3 * Generator of database load balancing objects.
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.
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.
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
24 use MediaWiki\MediaWikiServices
;
25 use MediaWiki\Services\DestructibleService
;
26 use MediaWiki\Logger\LoggerFactory
;
29 * Legacy MediaWiki-specific class for generating database load balancers
32 abstract class LBFactoryMW
extends LBFactory
implements DestructibleService
{
33 /** @noinspection PhpMissingParentConstructorInspection */
35 * Construct a factory based on a configuration array (typically from $wgLBFactoryConf)
37 * @TODO: inject objects via dependency framework
39 public function __construct( array $conf ) {
41 'domain' => wfWikiID(),
42 'hostname' => wfHostname(),
43 'trxProfiler' => Profiler
::instance()->getTransactionProfiler(),
44 'replLogger' => LoggerFactory
::getInstance( 'DBReplication' ),
45 'queryLogger' => LoggerFactory
::getInstance( 'wfLogDBError' ),
46 'connLogger' => LoggerFactory
::getInstance( 'wfLogDBError' ),
47 'perfLogger' => LoggerFactory
::getInstance( 'DBPerformance' ),
48 'errorLogger' => [ MWExceptionHandler
::class, 'logException' ]
50 // Use APC/memcached style caching, but avoids loops with CACHE_DB (T141804)
51 $sCache = ObjectCache
::getLocalServerInstance();
52 if ( $sCache->getQoS( $sCache::ATTR_EMULATION
) > $sCache::QOS_EMULATION_SQL
) {
53 $defaults['srvCache'] = $sCache;
55 $cCache = ObjectCache
::getLocalClusterInstance();
56 if ( $cCache->getQoS( $cCache::ATTR_EMULATION
) > $cCache::QOS_EMULATION_SQL
) {
57 $defaults['memCache'] = $cCache;
59 $wCache = ObjectCache
::getMainWANInstance();
60 if ( $wCache->getQoS( $wCache::ATTR_EMULATION
) > $wCache::QOS_EMULATION_SQL
) {
61 $defaults['wanCache'] = $wCache;
64 parent
::__construct( $conf +
$defaults );
68 * Returns the LBFactory class to use and the load balancer configuration.
70 * @todo instead of this, use a ServiceContainer for managing the different implementations.
72 * @param array $config (e.g. $wgLBFactoryConf)
73 * @return string Class name
75 public static function getLBFactoryClass( array $config ) {
76 // For configuration backward compatibility after removing
77 // underscores from class names in MediaWiki 1.23.
79 'LBFactory_Simple' => 'LBFactorySimple',
80 'LBFactory_Single' => 'LBFactorySingle',
81 'LBFactory_Multi' => 'LBFactoryMulti'
84 $class = $config['class'];
86 if ( isset( $bcClasses[$class] ) ) {
87 $class = $bcClasses[$class];
89 '$wgLBFactoryConf must be updated. See RELEASE-NOTES for details',
100 * @deprecated Since 1.28; use laggedReplicaUsed()
102 public function laggedSlaveUsed() {
103 return $this->laggedReplicaUsed();
106 protected function newChronologyProtector() {
107 $request = RequestContext
::getMain()->getRequest();
108 $chronProt = new ChronologyProtector(
109 ObjectCache
::getMainStashInstance(),
111 'ip' => $request->getIP(),
112 'agent' => $request->getHeader( 'User-Agent' ),
114 $request->getFloat( 'cpPosTime', $request->getCookie( 'cpPosTime', '' ) )
116 if ( PHP_SAPI
=== 'cli' ) {
117 $chronProt->setEnabled( false );
118 } elseif ( $request->getHeader( 'ChronologyProtection' ) === 'false' ) {
119 // Request opted out of using position wait logic. This is useful for requests
120 // done by the job queue or background ETL that do not have a meaningful session.
121 $chronProt->setWaitEnabled( false );
128 * Append ?cpPosTime parameter to a URL for ChronologyProtector purposes if needed
130 * Note that unlike cookies, this works accross domains
133 * @param float $time UNIX timestamp just before shutdown() was called
137 public function appendPreShutdownTimeAsQuery( $url, $time ) {
139 $this->forEachLB( function ( LoadBalancer
$lb ) use ( &$usedCluster ) {
140 $usedCluster |
= ( $lb->getServerCount() > 1 );
143 if ( !$usedCluster ) {
144 return $url; // no master/replica clusters touched
147 return wfAppendQuery( $url, [ 'cpPosTime' => $time ] );