex(), and Wikimedia\Rdbms\LoadBalancer\reuseConnection().

Referenced by Wikimedia\Rdbms\LoadBalancer\getReadOnlyReason().

◆ openConnection()

Wikimedia\Rdbms\LoadBalancer::openConnection	(	$i,
		$domain = false,
		$flags = 0 )

Open a connection to the server given by the specified index.

The index must be an actual index into the array. If a connection to the server is already open and not considered an "in use" foreign connection, this simply returns it.

Avoid using CONN_TRX_AUTOCOMMIT for databases with ATTR_DB_LEVEL_LOCKING (e.g. sqlite) in order to avoid deadlocks. ILoadBalancer::getServerAttributes() can be used to check such flags beforehand.

If the caller uses $domain or sets CONN_TRX_AUTOCOMMIT in $flags, then it must also call ILoadBalancer::reuseConnection() on the handle when finished using it. In all other cases, this is not necessary, though not harmful either.

Note: This method throws DBAccessError if ILoadBalancer::disable() was called

Parameters

int	$i	Server index (does not support DB_MASTER/DB_REPLICA)
string \| bool	$domain	Domain ID, or false for the current domain
int	$flags	Bitfield of CONN_* class constants (e.g. CONN_TRX_AUTOCOMMIT)

Returns: Database|bool Returns false on errors

Exceptions

DBAccessError

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 848 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$host, Wikimedia\Rdbms\LoadBalancer\getServerName(), Wikimedia\Rdbms\IDatabase\isOpen(), Wikimedia\Rdbms\LoadBalancer\KEY_LOCAL, Wikimedia\Rdbms\LoadBalancer\KEY_LOCAL_NOROUND, Wikimedia\Rdbms\LoadBalancer\openForeignConnection(), Wikimedia\Rdbms\LoadBalancer\reallyOpenConnection(), and servers.

Referenced by Wikimedia\Rdbms\LoadBalancer\doWait(), Wikimedia\Rdbms\LoadBalancer\getConnection(), Wikimedia\Rdbms\LoadBalancer\pickReaderIndex(), and Wikimedia\Rdbms\LoadBalancer\safeWaitForMasterPos().

◆ openForeignConnection()

Wikimedia\Rdbms\LoadBalancer::openForeignConnection	(	$i,
		$domain,
		$flags = 0 )

private

Open a connection to a foreign DB, or return one if it is already open.

Increments a reference count on the returned connection which locks the connection to the requested domain. This reference count can be decremented by calling reuseConnection().

If a connection is open to the appropriate server already, but with the wrong database, it will be switched to the right database and returned, as long as it has been freed first with reuseConnection().

On error, returns false, and the connection which caused the error will be available via $this->errorConnection.

Note: If disable() was called on this LoadBalancer, this method will throw a DBAccessError.

Parameters

int	$i	Server index
string	$domain	Domain ID to open
int	$flags	Class CONN_* constant bitfield

Returns: Database

Definition at line 938 of file LoadBalancer.php.

References key, Wikimedia\Rdbms\LoadBalancer\KEY_FOREIGN_FREE, Wikimedia\Rdbms\LoadBalancer\KEY_FOREIGN_FREE_NOROUND, Wikimedia\Rdbms\LoadBalancer\KEY_FOREIGN_INUSE, Wikimedia\Rdbms\LoadBalancer\KEY_FOREIGN_INUSE_NOROUND, Wikimedia\Rdbms\DatabaseDomain\newFromId(), Wikimedia\Rdbms\LoadBalancer\reallyOpenConnection(), and servers.

Referenced by Wikimedia\Rdbms\LoadBalancer\openConnection().

◆ pendingMasterChangeCallers()

Wikimedia\Rdbms\LoadBalancer::pendingMasterChangeCallers ( )

Get the list of callers that have pending master changes.

Returns: string[] List of method names

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1525 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\forEachOpenMasterConnection(), and Wikimedia\Rdbms\IDatabase\pendingWriteCallers().

