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, $fname=__METHOD__, $owner=null)
	Perform all pre-commit checks for things like replication safety.

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

	closeAll ( $fname=__METHOD__, $owner=null)
	Close all open connections.

	closeConnection (IDatabase $conn)
	Close a connection.

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

	commitMasterChanges ( $fname=__METHOD__, $owner=null)
	Issue COMMIT on all open master connections to flush changes and view snapshots.

	disable ( $fname=__METHOD__, $owner=null)
	Close all connections and disable this load balancer.

	finalizeMasterChanges ( $fname=__METHOD__, $owner=null)
	Run pre-commit callbacks and defer execution of post-commit callbacks.

	flushMasterSnapshots ( $fname=__METHOD__, $owner=null)
	Commit all master DB transactions so as to flush any REPEATABLE-READ or SSI snapshots.

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

	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 live handle for a real or virtual (DB_MASTER/DB_REPLICA) server index.

	getConnectionRef ( $i, $groups=[], $domain=false, $flags=0)
	Get a live database handle reference for a real or virtual (DB_MASTER/DB_REPLICA) server index.

	getLaggedReplicaMode ( $domain=false)

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

	getLazyConnectionRef ( $i, $groups=[], $domain=false, $flags=0)
	Get a database handle reference for a real or virtual (DB_MASTER/DB_REPLICA) server index.

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

	getMaintenanceConnectionRef ( $i, $groups=[], $domain=false, $flags=0)
	Get a live database handle for a real or virtual (DB_MASTER/DB_REPLICA) server index that can be used for data migrations and schema changes.

	getMasterPos ()
	Get the current master replication position.

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

	getReaderIndex ( $group=false, $domain=false)
	Get the server index of the reader connection for a given group.

	getReadOnlyReason ( $domain=false)

	getReplicaResumePos ()
	Get the highest DB replication position for chronology control purposes.

	getServerAttributes ( $i)

	getServerConnection ( $i, $domain, $flags=0)

	getServerCount ()
	Get the number of servers defined in configuration.

	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.

	getTransactionRoundStage ()

	getWriterIndex ()
	Get the server index of the master server.

	hasMasterChanges ()
	Whether there are pending changes or callbacks 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.

	hasReplicaServers ()
	Whether there are any replica servers configured.

	hasStreamingReplicaServers ()
	Whether any replica servers use streaming replication from the master server.

	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:

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

	openConnection ( $i, $domain=false, $flags=0)

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

	pingAll ()

	redefineLocalDomain ( $domain)
	Close all connection and redefine the local domain for testing or schema creation.

	resolveDomainID ( $domain)

	reuseConnection (IDatabase $conn)
	Mark a live handle as being available for reuse under a different database domain.

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

	runMasterTransactionIdleCallbacks ( $fname=__METHOD__, $owner=null)
	Consume and run all pending post-COMMIT/ROLLBACK callbacks and commit dangling transactions.

	runMasterTransactionListenerCallbacks ( $fname=__METHOD__, $owner=null)
	Run all recurring post-COMMIT/ROLLBACK listener 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)
	Wait for a replica DB to reach a specified master position.

	setDomainAliases (array $aliases)
	Convert certain database domains to alternative ones.

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

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

	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.

	setTempTablesOnlyMode ( $value, $domain)
	Indicate whether the tables on this domain are only temporary tables for testing.

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

	waitFor ( $pos)
	Set the master position to reach before the next generic group DB handle query.

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

	waitForMasterPos (IDatabase $conn, $pos=false, $timeout=null)
	Wait for a replica DB to reach a specified master position.

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

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

	getExistingReaderIndex ( $group)
	Get the server index chosen by the load balancer for use with the given query group.

	reallyOpenConnection ( $i, DatabaseDomain $domain, array $lbInfo)
	Open a new network connection to a server (uncached)

	resolveDomainInstance ( $domain)

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

	assertOwnership ( $fname, $owner)
	Assure that if this instance is owned, the caller is either the owner or is internal.

	assertTransactionRoundStage ( $stage)

	enforceConnectionFlags (IDatabase $conn, $flags)

	getConnectionIndex ( $i, array $groups, $domain)
	Get the server index to use for a specified server index and query group list.

	getCurrentConnectionCount ()

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

	getLoadMonitor ()
	Get a LoadMonitor instance.

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

	getMasterServerName ()

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

	getRoleFromIndex ( $i)

	getServerInfoStrict ( $i, $field=null)

	getTopologyRole ( $i, array $server)

	initConnFlags ( $flags)

	isMasterConnectionReadOnly (IDatabase $conn, $flags=0)

	isMasterRunningReadOnly (DatabaseDomain $domain)

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

	lazyLoadReplicationPositions ()
	Make sure that any "waitForPos" positions are loaded and available to doWait()

	pickAnyOpenConnection ( $candidateConns, $autocommit)

	pickReaderIndex (array $loads, $domain=false)

	reportConnectionError ()

	resolveGroups ( $groups, $i)
	Resolve $groups into a list of query groups defining as having database servers.

	sanitizeConnectionFlags ( $flags, $i, $domain)

	serverHasLoadInAnyGroup ( $i)

	setExistingReaderIndex ( $group, $index)
	Set the server index chosen by the load balancer for use with the given query group.

	setLocalDomain (DatabaseDomain $domain)

	setWaitForPositionIfHigher ( $pos)

	undoTransactionRoundFlags (Database $conn)

Static Private Member Functions
static	newTrackedConnectionsArray ()

Private Attributes
string	$agent
	Agent name for query profiling.

bool	$allowLagged = false
	Whether to disregard replica DB lag as a factor in replica DB selection.

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

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

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

int	$connectionCounter = 0
	Total number of new connections ever made with this instance.

LoggerInterface	$connLogger

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

string null	$defaultGroup
	Default query group to use with getConnection()

callable	$deprecationLogger
	Deprecation logger.

bool	$disabled = false

DatabaseDomain[] string[]	$domainAliases = []
	Map of (domain alias => DB domain)

Database	$errorConnection
	Connection handle that caused a problem.

callable	$errorLogger
	Exception logger.

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

string	$hostname
	Current server name.

	$id
	var int An identifier for this class instance

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.

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

int	$maxLag

int[]	$maxLagByIndex
	Map of (server index => seconds of lag considered "high")

DatabaseDomain[]	$nonLocalDomainCache = []
	Map of (domain ID => domain instance)

int null	$ownerId
	Integer ID of the managing LBFactory instance or null if none.

LoggerInterface	$perfLogger

callable null	$profiler
	An optional callback that returns a ScopedCallback instance, meant to profile the actual query execution in {.

LoggerInterface	$queryLogger

int[]	$readIndexByGroup = []
	The group replica server indexes keyed by group.

string bool	$readOnlyReason = false
	Reason this instance is read-only or false if not.

LoggerInterface	$replLogger

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

BagOStuff	$srvCache

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

bool[]	$tempTablesOnlyMode = []
	Map of (domain => whether to use "temp tables only" mode)

TransactionProfiler	$trxProfiler

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

string bool	$trxRoundId = false
	Explicit DBO_TRX transaction round active or false if none.

string	$trxRoundStage = self::ROUND_CURSORY
	Stage of the current transaction round in the transaction round life-cycle.

bool DBMasterPos	$waitForPos
	Replication sync position or false if not set.

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

WANObjectCache	$wanCache

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'

Static Private Attributes
static	$INFO_AUTOCOMMIT_ONLY = 'autoCommitOnly'

static	$INFO_FOREIGN_REF_COUNT = 'foreignPoolRefCount'

static	$INFO_FORIEGN = 'foreign'

static	$INFO_SERVER_INDEX = 'serverIndex'

Additional Inherited Members
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.

