Basic MySQL load monitor with no external dependencies Uses memcached to cache the replication lag for a short time. More...

Inheritance diagram for Wikimedia\Rdbms\LoadMonitorMySQL:

[legend]

Collaboration diagram for Wikimedia\Rdbms\LoadMonitorMySQL:

[legend]

Public Member Functions
	__construct (ILoadBalancer $lb, BagOStuff $srvCache, WANObjectCache $wCache, array $options=[])

Public Member Functions inherited from Wikimedia\Rdbms\LoadMonitor
	getLagTimes (array $serverIndexes, $domain)
	Get an estimate of replication lag (in seconds) for each server.

	scaleLoads (array &$weightByServer, $domain)
	Perform load ratio adjustment before deciding which server to use.

	setLogger (LoggerInterface $logger)

	setMockTime (&$time)

Protected Member Functions
	getWeightScale ( $index, IDatabase $conn=null)

Protected Member Functions inherited from Wikimedia\Rdbms\LoadMonitor
	computeServerStates (array $serverIndexes, $domain, $priorStates)

	getCurrentTime ()

	getNewScaleViaMovingAve ( $lastScale, $naiveScale, $movAveRatio)
	Get the moving average weight scale given a naive and the last iteration value.

	getServerStates (array $serverIndexes, $domain)

Private Attributes
float	$warmCacheRatio
	What buffer pool use ratio counts as "warm" (e.g.

Additional Inherited Members
Protected Attributes inherited from Wikimedia\Rdbms\LoadMonitor
ILoadBalancer	$lb

LoggerInterface	$replLogger

BagOStuff	$srvCache

WANObjectCache	$wanCache

Detailed Description

Basic MySQL load monitor with no external dependencies Uses memcached to cache the replication lag for a short time.

Definition at line 33 of file LoadMonitorMySQL.php.

Constructor & Destructor Documentation

◆ __construct()

Wikimedia\Rdbms\LoadMonitorMySQL::__construct	(	ILoadBalancer	$lb,
		BagOStuff	$srvCache,
		WANObjectCache	$wCache,
		array	$options = [] )

Parameters

ILoadBalancer	$lb
BagOStuff	$srvCache
WANObjectCache	$wCache
array	$options	movingAveRatio: moving average constant for server weight updates based on lag lagWarnThreshold: how many seconds of lag trigger warnings

Reimplemented from Wikimedia\Rdbms\LoadMonitor.

Definition at line 37 of file LoadMonitorMySQL.php.

References Wikimedia\Rdbms\LoadMonitor\$lb, and Wikimedia\Rdbms\LoadMonitor\$srvCache.

Member Function Documentation

◆ getWeightScale()

Wikimedia\Rdbms\LoadMonitorMySQL::getWeightScale	(		$index,
		IDatabase	$conn = null )

protected

Parameters

int	$index	Server index
IDatabase \| null	$conn	Connection handle or null on connection failure

Returns: float

Since: 1.28

Reimplemented from Wikimedia\Rdbms\LoadMonitor.

Definition at line 45 of file LoadMonitorMySQL.php.

References $res, and $s.

Member Data Documentation

◆ $warmCacheRatio

float Wikimedia\Rdbms\LoadMonitorMySQL::$warmCacheRatio

private

What buffer pool use ratio counts as "warm" (e.g.

0.5 for 50% usage)

Definition at line 35 of file LoadMonitorMySQL.php.

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

includes/libs/rdbms/loadmonitor/LoadMonitorMySQL.php

Public Member Functions

Protected Member Functions

Private Attributes