MediaWiki  1.33.0
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1 <?php
22 namespace Wikimedia\Rdbms;
35  private $warmCacheRatio;
37  public function __construct(
39  ) {
40  parent::__construct( $lb, $srvCache, $wCache, $options );
42  $this->warmCacheRatio = $options['warmCacheRatio'] ?? 0.0;
43  }
45  protected function getWeightScale( $index, IDatabase $conn = null ) {
46  if ( !$conn ) {
47  return parent::getWeightScale( $index, $conn );
48  }
50  $weight = 1.0;
51  if ( $this->warmCacheRatio > 0 ) {
52  $res = $conn->query( 'SHOW STATUS', __METHOD__ );
53  $s = $res ? $conn->fetchObject( $res ) : false;
54  if ( $s === false ) {
55  $host = $this->parent->getServerName( $index );
56  $this->replLogger->error( __METHOD__ . ": could not get status for $host" );
57  } else {
58  //
59  if ( $s->Innodb_buffer_pool_pages_total > 0 ) {
60  $ratio = $s->Innodb_buffer_pool_pages_data / $s->Innodb_buffer_pool_pages_total;
61  } else {
62  $ratio = 1.0;
63  }
64  // Stop caring once $ratio >= $this->warmCacheRatio
65  $weight *= min( $ratio / $this->warmCacheRatio, 1.0 );
66  }
67  }
69  return $weight;
70  }
71 }
Basic DB load monitor with no external dependencies Uses memcached to cache the replication lag for a...
Definition: LoadMonitor.php:36
BagOStuff $srvCache
Definition: LoadMonitor.php:40
getWeightScale( $index, IDatabase $conn=null)
Definition: LoadMonitorMySQL.php:45
Definition: ChronologyProtector.php:24
Class representing a cache/ephemeral data store.
Definition: BagOStuff.php:58
Definition: mergeMessageFileList.php:186
Definition: database.txt:21
injection txt This is an overview of how MediaWiki makes use of dependency injection The design described here grew from the discussion of RFC T384 The term dependency this means that anything an object needs to operate should be injected from the the object itself should only know narrow no concrete implementation of the logic it relies on The requirement to inject everything typically results in an architecture that based on two main types of and essentially stateless service objects that use other service objects to operate on the value objects As of the beginning MediaWiki is only starting to use the DI approach Much of the code still relies on global state or direct resulting in a highly cyclical dependency which acts as the top level factory for services in MediaWiki which can be used to gain access to default instances of various services MediaWikiServices however also allows new services to be defined and default services to be redefined Services are defined or redefined by providing a callback the instantiator that will return a new instance of the service When it will create an instance of MediaWikiServices and populate it with the services defined in the files listed by thereby bootstrapping the DI framework Per $wgServiceWiringFiles lists includes ServiceWiring php
Definition: injection.txt:35
Basic database interface for live and lazy-loaded relation database handles.
Definition: IDatabase.php:38
as see the revision history and available at free of to any person obtaining a copy of this software and associated documentation to deal in the Software without including without limitation the rights to use
Definition: MIT-LICENSE.txt:10
The wiki should then use memcached to cache various data To use multiple just add more items to the array To increase the weight of a make its entry a array("", 2))
Basic MySQL load monitor with no external dependencies Uses memcached to cache the replication lag fo...
Definition: LoadMonitorMySQL.php:33
Multi-datacenter aware caching interface.
Definition: WANObjectCache.php:116
null means default in associative array with keys and values unescaped Should be merged with default with a value of false meaning to suppress the attribute in associative array with keys and values unescaped & $options
Definition: hooks.txt:1985
float $warmCacheRatio
What buffer pool use ratio counts as "warm" (e.g.
Definition: LoadMonitorMySQL.php:35
__construct(ILoadBalancer $lb, BagOStuff $srvCache, WANObjectCache $wCache, array $options=[])
Definition: LoadMonitorMySQL.php:37
Database cluster connection, tracking, load balancing, and transaction manager interface.
Definition: ILoadBalancer.php:78