includes/db/MWLBFactory.php
<?php
/**
* Generator of database load balancing objects.
*
* 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
*/
use Liuggio\StatsdClient\Factory\StatsdDataFactoryInterface;
use MediaWiki\Config\Config;
use MediaWiki\Config\ServiceOptions;
use MediaWiki\Debug\MWDebug;
use MediaWiki\Deferred\DeferredUpdates;
use MediaWiki\Logger\LoggerFactory;
use MediaWiki\MainConfigNames;
use Wikimedia\ObjectCache\BagOStuff;
use Wikimedia\Rdbms\ChronologyProtector;
use Wikimedia\Rdbms\ConfiguredReadOnlyMode;
use Wikimedia\Rdbms\DatabaseDomain;
use Wikimedia\Rdbms\IDatabase;
use Wikimedia\Rdbms\ILBFactory;
use Wikimedia\RequestTimeout\CriticalSectionProvider;
/**
* MediaWiki-specific class for generating database load balancers
*
* @internal For use by core ServiceWiring only.
* @ingroup Database
*/
class MWLBFactory {
/** Cache of already-logged deprecation messages */
private static array $loggedDeprecations = [];
public const CORE_VIRTUAL_DOMAINS = [ 'virtual-botpasswords' ];
/**
* @internal For use by ServiceWiring
*/
public const APPLY_DEFAULT_CONFIG_OPTIONS = [
MainConfigNames::DBcompress,
MainConfigNames::DBDefaultGroup,
MainConfigNames::DBmwschema,
MainConfigNames::DBname,
MainConfigNames::DBpassword,
MainConfigNames::DBport,
MainConfigNames::DBprefix,
MainConfigNames::DBserver,
MainConfigNames::DBservers,
MainConfigNames::DBssl,
MainConfigNames::DBStrictWarnings,
MainConfigNames::DBtype,
MainConfigNames::DBuser,
MainConfigNames::DebugDumpSql,
MainConfigNames::DebugLogFile,
MainConfigNames::DebugToolbar,
MainConfigNames::ExternalServers,
MainConfigNames::SQLiteDataDir,
MainConfigNames::SQLMode,
MainConfigNames::VirtualDomainsMapping,
];
private ServiceOptions $options;
private ConfiguredReadOnlyMode $readOnlyMode;
private ChronologyProtector $chronologyProtector;
private BagOStuff $srvCache;
private WANObjectCache $wanCache;
private CriticalSectionProvider $csProvider;
private StatsdDataFactoryInterface $statsdDataFactory;
/** @var string[] */
private array $virtualDomains;
/**
* @param ServiceOptions $options
* @param ConfiguredReadOnlyMode $readOnlyMode
* @param ChronologyProtector $chronologyProtector
* @param BagOStuff $srvCache
* @param WANObjectCache $wanCache
* @param CriticalSectionProvider $csProvider
* @param StatsdDataFactoryInterface $statsdDataFactory
* @param string[] $virtualDomains
*/
public function __construct(
ServiceOptions $options,
ConfiguredReadOnlyMode $readOnlyMode,
ChronologyProtector $chronologyProtector,
BagOStuff $srvCache,
WANObjectCache $wanCache,
CriticalSectionProvider $csProvider,
StatsdDataFactoryInterface $statsdDataFactory,
array $virtualDomains
) {
$this->options = $options;
$this->readOnlyMode = $readOnlyMode;
$this->chronologyProtector = $chronologyProtector;
$this->srvCache = $srvCache;
$this->wanCache = $wanCache;
$this->csProvider = $csProvider;
$this->statsdDataFactory = $statsdDataFactory;
$this->virtualDomains = $virtualDomains;
}
/**
* @param array $lbConf Config for LBFactory::__construct()
* @return array
* @internal For use with service wiring
*/
public function applyDefaultConfig( array $lbConf ): array {
$this->options->assertRequiredOptions( self::APPLY_DEFAULT_CONFIG_OPTIONS );
$typesWithSchema = self::getDbTypesWithSchemas();
if ( Profiler::instance() instanceof ProfilerStub ) {
$profilerCallback = null;
} else {
$profilerCallback = static function ( $section ) {
return Profiler::instance()->scopedProfileIn( $section );
};
}
$lbConf += [
'localDomain' => new DatabaseDomain(
$this->options->get( MainConfigNames::DBname ),
$this->options->get( MainConfigNames::DBmwschema ),
$this->options->get( MainConfigNames::DBprefix )
),
'profiler' => $profilerCallback,
'trxProfiler' => Profiler::instance()->getTransactionProfiler(),
'logger' => LoggerFactory::getInstance( 'rdbms' ),
'errorLogger' => [ MWExceptionHandler::class, 'logException' ],
'deprecationLogger' => [ static::class, 'logDeprecation' ],
'statsdDataFactory' => $this->statsdDataFactory,
'cliMode' => MW_ENTRY_POINT === 'cli',
'readOnlyReason' => $this->readOnlyMode->getReason(),
'defaultGroup' => $this->options->get( MainConfigNames::DBDefaultGroup ),
'criticalSectionProvider' => $this->csProvider
];
$serversCheck = [];
// When making changes here, remember to also specify MediaWiki-specific options
// for Database classes in the relevant Installer subclass.
