8058bf29d2
Follows-up 499a1fe497 (I7d057a9438f1b09), which introduced a new one
after having fixed this in various commits [1]. Main reason being
that it adds duplicate entries in doc.wikimedia.org navigation for
the file name in addition to the class it defines.
[1] https://gerrit.wikimedia.org/r/q/message:ingroup+owner:Krinkle
Change-Id: I462cc4f83db5fee850c01fd990d4c8c518cd63e0
70 lines
2.2 KiB
PHP
70 lines
2.2 KiB
PHP
<?php
|
|
/**
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License along
|
|
* with this program; if not, write to the Free Software Foundation, Inc.,
|
|
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
|
|
* http://www.gnu.org/copyleft/gpl.html
|
|
*
|
|
* @file
|
|
*/
|
|
|
|
namespace Wikimedia\Rdbms;
|
|
|
|
use BagOStuff;
|
|
use WANObjectCache;
|
|
|
|
/**
|
|
* Basic MySQL load monitor with no external dependencies
|
|
* Uses memcached to cache the replication lag for a short time
|
|
*
|
|
* @ingroup Database
|
|
*/
|
|
class LoadMonitorMySQL extends LoadMonitor {
|
|
/** @var float What buffer pool use ratio counts as "warm" (e.g. 0.5 for 50% usage) */
|
|
private $warmCacheRatio;
|
|
|
|
public function __construct(
|
|
ILoadBalancer $lb, BagOStuff $srvCache, WANObjectCache $wCache, array $options = []
|
|
) {
|
|
parent::__construct( $lb, $srvCache, $wCache, $options );
|
|
|
|
$this->warmCacheRatio = $options['warmCacheRatio'] ?? 0.0;
|
|
}
|
|
|
|
protected function getWeightScale( $index, IDatabase $conn = null ) {
|
|
if ( $conn === null ) {
|
|
return parent::getWeightScale( $index, $conn );
|
|
}
|
|
|
|
$weight = 1.0;
|
|
if ( $this->warmCacheRatio > 0 ) {
|
|
$res = $conn->query( 'SHOW STATUS', __METHOD__ );
|
|
$s = $res ? $res->fetchObject() : false;
|
|
if ( $s === false ) {
|
|
$host = $this->lb->getServerName( $index );
|
|
$this->replLogger->error( __METHOD__ . ": could not get status for $host" );
|
|
} else {
|
|
// https://dev.mysql.com/doc/refman/5.7/en/server-status-variables.html
|
|
if ( $s->Innodb_buffer_pool_pages_total > 0 ) {
|
|
$ratio = $s->Innodb_buffer_pool_pages_data / $s->Innodb_buffer_pool_pages_total;
|
|
} else {
|
|
$ratio = 1.0;
|
|
}
|
|
// Stop caring once $ratio >= $this->warmCacheRatio
|
|
$weight *= min( $ratio / $this->warmCacheRatio, 1.0 );
|
|
}
|
|
}
|
|
|
|
return $weight;
|
|
}
|
|
}
|