includes/libs/rdbms/loadmonitor/ILoadMonitor.php

   1 <?php
   2 /**
   3  * Database load monitoring interface
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Database
  22  */
  23 use Psr\Log\LoggerAwareInterface;
  24
  25 /**
  26  * An interface for database load monitoring
  27  *
  28  * @ingroup Database
  29  */
  30 interface ILoadMonitor extends LoggerAwareInterface {
  31         /**
  32          * Construct a new LoadMonitor with a given LoadBalancer parent
  33          *
  34          * @param ILoadBalancer $lb LoadBalancer this instance serves
  35          * @param BagOStuff $sCache Local server memory cache
  36          * @param BagOStuff $cCache Local cluster memory cache
  37          * @param array $options Options map
  38          */
  39         public function __construct(
  40                 ILoadBalancer $lb, BagOStuff $sCache, BagOStuff $cCache, array $options = []
  41         );
  42
  43         /**
  44          * Perform pre-connection load ratio adjustment.
  45          * @param int[] &$weightByServer Map of (server index => integer weight)
  46          * @param string|bool $group The selected query group. Default: false
  47          * @param string|bool $domain Default: false
  48          */
  49         public function scaleLoads( array &$weightByServer, $group = false, $domain = false );
  50
  51         /**
  52          * Get an estimate of replication lag (in seconds) for each server
  53          *
  54          * Values may be "false" if replication is too broken to estimate
  55          *
  56          * @param integer[] $serverIndexes
  57          * @param string $domain
  58          *
  59          * @return array Map of (server index => float|int|bool)
  60          */
  61         public function getLagTimes( array $serverIndexes, $domain );
  62
  63         /**
  64          * Clear any process and persistent cache of lag times
  65          * @since 1.27
  66          */
  67         public function clearCaches();
  68 }