A multi-database, multi-master factory for Wikimedia and similar installations. More...

Inheritance diagram for Wikimedia\Rdbms\LBFactoryMulti:

Collaboration diagram for Wikimedia\Rdbms\LBFactoryMulti:

[legend]

Public Member Functions
	__construct (array $conf)

	forEachLB ( $callback, array $params=[])
	Execute a function for each tracked load balancer The callback is called with the load balancer as the first parameter, and $params passed as the subsequent parameters. More...

	getAllExternalLBs ()
	Get cached (tracked) load balancers for all external database clusters. More...

	getAllMainLBs ()
	Get cached (tracked) load balancers for all main database clusters. More...

	getExternalLB ( $cluster)
	Get a cached (tracked) load balancer for external storage. More...

	getMainLB ( $domain=false)
	Get a cached (tracked) load balancer object. More...

	newExternalLB ( $cluster)
	Create a new load balancer for external storage. More...

	newMainLB ( $domain=false)
	Create a new load balancer object. More...

Public Member Functions inherited from Wikimedia\Rdbms\LBFactory
	__construct (array $conf)
	Construct a manager of ILoadBalancer objects. More...

	__destruct ()

	appendShutdownCPIndexAsQuery ( $url, $index)
	Append ?cpPosIndex parameter to a URL for ChronologyProtector purposes if needed. More...

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

	closeAll ()
	Close all open database connections on all open load balancers. More...

	commitAll ( $fname=__METHOD__, array $options=[])
	Commit open transactions on all connections. More...

	commitAndWaitForReplication ( $fname, $ticket, array $opts=[])
	Convenience method for safely running commitMasterChanges()/waitForReplication() More...

	commitMasterChanges ( $fname=__METHOD__, array $options=[])
	Commit changes and clear view snapshots on all master connections. More...

	destroy ()
	Disables all load balancers. More...

	disableChronologyProtection ()
	Disable the ChronologyProtector for all load balancers. More...

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

	getChronologyProtectorClientId ()
	Get the client ID of the ChronologyProtector instance. More...

	getChronologyProtectorTouched ( $dbName)

	getEmptyTransactionTicket ( $fname)
	Get a token asserting that no transaction writes are active. More...

	getExternalLB ( $cluster)

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

	getMainLB ( $domain=false)

	hasMasterChanges ()
	Determine if any master connection has pending changes. More...

	hasOrMadeRecentMasterChanges ( $age=null)
	Determine if any master connection has pending/written changes from this request. More...

	hasTransactionRound ()
	Check if an explicit transaction round is active. More...

	isReadyForRoundOperations ()
	Check if transaction rounds can be started, committed, or rolled back right now. More...

	laggedReplicaUsed ()
	Detemine if any lagged replica DB connection was used. More...

	newExternalLB ( $cluster)

	newMainLB ( $domain=false)

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

	resolveDomainID ( $domain)

	rollbackMasterChanges ( $fname=__METHOD__)
	Rollback changes on all master connections. More...

	setAgentName ( $agent)

	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...

	setRequestInfo (array $info)

	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...

	setWaitForReplicationListener ( $name, callable $callback=null)
	Add a callback to be run in every call to waitForReplication() before waiting. More...

	shutdown ( $mode=self::SHUTDOWN_CHRONPROT_SYNC, callable $workCallback=null, &$cpIndex=null, &$cpClientId=null)
	Prepare all tracked load balancers for shutdown. More...

	waitForReplication (array $opts=[])
	Waits for the replica DBs to catch up to the current master position. More...

Private Member Functions
	getDatabaseFromDomain ( $domain=false)

	getSectionForDomain ( $domain=false)

	makeServerArray ( $template, $loads, $groupLoads)
	Make a server array as expected by LoadBalancer::__construct, using a template and load array. More...

	newLoadBalancer ( $template, $loads, $groupLoads, $readOnlyReason)
	Make a new load balancer object based on template and load array. More...

	reindexGroupLoads ( $groupLoads)
	Take a group load array indexed by group then server, and reindex it by server then group. More...

Private Attributes
array	$externalLoads = []
	A map of external storage cluster name to server load map. More...

array	$externalTemplateOverrides
	A set of server info keys overriding serverTemplate for external storage. More...

