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Wikimedia\Rdbms\LoadBalancer Class Reference

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

Inheritance diagram for Wikimedia\Rdbms\LoadBalancer:
Collaboration diagram for Wikimedia\Rdbms\LoadBalancer:

Public Member Functions

 __construct (array $params)
 Construct a manager of IDatabase connection objects. More...
 
 __destruct ()
 
 allowLagged ( $mode=null)
 Disables/enables lag checks. More...
 
 approveMasterChanges (array $options, $fname=__METHOD__, $owner=null)
 Perform all pre-commit checks for things like replication safety. More...
 
 beginMasterChanges ( $fname=__METHOD__, $owner=null)
 Flush any master transaction snapshots and set DBO_TRX (if DBO_DEFAULT is set) More...
 
 closeAll ()
 Close all open connections. More...
 
 closeConnection (IDatabase $conn)
 Close a connection. More...
 
 commitAll ( $fname=__METHOD__, $owner=null)
 Commit transactions on all open connections. More...
 
 commitMasterChanges ( $fname=__METHOD__, $owner=null)
 Issue COMMIT on all open master connections to flush changes and view snapshots. More...
 
 disable ()
 Disable this load balancer. More...
 
 finalizeMasterChanges ( $fname=__METHOD__, $owner=null)
 Run pre-commit callbacks and defer execution of post-commit callbacks. More...
 
 flushMasterSnapshots ( $fname=__METHOD__)
 Commit all master DB transactions so as to flush any REPEATABLE-READ or SSI snapshots. More...
 
 flushReplicaSnapshots ( $fname=__METHOD__)
 Commit all replica DB transactions so as to flush any REPEATABLE-READ or SSI snapshots. More...
 
 forEachOpenConnection ( $callback, array $params=[])
 Call a function with each open connection object. More...
 
 forEachOpenMasterConnection ( $callback, array $params=[])
 Call a function with each open connection object to a master. More...
 
 forEachOpenReplicaConnection ( $callback, array $params=[])
 Call a function with each open replica DB connection object. More...
 
 getAnyOpenConnection ( $i, $flags=0)
 Get any open connection to a given server index, local or foreign. More...
 
 getConnection ( $i, $groups=[], $domain=false, $flags=0)
 Get a live handle for a real or virtual (DB_MASTER/DB_REPLICA) server index. More...
 
 getConnectionRef ( $i, $groups=[], $domain=false, $flags=0)
 Get a live database handle reference for a real or virtual (DB_MASTER/DB_REPLICA) server index. More...
 
 getLaggedReplicaMode ( $domain=false)
 
 getLagTimes ( $domain=false)
 Get an estimate of replication lag (in seconds) for each server. More...
 
 getLazyConnectionRef ( $i, $groups=[], $domain=false, $flags=0)
 Get a database handle reference for a real or virtual (DB_MASTER/DB_REPLICA) server index. More...
 
 getLocalDomainID ()
 Get the local (and default) database domain ID of connection handles. More...
 
 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. More...
 
 getMasterPos ()
 Get the current master replication position. More...
 
 getMaxLag ( $domain=false)
 Get the hostname and lag time of the most-lagged replica server. More...
 
 getReaderIndex ( $group=false, $domain=false)
 Get the server index of the reader connection for a given group. More...
 
 getReadOnlyReason ( $domain=false, IDatabase $conn=null)
 
 getReplicaResumePos ()
 Get the highest DB replication position for chronology control purposes. More...
 
 getServerAttributes ( $i)
 
 getServerConnection ( $i, $domain, $flags=0)
 
 getServerCount ()
 Get the number of servers defined in configuration. More...
 
 getServerInfo ( $i)
 Return the server info structure for a given index or false if the index is invalid. More...
 
 getServerName ( $i)
 Get the host name or IP address of the server with the specified index. More...
 
 getServerType ( $i)
 Get DB type of the server with the specified index. More...
 
 getTransactionRoundStage ()
 
 getWriterIndex ()
 Get the server index of the master server. More...
 
 hasMasterChanges ()
 Whether there are pending changes or callbacks in a transaction by this thread. More...
 
 hasMasterConnection ()
 
 hasOrMadeRecentMasterChanges ( $age=null)
 Check if this load balancer object had any recent or still pending writes issued against it by this PHP thread. More...
 
 hasReplicaServers ()
 Whether there are any replica servers configured. More...
 