// Such as MysqlInstaller::openConnection and PostgresInstaller::openConnectionWithParams.
if ( $lbConf['class'] === Wikimedia\Rdbms\LBFactorySimple::class ) {
if ( isset( $lbConf['servers'] ) ) {
// Server array is already explicitly configured
} elseif ( is_array( $this->options->get( MainConfigNames::DBservers ) ) ) {
$lbConf['servers'] = [];
foreach ( $this->options->get( MainConfigNames::DBservers ) as $i => $server ) {
$lbConf['servers'][$i] = self::initServerInfo( $server, $this->options );
}
} else {
$server = self::initServerInfo(
[
'host' => $this->options->get( MainConfigNames::DBserver ),
'user' => $this->options->get( MainConfigNames::DBuser ),
'password' => $this->options->get( MainConfigNames::DBpassword ),
'dbname' => $this->options->get( MainConfigNames::DBname ),
'type' => $this->options->get( MainConfigNames::DBtype ),
'load' => 1
],
$this->options
);
if ( $this->options->get( MainConfigNames::DBssl ) ) {
$server['ssl'] = true;
}
$server['flags'] |= $this->options->get( MainConfigNames::DBcompress ) ? DBO_COMPRESS : 0;
if ( $this->options->get( MainConfigNames::DBStrictWarnings ) ) {
$server['strictWarnings'] = true;
}
$lbConf['servers'] = [ $server ];
}
if ( !isset( $lbConf['externalClusters'] ) ) {
$lbConf['externalClusters'] = $this->options->get( MainConfigNames::ExternalServers );
}
$serversCheck = $lbConf['servers'];
} elseif ( $lbConf['class'] === Wikimedia\Rdbms\LBFactoryMulti::class ) {
if ( isset( $lbConf['serverTemplate'] ) ) {
if ( in_array( $lbConf['serverTemplate']['type'], $typesWithSchema, true ) ) {
$lbConf['serverTemplate']['schema'] = $this->options->get( MainConfigNames::DBmwschema );
}
$lbConf['serverTemplate']['sqlMode'] = $this->options->get( MainConfigNames::SQLMode );
$serversCheck = [ $lbConf['serverTemplate'] ];
}
}
self::assertValidServerConfigs(
$serversCheck,
$this->options->get( MainConfigNames::DBname ),
$this->options->get( MainConfigNames::DBprefix )
);
$lbConf['chronologyProtector'] = $this->chronologyProtector;
$lbConf['srvCache'] = $this->srvCache;
$lbConf['wanCache'] = $this->wanCache;
$lbConf['virtualDomains'] = array_merge( $this->virtualDomains, self::CORE_VIRTUAL_DOMAINS );
$lbConf['virtualDomainsMapping'] = $this->options->get( MainConfigNames::VirtualDomainsMapping );
return $lbConf;
}
/**
* @return array
*/
private function getDbTypesWithSchemas(): array {
return [ 'postgres' ];
}
/**
* @param array $server
* @param ServiceOptions $options
* @return array
*/
private function initServerInfo( array $server, ServiceOptions $options ): array {
if ( $server['type'] === 'sqlite' ) {
$httpMethod = $_SERVER['REQUEST_METHOD'] ?? null;
// T93097: hint for how file-based databases (e.g. sqlite) should go about locking.
