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authorPierre Schmitz <pierre@archlinux.de>2014-12-27 15:41:37 +0100
committerPierre Schmitz <pierre@archlinux.de>2014-12-31 11:43:28 +0100
commitc1f9b1f7b1b77776192048005dcc66dcf3df2bfb (patch)
tree2b38796e738dd74cb42ecd9bfd151803108386bc /includes/db/LBFactoryMulti.php
parentb88ab0086858470dd1f644e64cb4e4f62bb2be9b (diff)
Update to MediaWiki 1.24.1
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+<?php
+/**
+ * Advanced generator of database load balancing objects for wiki farms.
+ *
+ * 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
+ * @ingroup Database
+ */
+
+/**
+ * A multi-wiki, multi-master factory for Wikimedia and similar installations.
+ * Ignores the old configuration globals
+ *
+ * Configuration:
+ * sectionsByDB A map of database names to section names.
+ *
+ * sectionLoads A 2-d map. For each section, gives a map of server names to
+ * load ratios. For example:
+ * array(
+ * 'section1' => array(
+ * 'db1' => 100,
+ * 'db2' => 100
+ * )
+ * )
+ *
+ * serverTemplate A server info associative array as documented for $wgDBservers.
+ * The host, hostName and load entries will be overridden.
+ *
+ * groupLoadsBySection A 3-d map giving server load ratios for each section and group.
+ * For example:
+ * array(
+ * 'section1' => array(
+ * 'group1' => array(
+ * 'db1' => 100,
+ * 'db2' => 100
+ * )
+ * )
+ * )
+ *
+ * groupLoadsByDB A 3-d map giving server load ratios by DB name.
+ *
+ * hostsByName A map of hostname to IP address.
+ *
+ * externalLoads A map of external storage cluster name to server load map.
+ *
+ * externalTemplateOverrides A set of server info keys overriding serverTemplate for external
+ * storage.
+ *
+ * templateOverridesByServer A 2-d map overriding serverTemplate and
+ * externalTemplateOverrides on a server-by-server basis. Applies
+ * to both core and external storage.
+ *
+ * templateOverridesByCluster A 2-d map overriding the server info by external storage cluster.
+ *
+ * masterTemplateOverrides An override array for all master servers.
+ *
+ * readOnlyBySection A map of section name to read-only message.
+ * Missing or false for read/write.
+ *
+ * @ingroup Database
+ */
+class LBFactoryMulti extends LBFactory {
+ // Required settings
+
+ /** @var array A map of database names to section names */
+ protected $sectionsByDB;
+
+ /**
+ * @var array A 2-d map. For each section, gives a map of server names to
+ * load ratios
+ */
+ protected $sectionLoads;
+
+ /**
+ * @var array A server info associative array as documented for
+ * $wgDBservers. The host, hostName and load entries will be
+ * overridden
+ */
+ protected $serverTemplate;
+
+ // Optional settings
+
+ /** @var array A 3-d map giving server load ratios for each section and group */
+ protected $groupLoadsBySection = array();
+
+ /** @var array A 3-d map giving server load ratios by DB name */
+ protected $groupLoadsByDB = array();
+
+ /** @var array A map of hostname to IP address */
+ protected $hostsByName = array();
+
+ /** @var array A map of external storage cluster name to server load map */
+ protected $externalLoads = array();
+
+ /**
+ * @var array A set of server info keys overriding serverTemplate for
+ * external storage
+ */
+ protected $externalTemplateOverrides;
+
+ /**
+ * @var array A 2-d map overriding serverTemplate and
+ * externalTemplateOverrides on a server-by-server basis. Applies to both
+ * core and external storage
+ */
+ protected $templateOverridesByServer;
+
+ /** @var array A 2-d map overriding the server info by external storage cluster */
+ protected $templateOverridesByCluster;
+
+ /** @var array An override array for all master servers */