LoadBalancer []	$extLBs = []

array	$groupLoadsByDB = []
	A 3-d map giving server load ratios by DB name. More...

array	$groupLoadsBySection = []
	A 3-d map giving server load ratios for each section and group. More...

array	$hostsByName = []
	A map of hostname to IP address. More...

string	$lastDomain

string	$lastSection

string	$loadMonitorClass = 'LoadMonitor'

LoadBalancer []	$mainLBs = []

array	$masterTemplateOverrides
	An override array for all master servers. More...

array bool	$readOnlyBySection = []
	A map of section name to read-only message. More...

array	$sectionLoads
	A 2-d map. More...

array	$sectionsByDB
	A map of database names to section names. More...

array []	$serverTemplate
	Server info associative array. More...

array	$templateOverridesByCluster
	A 2-d map overriding the server info by external storage cluster. More...

array	$templateOverridesBySection
	A 2-d map overriding the server info by section. More...

array	$templateOverridesByServer
	A 2-d map overriding serverTemplate and externalTemplateOverrides on a server-by-server basis. More...

Additional Inherited Members
Static Public Member Functions inherited from Wikimedia\Rdbms\LBFactory
static	getCPInfoFromCookieValue ( $value, $minTimestamp)

static	makeCookieValueFromCPIndex ( $index, $time, $clientId)

Public Attributes inherited from Wikimedia\Rdbms\LBFactory
const	ROUND_BEGINNING = 'within-begin'

const	ROUND_COMMIT_CALLBACKS = 'within-commit-callbacks'

const	ROUND_COMMITTING = 'within-commit'

const	ROUND_CURSORY = 'cursory'

const	ROUND_ROLLBACK_CALLBACKS = 'within-rollback-callbacks'

const	ROUND_ROLLING_BACK = 'within-rollback'

Public Attributes inherited from Wikimedia\Rdbms\ILBFactory
const	SHUTDOWN_CHRONPROT_ASYNC = 1

const	SHUTDOWN_CHRONPROT_SYNC = 2

const	SHUTDOWN_NO_CHRONPROT = 0

Protected Member Functions inherited from Wikimedia\Rdbms\LBFactory
	baseLoadBalancerParams ()
	Base parameters to ILoadBalancer::__construct() More...

	forEachLBCallMethod ( $methodName, array $args=[])
	Call a method of each tracked load balancer. More...

	getChronologyProtector ()

	initLoadBalancer (ILoadBalancer $lb)

	shutdownChronologyProtector (ChronologyProtector $cp, $workCallback, $mode, &$cpIndex=null)
	Get and record all of the staged DB positions into persistent memory storage. More...

Protected Attributes inherited from Wikimedia\Rdbms\LBFactory
DatabaseDomain	$localDomain
	Local domain. More...

int null	$maxLag

BagOStuff	$memStash

string bool	$readOnlyReason = false
	Reason all LBs are read-only or false if not. More...

BagOStuff	$srvCache

WANObjectCache	$wanCache

Detailed Description

A multi-database, multi-master factory for Wikimedia and similar installations.

Ignores the old configuration globals.

Definition at line 34 of file LBFactoryMulti.php.

Constructor & Destructor Documentation

◆ __construct()

Wikimedia\Rdbms\LBFactoryMulti::__construct ( array $conf )

See also: LBFactory::__construct()

Template override precedence (highest => lowest):

templateOverridesByServer
masterTemplateOverrides
templateOverridesBySection/templateOverridesByCluster
externalTemplateOverrides
serverTemplate Overrides only work on top level keys (so nested values will not be merged).

Server configuration maps should be of the format Database::factory() requires. Additionally, a 'max lag' key should also be set on server maps, indicating how stale the data can be before the load balancer tries to avoid using it. The map can have 'is static' set to disable blocking replication sync checks (intended for archive servers with unchanging data).

Parameters

array

$conf

Parameters of LBFactory::__construct() as well as:

sectionsByDB Map of database names to section names.
sectionLoads 2-d map. For each section, gives a map of server names to load ratios. For example: [ 'section1' => [ 'db1' => 100, 'db2' => 100 ] ]
serverTemplate Server configuration map intended for Database::factory(). Note that "host", "hostName" and "load" entries will be overridden by "sectionLoads" and "hostsByName".
groupLoadsBySection 3-d map giving server load ratios for each section/group. For example: [ 'section1' => [ 'group1' => [ 'db1' => 100, 'db2' => 100 ] ] ]
groupLoadsByDB 3-d map giving server load ratios by DB name.
hostsByName Map of hostname to IP address.
externalLoads Map of external storage cluster name to server load map.
externalTemplateOverrides Set of server configuration maps overriding "serverTemplate" for external storage.
templateOverridesByServer 2-d map overriding "serverTemplate" and "externalTemplateOverrides" on a server-by-server basis. Applies to both core and external storage.
templateOverridesBySection 2-d map overriding the server configuration maps by section.
templateOverridesByCluster 2-d map overriding the server configuration maps by external storage cluster.
masterTemplateOverrides Server configuration map overrides for all master servers.
loadMonitorClass Name of the LoadMonitor class to always use.
readOnlyBySection A map of section name to read-only message. Missing or false for read/write.