 hasStreamingReplicaServers ()
 Whether any replica servers use streaming replication from the master server. More...
 
 haveIndex ( $i)
 Returns true if the specified index is a valid server index. More...
 
 isNonZeroLoad ( $i)
 Returns true if the specified index is valid and has non-zero load. More...
 
 laggedReplicaUsed ()
 Checks whether the database for generic connections this request was both: More...
 
 laggedSlaveUsed ()
 
 lastMasterChangeTimestamp ()
 Get the timestamp of the latest write query done by this thread. More...
 
 openConnection ( $i, $domain=false, $flags=0)
 
 pendingMasterChangeCallers ()
 Get the list of callers that have pending master changes. More...
 
 pingAll ()
 
 redefineLocalDomain ( $domain)
 Close all connection and redefine the local domain for testing or schema creation. More...
 
 resolveDomainID ( $domain)
 
 reuseConnection (IDatabase $conn)
 Mark a live handle as being available for reuse under a different database domain. More...
 
 rollbackMasterChanges ( $fname=__METHOD__, $owner=null)
 Issue ROLLBACK only on master, only if queries were done on connection. More...
 
 runMasterTransactionIdleCallbacks ( $fname=__METHOD__, $owner=null)
 Consume and run all pending post-COMMIT/ROLLBACK callbacks and commit dangling transactions. More...
 
 runMasterTransactionListenerCallbacks ( $fname=__METHOD__, $owner=null)
 Run all recurring post-COMMIT/ROLLBACK listener callbacks. More...
 
 safeGetLag (IDatabase $conn)
 Get the lag in seconds for a given connection, or zero if this load balancer does not have replication enabled. More...
 
 safeWaitForMasterPos (IDatabase $conn, $pos=false, $timeout=null)
 Wait for a replica DB to reach a specified master position. More...
 
 setDomainPrefix ( $prefix)
 
 setIndexAliases (array $aliases)
 Convert certain index names to alternative names before querying the DB. More...
 
 setLocalDomainPrefix ( $prefix)
 Set a new table prefix for the existing local domain ID for testing. More...
 
 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. More...
 
 setTransactionListener ( $name, callable $callback=null)
 Set a callback via IDatabase::setTransactionListener() on all current and future master connections of this load balancer. More...
 
 waitFor ( $pos)
 Set the master position to reach before the next generic group DB handle query. More...
 
 waitForAll ( $pos, $timeout=null)
 Set the master wait position and wait for ALL replica DBs to catch up to it. More...
 
 waitForMasterPos (IDatabase $conn, $pos=false, $timeout=null)
 Wait for a replica DB to reach a specified master position. More...
 
 waitForOne ( $pos, $timeout=null)
 Set the master wait position and wait for a generic replica DB to catch up to it. More...
 

Public Attributes

const KEY_FOREIGN_FREE = 'foreignFree'
 
const KEY_FOREIGN_FREE_NOROUND = 'foreignFreeAutoCommit'
 
const KEY_FOREIGN_INUSE = 'foreignInUse'
 
const KEY_FOREIGN_INUSE_NOROUND = 'foreignInUseAutoCommit'
 
const KEY_LOCAL = 'local'
 
const KEY_LOCAL_NOROUND = 'localAutoCommit'
 

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". More...
 
 getExistingReaderIndex ( $group)
 Get the server index chosen by the load balancer for use with the given query group. More...
 
 reallyOpenConnection (array $server, DatabaseDomain $domain)
 Open a new network connection to a server (uncached) More...
 

Private Member Functions

 applyTransactionRoundFlags (Database $conn)
 Make all DB servers with DBO_DEFAULT/DBO_TRX set join the transaction round. More...
 
 assertOwnership ( $fname, $owner)
 
 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. More...
 
 getCurrentConnectionCount ()
 
 getForeignConnection ( $i, $domain, $flags=0)
 Open a connection to a foreign DB, or return one if it is already open. More...
 
 getLoadMonitor ()
 Get a LoadMonitor instance. More...
 
 getLocalConnection ( $i, $flags=0)
 Open a connection to a local DB, or return one if it is already open. More...
 
 getRandomNonLagged (array $loads, $domain=false, $maxLag=INF)
 
 getRoleFromIndex ( $i)
 
 getServerInfoStrict ( $i, $field=null)
 
 isOpen ( $index)
 Test if the specified index represents an open connection. More...
 
