includes/libs/rdbms/lbfactory/LBFactory.php

   1 <?php
   2 /**
   3  * Generator and manager of database load balancing objects
   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
  24 namespace Wikimedia\Rdbms;
  25
  26 use Psr\Log\LoggerInterface;
  27 use Wikimedia\ScopedCallback;
  28 use BagOStuff;
  29 use EmptyBagOStuff;
  30 use WANObjectCache;
  31 use Exception;
  32 use RuntimeException;
  33 use LogicException;
  34
  35 /**
  36  * An interface for generating database load balancers
  37  * @ingroup Database
  38  */
  39 abstract class LBFactory implements ILBFactory {
  40         /** @var ChronologyProtector */
  41         protected $chronProt;
  42         /** @var object|string Class name or object With profileIn/profileOut methods */
  43         protected $profiler;
  44         /** @var TransactionProfiler */
  45         protected $trxProfiler;
  46         /** @var LoggerInterface */
  47         protected $replLogger;
  48         /** @var LoggerInterface */
  49         protected $connLogger;
  50         /** @var LoggerInterface */
  51         protected $queryLogger;
  52         /** @var LoggerInterface */
  53         protected $perfLogger;
  54         /** @var callable Error logger */
  55         protected $errorLogger;
  56         /** @var callable Deprecation logger */
  57         protected $deprecationLogger;
  58         /** @var BagOStuff */
  59         protected $srvCache;
  60         /** @var BagOStuff */
  61         protected $memStash;
  62         /** @var WANObjectCache */
  63         protected $wanCache;
  64
  65         /** @var DatabaseDomain Local domain */
  66         protected $localDomain;
  67         /** @var string Local hostname of the app server */
  68         protected $hostname;
  69         /** @var array Web request information about the client */
  70         protected $requestInfo;
  71
  72         /** @var mixed */
  73         protected $ticket;
  74         /** @var string|bool String if a requested DBO_TRX transaction round is active */
  75         protected $trxRoundId = false;
  76         /** @var string|bool Reason all LBs are read-only or false if not */
  77         protected $readOnlyReason = false;
  78         /** @var callable[] */
  79         protected $replicationWaitCallbacks = [];
  80
  81         /** @var array[] $aliases Map of (table => (dbname, schema, prefix) map) */
  82         protected $tableAliases = [];
  83         /** @var string[] Map of (index alias => index) */
  84         protected $indexAliases = [];
  85
  86         /** @var bool Whether this PHP instance is for a CLI script */
  87         protected $cliMode;
  88         /** @var string Agent name for query profiling */
  89         protected $agent;
  90
  91         /** @var string One of the ROUND_* class constants */
  92         private $trxRoundStage = self::ROUND_CURSORY;
  93
  94         const ROUND_CURSORY = 'cursory';
  95         const ROUND_BEGINNING = 'within-begin';
  96         const ROUND_COMMITTING = 'within-commit';
  97         const ROUND_ROLLING_BACK = 'within-rollback';
  98         const ROUND_COMMIT_CALLBACKS = 'within-commit-callbacks';
  99         const ROUND_ROLLBACK_CALLBACKS = 'within-rollback-callbacks';
 100
 101         private static $loggerFields =
 102                 [ 'replLogger', 'connLogger', 'queryLogger', 'perfLogger' ];
 103
 104         public function __construct( array $conf ) {
 105                 $this->localDomain = isset( $conf['localDomain'] )
 106                         ? DatabaseDomain::newFromId( $conf['localDomain'] )
 107                         : DatabaseDomain::newUnspecified();
 108
 109                 if ( isset( $conf['readOnlyReason'] ) && is_string( $conf['readOnlyReason'] ) ) {
 110                         $this->readOnlyReason = $conf['readOnlyReason'];
 111                 }
 112
 113                 $this->srvCache = isset( $conf['srvCache'] ) ? $conf['srvCache'] : new EmptyBagOStuff();
 114                 $this->memStash = isset( $conf['memStash'] ) ? $conf['memStash'] : new EmptyBagOStuff();
 115                 $this->wanCache = isset( $conf['wanCache'] )
 116                         ? $conf['wanCache']
 117                         : WANObjectCache::newEmpty();
 118
 119                 foreach ( self::$loggerFields as $key ) {
 120                         $this->$key = isset( $conf[$key] ) ? $conf[$key] : new \Psr\Log\NullLogger();