Implements Wikimedia\Rdbms\ILBFactory.

Definition at line 146 of file LBFactoryMulti.php.

References as.

Member Function Documentation

◆ forEachLB()

Wikimedia\Rdbms\LBFactoryMulti::forEachLB	(		$callback,
		array	$params = `[]`
	)

Execute a function for each tracked load balancer The callback is called with the load balancer as the first parameter, and $params passed as the subsequent parameters.

Parameters

callable	$callback
array	$params

Implements Wikimedia\Rdbms\ILBFactory.

Definition at line 366 of file LBFactoryMulti.php.

References $params, and as.

◆ getAllExternalLBs()

Wikimedia\Rdbms\LBFactoryMulti::getAllExternalLBs ( )

Get cached (tracked) load balancers for all external database clusters.

Returns: ILoadBalancer[] Map of (cluster name => ILoadBalancer)

Since: 1.29

Implements Wikimedia\Rdbms\ILBFactory.

Definition at line 263 of file LBFactoryMulti.php.

References as, and Wikimedia\Rdbms\LBFactoryMulti\getExternalLB().

◆ getAllMainLBs()

Wikimedia\Rdbms\LBFactoryMulti::getAllMainLBs ( )

Get cached (tracked) load balancers for all main database clusters.

Returns: ILoadBalancer[] Map of (cluster name => ILoadBalancer)

Since: 1.29

Implements Wikimedia\Rdbms\ILBFactory.

Definition at line 252 of file LBFactoryMulti.php.

References $section, as, and Wikimedia\Rdbms\LBFactoryMulti\getMainLB().

◆ getDatabaseFromDomain()

Wikimedia\Rdbms\LBFactoryMulti::getDatabaseFromDomain ( $domain = false )

private

Parameters

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

Returns: string

Definition at line 360 of file LBFactoryMulti.php.

References Wikimedia\Rdbms\DatabaseDomain\newFromId().

Referenced by Wikimedia\Rdbms\LBFactoryMulti\getSectionForDomain(), and Wikimedia\Rdbms\LBFactoryMulti\newMainLB().

◆ getExternalLB()

Wikimedia\Rdbms\LBFactoryMulti::getExternalLB ( $cluster )

Get a cached (tracked) load balancer for external storage.

Parameters

string $cluster External storage cluster name

Returns: ILoadBalancer

Implements Wikimedia\Rdbms\ILBFactory.

Definition at line 244 of file LBFactoryMulti.php.

References Wikimedia\Rdbms\LBFactoryMulti\newExternalLB().

Referenced by Wikimedia\Rdbms\LBFactoryMulti\getAllExternalLBs().

◆ getMainLB()

Wikimedia\Rdbms\LBFactoryMulti::getMainLB ( $domain = false )

Get a cached (tracked) load balancer object.

Parameters

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

Returns: ILoadBalancer

Implements Wikimedia\Rdbms\ILBFactory.

Definition at line 215 of file LBFactoryMulti.php.

References $section, Wikimedia\Rdbms\LBFactoryMulti\getSectionForDomain(), and Wikimedia\Rdbms\LBFactoryMulti\newMainLB().

Referenced by Wikimedia\Rdbms\LBFactoryMulti\getAllMainLBs().

◆ getSectionForDomain()

Wikimedia\Rdbms\LBFactoryMulti::getSectionForDomain ( $domain = false )

private

Parameters

bool | string $domain

Returns: string

Definition at line 173 of file LBFactoryMulti.php.

References Wikimedia\Rdbms\LBFactoryMulti\$lastSection, $section, and Wikimedia\Rdbms\LBFactoryMulti\getDatabaseFromDomain().

Referenced by Wikimedia\Rdbms\LBFactoryMulti\getMainLB(), and Wikimedia\Rdbms\LBFactoryMulti\newMainLB().

◆ makeServerArray()

Wikimedia\Rdbms\LBFactoryMulti::makeServerArray	(	$template,
		$loads,
		$groupLoads
	)

private

Make a server array as expected by LoadBalancer::__construct, using a template and load array.

Parameters

array	$template
array	$loads
array	$groupLoads

Returns: array

Definition at line 303 of file LBFactoryMulti.php.

