From: Aaron Schulz <aschulz@wikimedia.org>
Date: Thu, 17 Aug 2017 19:31:23 +0000 (-0700)
Subject: Make mysql getHeartbeatData() method not count query/RTT in estimate
X-Git-Tag: 1.31.0-rc.0~2369^2
X-Git-Url: http://git.cyclocoop.org/%7B%24www_url%7Dadmin/password.php?a=commitdiff_plain;h=07cd19aeee112edad98832621b3f0b7b1d6f69a5;p=lhc%2Fweb%2Fwiklou.git

Make mysql getHeartbeatData() method not count query/RTT in estimate

Optimize for the common case where lag does not strictly increase
during trip times instead of being pessimistic.

Change-Id: Ibb0e3faad23862d397e1cc2a9f7e2a8293fa5f2b
---

diff --git a/includes/libs/rdbms/database/DatabaseMysqlBase.php b/includes/libs/rdbms/database/DatabaseMysqlBase.php
index 991e0c6660..692ddb70b8 100644
--- a/includes/libs/rdbms/database/DatabaseMysqlBase.php
+++ b/includes/libs/rdbms/database/DatabaseMysqlBase.php
@@ -778,6 +778,8 @@ abstract class DatabaseMysqlBase extends Database {
 	 * @see https://www.percona.com/doc/percona-toolkit/2.1/pt-heartbeat.html
 	 */
 	protected function getHeartbeatData( array $conds ) {
+		// Query time and trip time are not counted
+		$nowUnix = microtime( true );
 		// Do not bother starting implicit transactions here
 		$this->clearFlag( self::DBO_TRX, self::REMEMBER_PRIOR );
 		try {
@@ -793,7 +795,7 @@ abstract class DatabaseMysqlBase extends Database {
 			$this->restoreFlags();
 		}
 
-		return [ $row ? $row->ts : null, microtime( true ) ];
+		return [ $row ? $row->ts : null, $nowUnix ];
 	}
 
 	protected function getApproximateLagStatus() {