 lazyLoadReplicationPositions ()
 Make sure that any "waitForPos" positions are loaded and available to doWait() More...
 
 masterRunningReadOnly ( $domain, IDatabase $conn=null)
 
 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. More...
 
 sanitizeConnectionFlags ( $flags, $i)
 
 setExistingReaderIndex ( $group, $index)
 Set the server index chosen by the load balancer for use with the given query group. More...
 
 setLocalDomain (DatabaseDomain $domain)
 
 setWaitForPositionIfHigher ( $pos)
 
 undoTransactionRoundFlags (Database $conn)
 

Static Private Member Functions

static newTrackedConnectionsArray ()
 

Private Attributes

string $agent
 Agent name for query profiling. More...
 
bool $allowLagged
 Whether to disregard replica DB lag as a factor in replica DB selection. More...
 
callable null $chronologyCallback
 Callback to run before the first connection attempt. More...
 
bool $cliMode
 Whether this PHP instance is for a CLI script. More...
 
bool $connectionAttempted = false
 Whether any connection has been attempted yet. More...
 
int $connectionCounter = 0
 Total number of new connections ever made with this instance. More...
 
LoggerInterface $connLogger
 
Database [][][] $conns
 Map of (connection category => server index => IDatabase[]) More...
 
string null $defaultGroup
 Default query group to use with getConnection() More...
 
callable $deprecationLogger
 Deprecation logger. More...
 
bool $disabled = false
 
Database $errorConnection
 Connection handle that caused a problem. More...
 
callable $errorLogger
 Exception logger. More...
 
array [] $groupLoads
 Map of (group => server index => weight) More...
 
string $hostname
 Current server name. More...
 
string [] $indexAliases = []
 Map of (index alias => index) More...
 
bool $laggedReplicaMode = false
 Whether the generic reader fell back to a lagged replica DB. More...
 
string $lastError = 'Unknown error'
 The last DB selection or connection error. More...
 
ILoadMonitor $loadMonitor
 
array $loadMonitorConfig
 The LoadMonitor configuration. More...
 
DatabaseDomain $localDomain
 Local DB domain ID and default for selectDB() calls. More...
 
string $localDomainIdAlias
 Alternate local DB domain instead of DatabaseDomain::getId() More...
 
int $maxLag
 Amount of replication lag, in seconds, that is considered "high". More...
 
int null $ownerId
 Integer ID of the managing LBFactory instance or null if none. More...
 
LoggerInterface $perfLogger
 
mixed $profiler
 Class name or object With profileIn/profileOut methods. More...
 
LoggerInterface $queryLogger
 
int [] $readIndexByGroup = []
 The group replica server indexes keyed by group. More...
 
string bool $readOnlyReason = false
 Reason this instance is read-only or false if not. More...
 
LoggerInterface $replLogger
 
array [] $servers
 Map of (server index => server config array) More...
 
BagOStuff $srvCache
 
 $tableAliases = []
 
TransactionProfiler $trxProfiler
 
array [] $trxRecurringCallbacks = []
 Map of (name => callable) More...
 
string bool $trxRoundId = false
 Explicit DBO_TRX transaction round active or false if none. More...
 
string $trxRoundStage = self::ROUND_CURSORY
 Stage of the current transaction round in the transaction round life-cycle. More...
 
bool DBMasterPos $waitForPos
 Replication sync position or false if not set. More...
 
int $waitTimeout
 Seconds to spend waiting on replica DB lag to resolve. More...
 
WANObjectCache $wanCache
 

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$paramsParameter map with keys:
  • servers : List of server info structures
  • localDomain: A DatabaseDomain or domain ID string
  • loadMonitor : Name of a class used to fetch server lag and load
  • readOnlyReason : Reason the master DB is read-only if so [optional]
  • waitTimeout : Maximum time to wait for replicas for consistency [optional]
  • maxLag: 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.

Definition at line 162 of file LoadBalancer.php.

References $e, Wikimedia\Rdbms\LoadBalancer\$maxLag, Wikimedia\Rdbms\LoadBalancer\allowLagged(), as, WANObjectCache\newEmpty(), Wikimedia\Rdbms\DatabaseDomain\newFromId(), Wikimedia\Rdbms\DatabaseDomain\newUnspecified(), null, servers, and Wikimedia\Rdbms\LoadBalancer\setLocalDomain().