◆ pickReaderIndex()

Wikimedia\Rdbms\LoadBalancer::pickReaderIndex	(	array	$loads,
			$domain = false )

private

Parameters

array	$loads	List of server weights
string \| bool	$domain

Returns: array (reader index, lagged replica mode) or false on failure

Definition at line 410 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$laggedReplicaMode, Wikimedia\Rdbms\LoadBalancer\$loads, Wikimedia\Rdbms\LoadBalancer\allowLagged(), false, Wikimedia\Rdbms\LoadBalancer\getRandomNonLagged(), Wikimedia\Rdbms\LoadBalancer\getServerName(), Wikimedia\Rdbms\LoadBalancer\openConnection(), ArrayUtils\pickRandom(), and Wikimedia\Rdbms\LoadBalancer\reuseConnection().

Referenced by Wikimedia\Rdbms\LoadBalancer\getReaderIndex().

◆ pingAll()

Wikimedia\Rdbms\LoadBalancer::pingAll ( )

Returns: bool

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1630 of file LoadBalancer.php.

References $success, Wikimedia\Rdbms\LoadBalancer\forEachOpenConnection(), and Wikimedia\Rdbms\IDatabase\ping().

◆ reallyOpenConnection()

Wikimedia\Rdbms\LoadBalancer::reallyOpenConnection	(	array	$server,
		DatabaseDomain	$domainOverride )

protected

Open a new network connection to a server (uncached)

Returns a Database object whether or not the connection was successful.

Parameters

array	$server
DatabaseDomain	$domainOverride	Use an unspecified domain to not select any database

Returns: Database

Exceptions

DBAccessError
InvalidArgumentException

Reimplemented in Wikimedia\Rdbms\LoadBalancerSingle.

Definition at line 1049 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\openConnection(), and Wikimedia\Rdbms\LoadBalancer\openForeignConnection().

◆ reportConnectionError()

Wikimedia\Rdbms\LoadBalancer::reportConnectionError ( )

private

Exceptions

DBConnectionError

Definition at line 1125 of file LoadBalancer.php.

References $context, Wikimedia\Rdbms\LoadBalancer\$errorConnection, and Wikimedia\Rdbms\LoadBalancer\$lastError.

Referenced by Wikimedia\Rdbms\LoadBalancer\getConnection().

◆ reuseConnection()

Wikimedia\Rdbms\LoadBalancer::reuseConnection ( IDatabase $conn )

Mark a foreign connection as being available for reuse under a different DB domain.

This mechanism is reference-counted, and must be called the same number of times as getConnection() to work.

Parameters

IDatabase $conn

Exceptions

InvalidArgumentException

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 769 of file LoadBalancer.php.

References Wikimedia\Rdbms\IDatabase\getDomainID(), Wikimedia\Rdbms\IDatabase\getLBInfo(), Wikimedia\Rdbms\LoadBalancer\KEY_FOREIGN_FREE, Wikimedia\Rdbms\LoadBalancer\KEY_FOREIGN_FREE_NOROUND, Wikimedia\Rdbms\LoadBalancer\KEY_FOREIGN_INUSE, Wikimedia\Rdbms\LoadBalancer\KEY_FOREIGN_INUSE_NOROUND, and Wikimedia\Rdbms\IDatabase\setLBInfo().

Referenced by Wikimedia\Rdbms\LoadBalancer\getLaggedReplicaMode(), Wikimedia\Rdbms\LoadBalancer\masterRunningReadOnly(), and Wikimedia\Rdbms\LoadBalancer\pickReaderIndex().

◆ rollbackMasterChanges()

Wikimedia\Rdbms\LoadBalancer::rollbackMasterChanges ( $fname = __METHOD__ )

Issue ROLLBACK only on master, only if queries were done on connection.

Parameters

string $fname Caller name

Exceptions

DBExpectedError

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1429 of file LoadBalancer.php.

References $fname, false, Wikimedia\Rdbms\LoadBalancer\forEachOpenMasterConnection(), Wikimedia\Rdbms\IDatabase\rollback(), and Wikimedia\Rdbms\LoadBalancer\undoTransactionRoundFlags().

◆ runMasterPostTrxCallbacks()

Wikimedia\Rdbms\LoadBalancer::runMasterPostTrxCallbacks ( $type )

Issue all pending post-COMMIT/ROLLBACK callbacks.

Use this only for mutli-database commits

Parameters

int $type IDatabase::TRIGGER_* constant

Returns: Exception|null The first exception or null if there were none

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1395 of file LoadBalancer.php.