References $template, as, DBO_DEFAULT, and Wikimedia\Rdbms\LBFactoryMulti\reindexGroupLoads().

Referenced by Wikimedia\Rdbms\LBFactoryMulti\newLoadBalancer().

◆ newExternalLB()

Wikimedia\Rdbms\LBFactoryMulti::newExternalLB ( $cluster )

Create a new load balancer for external storage.

The resulting object will be untracked, not chronology-protected, and the caller is responsible for cleaning it up.

This method is for only advanced usage and callers should almost always use getExternalLB() instead. This method can be useful when a table is used as a key/value store. In that cases, one might want to query it in autocommit mode (DBO_TRX off) but still use DBO_TRX transaction rounds on other tables.

Parameters

string $cluster External storage cluster name

Returns: ILoadBalancer

Implements Wikimedia\Rdbms\ILBFactory.

Definition at line 224 of file LBFactoryMulti.php.

References Wikimedia\Rdbms\LBFactoryMulti\$serverTemplate, $template, and Wikimedia\Rdbms\LBFactoryMulti\newLoadBalancer().

Referenced by Wikimedia\Rdbms\LBFactoryMulti\getExternalLB().

◆ newLoadBalancer()

Wikimedia\Rdbms\LBFactoryMulti::newLoadBalancer	(	$template,
		$loads,
		$groupLoads,
		$readOnlyReason
	)

private

Make a new load balancer object based on template and load array.

Parameters

array	$template
array	$loads
array	$groupLoads
string \| bool	$readOnlyReason

Returns: LoadBalancer

Definition at line 281 of file LBFactoryMulti.php.

References Wikimedia\Rdbms\LBFactory\$readOnlyReason, $template, Wikimedia\Rdbms\LBFactory\baseLoadBalancerParams(), Wikimedia\Rdbms\LBFactory\initLoadBalancer(), and Wikimedia\Rdbms\LBFactoryMulti\makeServerArray().

Referenced by Wikimedia\Rdbms\LBFactoryMulti\newExternalLB(), and Wikimedia\Rdbms\LBFactoryMulti\newMainLB().

◆ newMainLB()

Wikimedia\Rdbms\LBFactoryMulti::newMainLB ( $domain = false )

Create a new load balancer object.

The resulting object will be untracked, not chronology-protected, and the caller is responsible for cleaning it up.

This method is for only advanced usage and callers should almost always use getMainLB() instead. This method can be useful when a table is used as a key/value store. In that cases, one might want to query it in autocommit mode (DBO_TRX off) but still use DBO_TRX transaction rounds on other tables.

Parameters

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

Returns: ILoadBalancer

Implements Wikimedia\Rdbms\ILBFactory.

Definition at line 186 of file LBFactoryMulti.php.

References Wikimedia\Rdbms\LBFactory\$readOnlyReason, $section, Wikimedia\Rdbms\LBFactoryMulti\$serverTemplate, $template, Wikimedia\Rdbms\LBFactoryMulti\getDatabaseFromDomain(), Wikimedia\Rdbms\LBFactoryMulti\getSectionForDomain(), and Wikimedia\Rdbms\LBFactoryMulti\newLoadBalancer().

Referenced by Wikimedia\Rdbms\LBFactoryMulti\getMainLB().

◆ reindexGroupLoads()

Wikimedia\Rdbms\LBFactoryMulti::reindexGroupLoads ( $groupLoads )

private

Take a group load array indexed by group then server, and reindex it by server then group.

Parameters

array $groupLoads

Returns: array

Definition at line 345 of file LBFactoryMulti.php.

References as.

Referenced by Wikimedia\Rdbms\LBFactoryMulti\makeServerArray().

Member Data Documentation

◆ $externalLoads

array Wikimedia\Rdbms\LBFactoryMulti::$externalLoads = []

private

A map of external storage cluster name to server load map.

Definition at line 55 of file LBFactoryMulti.php.

◆ $externalTemplateOverrides

array Wikimedia\Rdbms\LBFactoryMulti::$externalTemplateOverrides

private

A set of server info keys overriding serverTemplate for external storage.

Definition at line 60 of file LBFactoryMulti.php.

◆ $extLBs

LoadBalancer [] Wikimedia\Rdbms\LBFactoryMulti::$extLBs = []

private

Definition at line 82 of file LBFactoryMulti.php.

◆ $groupLoadsByDB

array Wikimedia\Rdbms\LBFactoryMulti::$groupLoadsByDB = []

private

A 3-d map giving server load ratios by DB name.