◆ __destruct()

Wikimedia\Rdbms\LoadBalancer::__destruct ( )

Definition at line 2289 of file LoadBalancer.php.

References class, and 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 1980 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$allowLagged, and null.

Referenced by Wikimedia\Rdbms\LoadBalancer\__construct(), 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 1812 of file LoadBalancer.php.

References DBO_DEFAULT, DBO_TRX, 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$optionsIncludes:
  • maxWriteDuration : max write query duration time in seconds
string$fnameCaller name
int | null$ownerID of the calling instance (e.g. the LBFactory ID)
Exceptions
DBTransactionError

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1554 of file LoadBalancer.php.

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

◆ assertOwnership()

◆ assertTransactionRoundStage()

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

◆ 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:

Parameters
string$fnameCaller name
int | null$ownerID of the calling instance (e.g. the LBFactory ID)
Exceptions
DBExpectedError

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1588 of file LoadBalancer.php.

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

◆ closeAll()

◆ 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 1497 of file LoadBalancer.php.

References $type, as, 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$fnameCaller name
int | null$ownerID of the calling instance (e.g. the LBFactory ID)
Exceptions
DBExpectedError

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1523 of file LoadBalancer.php.

References $fname, 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$fnameCaller name
int | null$ownerID of the calling instance (e.g. the LBFactory ID)
Exceptions
DBExpectedError

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1613 of file LoadBalancer.php.

References $e, Wikimedia\Rdbms\LoadBalancer\$errorLogger, $fname, Wikimedia\Rdbms\LoadBalancer\assertOwnership(), Wikimedia\Rdbms\LoadBalancer\assertTransactionRoundStage(), Wikimedia\Rdbms\IDatabase\commit(), false, Wikimedia\Rdbms\LoadBalancer\forEachOpenMasterConnection(), null, Wikimedia\Rdbms\LoadBalancer\undoTransactionRoundFlags(), and use.

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

◆ disable()

Wikimedia\Rdbms\LoadBalancer::disable ( )

Disable this load balancer.

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

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1480 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\closeAll().

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

◆ doWait()

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

Wait for a given replica DB to catch up to the master pos stored in "waitForPos".

Parameters
int$indexSpecific server index
bool$openCheck the server even if a new connection has to be made
int | null$timeoutMax seconds to wait; default is "waitTimeout"
Returns
bool

Definition at line 772 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\closeConnection(), Wikimedia\Rdbms\LoadBalancer\getAnyOpenConnection(), Wikimedia\Rdbms\LoadBalancer\getServerConnection(), Wikimedia\Rdbms\LoadBalancer\getServerName(), Wikimedia\Rdbms\DBMasterPos\hasReached(), null, and IExpiringStore\TTL_DAY.

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

◆ 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$fnameCaller name
int | null$ownerID 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 1529 of file LoadBalancer.php.

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

◆ flushMasterSnapshots()

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

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$fnameCaller name

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1851 of file LoadBalancer.php.

References $fname, Wikimedia\Rdbms\IDatabase\flushSnapshot(), Wikimedia\Rdbms\LoadBalancer\forEachOpenMasterConnection(), and use.

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

◆ flushReplicaSnapshots()

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

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

Parameters
string$fnameCaller name

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1845 of file LoadBalancer.php.

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

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 2000 of file LoadBalancer.php.

References $params, and as.

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

◆ forEachOpenMasterConnection()

◆ 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 2022 of file LoadBalancer.php.

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

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

◆ getAnyOpenConnection()

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

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

Use CONN_TRX_AUTOCOMMIT to only look for connections opened with that flag. Avoid the use of transaction methods like IDatabase::begin() or IDatabase::startAtomic() on any such connections.

Parameters
int$iServer index or DB_MASTER/DB_REPLICA
int$flagsBitfield of CONN_* class constants
Returns
Database|bool False if no such connection is open

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 706 of file LoadBalancer.php.

References as, DB_MASTER, DB_REPLICA, 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.