Detailed Description

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

Definition at line 42 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 : List of server info structures
localDomain: A DatabaseDomain or domain ID string
loadMonitor : LoadMonitor::__construct() parameters with "class" field. [optional]
readOnlyReason : Reason the master DB is read-only if so [optional]
waitTimeout : Maximum time to wait for replicas for consistency [optional]
maxLag: Try to avoid DB replicas with lag above this many seconds [optional]
srvCache : BagOStuff object for server cache [optional]
wanCache : WANObjectCache object [optional]
chronologyCallback: Callback to run before the first connection attempt [optional]
defaultGroup: Default query group; the generic group if not specified [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]
roundStage: STAGE_POSTCOMMIT_* class constant; for internal use [optional]
ownerId: integer ID of an LBFactory instance that manages this instance [optional]

Exceptions

InvalidArgumentException

Implements Wikimedia\Rdbms\ILoadBalancer.

Reimplemented in Wikimedia\Rdbms\LoadBalancerSingle.

Definition at line 181 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$localDomain, Wikimedia\Rdbms\LoadBalancer\$maxLag, Wikimedia\Rdbms\DatabaseDomain\newFromId(), Wikimedia\Rdbms\LoadBalancer\newTrackedConnectionsArray(), Wikimedia\Rdbms\DatabaseDomain\newUnspecified(), and Wikimedia\Rdbms\LoadBalancer\setLocalDomain().

◆ __destruct()

Wikimedia\Rdbms\LoadBalancer::__destruct ( )

Reimplemented in Wikimedia\Rdbms\LoadBalancerSingle.

Definition at line 2428 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 2117 of file LoadBalancer.php.

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

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

◆ applyTransactionRoundFlags()

Wikimedia\Rdbms\LoadBalancer::applyTransactionRoundFlags ( Database $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

Database $conn

Definition at line 1917 of file LoadBalancer.php.

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

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

◆ approveMasterChanges()

Wikimedia\Rdbms\LoadBalancer::approveMasterChanges	(	array	$options,
			$fname = `__METHOD__`,
			$owner = `null`
	)

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
string	$fname	Caller name
int \| null	$owner	ID of the calling instance (e.g. the LBFactory ID)

Exceptions

DBTransactionError

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1630 of file LoadBalancer.php.

References Wikimedia\Rdbms\IDatabase\assertNoOpenTransactions(), Wikimedia\Rdbms\LoadBalancer\assertOwnership(), Wikimedia\Rdbms\LoadBalancer\assertTransactionRoundStage(), Wikimedia\Rdbms\LoadBalancer\forEachOpenMasterConnection(), Wikimedia\Rdbms\IDatabase\pendingWriteQueryDuration(), Wikimedia\Rdbms\IDatabase\ping(), and Wikimedia\Rdbms\IDatabase\writesOrCallbacksPending().

◆ assertOwnership()

Wikimedia\Rdbms\LoadBalancer::assertOwnership	(	$fname,
		$owner
	)

private

Assure that if this instance is owned, the caller is either the owner or is internal.

If an LBFactory owns the LoadBalancer, then certain methods should only called through that LBFactory to avoid broken contracts. Otherwise, those methods can publically be called by anything. In any case, internal methods from the LoadBalancer itself should always be allowed.

Parameters

string	$fname
int \| null	$owner	Owner ID of the caller

Exceptions

DBTransactionError

Definition at line 1899 of file LoadBalancer.php.

◆ assertTransactionRoundStage()

Wikimedia\Rdbms\LoadBalancer::assertTransactionRoundStage ( $stage )

private

Parameters

string | string[] $stage

Exceptions

DBTransactionError

Definition at line 1870 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\approveMasterChanges(), Wikimedia\Rdbms\LoadBalancer\beginMasterChanges(), Wikimedia\Rdbms\LoadBalancer\commitMasterChanges(), and Wikimedia\Rdbms\LoadBalancer\finalizeMasterChanges().

◆ beginMasterChanges()

Wikimedia\Rdbms\LoadBalancer::beginMasterChanges	(	$fname = `__METHOD__`,
		$owner = `null`
	)

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	Caller name
int \| null	$owner	ID of the calling instance (e.g. the LBFactory ID)

Exceptions

DBExpectedError

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1668 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\applyTransactionRoundFlags(), Wikimedia\Rdbms\LoadBalancer\assertOwnership(), Wikimedia\Rdbms\LoadBalancer\assertTransactionRoundStage(), Wikimedia\Rdbms\LoadBalancer\flushMasterSnapshots(), and Wikimedia\Rdbms\LoadBalancer\forEachOpenMasterConnection().

◆ closeAll()

Wikimedia\Rdbms\LoadBalancer::closeAll	(	$fname = `__METHOD__`,
		$owner = `null`
	)

Close all open connections.

Parameters

string	$fname	Caller name
int \| null	$owner	ID of the calling instance (e.g. the LBFactory ID)

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1554 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\assertOwnership(), Wikimedia\Rdbms\IDatabase\close(), Wikimedia\Rdbms\LoadBalancer\forEachOpenConnection(), Wikimedia\Rdbms\IDatabase\getServer(), and Wikimedia\Rdbms\LoadBalancer\newTrackedConnectionsArray().

Referenced by Wikimedia\Rdbms\LoadBalancer\disable(), and Wikimedia\Rdbms\LoadBalancer\redefineLocalDomain().

◆ 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 1569 of file LoadBalancer.php.

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

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

◆ commitAll()

Wikimedia\Rdbms\LoadBalancer::commitAll	(	$fname = `__METHOD__`,
		$owner = `null`
	)

Commit transactions on all open connections.

Parameters

string	$fname	Caller name
int \| null	$owner	ID of the calling instance (e.g. the LBFactory ID)

Exceptions

DBExpectedError

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1595 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\commitMasterChanges(), Wikimedia\Rdbms\LoadBalancer\flushMasterSnapshots(), and Wikimedia\Rdbms\LoadBalancer\flushReplicaSnapshots().

◆ commitMasterChanges()

Wikimedia\Rdbms\LoadBalancer::commitMasterChanges	(	$fname = `__METHOD__`,
		$owner = `null`
	)

Issue COMMIT on all open master connections to flush changes and view snapshots.

Parameters

string	$fname	Caller name
int \| null	$owner	ID of the calling instance (e.g. the LBFactory ID)

Exceptions

DBExpectedError

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1697 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$errorLogger, Wikimedia\Rdbms\LoadBalancer\assertOwnership(), Wikimedia\Rdbms\LoadBalancer\assertTransactionRoundStage(), Wikimedia\Rdbms\IDatabase\commit(), Wikimedia\Rdbms\LoadBalancer\forEachOpenMasterConnection(), and Wikimedia\Rdbms\LoadBalancer\undoTransactionRoundFlags().

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

◆ disable()

Wikimedia\Rdbms\LoadBalancer::disable	(	$fname = `__METHOD__`,
		$owner = `null`
	)

Close all connections and disable this load balancer.

Any attempt to open a new connection will result in a DBAccessError.

Parameters

string	$fname	Caller name
int \| null	$owner	ID of the calling instance (e.g. the LBFactory ID)

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1548 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\assertOwnership(), and 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 "waitForPos".

Parameters

int	$index	Specific server index
bool	$open	Check the server even if a new connection has to be made
int \| null	$timeout	Max seconds to wait; default is "waitTimeout"

Returns: bool

Definition at line 825 of file LoadBalancer.php.