Definition at line 51 of file LBFactoryMulti.php.

◆ $groupLoadsBySection

array Wikimedia\Rdbms\LBFactoryMulti::$groupLoadsBySection = []

private

A 3-d map giving server load ratios for each section and group.

Definition at line 49 of file LBFactoryMulti.php.

◆ $hostsByName

array Wikimedia\Rdbms\LBFactoryMulti::$hostsByName = []

private

A map of hostname to IP address.

Definition at line 53 of file LBFactoryMulti.php.

◆ $lastDomain

string Wikimedia\Rdbms\LBFactoryMulti::$lastDomain

private

Definition at line 86 of file LBFactoryMulti.php.

◆ $lastSection

string Wikimedia\Rdbms\LBFactoryMulti::$lastSection

private

Definition at line 88 of file LBFactoryMulti.php.

Referenced by Wikimedia\Rdbms\LBFactoryMulti\getSectionForDomain().

◆ $loadMonitorClass

string Wikimedia\Rdbms\LBFactoryMulti::$loadMonitorClass = 'LoadMonitor'

private

Definition at line 84 of file LBFactoryMulti.php.

◆ $mainLBs

LoadBalancer [] Wikimedia\Rdbms\LBFactoryMulti::$mainLBs = []

private

Definition at line 80 of file LBFactoryMulti.php.

◆ $masterTemplateOverrides

array Wikimedia\Rdbms\LBFactoryMulti::$masterTemplateOverrides

private

An override array for all master servers.

Definition at line 72 of file LBFactoryMulti.php.

◆ $readOnlyBySection

array bool Wikimedia\Rdbms\LBFactoryMulti::$readOnlyBySection = []

private

A map of section name to read-only message.

Missing or false for read/write

Definition at line 77 of file LBFactoryMulti.php.

◆ $sectionLoads

array Wikimedia\Rdbms\LBFactoryMulti::$sectionLoads

private

A 2-d map.

For each section, gives a map of server names to load ratios

Definition at line 41 of file LBFactoryMulti.php.

◆ $sectionsByDB

array Wikimedia\Rdbms\LBFactoryMulti::$sectionsByDB

private

A map of database names to section names.

Definition at line 36 of file LBFactoryMulti.php.

◆ $serverTemplate

array [] Wikimedia\Rdbms\LBFactoryMulti::$serverTemplate

private

Server info associative array.

Note: The host, hostName and load entries will be overridden

Definition at line 46 of file LBFactoryMulti.php.

Referenced by Wikimedia\Rdbms\LBFactoryMulti\newExternalLB(), and Wikimedia\Rdbms\LBFactoryMulti\newMainLB().

◆ $templateOverridesByCluster

array Wikimedia\Rdbms\LBFactoryMulti::$templateOverridesByCluster

private

A 2-d map overriding the server info by external storage cluster.

Definition at line 70 of file LBFactoryMulti.php.

◆ $templateOverridesBySection

array Wikimedia\Rdbms\LBFactoryMulti::$templateOverridesBySection

private

A 2-d map overriding the server info by section.

Definition at line 68 of file LBFactoryMulti.php.

◆ $templateOverridesByServer

array Wikimedia\Rdbms\LBFactoryMulti::$templateOverridesByServer

private

A 2-d map overriding serverTemplate and externalTemplateOverrides on a server-by-server basis.

Applies to both core and external storage

Definition at line 66 of file LBFactoryMulti.php.

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

includes/libs/rdbms/lbfactory/LBFactoryMulti.php

Public Member Functions

Private Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ __construct()

Member Function Documentation

◆ forEachLB()

◆ getAllExternalLBs()

◆ getAllMainLBs()

◆ getDatabaseFromDomain()

◆ getExternalLB()

◆ getMainLB()

◆ getSectionForDomain()

◆ makeServerArray()

◆ newExternalLB()

◆ newLoadBalancer()

◆ newMainLB()

◆ reindexGroupLoads()

Member Data Documentation

◆ $externalLoads

◆ $externalTemplateOverrides

◆ $extLBs

◆ $groupLoadsByDB

◆ $groupLoadsBySection

◆ $hostsByName

◆ $lastDomain

◆ $lastSection

◆ $loadMonitorClass

◆ $mainLBs

◆ $masterTemplateOverrides

◆ $readOnlyBySection

◆ $sectionLoads

◆ $sectionsByDB

◆ $serverTemplate

◆ $templateOverridesByCluster

◆ $templateOverridesBySection

◆ $templateOverridesByServer