References $e, $type, Wikimedia\Rdbms\LoadBalancer\forEachOpenMasterConnection(), Wikimedia\Rdbms\Database\runTransactionListenerCallbacks(), Wikimedia\Rdbms\Database\setTrxEndCallbackSuppression(), Wikimedia\Rdbms\Database\trxLevel(), and Wikimedia\Rdbms\Database\writesPending().

◆ safeGetLag()

Wikimedia\Rdbms\LoadBalancer::safeGetLag ( IDatabase $conn )

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.

Parameters

IDatabase $conn

Returns: int|bool Returns false on error

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1718 of file LoadBalancer.php.

References Wikimedia\Rdbms\IDatabase\getLag(), and Wikimedia\Rdbms\LoadBalancer\getServerCount().

◆ safeWaitForMasterPos()

Wikimedia\Rdbms\LoadBalancer::safeWaitForMasterPos	(	IDatabase	$conn,
			$pos = false,
			$timeout = null )

Parameters

IDatabase	$conn
DBMasterPos \| bool	$pos
int \| null	$timeout

Returns: bool

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1732 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$waitTimeout, Wikimedia\Rdbms\LoadBalancer\closeConnection(), Wikimedia\Rdbms\LoadBalancer\getAnyOpenConnection(), Wikimedia\Rdbms\IDatabase\getLBInfo(), Wikimedia\Rdbms\IDatabase\getServer(), Wikimedia\Rdbms\LoadBalancer\getServerCount(), Wikimedia\Rdbms\LoadBalancer\getWriterIndex(), Wikimedia\Rdbms\IDatabase\masterPosWait(), and Wikimedia\Rdbms\LoadBalancer\openConnection().

◆ setDomainPrefix()

Wikimedia\Rdbms\LoadBalancer::setDomainPrefix ( $prefix )

Set a new table prefix for the existing local domain ID for testing.

Parameters

string $prefix

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1800 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\forEachOpenConnection(), Wikimedia\Rdbms\IDatabase\getLBInfo(), and Wikimedia\Rdbms\LoadBalancer\setLocalDomain().

◆ setIndexAliases()

Wikimedia\Rdbms\LoadBalancer::setIndexAliases ( array $aliases )

Convert certain index names to alternative names before querying the DB.

Note that this applies to indexes regardless of the table they belong to.

This can be employed when an index was renamed X => Y in code, but the new Y-named indexes were not yet built on all DBs. After all the Y-named ones are added by the DBA, the aliases can be removed, and then the old X-named indexes dropped.

Parameters

string[] $aliases

Returns: mixed

Since: 1.31

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1796 of file LoadBalancer.php.

◆ setLocalDomain()

Wikimedia\Rdbms\LoadBalancer::setLocalDomain ( DatabaseDomain $domain )

private

Parameters

DatabaseDomain $domain

Definition at line 1835 of file LoadBalancer.php.

References Wikimedia\Rdbms\DatabaseDomain\getDatabase().

Referenced by Wikimedia\Rdbms\LoadBalancer\__construct(), and Wikimedia\Rdbms\LoadBalancer\setDomainPrefix().

◆ setTableAliases()

Wikimedia\Rdbms\LoadBalancer::setTableAliases ( array $aliases )

Make certain table names use their own database, schema, and table prefix when passed into SQL queries pre-escaped and without a qualified database name.

For example, "user" can be converted to "myschema.mydbname.user" for convenience. Appearances like user, somedb.user, somedb.someschema.user will used literally.

Calling this twice will completely clear any old table aliases. Also, note that callers are responsible for making sure the schemas and databases actually exist.

Parameters

array[] $aliases Map of (table => (dbname, schema, prefix) map)

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1792 of file LoadBalancer.php.

◆ setTransactionListener()

Wikimedia\Rdbms\LoadBalancer::setTransactionListener	(		$name,
		callable	$callback = null )

Set a callback via IDatabase::setTransactionListener() on all current and future master connections of this load balancer.

Parameters

string	$name	Callback name
callable \| null	$callback

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1779 of file LoadBalancer.php.

References $name, Wikimedia\Rdbms\LoadBalancer\forEachOpenMasterConnection(), and Wikimedia\Rdbms\IDatabase\setTransactionListener().