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

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

◆ enforceConnectionFlags()

Wikimedia\Rdbms\LoadBalancer::enforceConnectionFlags	(	IDatabase	$conn,
			$flags
	)

private

Parameters

IDatabase	$conn
int	$flags

Exceptions

DBUnexpectedError

Definition at line 375 of file LoadBalancer.php.

References Wikimedia\Rdbms\IDatabase\clearFlag(), and Wikimedia\Rdbms\IDatabase\trxLevel().

Referenced by Wikimedia\Rdbms\LoadBalancer\getAnyOpenConnection(), and Wikimedia\Rdbms\LoadBalancer\getServerConnection().

◆ finalizeMasterChanges()

Wikimedia\Rdbms\LoadBalancer::finalizeMasterChanges	(	$fname = `__METHOD__`,
		$owner = `null`
	)

Run pre-commit callbacks and defer execution of post-commit callbacks.

Use this only for mutli-database commits

Parameters

string	$fname	Caller name
int \| null	$owner	ID of the calling instance (e.g. the LBFactory ID)

Returns: int Number of pre-commit callbacks run (since 1.32)

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1601 of file LoadBalancer.php.

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

◆ flushMasterSnapshots()

Wikimedia\Rdbms\LoadBalancer::flushMasterSnapshots	(	$fname = `__METHOD__`,
		$owner = `null`
	)

Commit all master DB transactions so as to flush any REPEATABLE-READ or SSI snapshots.

An error will be thrown if a connection has pending writes or callbacks

Parameters

string	$fname	Caller name
int \| null	$owner	ID of the calling instance (e.g. the LBFactory ID)

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1957 of file LoadBalancer.php.

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

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

◆ flushReplicaSnapshots()

Wikimedia\Rdbms\LoadBalancer::flushReplicaSnapshots	(	$fname = `__METHOD__`,
		$owner = `null`
	)

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

Parameters

string	$fname	Caller name
int \| null	$owner	ID of the calling instance (e.g. the LBFactory ID)

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1950 of file LoadBalancer.php.

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

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

◆ 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 2137 of file LoadBalancer.php.

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

◆ 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 2147 of file LoadBalancer.php.

References 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 2159 of file LoadBalancer.php.

References 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. Avoid the use of transaction methods like IDatabase::begin() or IDatabase::startAtomic() on any such connections.

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 759 of file LoadBalancer.php.

References Wikimedia\Rdbms\ILoadBalancer\DB_MASTER, Wikimedia\Rdbms\LoadBalancer\enforceConnectionFlags(), Wikimedia\Rdbms\LoadBalancer\getWriterIndex(), and Wikimedia\Rdbms\LoadBalancer\pickAnyOpenConnection().

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

◆ getConnection()

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

Get a live handle for a real or virtual (DB_MASTER/DB_REPLICA) server index.

The server index, $i, can be one of the following:

DB_REPLICA: a server index will be selected by the load balancer based on read weight, connectivity, and replication lag. Note that the master server might be configured with read weight. If $groups is empty then it means "the generic group", in which case all servers defined with read weight will be considered. Additional query groups can be configured, having their own list of server indexes and read weights. If a query group list is provided in $groups, then each recognized group will be tried, left-to-right, until server index selection succeeds or all groups have been tried, in which case the generic group will be tried.
DB_MASTER: the master server index will be used; the same as getWriterIndex(). The value of $groups should be [] when using this server index.
Specific server index: a positive integer can be provided to use the server with that index. An error will be thrown in no such server index is recognized. This server selection method is usually only useful for internal load balancing logic. The value of $groups should be [] when using a specific server index.

Handles acquired by this method, getConnectionRef(), getLazyConnectionRef(), and getMaintenanceConnectionRef() use the same set of shared connection pools. Callers that get a local DB domain handle for the same server will share one handle for all of those callers using CONN_TRX_AUTOCOMMIT (via $flags) and one handle for all of those callers not using CONN_TRX_AUTOCOMMIT. Callers that get a foreign DB domain handle (via $domain) will share any handle that has the right CONN_TRX_AUTOCOMMIT mode and is already on the right DB domain. Otherwise, one of the "free for reuse" handles will be claimed or a new handle will be made if there are none.

Handle sharing is particularly useful when callers get local DB domain (the default), transaction round aware (the default), DB_MASTER handles. All such callers will operate within a single database transaction as a consequence. Handle sharing is also useful when callers get local DB domain (the default), transaction round aware (the default), samely query grouped (the default), DB_REPLICA handles. All such callers will operate within a single database transaction as a consequence.

Callers of this function that use a non-local $domain must call reuseConnection() after their last query on this handle executed. This lets the load balancer share the handle with other callers requesting connections on different database domains.

Use CONN_TRX_AUTOCOMMIT to use a separate pool of only auto-commit handles. This flag is ignored for databases with ATTR_DB_LEVEL_LOCKING (e.g. sqlite) in order to avoid deadlocks. getServerAttributes() can be used to check such attributes beforehand. Avoid using IDatabase::begin() and IDatabase::commit() on such handles. If it is not possible to avoid using methods like IDatabase::startAtomic() and IDatabase::endAtomic(), callers should at least make sure that the atomic sections are closed on failure via try/catch and IDatabase::cancelAtomic().

See also: ILoadBalancer::reuseConnection(); ILoadBalancer::getServerAttributes()

Parameters

int	$i	Server index (overrides $groups) or DB_MASTER/DB_REPLICA
string[] \| string	$groups	Query group(s) in preference order; [] for the default group
string \| bool	$domain	DB domain ID or false for the local domain
int	$flags	Bitfield of CONN_* class constants

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

Returns: IDatabase|bool This returns false on failure if CONN_SILENCE_ERRORS is set

Exceptions

DBError	If no live handle can be obtained and CONN_SILENCE_ERRORS is not set
DBAccessError	If disable() was previously called
InvalidArgumentException

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 894 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\getConnectionIndex(), Wikimedia\Rdbms\LoadBalancer\getExistingReaderIndex(), Wikimedia\Rdbms\LoadBalancer\getLaggedReplicaMode(), Wikimedia\Rdbms\LoadBalancer\getServerConnection(), Wikimedia\Rdbms\LoadBalancer\getWriterIndex(), Wikimedia\Rdbms\LoadBalancer\resolveDomainID(), Wikimedia\Rdbms\LoadBalancer\resolveGroups(), and Wikimedia\Rdbms\LoadBalancer\sanitizeConnectionFlags().

Referenced by Wikimedia\Rdbms\LoadBalancer\getConnectionRef(), Wikimedia\Rdbms\LoadBalancer\getMaintenanceConnectionRef(), Wikimedia\Rdbms\LoadBalancer\getMasterPos(), and Wikimedia\Rdbms\LoadBalancer\openConnection().

◆ getConnectionIndex()

Wikimedia\Rdbms\LoadBalancer::getConnectionIndex	(		$i,
		array	$groups,
			$domain
	)

private

Get the server index to use for a specified server index and query group list.

Parameters

int	$i	Specific server index or DB_MASTER/DB_REPLICA
string[]	$groups	Non-empty query group list in preference order
string \| bool	$domain

Returns: int A specific server index (replica DBs are checked for connectivity)

Definition at line 477 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$lastError, Wikimedia\Rdbms\LoadBalancer\getReaderIndex(), Wikimedia\Rdbms\LoadBalancer\getWriterIndex(), and Wikimedia\Rdbms\LoadBalancer\reportConnectionError().

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

◆ getConnectionRef()

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

Get a live database handle reference for a real or virtual (DB_MASTER/DB_REPLICA) server index.