Calling functions that use $domain must call reuseConnection() once the last query of the function is executed. This lets the load balancer share this 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$iServer index (overrides $groups) or DB_MASTER/DB_REPLICA
string[]|string$groups Query group(s) in preference order; [] for the default group
string | bool$domainDB domain ID or false for the local domain
int$flagsBitfield 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
DBErrorIf no live handle can be obtained and CONN_SILENCE_ERRORS is not set
DBAccessErrorIf disable() was previously called
InvalidArgumentException

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 862 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$iSpecific server index or DB_MASTER/DB_REPLICA
string[]$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 437 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$lastError, as, DB_MASTER, DB_REPLICA, Wikimedia\Rdbms\LoadBalancer\getReaderIndex(), Wikimedia\Rdbms\LoadBalancer\getWriterIndex(), null, Wikimedia\Rdbms\LoadBalancer\reportConnectionError(), and servers.

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$iServer index or DB_MASTER/DB_REPLICA
string[]|string$groups Query group(s) in preference order; [] for the default group
string | bool$domainDB domain ID or false for the local domain
int$flagsBitfield of CONN_* class constants (e.g. CONN_TRX_AUTOCOMMIT)
Returns
DBConnRef

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1004 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 2038 of file LoadBalancer.php.

References as.

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$groupQuery group; use false for the generic group
Returns
int Server index or -1 if none was chosen

Definition at line 522 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$iServer index
string$domainDomain ID to open
int$flagsClass CONN_* constant bitfield
Returns
Database|bool Returns false on connection error
Exceptions
DBErrorWhen database selection fails
InvalidArgumentExceptionWhen the server index is invalid
UnexpectedValueExceptionWhen the DB domain of the connection is corrupted

Definition at line 1125 of file LoadBalancer.php.

References as, Wikimedia\Rdbms\LoadBalancer\getServerInfoStrict(), Wikimedia\Rdbms\DatabaseDomain\newFromId(), null, and Wikimedia\Rdbms\LoadBalancer\reallyOpenConnection().

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

◆ getLaggedReplicaMode()

Wikimedia\Rdbms\LoadBalancer::getLaggedReplicaMode (   $domain = false)
Note
This method will trigger a DB connection if not yet done
Parameters
string | bool$domainDB 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 1903 of file LoadBalancer.php.

References $e, 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 2068 of file LoadBalancer.php.

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

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

◆ getLazyConnectionRef()

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

Get a database 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$iServer index or DB_MASTER/DB_REPLICA
string[]|string$groups Query group(s) in preference order; [] for the default group
string | bool$domainDB domain ID or false for the local domain
int$flagsBitfield of CONN_* class constants (e.g. CONN_TRX_AUTOCOMMIT)
Returns
DBConnRef

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1011 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

◆ 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$iServer index
int$flagsClass CONN_* constant bitfield
Returns
Database
Exceptions
InvalidArgumentExceptionWhen the server index is invalid
UnexpectedValueExceptionWhen the DB domain of the connection is corrupted

Definition at line 1061 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\getServerInfoStrict(), Wikimedia\Rdbms\LoadBalancer\getServerName(), 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 258 of file LoadBalancer.php.

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

◆ 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$iServer index or DB_MASTER/DB_REPLICA
string[]|string$groups Query group(s) in preference order; [] for the default group
string | bool$domainDB domain ID or false for the local domain
int$flagsBitfield of CONN_* class constants (e.g. CONN_TRX_AUTOCOMMIT)
Returns
MaintainableDBConnRef

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1018 of file LoadBalancer.php.

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

◆ getMasterPos()

Wikimedia\Rdbms\LoadBalancer::getMasterPos ( )

◆ 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$domainDomain ID or false for the default database
Returns
array ( host, max lag, index of max lagged host )

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 2049 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$maxLag, as, 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$domainDomain to get non-lagged for
int$maxLagRestrict the maximum allowed lag to this many seconds
Returns
bool|int|string

Definition at line 380 of file LoadBalancer.php.

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

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$groupQuery group or false for the generic group
string | bool$domainDB domain ID or false for the local domain
Exceptions
DBErrorIf no live handle can be obtained
Returns
bool|int|string

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 462 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\doWait(), Wikimedia\Rdbms\LoadBalancer\getExistingReaderIndex(), Wikimedia\Rdbms\LoadBalancer\getLoadMonitor(), Wikimedia\Rdbms\LoadBalancer\getServerCount(), Wikimedia\Rdbms\LoadBalancer\getServerName(), Wikimedia\Rdbms\LoadBalancer\getWriterIndex(), Wikimedia\Rdbms\LoadBalancer\lazyLoadReplicationPositions(), list, Wikimedia\Rdbms\LoadBalancer\pickReaderIndex(), and Wikimedia\Rdbms\LoadBalancer\setExistingReaderIndex().