+ protected $masterTemplateOverrides;
+
+ /**
+ * @var array|bool A map of section name to read-only message. Missing or
+ * false for read/write
+ */
+ protected $readOnlyBySection = array();
+
+ // Other stuff
+
+ /** @var array Load balancer factory configuration */
+ protected $conf;
+
+ /** @var LoadBalancer[] */
+ protected $mainLBs = array();
+
+ /** @var LoadBalancer[] */
+ protected $extLBs = array();
+
+ /** @var string */
+ protected $lastWiki;
+
+ /** @var string */
+ protected $lastSection;
+
+ /**
+ * @param array $conf
+ * @throws MWException
+ */
+ function __construct( $conf ) {
+ $this->chronProt = new ChronologyProtector;
+ $this->conf = $conf;
+ $required = array( 'sectionsByDB', 'sectionLoads', 'serverTemplate' );
+ $optional = array( 'groupLoadsBySection', 'groupLoadsByDB', 'hostsByName',
+ 'externalLoads', 'externalTemplateOverrides', 'templateOverridesByServer',
+ 'templateOverridesByCluster', 'masterTemplateOverrides',
+ 'readOnlyBySection' );
+
+ foreach ( $required as $key ) {
+ if ( !isset( $conf[$key] ) ) {
+ throw new MWException( __CLASS__ . ": $key is required in configuration" );
+ }
+ $this->$key = $conf[$key];
+ }
+
+ foreach ( $optional as $key ) {
+ if ( isset( $conf[$key] ) ) {
+ $this->$key = $conf[$key];
+ }
+ }
+
+ // Check for read-only mode
+ $section = $this->getSectionForWiki();
+ if ( !empty( $this->readOnlyBySection[$section] ) ) {
+ global $wgReadOnly;
+ $wgReadOnly = $this->readOnlyBySection[$section];
+ }
+ }
+
+ /**
+ * @param bool|string $wiki
+ * @return string
+ */
+ function getSectionForWiki( $wiki = false ) {
+ if ( $this->lastWiki === $wiki ) {
+ return $this->lastSection;
+ }
+ list( $dbName, ) = $this->getDBNameAndPrefix( $wiki );
+ if ( isset( $this->sectionsByDB[$dbName] ) ) {
+ $section = $this->sectionsByDB[$dbName];
+ } else {
+ $section = 'DEFAULT';
+ }
+ $this->lastSection = $section;
+ $this->lastWiki = $wiki;
+
+ return $section;
+ }
+
+ /**
+ * @param bool|string $wiki
+ * @return LoadBalancer
+ */
+ function newMainLB( $wiki = false ) {
+ list( $dbName, ) = $this->getDBNameAndPrefix( $wiki );
+ $section = $this->getSectionForWiki( $wiki );
+ $groupLoads = array();
+ if ( isset( $this->groupLoadsByDB[$dbName] ) ) {
+ $groupLoads = $this->groupLoadsByDB[$dbName];
+ }
+
+ if ( isset( $this->groupLoadsBySection[$section] ) ) {
+ $groupLoads = array_merge_recursive( $groupLoads, $this->groupLoadsBySection[$section] );
+ }
+
+ return $this->newLoadBalancer(
+ $this->serverTemplate,
+ $this->sectionLoads[$section],
+ $groupLoads
+ );
+ }
+
+ /**
+ * @param bool|string $wiki
+ * @return LoadBalancer
+ */
+ function getMainLB( $wiki = false ) {
+ $section = $this->getSectionForWiki( $wiki );
+ if ( !isset( $this->mainLBs[$section] ) ) {
+ $lb = $this->newMainLB( $wiki, $section );
+ $lb->parentInfo( array( 'id' => "main-$section" ) );
+ $this->chronProt->initLB( $lb );
+ $this->mainLBs[$section] = $lb;
+ }
+
+ return $this->mainLBs[$section];
+ }
+
+ /**
+ * @param string $cluster
+ * @param bool|string $wiki
+ * @throws MWException
+ * @return LoadBalancer
+ */
+ function newExternalLB( $cluster, $wiki = false ) {
+ if ( !isset( $this->externalLoads[$cluster] ) ) {
+ throw new MWException( __METHOD__ . ": Unknown cluster \"$cluster\"" );
+ }
+ $template = $this->serverTemplate;
+ if ( isset( $this->externalTemplateOverrides ) ) {
+ $template = $this->externalTemplateOverrides + $template;
+ }
+ if ( isset( $this->templateOverridesByCluster[$cluster] ) ) {
+ $template = $this->templateOverridesByCluster[$cluster] + $template;
+ }
+
+ return $this->newLoadBalancer( $template, $this->externalLoads[$cluster], array() );
+ }
+
+ /**
+ * @param string $cluster External storage cluster, or false for core