◆ setWaitForPositionIfHigher()

Wikimedia\Rdbms\LoadBalancer::setWaitForPositionIfHigher ( $pos )

private

Parameters

DBMasterPos | bool $pos

Definition at line 560 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\waitFor().

◆ suppressTransactionEndCallbacks()

Wikimedia\Rdbms\LoadBalancer::suppressTransactionEndCallbacks ( )

Suppress all pending post-COMMIT/ROLLBACK callbacks.

Use this only for mutli-database commits

Returns: Exception|null The first exception or null if there were none

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1442 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\forEachOpenMasterConnection(), and Wikimedia\Rdbms\Database\setTrxEndCallbackSuppression().

◆ undoTransactionRoundFlags()

Wikimedia\Rdbms\LoadBalancer::undoTransactionRoundFlags ( IDatabase $conn )

private

Parameters

IDatabase $conn

Definition at line 1476 of file LoadBalancer.php.

References Wikimedia\Rdbms\IDatabase\getFlag(), Wikimedia\Rdbms\IDatabase\getLBInfo(), Wikimedia\Rdbms\IDatabase\restoreFlags(), and Wikimedia\Rdbms\IDatabase\setLBInfo().

Referenced by Wikimedia\Rdbms\LoadBalancer\commitAll(), Wikimedia\Rdbms\LoadBalancer\commitMasterChanges(), and Wikimedia\Rdbms\LoadBalancer\rollbackMasterChanges().

◆ waitFor()

Wikimedia\Rdbms\LoadBalancer::waitFor ( $pos )

Set the master wait position.

If a DB_REPLICA connection has been opened already, then wait immediately. Otherwise sets a variable telling it to wait if such a connection is opened.

This only applies to connections to the generic replica DB for this request. If a timeout happens when waiting, then getLaggedReplicaMode()/laggedReplicaUsed() will return true.

Parameters

DBMasterPos | bool $pos Master position or false

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 486 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$readIndex, Wikimedia\Rdbms\LoadBalancer\$waitForPos, Wikimedia\Rdbms\LoadBalancer\doWait(), and Wikimedia\Rdbms\LoadBalancer\setWaitForPositionIfHigher().

◆ waitForAll()

Wikimedia\Rdbms\LoadBalancer::waitForAll	(		$pos,
			$timeout = null )

Set the master wait position and wait for ALL replica DBs to catch up to it.

Parameters

DBMasterPos \| bool	$pos	Master position or false
int	$timeout	Max seconds to wait; default is mWaitTimeout

Returns: bool Success (able to connect and no timeouts reached)

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 530 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$waitForPos, Wikimedia\Rdbms\LoadBalancer\$waitTimeout, Wikimedia\Rdbms\LoadBalancer\doWait(), and servers.

◆ waitForOne()

Wikimedia\Rdbms\LoadBalancer::waitForOne	(		$pos,
			$timeout = null )

Set the master wait position and wait for a "generic" replica DB to catch up to it.

This can be used a faster proxy for waitForAll()

Parameters

DBMasterPos \| bool	$pos	Master position or false
int	$timeout	Max seconds to wait; default is mWaitTimeout

Returns: bool Success (able to connect and no timeouts reached)

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 503 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$loads, Wikimedia\Rdbms\LoadBalancer\$readIndex, Wikimedia\Rdbms\LoadBalancer\$waitForPos, Wikimedia\Rdbms\LoadBalancer\doWait(), Wikimedia\Rdbms\LoadBalancer\getWriterIndex(), and ArrayUtils\pickRandom().

Member Data Documentation

◆ $agent

string Wikimedia\Rdbms\LoadBalancer::$agent

protected

Agent name for query profiling.

Definition at line 111 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\reallyOpenConnection().

◆ $allowLagged

bool Wikimedia\Rdbms\LoadBalancer::$allowLagged

private

Whether to disregard replica DB lag as a factor in replica DB selection.

Definition at line 51 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\allowLagged().

◆ $allReplicasDownMode

bool Wikimedia\Rdbms\LoadBalancer::$allReplicasDownMode = false

private

Whether the generic reader fell back to a lagged replica DB.

Definition at line 91 of file LoadBalancer.php.