The CONN_TRX_AUTOCOMMIT flag is ignored for databases with ATTR_DB_LEVEL_LOCKING (e.g. sqlite) in order to avoid deadlocks. getServerAttributes() can be used to check such flags beforehand. Avoid the use of begin() or startAtomic() on any CONN_TRX_AUTOCOMMIT connections.

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

Parameters

int	$i	Server index or DB_MASTER/DB_REPLICA
string[] \| string	$groups	Query group(s) in preference order; [] for the default group
string \| bool	$domain	DB domain ID or false for the local domain
int	$flags	Bitfield of CONN_* class constants (e.g. CONN_TRX_AUTOCOMMIT)

Returns: DBConnRef

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1030 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\getConnection(), Wikimedia\Rdbms\LoadBalancer\getRoleFromIndex(), and Wikimedia\Rdbms\LoadBalancer\resolveDomainID().

◆ getCurrentConnectionCount()

Wikimedia\Rdbms\LoadBalancer::getCurrentConnectionCount ( )

private

Returns: int

Definition at line 2175 of file LoadBalancer.php.

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

◆ getExistingReaderIndex()

Wikimedia\Rdbms\LoadBalancer::getExistingReaderIndex ( $group )

protected

Get the server index chosen by the load balancer for use with the given query group.

Parameters

string $group Query group; use false for the generic group

Returns: int Server index or -1 if none was chosen

Definition at line 562 of file LoadBalancer.php.

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

◆ getForeignConnection()

Wikimedia\Rdbms\LoadBalancer::getForeignConnection	(	$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	Specific server index
string	$domain	Domain ID to open
int	$flags	Class CONN_* constant bitfield

Returns: Database|bool Returns false on connection error

Exceptions

DBError	When database selection fails
InvalidArgumentException	When the server index is invalid
UnexpectedValueException	When the DB domain of the connection is corrupted

Definition at line 1149 of file LoadBalancer.php.

References 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(), and Wikimedia\Rdbms\LoadBalancer\reallyOpenConnection().

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

◆ getLaggedReplicaMode()

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

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

Parameters

string | bool $domain DB domain ID or false for the local domain

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

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 2010 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$laggedReplicaMode, Wikimedia\Rdbms\LoadBalancer\getReaderIndex(), and Wikimedia\Rdbms\LoadBalancer\hasStreamingReplicaServers().

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

◆ 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 2205 of file LoadBalancer.php.

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

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 handle reference for a real or virtual (DB_MASTER/DB_REPLICA) server index.

The handle's methods simply proxy to those of an underlying IDatabase handle which takes care of the actual connection and query logic.

The CONN_TRX_AUTOCOMMIT flag is ignored for databases with ATTR_DB_LEVEL_LOCKING (e.g. sqlite) in order to avoid deadlocks. getServerAttributes() can be used to check such flags beforehand. Avoid the use of begin() or startAtomic() on any CONN_TRX_AUTOCOMMIT connections.

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

Parameters

int	$i	Server index or DB_MASTER/DB_REPLICA
string[] \| string	$groups	Query group(s) in preference order; [] for the default group
string \| bool	$domain	DB domain ID or false for the local domain
int	$flags	Bitfield of CONN_* class constants (e.g. CONN_TRX_AUTOCOMMIT)

Returns: DBConnRef

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1037 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\getRoleFromIndex(), and Wikimedia\Rdbms\LoadBalancer\resolveDomainID().

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

◆ getLoadMonitor()

Wikimedia\Rdbms\LoadBalancer::getLoadMonitor ( )

private

Get a LoadMonitor instance.

Returns: ILoadMonitor

Definition at line 393 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$loadMonitor.

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

◆ getLocalConnection()

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

private

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

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	Specific server index
int	$flags	Class CONN_* constant bitfield

Returns: Database

Exceptions

InvalidArgumentException	When the server index is invalid
UnexpectedValueException	When the DB domain of the connection is corrupted

Definition at line 1087 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\KEY_LOCAL, Wikimedia\Rdbms\LoadBalancer\KEY_LOCAL_NOROUND, and Wikimedia\Rdbms\LoadBalancer\reallyOpenConnection().

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

◆ 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

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 271 of file LoadBalancer.php.

◆ getMaintenanceConnectionRef()

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

Get a live database handle for a real or virtual (DB_MASTER/DB_REPLICA) server index that can be used for data migrations and schema changes.

The handle's methods simply proxy to those of an underlying IDatabase handle which takes care of the actual connection and query logic.

The CONN_TRX_AUTOCOMMIT flag is ignored for databases with ATTR_DB_LEVEL_LOCKING (e.g. sqlite) in order to avoid deadlocks. getServerAttributes() can be used to check such flags beforehand. Avoid the use of begin() or startAtomic() on any CONN_TRX_AUTOCOMMIT connections.

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

Parameters

int	$i	Server index or DB_MASTER/DB_REPLICA
string[] \| string	$groups	Query group(s) in preference order; [] for the default group
string \| bool	$domain	DB domain ID or false for the local domain
int	$flags	Bitfield of CONN_* class constants (e.g. CONN_TRX_AUTOCOMMIT)

Returns: MaintainableDBConnRef

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1044 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\getConnection(), Wikimedia\Rdbms\LoadBalancer\getRoleFromIndex(), and Wikimedia\Rdbms\LoadBalancer\resolveDomainID().

◆ getMasterPos()

Wikimedia\Rdbms\LoadBalancer::getMasterPos ( )

Get the current master replication position.

Returns: DBMasterPos|bool Returns false if not applicable

Exceptions

DBError

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1495 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\closeConnection(), Wikimedia\Rdbms\LoadBalancer\getAnyOpenConnection(), Wikimedia\Rdbms\LoadBalancer\getConnection(), Wikimedia\Rdbms\LoadBalancer\getWriterIndex(), and Wikimedia\Rdbms\LoadBalancer\reportConnectionError().

◆ getMasterServerName()

Wikimedia\Rdbms\LoadBalancer::getMasterServerName ( )

private

Returns: string Name of the master server of the relevant DB cluster (e.g. "db1052")

Definition at line 2424 of file LoadBalancer.php.

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

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

◆ getMaxLag()

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

Get the hostname and lag time of the most-lagged replica server.

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 2186 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$maxLag, Wikimedia\Rdbms\LoadBalancer\getLagTimes(), Wikimedia\Rdbms\LoadBalancer\getServerInfoStrict(), and Wikimedia\Rdbms\LoadBalancer\hasReplicaServers().

◆ 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 420 of file LoadBalancer.php.

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

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

◆ getReaderIndex()

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

Get the server index of the reader connection for a given group.

This takes into account load ratios and lag times. It should return a consistent index during the life time of the load balancer. This initially checks replica DBs for connectivity to avoid returning an unusable server. This means that connections might be attempted by calling this method (usally one at the most but possibly more). Subsequent calls with the same $group will not need to make new connection attempts since the acquired connection for each group is preserved.

Parameters

string \| bool	$group	Query group or false for the generic group
string \| bool	$domain	DB domain ID or false for the local domain

Returns: int|bool Returns false if no live handle can be obtained

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 502 of file LoadBalancer.php.

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

◆ getReadOnlyReason()

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

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

Parameters

string | bool $domain DB domain ID or false for the local domain

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

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 2027 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$readOnlyReason, Wikimedia\Rdbms\LoadBalancer\getExistingReaderIndex(), Wikimedia\Rdbms\LoadBalancer\getLaggedReplicaMode(), Wikimedia\Rdbms\LoadBalancer\isMasterRunningReadOnly(), Wikimedia\Rdbms\DatabaseDomain\newFromId(), and Wikimedia\Rdbms\LoadBalancer\resolveDomainID().