// See https://www.sqlite.org/lang_transaction.html
// See https://www.sqlite.org/lockingv3.html#shared_lock
$isHttpRead = in_array( $httpMethod, [ 'GET', 'HEAD', 'OPTIONS', 'TRACE' ] );
if ( MW_ENTRY_POINT === 'rest' && !$isHttpRead ) {
// Hack to support some re-entrant invocations using sqlite
// See: T259685, T91820
$request = \MediaWiki\Rest\EntryPoint::getMainRequest();
if ( $request->hasHeader( 'Promise-Non-Write-API-Action' ) ) {
$isHttpRead = true;
}
}
$server += [
'dbDirectory' => $options->get( MainConfigNames::SQLiteDataDir ),
'trxMode' => $isHttpRead ? 'DEFERRED' : 'IMMEDIATE'
];
} elseif ( $server['type'] === 'postgres' ) {
$server += [ 'port' => $options->get( MainConfigNames::DBport ) ];
}
if ( in_array( $server['type'], self::getDbTypesWithSchemas(), true ) ) {
$server += [ 'schema' => $options->get( MainConfigNames::DBmwschema ) ];
}
$flags = $server['flags'] ?? DBO_DEFAULT;
if ( $options->get( MainConfigNames::DebugDumpSql )
|| $options->get( MainConfigNames::DebugLogFile )
|| $options->get( MainConfigNames::DebugToolbar )
) {
$flags |= DBO_DEBUG;
}
$server['flags'] = $flags;
$server += [
'tablePrefix' => $options->get( MainConfigNames::DBprefix ),
'sqlMode' => $options->get( MainConfigNames::SQLMode ),
];
return $server;
}
/**
* @param array $servers
* @param string $ldDB Local domain database name
* @param string $ldTP Local domain prefix
*/
private function assertValidServerConfigs( array $servers, string $ldDB, string $ldTP ): void {
foreach ( $servers as $server ) {
$type = $server['type'] ?? null;
$srvDB = $server['dbname'] ?? null; // server DB
$srvTP = $server['tablePrefix'] ?? ''; // server table prefix
if ( $type === 'mysql' ) {
// A DB name is not needed to connect to mysql; 'dbname' is useless.
// This field only defines the DB to use for unspecified DB domains.
if ( $srvDB !== null && $srvDB !== $ldDB ) {
self::reportMismatchedDBs( $srvDB, $ldDB );
}
} elseif ( $type === 'postgres' ) {
if ( $srvTP !== '' ) {
self::reportIfPrefixSet( $srvTP, $type );
}
}
if ( $srvTP !== '' && $srvTP !== $ldTP ) {
self::reportMismatchedPrefixes( $srvTP, $ldTP );
}
}
}
/**
* @param string $prefix Table prefix
* @param string $dbType Database type
* @return never
*/
private function reportIfPrefixSet( string $prefix, string $dbType ) {
$e = new UnexpectedValueException(
"\$wgDBprefix is set to '$prefix' but the database type is '$dbType'. " .
"MediaWiki does not support using a table prefix with this RDBMS type."
);
MWExceptionRenderer::output( $e, MWExceptionRenderer::AS_RAW );
exit;
}
/**
* @param string $srvDB Server config database
* @param string $ldDB Local DB domain database
* @return never
*/
private function reportMismatchedDBs( string $srvDB, string $ldDB ) {
$e = new UnexpectedValueException(
"\$wgDBservers has dbname='$srvDB' but \$wgDBname='$ldDB'. " .
"Set \$wgDBname to the database used by this wiki project. " .
"There is rarely a need to set 'dbname' in \$wgDBservers. " .
"Cross-wiki database access, use of WikiMap::getCurrentWikiDbDomain(), " .
"use of Database::getDomainId(), and other features are not reliable when " .
"\$wgDBservers does not match the local wiki database/prefix."
);
MWExceptionRenderer::output( $e, MWExceptionRenderer::AS_RAW );
exit;
}
/**
* @param string $srvTP Server config table prefix
* @param string $ldTP Local DB domain database
* @return never
*/
private function reportMismatchedPrefixes( string $srvTP, string $ldTP ) {
$e = new UnexpectedValueException(
"\$wgDBservers has tablePrefix='$srvTP' but \$wgDBprefix='$ldTP'. " .
"Set \$wgDBprefix to the table prefix used by this wiki project. " .
"There is rarely a need to set 'tablePrefix' in \$wgDBservers. " .