◆ $chronologyCallback

callable null Wikimedia\Rdbms\LoadBalancer::$chronologyCallback

private

Callback to run before the first connection attempt.

Definition at line 64 of file LoadBalancer.php.

◆ $cliMode

bool Wikimedia\Rdbms\LoadBalancer::$cliMode

protected

Whether this PHP instance is for a CLI script.

Definition at line 109 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\reallyOpenConnection().

◆ $connectionAttempted

bool Wikimedia\Rdbms\LoadBalancer::$connectionAttempted = false

private

Whether any connection has been attempted yet.

Definition at line 121 of file LoadBalancer.php.

◆ $connLogger

LoggerInterface Wikimedia\Rdbms\LoadBalancer::$connLogger

protected

Definition at line 76 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\reallyOpenConnection().

◆ $conns

Database [][][] Wikimedia\Rdbms\LoadBalancer::$conns

private

Map of (connection category => server index => IDatabase[])

Definition at line 45 of file LoadBalancer.php.

◆ $connsOpened

int Wikimedia\Rdbms\LoadBalancer::$connsOpened = 0

private

Total connections opened.

Definition at line 97 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\closeConnection(), and Wikimedia\Rdbms\LoadBalancer\getConnection().

◆ $deprecationLogger

callable Wikimedia\Rdbms\LoadBalancer::$deprecationLogger

private

Deprecation logger.

Definition at line 116 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\reallyOpenConnection().

◆ $disabled

bool Wikimedia\Rdbms\LoadBalancer::$disabled = false

private

Definition at line 119 of file LoadBalancer.php.

◆ $errorConnection

Database Wikimedia\Rdbms\LoadBalancer::$errorConnection

private

DB connection object that caused a problem.

Definition at line 83 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\reportConnectionError().

◆ $errorLogger

callable Wikimedia\Rdbms\LoadBalancer::$errorLogger

private

Exception logger.

Definition at line 114 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\reallyOpenConnection().

◆ $groupLoads

array [] Wikimedia\Rdbms\LoadBalancer::$groupLoads

private

Map of (group => server index => weight)

Definition at line 49 of file LoadBalancer.php.

◆ $host

string Wikimedia\Rdbms\LoadBalancer::$host

private

Current server name.

Definition at line 107 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\closeAll(), Wikimedia\Rdbms\LoadBalancer\closeConnection(), Wikimedia\Rdbms\LoadBalancer\getConnection(), Wikimedia\Rdbms\LoadBalancer\getMaxLag(), Wikimedia\Rdbms\LoadBalancer\getRandomNonLagged(), and Wikimedia\Rdbms\LoadBalancer\openConnection().

◆ $indexAliases

string [] Wikimedia\Rdbms\LoadBalancer::$indexAliases = []

private

Map of (index alias => index)

Definition at line 59 of file LoadBalancer.php.

◆ $laggedReplicaMode

bool Wikimedia\Rdbms\LoadBalancer::$laggedReplicaMode = false

private

Whether the generic reader fell back to a lagged replica DB.

Definition at line 89 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\getLaggedReplicaMode(), Wikimedia\Rdbms\LoadBalancer\getReaderIndex(), Wikimedia\Rdbms\LoadBalancer\laggedReplicaUsed(), and Wikimedia\Rdbms\LoadBalancer\pickReaderIndex().

◆ $lastError

string Wikimedia\Rdbms\LoadBalancer::$lastError = 'Unknown error'

private

The last DB selection or connection error.

Definition at line 93 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\getConnection(), and Wikimedia\Rdbms\LoadBalancer\reportConnectionError().

◆ $loadMonitor

ILoadMonitor Wikimedia\Rdbms\LoadBalancer::$loadMonitor

private

Definition at line 62 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\getLoadMonitor().

◆ $loadMonitorConfig

array Wikimedia\Rdbms\LoadBalancer::$loadMonitorConfig

private

The LoadMonitor configuration.

Definition at line 55 of file LoadBalancer.php.

◆ $loads

float [] Wikimedia\Rdbms\LoadBalancer::$loads

private

Map of (server index => weight)

Definition at line 47 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\getRandomNonLagged(), Wikimedia\Rdbms\LoadBalancer\getReaderIndex(), Wikimedia\Rdbms\LoadBalancer\pickReaderIndex(), and Wikimedia\Rdbms\LoadBalancer\waitForOne().