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

◆ getReadOnlyReason()

Wikimedia\Rdbms\LoadBalancer::getReadOnlyReason (   $domain = false,
IDatabase  $conn = null 
)
Note
This method may trigger a DB connection if not yet done
Parameters
string | bool$domainDB domain ID or false for the local domain
IDatabase | null$connDB master connection; used to avoid loops [optional]
Returns
string|bool Reason the master is read-only or false if it is not

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1934 of file LoadBalancer.php.

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

◆ 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 1450 of file LoadBalancer.php.

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

◆ getRoleFromIndex()

Wikimedia\Rdbms\LoadBalancer::getRoleFromIndex (   $i)
private
Parameters
int$iServer index or DB_MASTER/DB_REPLICA
Returns
int One of DB_MASTER/DB_REPLICA

Definition at line 1030 of file LoadBalancer.php.

References 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 (   $i)
Parameters
int$iServer index
Returns
array (Database::ATTRIBUTE_* constant => value) for all such constants
Since
1.31

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1215 of file LoadBalancer.php.

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

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

◆ getServerConnection()

◆ getServerCount()

Wikimedia\Rdbms\LoadBalancer::getServerCount ( )

◆ 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 1419 of file LoadBalancer.php.

References servers.

◆ getServerInfoStrict()

Wikimedia\Rdbms\LoadBalancer::getServerInfoStrict (   $i,
  $field = null 
)
private
Parameters
int$iServer index
string | null$fieldServer index field [optional]
Returns
array|mixed
Exceptions
InvalidArgumentException

Definition at line 2273 of file LoadBalancer.php.

References null, and servers.

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

◆ getServerName()

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

◆ 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 1423 of file LoadBalancer.php.

References servers.

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

◆ getTransactionRoundStage()

Wikimedia\Rdbms\LoadBalancer::getTransactionRoundStage ( )
Returns
string
Since
1.32

Definition at line 1861 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$trxRoundStage.

◆ getWriterIndex()

◆ 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 1869 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\forEachOpenMasterConnection(), use, 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 1865 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$ageHow many seconds ago is "recent" [defaults to mWaitTimeout]
Returns
bool

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1887 of file LoadBalancer.php.

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

◆ 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 1399 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 1403 of file LoadBalancer.php.

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

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 1380 of file LoadBalancer.php.

References servers.

◆ isNonZeroLoad()

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

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

Parameters
int$i
Returns
bool
Deprecated:
Since 1.34

Definition at line 1391 of file LoadBalancer.php.

References servers.

◆ isOpen()

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

Test if the specified index represents an open connection.

Parameters
int$indexServer index
Returns
bool

Definition at line 1228 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 1921 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$laggedReplicaMode.

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

◆ laggedSlaveUsed()

Wikimedia\Rdbms\LoadBalancer::laggedSlaveUsed ( )
Returns
bool
Since
1.27
Deprecated:
Since 1.28; use laggedReplicaUsed()

Definition at line 1930 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\laggedReplicaUsed().

◆ lastMasterChangeTimestamp()

Wikimedia\Rdbms\LoadBalancer::lastMasterChangeTimestamp ( )

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

Returns
float|bool UNIX timestamp or false

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1878 of file LoadBalancer.php.

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

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 1330 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\$chronologyCallback.

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

◆ masterRunningReadOnly()

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

◆ newTrackedConnectionsArray()

static Wikimedia\Rdbms\LoadBalancer::newTrackedConnectionsArray ( )
staticprivate

Definition at line 245 of file LoadBalancer.php.

◆ 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 1043 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 1894 of file LoadBalancer.php.

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

◆ pickAnyOpenConnection()

Wikimedia\Rdbms\LoadBalancer::pickAnyOpenConnection (   $candidateConns,
  $autocommit 
)
private
Parameters
IDatabase[]$candidateConns
bool$autocommitWhether to only look for auto-commit connections
Returns
IDatabase|false An appropriate open connection or false if none found

Definition at line 741 of file LoadBalancer.php.

References as.

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

◆ pickReaderIndex()

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

◆ pingAll()

Wikimedia\Rdbms\LoadBalancer::pingAll ( )

◆ reallyOpenConnection()

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

◆ 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 2246 of file LoadBalancer.php.