+ * @param bool|string $wiki Wiki ID, or false for the current wiki
+ * @return LoadBalancer
+ */
+ function &getExternalLB( $cluster, $wiki = false ) {
+ if ( !isset( $this->extLBs[$cluster] ) ) {
+ $this->extLBs[$cluster] = $this->newExternalLB( $cluster, $wiki );
+ $this->extLBs[$cluster]->parentInfo( array( 'id' => "ext-$cluster" ) );
+ $this->chronProt->initLB( $this->extLBs[$cluster] );
+ }
+
+ return $this->extLBs[$cluster];
+ }
+
+ /**
+ * Make a new load balancer object based on template and load array
+ *
+ * @param array $template
+ * @param array $loads
+ * @param array $groupLoads
+ * @return LoadBalancer
+ */
+ function newLoadBalancer( $template, $loads, $groupLoads ) {
+ $servers = $this->makeServerArray( $template, $loads, $groupLoads );
+ $lb = new LoadBalancer( array(
+ 'servers' => $servers,
+ ) );
+
+ return $lb;
+ }
+
+ /**
+ * Make a server array as expected by LoadBalancer::__construct, using a template and load array
+ *
+ * @param array $template
+ * @param array $loads
+ * @param array $groupLoads
+ * @return array
+ */
+ function makeServerArray( $template, $loads, $groupLoads ) {
+ $servers = array();
+ $master = true;
+ $groupLoadsByServer = $this->reindexGroupLoads( $groupLoads );
+ foreach ( $groupLoadsByServer as $server => $stuff ) {
+ if ( !isset( $loads[$server] ) ) {
+ $loads[$server] = 0;
+ }
+ }
+ foreach ( $loads as $serverName => $load ) {
+ $serverInfo = $template;
+ if ( $master ) {
+ $serverInfo['master'] = true;
+ if ( isset( $this->masterTemplateOverrides ) ) {
+ $serverInfo = $this->masterTemplateOverrides + $serverInfo;
+ }
+ $master = false;
+ }
+ if ( isset( $this->templateOverridesByServer[$serverName] ) ) {
+ $serverInfo = $this->templateOverridesByServer[$serverName] + $serverInfo;
+ }
+ if ( isset( $groupLoadsByServer[$serverName] ) ) {
+ $serverInfo['groupLoads'] = $groupLoadsByServer[$serverName];
+ }
+ if ( isset( $this->hostsByName[$serverName] ) ) {
+ $serverInfo['host'] = $this->hostsByName[$serverName];
+ } else {
+ $serverInfo['host'] = $serverName;
+ }
+ $serverInfo['hostName'] = $serverName;
+ $serverInfo['load'] = $load;
+ $servers[] = $serverInfo;
+ }
+
+ return $servers;
+ }
+
+ /**
+ * Take a group load array indexed by group then server, and reindex it by server then group
+ * @param array $groupLoads
+ * @return array
+ */
+ function reindexGroupLoads( $groupLoads ) {
+ $reindexed = array();
+ foreach ( $groupLoads as $group => $loads ) {
+ foreach ( $loads as $server => $load ) {
+ $reindexed[$server][$group] = $load;
+ }
+ }
+
+ return $reindexed;
+ }
+
+ /**
+ * Get the database name and prefix based on the wiki ID
+ * @param bool|string $wiki
+ * @return array
+ */
+ function getDBNameAndPrefix( $wiki = false ) {
+ if ( $wiki === false ) {
+ global $wgDBname, $wgDBprefix;
+
+ return array( $wgDBname, $wgDBprefix );
+ } else {
+ return wfSplitWikiID( $wiki );
+ }
+ }
+
+ /**
+ * Execute a function for each tracked load balancer
+ * The callback is called with the load balancer as the first parameter,
+ * and $params passed as the subsequent parameters.
+ * @param callable $callback
+ * @param array $params
+ */
+ function forEachLB( $callback, $params = array() ) {
+ foreach ( $this->mainLBs as $lb ) {
+ call_user_func_array( $callback, array_merge( array( $lb ), $params ) );
+ }
+ foreach ( $this->extLBs as $lb ) {
+ call_user_func_array( $callback, array_merge( array( $lb ), $params ) );
+ }
+ }
+
+ function shutdown() {
+ foreach ( $this->mainLBs as $lb ) {
+ $this->chronProt->shutdownLB( $lb );
+ }
+ foreach ( $this->extLBs as $extLB ) {
+ $this->chronProt->shutdownLB( $extLB );
+ }
+ $this->chronProt->shutdown();
+ $this->commitMasterChanges();
+ }
+}