From: jenkins-bot <jenkins-bot@gerrit.wikimedia.org>
Date: Thu, 8 Jan 2015 19:49:53 +0000 (+0000)
Subject: Merge "Log to DBPerformance log when many LB connections are acquired"
X-Git-Tag: 1.31.0-rc.0~12749
X-Git-Url: http://git.cyclocoop.org/%22%20.%20generer_url_ecrire%28%22auteur_infos%22%2C%22id_auteur=%24connect_id_auteur%22%29%20.%20%22?a=commitdiff_plain;h=972eadb6565e072f01c0b3f73b843d32e1b0a91f;hp=534a0f99ba2ff4c1e1585a415bbc3a9960ed067b;p=lhc%2Fweb%2Fwiklou.git

Merge "Log to DBPerformance log when many LB connections are acquired"
---

diff --git a/includes/db/LoadBalancer.php b/includes/db/LoadBalancer.php
index 8618ae6ab4..4c9fd3240c 100644
--- a/includes/db/LoadBalancer.php
+++ b/includes/db/LoadBalancer.php
@@ -58,9 +58,14 @@ class LoadBalancer {
 	private $mLaggedSlaveMode;
 	/** @var string The last DB selection or connection error */
 	private $mLastError = 'Unknown error';
+	/** @var integer Total connections opened */
+	private $connsOpened = 0;
 	/** @var ProcessCacheLRU */
 	private $mProcCache;
 
+	/** @var integer Warn when this many connection are held */
+	const CONN_HELD_WARN_THRESHOLD = 10;
+
 	/**
 	 * @param array $params Array with keys:
 	 *   servers           Required. Array of server info structures.
@@ -734,6 +739,14 @@ class LoadBalancer {
 			$server['dbname'] = $dbNameOverride;
 		}
 
+		// Log when many connection are made on requests
+		if ( ++$this->connsOpened >= self::CONN_HELD_WARN_THRESHOLD ) {
+			$masterAddr = $this->getServerName( 0 );
+			wfDebugLog( 'DBPerformance', __METHOD__ . ": " .
+				"{$this->connsOpened}+ connections made (master=$masterAddr)\n" .
+				wfBacktrace( true ) );
+		}
+
 		# Create object
 		try {
 			$db = DatabaseBase::factory( $server['type'], $server );
@@ -905,6 +918,7 @@ class LoadBalancer {
 			'foreignFree' => array(),
 			'foreignUsed' => array(),
 		);
+		$this->connsOpened = 0;
 	}
 
 	/**
@@ -921,6 +935,7 @@ class LoadBalancer {
 					if ( $conn === $candidateConn ) {
 						$conn->close();
 						unset( $this->mConns[$i1][$i2][$i3] );
+						--$this->connsOpened;
 						$done = true;
 						break;
 					}