"Cross-wiki database access, use of WikiMap::getCurrentWikiDbDomain(), " .
"use of Database::getDomainId(), and other features are not reliable when " .
"\$wgDBservers does not match the local wiki database/prefix."
);
MWExceptionRenderer::output( $e, MWExceptionRenderer::AS_RAW );
exit;
}
/**
* Decide which LBFactory class to use.
*
* @internal For use by ServiceWiring
* @param array $config (e.g. $wgLBFactoryConf)
* @return string Class name
*/
public function getLBFactoryClass( array $config ): string {
$compat = [
// For LocalSettings.php compat after removing underscores (since 1.23).
'LBFactory_Single' => Wikimedia\Rdbms\LBFactorySingle::class,
'LBFactory_Simple' => Wikimedia\Rdbms\LBFactorySimple::class,
'LBFactory_Multi' => Wikimedia\Rdbms\LBFactoryMulti::class,
// For LocalSettings.php compat after moving classes to namespaces (since 1.29).
'LBFactorySingle' => Wikimedia\Rdbms\LBFactorySingle::class,
'LBFactorySimple' => Wikimedia\Rdbms\LBFactorySimple::class,
'LBFactoryMulti' => Wikimedia\Rdbms\LBFactoryMulti::class
];
$class = $config['class'];
return $compat[$class] ?? $class;
}
/**
* @param ILBFactory $lbFactory
*/
public function setDomainAliases( ILBFactory $lbFactory ): void {
$domain = DatabaseDomain::newFromId( $lbFactory->getLocalDomainID() );
// For compatibility with hyphenated $wgDBname values on older wikis, handle callers
// that assume corresponding database domain IDs and wiki IDs have identical values
$rawLocalDomain = strlen( $domain->getTablePrefix() )
? "{$domain->getDatabase()}-{$domain->getTablePrefix()}"
: (string)$domain->getDatabase();
$lbFactory->setDomainAliases( [ $rawLocalDomain => $domain ] );
}
/**
* Apply global state from the current web request or other PHP process.
*
* This technically violates the principle constraint on ServiceWiring to be
* deterministic for a given site configuration. The exemption made here
* is solely to aid in debugging and influence non-nominal behaviour such
* as ChronologyProtector. That is, the state applied here must never change
* the logical destination or meaning of any database-related methods, it
* merely applies preferences and debugging information.
*
* The code here must be non-essential, with LBFactory behaving the same toward
* its consumers regardless of whether this is applied or not.
*
* For example, something may instantiate LBFactory for the current wiki without
* calling this, and its consumers must not be able to tell the difference.
* Likewise, in the future MediaWiki may instantiate service wiring and LBFactory
* for a foreign wiki in the same farm and apply the current global state to that,
* and that should be fine as well.
*
* @param ILBFactory $lbFactory
* @param Config $config
* @param IBufferingStatsdDataFactory $stats
*/
public function applyGlobalState(
ILBFactory $lbFactory,
Config $config,
IBufferingStatsdDataFactory $stats
): void {
if ( MW_ENTRY_POINT === 'cli' ) {
$lbFactory->getMainLB()->setTransactionListener(
__METHOD__,
static function ( $trigger ) use ( $stats, $config ) {
// During maintenance scripts and PHPUnit integration tests, we let
// DeferredUpdates run immediately from addUpdate(), unless a transaction
// is active. Notify DeferredUpdates after any commit to try now.
// See DeferredUpdates::tryOpportunisticExecute for why.
if ( $trigger === IDatabase::TRIGGER_COMMIT ) {
DeferredUpdates::tryOpportunisticExecute();
}
// Flush stats periodically in long-running CLI scripts to avoid OOM (T181385)
MediaWiki::emitBufferedStatsdData( $stats, $config );
}
);
$lbFactory->setWaitForReplicationListener(
__METHOD__,
static function () use ( $stats, $config ) {
// Flush stats periodically in long-running CLI scripts to avoid OOM (T181385)
MediaWiki::emitBufferedStatsdData( $stats, $config );
}
);
}
}
/**
* Log a database deprecation warning
*
* @param string $msg Deprecation message
*/
public static function logDeprecation( string $msg ): void {
if ( isset( self::$loggedDeprecations[$msg] ) ) {
return;
}
self::$loggedDeprecations[$msg] = true;
MWDebug::sendRawDeprecated( $msg, true, wfGetCaller() );
}
}