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

◆ reportConnectionError()

◆ resolveDomainID()

Wikimedia\Rdbms\LoadBalancer::resolveDomainID (   $domain)
Parameters
DatabaseDomain | string | bool$domainDatabase 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 262 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\getLocalDomainID().

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

◆ 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$groups Query group(s) in preference order, [], or false
int$iSpecific server index or DB_MASTER/DB_REPLICA
Returns
string[] Non-empty group list in preference order with the default group appended

Definition at line 278 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 944 of file LoadBalancer.php.

References Wikimedia\Rdbms\IDatabase\getDomainID(), Wikimedia\Rdbms\IDatabase\getLBInfo(), null, and Wikimedia\Rdbms\IDatabase\setLBInfo().

Referenced by Wikimedia\Rdbms\LoadBalancer\masterRunningReadOnly(), 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$fnameCaller name
int | null$ownerID of the calling instance (e.g. the LBFactory ID)
Exceptions
DBExpectedError

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 1750 of file LoadBalancer.php.

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

◆ runMasterTransactionIdleCallbacks()

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

◆ runMasterTransactionListenerCallbacks()

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

Run all recurring post-COMMIT/ROLLBACK listener callbacks.

Parameters
string$fnameCaller name
int | null$ownerID 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 1722 of file LoadBalancer.php.

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

◆ 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 2101 of file LoadBalancer.php.

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

◆ 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$connReplica DB
DBMasterPos | bool$posMaster position; default: current position
int$timeoutTimeout in seconds [optional]
Returns
bool Success
Since
1.28
Deprecated:
Since 1.34 Use waitForMasterPos() instead

Definition at line 2181 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\waitForMasterPos().

◆ sanitizeConnectionFlags()

Wikimedia\Rdbms\LoadBalancer::sanitizeConnectionFlags (   $flags,
  $i 
)
private
Parameters
int$flagsBitfield of class CONN_* constants
int$iSpecific server index or DB_MASTER/DB_REPLICA
Returns
int Sanitized bitfield

Definition at line 303 of file LoadBalancer.php.

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

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

◆ setDomainPrefix()

Wikimedia\Rdbms\LoadBalancer::setDomainPrefix (   $prefix)
Parameters
string$prefix
Deprecated:
Since 1.33

Definition at line 2210 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\setLocalDomainPrefix().

◆ 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$groupQuery group; use false for the generic group
int$indexThe index of a specific server

Definition at line 532 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 2202 of file LoadBalancer.php.

◆ setLocalDomain()

◆ setLocalDomainPrefix()

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

◆ 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 2198 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$nameCallback name
callable | null$callback

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 2185 of file LoadBalancer.php.

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

◆ setWaitForPositionIfHigher()

Wikimedia\Rdbms\LoadBalancer::setWaitForPositionIfHigher (   $pos)
private
Parameters
DBMasterPos | bool$pos

Definition at line 696 of file LoadBalancer.php.

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

◆ undoTransactionRoundFlags()

◆ 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$posMaster position or false

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 623 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$posMaster position or false
int | null$timeoutMax seconds to wait; default is mWaitTimeout
Returns
bool Success (able to connect and no timeouts reached)

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 666 of file LoadBalancer.php.

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

◆ 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$connReplica DB
DBMasterPos | bool$posMaster position; default: current position
int$timeoutTimeout in seconds [optional]
Returns
bool Success
Since
1.34

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 2111 of file LoadBalancer.php.

References Wikimedia\Rdbms\LoadBalancer\closeConnection(), Wikimedia\Rdbms\LoadBalancer\getAnyOpenConnection(), Wikimedia\Rdbms\IDatabase\getLBInfo(), Wikimedia\Rdbms\IDatabase\getServer(), Wikimedia\Rdbms\LoadBalancer\getServerConnection(), Wikimedia\Rdbms\LoadBalancer\getServerCount(), Wikimedia\Rdbms\LoadBalancer\getWriterIndex(), Wikimedia\Rdbms\IDatabase\masterPosWait(), and null.

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$posMaster position or false
int | null$timeoutMax seconds to wait; default is mWaitTimeout
Returns
bool Success (able to connect and no timeouts reached)

Implements Wikimedia\Rdbms\ILoadBalancer.

Definition at line 639 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 96 of file LoadBalancer.php.