◆ getReplicaResumePos()

Wikimedia\Rdbms\LoadBalancer::getReplicaResumePos ( )

Get the highest DB replication position for chronology control purposes.

If there is only a master server then this returns false. If replication is present and correctly configured, then this returns the highest replication position of any server with an open connection. That position can later be passed to waitFor() on a new load balancer instance to make sure that queries on the new connections see data at least as up-to-date as queries (prior to this method call) on the old connections.

This can be useful for implementing session consistency, where the session will be resumed accross multiple HTTP requests or CLI script instances.

Returns: DBMasterPos|bool Replication position or false if not applicable

Since: 1.34

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1518 of file LoadBalancer.php.

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

◆ getRoleFromIndex()

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

private

Parameters

int $i Server index or DB_MASTER/DB_REPLICA

Returns: int One of DB_MASTER/DB_REPLICA

Definition at line 1056 of file LoadBalancer.php.

References Wikimedia\Rdbms\ILoadBalancer\DB_MASTER, DB_REPLICA, and Wikimedia\Rdbms\LoadBalancer\getWriterIndex().

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

◆ 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 1242 of file LoadBalancer.php.

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

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

◆ getServerConnection()

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

Parameters

int	$i	Specific server index
string	$domain	Resolved DB domain
int	$flags	Bitfield of class CONN_* constants

Returns: IDatabase|bool

Exceptions

InvalidArgumentException When the server index is invalid

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 927 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$connectionCounter, Wikimedia\Rdbms\LoadBalancer\$readOnlyReason, Wikimedia\Rdbms\LoadBalancer\enforceConnectionFlags(), Wikimedia\Rdbms\LoadBalancer\getForeignConnection(), Wikimedia\Rdbms\LoadBalancer\getLocalConnection(), Wikimedia\Rdbms\LoadBalancer\getWriterIndex(), Wikimedia\Rdbms\LoadBalancer\isMasterConnectionReadOnly(), and Wikimedia\Rdbms\LoadBalancer\reportConnectionError().

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

◆ getServerCount()

Wikimedia\Rdbms\LoadBalancer::getServerCount ( )

Get the number of servers defined in configuration.

Returns: int

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1463 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\getReaderIndex(), Wikimedia\Rdbms\LoadBalancer\getReplicaResumePos(), Wikimedia\Rdbms\LoadBalancer\hasReplicaServers(), and Wikimedia\Rdbms\LoadBalancer\waitForAll().

◆ 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 1487 of file LoadBalancer.php.

◆ getServerInfoStrict()

Wikimedia\Rdbms\LoadBalancer::getServerInfoStrict	(	$i,
		$field = `null`
	)

private

Parameters

int	$i	Server index
string \| null	$field	Server index field [optional]

Returns: array|mixed

Exceptions

InvalidArgumentException

Definition at line 2405 of file LoadBalancer.php.

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

◆ 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 1481 of file LoadBalancer.php.

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

◆ 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 1491 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\getServerAttributes(), and Wikimedia\Rdbms\LoadBalancer\sanitizeConnectionFlags().

◆ getTopologyRole()

Wikimedia\Rdbms\LoadBalancer::getTopologyRole	(		$i,
		array	$server
	)

private

Parameters

int	$i	Specific server index
array	$server	Server config map

Returns: string IDatabase::ROLE_* constant

Definition at line 1368 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\getWriterIndex().

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

◆ getTransactionRoundStage()

Wikimedia\Rdbms\LoadBalancer::getTransactionRoundStage ( )

Returns: string

Since: 1.32

Definition at line 1968 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$trxRoundStage.

◆ getWriterIndex()

Wikimedia\Rdbms\LoadBalancer::getWriterIndex ( )

Get the server index of the master server.

Returns: int

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1437 of file LoadBalancer.php.

◆ hasMasterChanges()

Wikimedia\Rdbms\LoadBalancer::hasMasterChanges ( )

Whether there are pending changes or callbacks in a transaction by this thread.

Returns: bool

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1976 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 1972 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 | null $age How many seconds ago is "recent" [defaults to mWaitTimeout]

Returns: bool

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1994 of file LoadBalancer.php.

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

◆ hasReplicaServers()

Wikimedia\Rdbms\LoadBalancer::hasReplicaServers ( )

Whether there are any replica servers configured.

This counts both servers using streaming replication from the master server and servers that just have a clone of the static dataset found on the master server

Returns: int

Since: 1.34

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1467 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\getServerCount().

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

◆ hasStreamingReplicaServers()

Wikimedia\Rdbms\LoadBalancer::hasStreamingReplicaServers ( )

Whether any replica servers use streaming replication from the master server.

Generally this is one less than getServerCount(), though it might otherwise return a lower number if some of the servers are configured with "is static". That flag is used when both the server has no active replication setup and the dataset is either read-only or occasionally updated out-of-band. For example, a script might import a new geographic information dataset each week by writing it to each server and later directing the application to use the new version.

It is possible for some replicas to be configured with "is static" but not others, though it generally should either be set for all or none of the replicas.

If this returns zero, this means that there is generally no reason to execute replication wait logic for session consistency and lag reduction.

Returns: int

Since: 1.34

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1471 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\getWriterIndex().

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

◆ haveIndex()

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

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

Parameters

int $i

Returns: bool

Deprecated:: Since 1.34

Definition at line 1448 of file LoadBalancer.php.

◆ initConnFlags()

Wikimedia\Rdbms\LoadBalancer::initConnFlags ( $flags )

private

See also: IDatabase::DBO_DEFAULT

Parameters

int $flags Bit field of IDatabase::DBO_* constants from configuration

Returns: int Bit field of IDatabase::DBO_* constants to use with Database::factory()

Definition at line 1383 of file LoadBalancer.php.

References DBO_TRX.

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

◆ isMasterConnectionReadOnly()

Wikimedia\Rdbms\LoadBalancer::isMasterConnectionReadOnly	(	IDatabase	$conn,
			$flags = `0`
	)

private

Parameters

IDatabase	$conn	Master connection
int	$flags	Bitfield of class CONN_* constants

Returns: bool Whether the entire server or currently selected DB/schema is read-only

Definition at line 2048 of file LoadBalancer.php.

References Wikimedia\Rdbms\IDatabase\dbSchema(), Wikimedia\Rdbms\IDatabase\getDBname(), Wikimedia\Rdbms\IDatabase\getServer(), and Wikimedia\Rdbms\IDatabase\serverIsReadOnly().

Referenced by Wikimedia\Rdbms\LoadBalancer\getServerConnection(), and Wikimedia\Rdbms\LoadBalancer\isMasterRunningReadOnly().

◆ isMasterRunningReadOnly()

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

private

Parameters

DatabaseDomain $domain

Returns: bool Whether the entire master server or the local domain DB is read-only

Definition at line 2085 of file LoadBalancer.php.

References Wikimedia\Rdbms\DatabaseDomain\getDatabase(), Wikimedia\Rdbms\DatabaseDomain\getId(), Wikimedia\Rdbms\DatabaseDomain\getSchema(), Wikimedia\Rdbms\LoadBalancer\getServerConnection(), Wikimedia\Rdbms\LoadBalancer\getWriterIndex(), Wikimedia\Rdbms\LoadBalancer\isMasterConnectionReadOnly(), and Wikimedia\Rdbms\LoadBalancer\reuseConnection().

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

◆ isNonZeroLoad()

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

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

Parameters

int $i

Returns: bool

Deprecated:: Since 1.34

Definition at line 1459 of file LoadBalancer.php.