◆ $localDomain

DatabaseDomain Wikimedia\Rdbms\LoadBalancer::$localDomain

private

Local Domain ID and default for selectDB() calls.

Definition at line 103 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\__construct(), Wikimedia\Rdbms\LoadBalancer\getConnectionRef(), Wikimedia\Rdbms\LoadBalancer\getLazyConnectionRef(), and Wikimedia\Rdbms\LoadBalancer\getMaintenanceConnectionRef().

◆ $localDomainIdAlias

string Wikimedia\Rdbms\LoadBalancer::$localDomainIdAlias

private

Alternate ID string for the domain instead of DatabaseDomain::getId()

Definition at line 105 of file LoadBalancer.php.

◆ $maxLag

int Wikimedia\Rdbms\LoadBalancer::$maxLag = self::MAX_LAG_DEFAULT

private

Definition at line 123 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\__construct(), Wikimedia\Rdbms\LoadBalancer\getMaxLag(), and Wikimedia\Rdbms\LoadBalancer\getRandomNonLagged().

◆ $perfLogger

LoggerInterface Wikimedia\Rdbms\LoadBalancer::$perfLogger

protected

Definition at line 80 of file LoadBalancer.php.

◆ $profiler

object string Wikimedia\Rdbms\LoadBalancer::$profiler

protected

Class name or object With profileIn/profileOut methods.

Definition at line 70 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\reallyOpenConnection().

◆ $queryLogger

LoggerInterface Wikimedia\Rdbms\LoadBalancer::$queryLogger

protected

Definition at line 78 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\reallyOpenConnection().

◆ $readIndex

int Wikimedia\Rdbms\LoadBalancer::$readIndex

private

The generic (not query grouped) replica DB index (of $mServers)

Definition at line 85 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\getReaderIndex(), Wikimedia\Rdbms\LoadBalancer\waitFor(), and Wikimedia\Rdbms\LoadBalancer\waitForOne().

◆ $readOnlyReason

string bool Wikimedia\Rdbms\LoadBalancer::$readOnlyReason = false

private

Reason the LB is read-only or false if not.

Definition at line 95 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\getReadOnlyReason().

◆ $replLogger

LoggerInterface Wikimedia\Rdbms\LoadBalancer::$replLogger

protected

Definition at line 74 of file LoadBalancer.php.

◆ $servers

array [] Wikimedia\Rdbms\LoadBalancer::$servers

private

Map of (server index => server config array)

Definition at line 43 of file LoadBalancer.php.

◆ $srvCache

BagOStuff Wikimedia\Rdbms\LoadBalancer::$srvCache

private

Definition at line 66 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\reallyOpenConnection().

◆ $tableAliases

Wikimedia\Rdbms\LoadBalancer::$tableAliases = []

private

Definition at line 57 of file LoadBalancer.php.

◆ $trxProfiler

TransactionProfiler Wikimedia\Rdbms\LoadBalancer::$trxProfiler

protected

Definition at line 72 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\reallyOpenConnection().

◆ $trxRecurringCallbacks

array [] Wikimedia\Rdbms\LoadBalancer::$trxRecurringCallbacks = []

private

Map of (name => callable)

Definition at line 101 of file LoadBalancer.php.

◆ $trxRoundId

string bool Wikimedia\Rdbms\LoadBalancer::$trxRoundId = false

private

String if a requested DBO_TRX transaction round is active.

Definition at line 99 of file LoadBalancer.php.

◆ $waitForPos

bool DBMasterPos Wikimedia\Rdbms\LoadBalancer::$waitForPos

private

False if not set.

Definition at line 87 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\waitFor(), Wikimedia\Rdbms\LoadBalancer\waitForAll(), and Wikimedia\Rdbms\LoadBalancer\waitForOne().

◆ $waitTimeout

int Wikimedia\Rdbms\LoadBalancer::$waitTimeout

private

Seconds to spend waiting on replica DB lag to resolve.

Definition at line 53 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\doWait(), Wikimedia\Rdbms\LoadBalancer\safeWaitForMasterPos(), and Wikimedia\Rdbms\LoadBalancer\waitForAll().

◆ $wanCache

WANObjectCache Wikimedia\Rdbms\LoadBalancer::$wanCache

private

Definition at line 68 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\masterRunningReadOnly().