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

◆ $allowLagged

bool Wikimedia\Rdbms\LoadBalancer::$allowLagged
private

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

Definition at line 79 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 94 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 122 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 118 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 58 of file LoadBalancer.php.

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

◆ $conns

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

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

Definition at line 72 of file LoadBalancer.php.

◆ $defaultGroup

string null Wikimedia\Rdbms\LoadBalancer::$defaultGroup
private

Default query group to use with getConnection()

Definition at line 89 of file LoadBalancer.php.

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

◆ $deprecationLogger

callable Wikimedia\Rdbms\LoadBalancer::$deprecationLogger
private

Deprecation logger.

Definition at line 66 of file LoadBalancer.php.

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

◆ $disabled

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

Definition at line 120 of file LoadBalancer.php.

◆ $errorConnection

Database Wikimedia\Rdbms\LoadBalancer::$errorConnection
private

Connection handle that caused a problem.

Definition at line 106 of file LoadBalancer.php.

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

◆ $errorLogger

callable Wikimedia\Rdbms\LoadBalancer::$errorLogger
private

◆ $groupLoads

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

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

Definition at line 77 of file LoadBalancer.php.

◆ $hostname

string Wikimedia\Rdbms\LoadBalancer::$hostname
private

Current server name.

Definition at line 92 of file LoadBalancer.php.

◆ $indexAliases

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

Map of (index alias => index)

Definition at line 101 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 112 of file LoadBalancer.php.

Referenced by Wikimedia\Rdbms\LoadBalancer\getLaggedReplicaMode(), 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 114 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 83 of file LoadBalancer.php.

◆ $localDomain

DatabaseDomain Wikimedia\Rdbms\LoadBalancer::$localDomain
private

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

Definition at line 69 of file LoadBalancer.php.

◆ $localDomainIdAlias

string Wikimedia\Rdbms\LoadBalancer::$localDomainIdAlias
private

Alternate local DB domain instead of DatabaseDomain::getId()

Definition at line 85 of file LoadBalancer.php.

◆ $maxLag

int Wikimedia\Rdbms\LoadBalancer::$maxLag
private

Amount of replication lag, in seconds, that is considered "high".

Definition at line 87 of file LoadBalancer.php.

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

◆ $ownerId

int null Wikimedia\Rdbms\LoadBalancer::$ownerId
private

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

Definition at line 125 of file LoadBalancer.php.

◆ $perfLogger

LoggerInterface Wikimedia\Rdbms\LoadBalancer::$perfLogger
private

Definition at line 62 of file LoadBalancer.php.

◆ $profiler

mixed Wikimedia\Rdbms\LoadBalancer::$profiler
private

Class name or object With profileIn/profileOut methods.

Definition at line 52 of file LoadBalancer.php.

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

◆ $queryLogger

LoggerInterface Wikimedia\Rdbms\LoadBalancer::$queryLogger
private

Definition at line 60 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 108 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 116 of file LoadBalancer.php.

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

◆ $replLogger

LoggerInterface Wikimedia\Rdbms\LoadBalancer::$replLogger
private

Definition at line 56 of file LoadBalancer.php.

◆ $servers

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

Map of (server index => server config array)

Definition at line 75 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

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

Definition at line 99 of file LoadBalancer.php.

◆ $trxProfiler

TransactionProfiler Wikimedia\Rdbms\LoadBalancer::$trxProfiler
private

Definition at line 54 of file LoadBalancer.php.

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

◆ $trxRecurringCallbacks

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

Map of (name => callable)

Definition at line 103 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 127 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 129 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 110 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 81 of file LoadBalancer.php.

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

◆ $wanCache

WANObjectCache Wikimedia\Rdbms\LoadBalancer::$wanCache
private

Definition at line 50 of file LoadBalancer.php.

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

◆ KEY_FOREIGN_FREE

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

Definition at line 142 of file LoadBalancer.php.

◆ KEY_FOREIGN_FREE_NOROUND

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

Definition at line 146 of file LoadBalancer.php.

◆ KEY_FOREIGN_INUSE

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

Definition at line 143 of file LoadBalancer.php.

◆ KEY_FOREIGN_INUSE_NOROUND

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

Definition at line 147 of file LoadBalancer.php.

◆ KEY_LOCAL

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

Definition at line 141 of file LoadBalancer.php.

◆ KEY_LOCAL_NOROUND

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

Definition at line 145 of file LoadBalancer.php.


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