◆ isOpen()

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

private

Test if the specified index represents an open connection.

Parameters

int $index Server index

Returns: bool

Definition at line 1255 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 2023 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$laggedReplicaMode.

◆ 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 1985 of file LoadBalancer.php.

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

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

◆ lazyLoadReplicationPositions()

Wikimedia\Rdbms\LoadBalancer::lazyLoadReplicationPositions ( )

private

Make sure that any "waitForPos" positions are loaded and available to doWait()

Definition at line 1398 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$chronologyCallback.

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

◆ newTrackedConnectionsArray()

static Wikimedia\Rdbms\LoadBalancer::newTrackedConnectionsArray ( )

staticprivate

Definition at line 258 of file LoadBalancer.php.

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

◆ openConnection()

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

Parameters

int	$i
string \| bool	$domain
int	$flags

Returns: Database|bool Live database handle or false on failure

Deprecated:: Since 1.34 Use getConnection() instead

Definition at line 1069 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\getConnection().

◆ 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 2001 of file LoadBalancer.php.

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

◆ pickAnyOpenConnection()

Wikimedia\Rdbms\LoadBalancer::pickAnyOpenConnection	(	$candidateConns,
		$autocommit
	)

private

Parameters

IDatabase[]	$candidateConns
bool	$autocommit	Whether to only look for auto-commit connections

Returns: IDatabase|false An appropriate open connection or false if none found

Definition at line 794 of file LoadBalancer.php.

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

◆ 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, false) on failure

Definition at line 584 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$laggedReplicaMode, Wikimedia\Rdbms\LoadBalancer\allowLagged(), Wikimedia\Rdbms\LoadBalancer\getRandomNonLagged(), Wikimedia\Rdbms\LoadBalancer\getServerConnection(), Wikimedia\Rdbms\LoadBalancer\getServerName(), 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 2126 of file LoadBalancer.php.

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

◆ reallyOpenConnection()

Wikimedia\Rdbms\LoadBalancer::reallyOpenConnection	(		$i,
		DatabaseDomain	$domain,
		array	$lbInfo
	)

protected

Open a new network connection to a server (uncached)

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

Parameters

int	$i	Specific server index
DatabaseDomain	$domain	Domain the connection is for, possibly unspecified
array	$lbInfo	Additional information for setLBInfo()

Returns: Database

Exceptions

DBAccessError
InvalidArgumentException

Reimplemented in Wikimedia\Rdbms\LoadBalancerSingle.

Definition at line 1271 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\getForeignConnection(), and Wikimedia\Rdbms\LoadBalancer\getLocalConnection().

◆ redefineLocalDomain()

Wikimedia\Rdbms\LoadBalancer::redefineLocalDomain ( $domain )

Close all connection and redefine the local domain for testing or schema creation.

Parameters

DatabaseDomain | string $domain

Since: 1.33

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 2375 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\closeAll(), Wikimedia\Rdbms\DatabaseDomain\newFromId(), and Wikimedia\Rdbms\LoadBalancer\setLocalDomain().

◆ reportConnectionError()

Wikimedia\Rdbms\LoadBalancer::reportConnectionError ( )

private

Exceptions

DBConnectionError

Definition at line 1409 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$errorConnection, Wikimedia\Rdbms\LoadBalancer\$lastError, and Wikimedia\Rdbms\Database\getServer().

Referenced by Wikimedia\Rdbms\LoadBalancer\getConnectionIndex(), Wikimedia\Rdbms\LoadBalancer\getMasterPos(), and Wikimedia\Rdbms\LoadBalancer\getServerConnection().

◆ resolveDomainID()

Wikimedia\Rdbms\LoadBalancer::resolveDomainID ( $domain )

Parameters

DatabaseDomain | string | bool $domain Database domain

Returns: string Value of $domain if it is foreign or the local domain otherwise

Since: 1.32

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 275 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\resolveDomainInstance().

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

◆ resolveDomainInstance()

Wikimedia\Rdbms\LoadBalancer::resolveDomainInstance ( $domain )

finalprotected

Parameters

DatabaseDomain | string | bool $domain

Returns: DatabaseDomain

Definition at line 283 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$localDomain, and Wikimedia\Rdbms\DatabaseDomain\newFromId().

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

◆ resolveGroups()

Wikimedia\Rdbms\LoadBalancer::resolveGroups	(	$groups,
		$i
	)

private

Resolve $groups into a list of query groups defining as having database servers.

Parameters

string[] \| string \| bool	$groups	Query group(s) in preference order, [], or false
int	$i	Specific server index or DB_MASTER/DB_REPLICA

Returns: string[] Non-empty group list in preference order with the default group appended

Definition at line 311 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$defaultGroup.

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

◆ reuseConnection()

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

Mark a live handle as being available for reuse under a different database domain.

This mechanism is reference-counted, and must be called the same number of times as getConnection() to work. Never call this on handles acquired via getConnectionRef(), getLazyConnectionRef(), and getMaintenanceConnectionRef(), as they already manage the logic of calling this method when they fall out of scope in PHP.

See also: ILoadBalancer::getConnection()

Parameters

IDatabase $conn

Exceptions

LogicException

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 980 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\isMasterRunningReadOnly(), and Wikimedia\Rdbms\LoadBalancer\pickReaderIndex().

◆ rollbackMasterChanges()

Wikimedia\Rdbms\LoadBalancer::rollbackMasterChanges	(	$fname = `__METHOD__`,
		$owner = `null`
	)

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

Parameters

string	$fname	Caller name
int \| null	$owner	ID of the calling instance (e.g. the LBFactory ID)

Exceptions

DBExpectedError

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1844 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\assertOwnership(), Wikimedia\Rdbms\LoadBalancer\forEachOpenMasterConnection(), Wikimedia\Rdbms\IDatabase\rollback(), and Wikimedia\Rdbms\LoadBalancer\undoTransactionRoundFlags().

◆ runMasterTransactionIdleCallbacks()

Wikimedia\Rdbms\LoadBalancer::runMasterTransactionIdleCallbacks	(	$fname = `__METHOD__`,
		$owner = `null`
	)

Consume and run all pending post-COMMIT/ROLLBACK callbacks and commit dangling transactions.

Parameters

string	$fname	Caller name
int \| null	$owner	ID of the calling instance (e.g. the LBFactory ID)

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

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1737 of file LoadBalancer.php.

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

◆ runMasterTransactionListenerCallbacks()

Wikimedia\Rdbms\LoadBalancer::runMasterTransactionListenerCallbacks	(	$fname = `__METHOD__`,
		$owner = `null`
	)

Run all recurring post-COMMIT/ROLLBACK listener callbacks.

Parameters

string	$fname	Caller name
int \| null	$owner	ID of the calling instance (e.g. the LBFactory ID)

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

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1812 of file LoadBalancer.php.

References $type, Wikimedia\Rdbms\LoadBalancer\assertOwnership(), Wikimedia\Rdbms\LoadBalancer\forEachOpenMasterConnection(), and Wikimedia\Rdbms\Database\runTransactionListenerCallbacks().

◆ 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

Deprecated:: Since 1.34 Use IDatabase::getLag() instead

Definition at line 2238 of file LoadBalancer.php.

References Wikimedia\Rdbms\IDatabase\getLag().

◆ safeWaitForMasterPos()

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

Wait for a replica DB to reach a specified master position.

This will connect to the master to get an accurate position if $pos is not given

Parameters

IDatabase	$conn	Replica DB
DBMasterPos \| bool	$pos	Master position; default: current position
int	$timeout	Timeout in seconds [optional]

Returns: bool Success

Since: 1.28

Deprecated:: Since 1.34 Use waitForMasterPos() instead

Definition at line 2314 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\waitForMasterPos().

