MediaWiki  REL1_31
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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 = isset( $options['warmCacheRatio'] )
43  ? $options['warmCacheRatio']
44  : 0.0;
45  }
47  protected function getWeightScale( $index, IDatabase $conn = null ) {
48  if ( !$conn ) {
49  return parent::getWeightScale( $index, $conn );
50  }
52  $weight = 1.0;
53  if ( $this->warmCacheRatio > 0 ) {
54  $res = $conn->query( 'SHOW STATUS', __METHOD__ );
55  $s = $res ? $conn->fetchObject( $res ) : false;
56  if ( $s === false ) {
57  $host = $this->parent->getServerName( $index );
58  $this->replLogger->error( __METHOD__ . ": could not get status for $host" );
59  } else {
60  //
61  if ( $s->Innodb_buffer_pool_pages_total > 0 ) {
62  $ratio = $s->Innodb_buffer_pool_pages_data / $s->Innodb_buffer_pool_pages_total;
63  } else {
64  $ratio = 1.0;
65  }
66  // Stop caring once $ratio >= $this->warmCacheRatio
67  $weight *= min( $ratio / $this->warmCacheRatio, 1.0 );
68  }
69  }
71  return $weight;
72  }
73 }
Basic DB load monitor with no external dependencies Uses memcached to cache the replication lag for a...
Definition: LoadMonitor.php:36
Apache License January AND DISTRIBUTION Definitions License shall mean the terms and conditions for use
Definition: APACHE-LICENSE-2.0.txt:10
BagOStuff $srvCache
Definition: LoadMonitor.php:40
the array() calling protocol came about after MediaWiki 1.4rc1.
getWeightScale( $index, IDatabase $conn=null)
Definition: LoadMonitorMySQL.php:47
Definition: ChronologyProtector.php:24
interface is intended to be more or less compatible with the PHP memcached client.
Definition: BagOStuff.php:47
Definition: mergeMessageFileList.php:187
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:37
Basic database interface for live and lazy-loaded relation database handles.
Definition: IDatabase.php:38
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:2001
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:87
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