X-Git-Url: https://scripts.mit.edu/gitweb/autoinstallsdev/mediawiki.git/blobdiff_plain/19e297c21b10b1b8a3acad5e73fc71dcb35db44a..6932310fd58ebef145fa01eb76edf7150284d8ea:/includes/db/LoadMonitor.php

diff --git a/includes/db/LoadMonitor.php b/includes/db/LoadMonitor.php
deleted file mode 100644
index 9b959728..00000000
--- 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;
-		}
-	}
-}
-