◆ sanitizeConnectionFlags()

Wikimedia\Rdbms\LoadBalancer::sanitizeConnectionFlags	(	$flags,
		$i,
		$domain
	)

private

Parameters

int	$flags	Bitfield of class CONN_* constants
int	$i	Specific server index or DB_MASTER/DB_REPLICA
string	$domain	Database domain

Returns: int Sanitized bitfield

Definition at line 337 of file LoadBalancer.php.

References $type, Wikimedia\Rdbms\LoadBalancer\getServerAttributes(), Wikimedia\Rdbms\LoadBalancer\getServerType(), and Wikimedia\Rdbms\LoadBalancer\getWriterIndex().

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

◆ serverHasLoadInAnyGroup()

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

private

Parameters

int $i Specific server index

Returns: bool

Definition at line 736 of file LoadBalancer.php.

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

◆ setDomainAliases()

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

Convert certain database domains to alternative ones.

This can be used for backwards compatibility logic.

Parameters

DatabaseDomain[] | string[] $aliases Map of (domain alias => domain)

Since: 1.35

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 2339 of file LoadBalancer.php.

◆ setExistingReaderIndex()

Wikimedia\Rdbms\LoadBalancer::setExistingReaderIndex	(	$group,
		$index
	)

private

Set the server index chosen by the load balancer for use with the given query group.

Parameters

string	$group	Query group; use false for the generic group
int	$index	The index of a specific server

Definition at line 572 of file LoadBalancer.php.

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

◆ 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

Since: 1.31

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 2335 of file LoadBalancer.php.

◆ setLocalDomain()

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

private

Parameters

DatabaseDomain $domain

Definition at line 2395 of file LoadBalancer.php.

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

◆ setLocalDomainPrefix()

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

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

Parameters

string $prefix

Since: 1.33

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 2343 of file LoadBalancer.php.

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

◆ 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 2331 of file LoadBalancer.php.

◆ setTempTablesOnlyMode()

Wikimedia\Rdbms\LoadBalancer::setTempTablesOnlyMode	(	$value,
		$domain
	)

Indicate whether the tables on this domain are only temporary tables for testing.

In "temporary tables mode", the ILoadBalancer::CONN_TRX_AUTOCOMMIT flag is ignored

Parameters

bool	$value
string	$domain

Returns: bool Whether "temporary tables mode" was active

Since: 1.34

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 2381 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 2318 of file LoadBalancer.php.

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

◆ setWaitForPositionIfHigher()

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

private

Parameters

DBMasterPos | bool $pos

Definition at line 749 of file LoadBalancer.php.

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

◆ undoTransactionRoundFlags()

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

private

Parameters

Database $conn

Definition at line 1936 of file LoadBalancer.php.

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

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

◆ waitFor()

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

Set the master position to reach before the next generic group DB handle query.

If a generic replica DB connection is already open then this immediately waits for that DB to catch up to the specified replication position. Otherwise, it will do so once such a connection is opened.

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 662 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$waitForPos, Wikimedia\Rdbms\LoadBalancer\doWait(), Wikimedia\Rdbms\LoadBalancer\getExistingReaderIndex(), 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 \| null	$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 705 of file LoadBalancer.php.

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

◆ waitForMasterPos()

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

Wait for a replica DB to reach a specified master position.

If $conn is not a replica server connection, then this will return true. Otherwise, if $pos is not provided, this will connect to the master server to get an accurate position.

Parameters

IDatabase	$conn	Replica DB
DBMasterPos \| bool	$pos	Master position; default: current position
int	$timeout	Timeout in seconds [optional]

Returns: bool Success

Since: 1.34

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 2242 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\getServerConnection(), Wikimedia\Rdbms\LoadBalancer\getWriterIndex(), and Wikimedia\Rdbms\IDatabase\masterPosWait().

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

◆ 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 \| null	$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 678 of file LoadBalancer.php.

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

Member Data Documentation

◆ $agent

string Wikimedia\Rdbms\LoadBalancer::$agent

private

Agent name for query profiling.

Definition at line 99 of file LoadBalancer.php.

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

◆ $allowLagged

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

private

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

Definition at line 123 of file LoadBalancer.php.

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

◆ $chronologyCallback

callable null Wikimedia\Rdbms\LoadBalancer::$chronologyCallback

private

Callback to run before the first connection attempt.

Definition at line 46 of file LoadBalancer.php.

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

◆ $cliMode

bool Wikimedia\Rdbms\LoadBalancer::$cliMode

private

Whether this PHP instance is for a CLI script.

Definition at line 97 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 135 of file LoadBalancer.php.

◆ $connectionCounter

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

private

Total number of new connections ever made with this instance.

Definition at line 131 of file LoadBalancer.php.

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

◆ $connLogger

LoggerInterface Wikimedia\Rdbms\LoadBalancer::$connLogger

private

Definition at line 59 of file LoadBalancer.php.

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

◆ $conns

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

private

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

Definition at line 77 of file LoadBalancer.php.

◆ $defaultGroup

string null Wikimedia\Rdbms\LoadBalancer::$defaultGroup

private

Default query group to use with getConnection()

Definition at line 92 of file LoadBalancer.php.

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

◆ $deprecationLogger

callable Wikimedia\Rdbms\LoadBalancer::$deprecationLogger

private

Deprecation logger.

Definition at line 69 of file LoadBalancer.php.

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

◆ $disabled

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

private

Definition at line 133 of file LoadBalancer.php.

◆ $domainAliases

DatabaseDomain [] string [] Wikimedia\Rdbms\LoadBalancer::$domainAliases = []

private

Map of (domain alias => DB domain)

Definition at line 106 of file LoadBalancer.php.

◆ $errorConnection

Database Wikimedia\Rdbms\LoadBalancer::$errorConnection

private

Connection handle that caused a problem.

Definition at line 117 of file LoadBalancer.php.

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

◆ $errorLogger

callable Wikimedia\Rdbms\LoadBalancer::$errorLogger

private

Exception logger.

Definition at line 67 of file LoadBalancer.php.

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

◆ $groupLoads

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

private

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

Definition at line 82 of file LoadBalancer.php.

◆ $hostname

string Wikimedia\Rdbms\LoadBalancer::$hostname

private

Current server name.

Definition at line 95 of file LoadBalancer.php.

◆ $id

Wikimedia\Rdbms\LoadBalancer::$id

private

var int An identifier for this class instance

Definition at line 138 of file LoadBalancer.php.

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

◆ $indexAliases

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

private

Map of (index alias => index)

Definition at line 104 of file LoadBalancer.php.

◆ $INFO_AUTOCOMMIT_ONLY

Wikimedia\Rdbms\LoadBalancer::$INFO_AUTOCOMMIT_ONLY = 'autoCommitOnly'

staticprivate

Definition at line 146 of file LoadBalancer.php.

◆ $INFO_FOREIGN_REF_COUNT

Wikimedia\Rdbms\LoadBalancer::$INFO_FOREIGN_REF_COUNT = 'foreignPoolRefCount'

staticprivate

Definition at line 148 of file LoadBalancer.php.

◆ $INFO_FORIEGN

Wikimedia\Rdbms\LoadBalancer::$INFO_FORIEGN = 'foreign'

staticprivate

Definition at line 147 of file LoadBalancer.php.

◆ $INFO_SERVER_INDEX

Wikimedia\Rdbms\LoadBalancer::$INFO_SERVER_INDEX = 'serverIndex'

staticprivate

Definition at line 145 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 125 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 127 of file LoadBalancer.php.

