MediaWiki 1.30.2

[autoinstallsdev/mediawiki.git] / includes / db / LoadMonitor.php

diff --git a/includes/db/LoadMonitor.php b/includes/db/LoadMonitor.php
deleted file mode 100644 (file)
index 9b95972..0000000
--- a/includes/db/LoadMonitor.php
+++ /dev/null
@@ -1,132 +0,0 @@
-<?php
-/**
- * Database load monitoring
- *
- * @file
- * @ingroup Database
- */
-
-/**
- * An interface for database load monitoring
- *
- * @ingroup Database
- */
-interface LoadMonitor {
-       /**
-        * Construct a new LoadMonitor with a given LoadBalancer parent
-        */
-       function __construct( $parent );
-       
-       /**
-        * Perform pre-connection load ratio adjustment.
-        * @param $loads Array
-        * @param $group String: the selected query group
-        * @param $wiki String
-        */
-       function scaleLoads( &$loads, $group = false, $wiki = false );
-
-       /**
-        * Perform post-connection backoff.
-        *
-        * If the connection is in overload, this should return a backoff factor 
-        * which will be used to control polling time. The number of threads 
-        * connected is a good measure.
-        *
-        * If there is no overload, zero can be returned.
-        *
-        * A threshold thread count is given, the concrete class may compare this 
-        * to the running thread count. The threshold may be false, which indicates
-        * that the sysadmin has not configured this feature.
-        *
-        * @param $conn DatabaseBase
-        * @param $threshold Float
-        */
-       function postConnectionBackoff( $conn, $threshold );
-
-       /**
-        * Return an estimate of replication lag for each server
-        */
-       function getLagTimes( $serverIndexes, $wiki );
-}
-
-
-/**
- * Basic MySQL load monitor with no external dependencies
- * Uses memcached to cache the replication lag for a short time
- *
- * @ingroup Database
- */
-class LoadMonitor_MySQL implements LoadMonitor {
-       var $parent; // LoadBalancer
-
-       function __construct( $parent ) {
-               $this->parent = $parent;
-       }
-
-       function scaleLoads( &$loads, $group = false, $wiki = false ) {
-       }
-
-       function getLagTimes( $serverIndexes, $wiki ) {
-               wfProfileIn( __METHOD__ );
-               $expiry = 5;
-               $requestRate = 10;
-
-               global $wgMemc;
-               if ( empty( $wgMemc ) )
-                       $wgMemc = wfGetMainCache();
-               
-               $masterName = $this->parent->getServerName( 0 );
-               $memcKey = wfMemcKey( 'lag_times', $masterName );
-               $times = $wgMemc->get( $memcKey );
-               if ( $times ) {
-                       # Randomly recache with probability rising over $expiry
-                       $elapsed = time() - $times['timestamp'];
-                       $chance = max( 0, ( $expiry - $elapsed ) * $requestRate );
-                       if ( mt_rand( 0, $chance ) != 0 ) {
-                               unset( $times['timestamp'] );
-                               wfProfileOut( __METHOD__ );
-                               return $times;
-                       }
-                       wfIncrStats( 'lag_cache_miss_expired' );
-               } else {
-                       wfIncrStats( 'lag_cache_miss_absent' );
-               }
-
-               # Cache key missing or expired
-
-               $times = array();
-               foreach ( $serverIndexes as $i ) {
-                       if ($i == 0) { # Master
-                               $times[$i] = 0;
-                       } elseif ( false !== ( $conn = $this->parent->getAnyOpenConnection( $i ) ) ) {
-                               $times[$i] = $conn->getLag();
-                       } elseif ( false !== ( $conn = $this->parent->openConnection( $i, $wiki ) ) ) {
-                               $times[$i] = $conn->getLag();
-                       }
-               }
-
-               # Add a timestamp key so we know when it was cached
-               $times['timestamp'] = time();
-               $wgMemc->set( $memcKey, $times, $expiry );
-
-               # But don't give the timestamp to the caller
-               unset($times['timestamp']);
-               $lagTimes = $times;
-
-               wfProfileOut( __METHOD__ );
-               return $lagTimes;
-       }
-
-       function postConnectionBackoff( $conn, $threshold ) {
-               if ( !$threshold ) {
-                       return 0;
-               }
-               $status = $conn->getStatus("Thread%");
-               if ( $status['Threads_running'] > $threshold ) {
-                       return $status['Threads_connected'];
-               } else {
-                       return 0;
-               }
-       }
-}
-