◆ KEY_FOREIGN_FREE

const Wikimedia\Rdbms\LoadBalancer::KEY_FOREIGN_FREE = 'foreignFree'

Definition at line 136 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\openForeignConnection(), and Wikimedia\Rdbms\LoadBalancer\reuseConnection().

◆ KEY_FOREIGN_FREE_NOROUND

const Wikimedia\Rdbms\LoadBalancer::KEY_FOREIGN_FREE_NOROUND = 'foreignFreeAutoCommit'

Definition at line 140 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\openForeignConnection(), and Wikimedia\Rdbms\LoadBalancer\reuseConnection().

◆ KEY_FOREIGN_INUSE

const Wikimedia\Rdbms\LoadBalancer::KEY_FOREIGN_INUSE = 'foreignInUse'

Definition at line 137 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\openForeignConnection(), and Wikimedia\Rdbms\LoadBalancer\reuseConnection().

◆ KEY_FOREIGN_INUSE_NOROUND

const Wikimedia\Rdbms\LoadBalancer::KEY_FOREIGN_INUSE_NOROUND = 'foreignInUseAutoCommit'

Definition at line 141 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\openForeignConnection(), and Wikimedia\Rdbms\LoadBalancer\reuseConnection().

◆ KEY_LOCAL

const Wikimedia\Rdbms\LoadBalancer::KEY_LOCAL = 'local'

Definition at line 135 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\openConnection().

◆ KEY_LOCAL_NOROUND

const Wikimedia\Rdbms\LoadBalancer::KEY_LOCAL_NOROUND = 'localAutoCommit'

Definition at line 139 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\openConnection().

The documentation for this class was generated from the following file:

includes/libs/rdbms/loadbalancer/LoadBalancer.php

Public Member Functions

Public Attributes

Protected Member Functions

Protected Attributes

Private Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ __construct()

◆ __destruct()

Member Function Documentation

◆ allowLagged()

◆ applyTransactionRoundFlags()

◆ approveMasterChanges()

◆ beginMasterChanges()

◆ closeAll()

◆ closeConnection()

◆ commitAll()

◆ commitMasterChanges()

◆ disable()

◆ doWait()

◆ finalizeMasterChanges()

◆ flushReplicaSnapshots()

◆ forEachOpenConnection()

◆ forEachOpenMasterConnection()

◆ forEachOpenReplicaConnection()

◆ getAnyOpenConnection()

◆ getConnection()

◆ getConnectionRef()

◆ getLaggedReplicaMode()

◆ getLaggedSlaveMode()

◆ getLagTimes()

◆ getLazyConnectionRef()

◆ getLoadMonitor()

◆ getLocalDomainID()

◆ getMaintenanceConnectionRef()

◆ getMasterPos()

◆ getMaxLag()

◆ getRandomNonLagged()

◆ getReaderIndex()

◆ getReadOnlyReason()

◆ getScopedPHPBehaviorForCommit()

◆ getServerAttributes()

◆ getServerCount()

◆ getServerInfo()

◆ getServerName()

◆ getServerType()

◆ getWriterIndex()

◆ hasMasterChanges()

◆ hasMasterConnection()

◆ hasOrMadeRecentMasterChanges()

◆ haveIndex()

◆ isNonZeroLoad()

◆ isOpen()

◆ laggedReplicaUsed()

◆ laggedSlaveUsed()

◆ lastMasterChangeTimestamp()

◆ masterRunningReadOnly()

◆ openConnection()

◆ openForeignConnection()

◆ pendingMasterChangeCallers()

◆ pickReaderIndex()

◆ pingAll()

◆ reallyOpenConnection()

◆ reportConnectionError()

◆ reuseConnection()

◆ rollbackMasterChanges()

◆ runMasterPostTrxCallbacks()

◆ safeGetLag()

◆ safeWaitForMasterPos()

◆ setDomainPrefix()

◆ setIndexAliases()

◆ setLocalDomain()

◆ setTableAliases()

◆ setTransactionListener()

◆ setWaitForPositionIfHigher()

◆ suppressTransactionEndCallbacks()

◆ undoTransactionRoundFlags()

◆ waitFor()

◆ waitForAll()