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

◆ $loadMonitor

ILoadMonitor Wikimedia\Rdbms\LoadBalancer::$loadMonitor

private

Definition at line 44 of file LoadBalancer.php.

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

◆ $loadMonitorConfig

array Wikimedia\Rdbms\LoadBalancer::$loadMonitorConfig

private

The LoadMonitor configuration.

Definition at line 88 of file LoadBalancer.php.

◆ $localDomain

DatabaseDomain Wikimedia\Rdbms\LoadBalancer::$localDomain

private

Local DB domain ID and default for selectDB() calls.

Definition at line 72 of file LoadBalancer.php.

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

◆ $maxLag

int Wikimedia\Rdbms\LoadBalancer::$maxLag

private

Definition at line 90 of file LoadBalancer.php.

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

◆ $maxLagByIndex

int [] Wikimedia\Rdbms\LoadBalancer::$maxLagByIndex

private

Map of (server index => seconds of lag considered "high")

Definition at line 84 of file LoadBalancer.php.

◆ $nonLocalDomainCache

DatabaseDomain [] Wikimedia\Rdbms\LoadBalancer::$nonLocalDomainCache = []

private

Map of (domain ID => domain instance)

Definition at line 143 of file LoadBalancer.php.

◆ $ownerId

int null Wikimedia\Rdbms\LoadBalancer::$ownerId

private

Integer ID of the managing LBFactory instance or null if none.

Definition at line 140 of file LoadBalancer.php.

◆ $perfLogger

LoggerInterface Wikimedia\Rdbms\LoadBalancer::$perfLogger

private

Definition at line 65 of file LoadBalancer.php.

◆ $profiler

callable null Wikimedia\Rdbms\LoadBalancer::$profiler

private

An optional callback that returns a ScopedCallback instance, meant to profile the actual query execution in {.

See also: Database::doQuery}

Definition at line 55 of file LoadBalancer.php.

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

◆ $queryLogger

LoggerInterface Wikimedia\Rdbms\LoadBalancer::$queryLogger

private

Definition at line 61 of file LoadBalancer.php.

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

◆ $readIndexByGroup

int [] Wikimedia\Rdbms\LoadBalancer::$readIndexByGroup = []

private

The group replica server indexes keyed by group.

Definition at line 119 of file LoadBalancer.php.

◆ $readOnlyReason

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

private

Reason this instance is read-only or false if not.

Definition at line 129 of file LoadBalancer.php.

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

◆ $replLogger

LoggerInterface Wikimedia\Rdbms\LoadBalancer::$replLogger

private

Definition at line 63 of file LoadBalancer.php.

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

◆ $servers

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

private

Map of (server index => server config array)

Definition at line 80 of file LoadBalancer.php.

◆ $srvCache

BagOStuff Wikimedia\Rdbms\LoadBalancer::$srvCache

private

Definition at line 48 of file LoadBalancer.php.

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

◆ $tableAliases

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

private

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

Definition at line 102 of file LoadBalancer.php.

◆ $tempTablesOnlyMode

bool [] Wikimedia\Rdbms\LoadBalancer::$tempTablesOnlyMode = []

private

Map of (domain => whether to use "temp tables only" mode)

Definition at line 110 of file LoadBalancer.php.

◆ $trxProfiler

TransactionProfiler Wikimedia\Rdbms\LoadBalancer::$trxProfiler

private

Definition at line 57 of file LoadBalancer.php.

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

◆ $trxRecurringCallbacks

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

private

Map of (name => callable)

Definition at line 108 of file LoadBalancer.php.

◆ $trxRoundId

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

private

Explicit DBO_TRX transaction round active or false if none.

Definition at line 113 of file LoadBalancer.php.

◆ $trxRoundStage

string Wikimedia\Rdbms\LoadBalancer::$trxRoundStage = self::ROUND_CURSORY

private

Stage of the current transaction round in the transaction round life-cycle.

Definition at line 115 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\getTransactionRoundStage(), and Wikimedia\Rdbms\LoadBalancer\runMasterTransactionIdleCallbacks().

◆ $waitForPos

bool DBMasterPos Wikimedia\Rdbms\LoadBalancer::$waitForPos

private

Replication sync position or false if not set.

Definition at line 121 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 86 of file LoadBalancer.php.

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

◆ $wanCache

WANObjectCache Wikimedia\Rdbms\LoadBalancer::$wanCache

private

Definition at line 50 of file LoadBalancer.php.

◆ KEY_FOREIGN_FREE

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

private

Definition at line 161 of file LoadBalancer.php.

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

◆ KEY_FOREIGN_FREE_NOROUND

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

private

Definition at line 165 of file LoadBalancer.php.

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

◆ KEY_FOREIGN_INUSE

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

private

Definition at line 162 of file LoadBalancer.php.

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

◆ KEY_FOREIGN_INUSE_NOROUND

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

private

Definition at line 166 of file LoadBalancer.php.

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

◆ KEY_LOCAL

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

private

Definition at line 160 of file LoadBalancer.php.

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

◆ KEY_LOCAL_NOROUND

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

private

Definition at line 164 of file LoadBalancer.php.

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

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

includes/libs/rdbms/loadbalancer/LoadBalancer.php

Public Member Functions

Protected Member Functions

Private Member Functions

Static Private Member Functions

Private Attributes

Static Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ __construct()

◆ __destruct()

Member Function Documentation

◆ allowLagged()

◆ applyTransactionRoundFlags()

◆ approveMasterChanges()

◆ assertOwnership()

◆ assertTransactionRoundStage()

◆ beginMasterChanges()

◆ closeAll()

◆ closeConnection()

◆ commitAll()

◆ commitMasterChanges()

◆ disable()

◆ doWait()

◆ enforceConnectionFlags()

◆ finalizeMasterChanges()

◆ flushMasterSnapshots()

◆ flushReplicaSnapshots()

◆ forEachOpenConnection()

◆ forEachOpenMasterConnection()

◆ forEachOpenReplicaConnection()

◆ getAnyOpenConnection()

◆ getConnection()

◆ getConnectionIndex()

◆ getConnectionRef()

◆ getCurrentConnectionCount()

◆ getExistingReaderIndex()

◆ getForeignConnection()

◆ getLaggedReplicaMode()

◆ getLagTimes()

◆ getLazyConnectionRef()

◆ getLoadMonitor()

◆ getLocalConnection()

◆ getLocalDomainID()

◆ getMaintenanceConnectionRef()

◆ getMasterPos()

◆ getMasterServerName()

◆ getMaxLag()

◆ getRandomNonLagged()

◆ getReaderIndex()

◆ getReadOnlyReason()

◆ getReplicaResumePos()

◆ getRoleFromIndex()

◆ getServerAttributes()

◆ getServerConnection()

◆ getServerCount()

◆ getServerInfo()

◆ getServerInfoStrict()

◆ getServerName()

◆ getServerType()

◆ getTopologyRole()

◆ getTransactionRoundStage()

◆ getWriterIndex()

◆ hasMasterChanges()

◆ hasMasterConnection()

◆ hasOrMadeRecentMasterChanges()

◆ hasReplicaServers()

◆ hasStreamingReplicaServers()

◆ haveIndex()

◆ initConnFlags()

◆ isMasterConnectionReadOnly()

◆ isMasterRunningReadOnly()

◆ isNonZeroLoad()

◆ isOpen()

◆ laggedReplicaUsed()

◆ lastMasterChangeTimestamp()

◆ lazyLoadReplicationPositions()

◆ newTrackedConnectionsArray()

◆ openConnection()

◆ pendingMasterChangeCallers()