 121                 }
 122                 $this->errorLogger = isset( $conf['errorLogger'] )
 123                         ? $conf['errorLogger']
 124                         : function ( Exception $e ) {
 125                                 trigger_error( get_class( $e ) . ': ' . $e->getMessage(), E_USER_WARNING );
 126                         };
 127                 $this->deprecationLogger = isset( $conf['deprecationLogger'] )
 128                         ? $conf['deprecationLogger']
 129                         : function ( $msg ) {
 130                                 trigger_error( $msg, E_USER_DEPRECATED );
 131                         };
 132
 133                 $this->profiler = isset( $conf['profiler'] ) ? $conf['profiler'] : null;
 134                 $this->trxProfiler = isset( $conf['trxProfiler'] )
 135                         ? $conf['trxProfiler']
 136                         : new TransactionProfiler();
 137
 138                 $this->requestInfo = [
 139                         'IPAddress' => isset( $_SERVER[ 'REMOTE_ADDR' ] ) ? $_SERVER[ 'REMOTE_ADDR' ] : '',
 140                         'UserAgent' => isset( $_SERVER['HTTP_USER_AGENT'] ) ? $_SERVER['HTTP_USER_AGENT'] : '',
 141                         'ChronologyProtection' => 'true',
 142                         'ChronologyPositionIndex' => isset( $_GET['cpPosIndex'] ) ? $_GET['cpPosIndex'] : null
 143                 ];
 144
 145                 $this->cliMode = isset( $conf['cliMode'] )
 146                         ? $conf['cliMode']
 147                         : ( PHP_SAPI === 'cli' || PHP_SAPI === 'phpdbg' );
 148                 $this->hostname = isset( $conf['hostname'] ) ? $conf['hostname'] : gethostname();
 149                 $this->agent = isset( $conf['agent'] ) ? $conf['agent'] : '';
 150
 151                 $this->ticket = mt_rand();
 152         }
 153
 154         public function destroy() {
 155                 $this->shutdown( self::SHUTDOWN_NO_CHRONPROT );
 156                 $this->forEachLBCallMethod( 'disable' );
 157         }
 158
 159         public function shutdown(
 160                 $mode = self::SHUTDOWN_CHRONPROT_SYNC, callable $workCallback = null, &$cpIndex = null
 161         ) {
 162                 $chronProt = $this->getChronologyProtector();
 163                 if ( $mode === self::SHUTDOWN_CHRONPROT_SYNC ) {
 164                         $this->shutdownChronologyProtector( $chronProt, $workCallback, 'sync', $cpIndex );
 165                 } elseif ( $mode === self::SHUTDOWN_CHRONPROT_ASYNC ) {
 166                         $this->shutdownChronologyProtector( $chronProt, null, 'async', $cpIndex );
 167                 }
 168
 169                 $this->commitMasterChanges( __METHOD__ ); // sanity
 170         }
 171
 172         /**
 173          * @see ILBFactory::newMainLB()
 174          * @param bool $domain
 175          * @return ILoadBalancer
 176          */
 177         abstract public function newMainLB( $domain = false );
 178
 179         /**
 180          * @see ILBFactory::getMainLB()
 181          * @param bool $domain
 182          * @return ILoadBalancer
 183          */
 184         abstract public function getMainLB( $domain = false );
 185
 186         /**
 187          * @see ILBFactory::newExternalLB()
 188          * @param string $cluster
 189          * @return ILoadBalancer
 190          */
 191         abstract public function newExternalLB( $cluster );
 192
 193         /**
 194          * @see ILBFactory::getExternalLB()
 195          * @param string $cluster
 196          * @return ILoadBalancer
 197          */
 198         abstract public function getExternalLB( $cluster );
 199
 200         /**
 201          * Call a method of each tracked load balancer
 202          *
 203          * @param string $methodName
 204          * @param array $args
 205          */
 206         protected function forEachLBCallMethod( $methodName, array $args = [] ) {
 207                 $this->forEachLB(
 208                         function ( ILoadBalancer $loadBalancer, $methodName, array $args ) {
 209                                 call_user_func_array( [ $loadBalancer, $methodName ], $args );
 210                         },
 211                         [ $methodName, $args ]
 212                 );
 213         }
 214
 215         public function flushReplicaSnapshots( $fname = __METHOD__ ) {
 216                 $this->forEachLBCallMethod( 'flushReplicaSnapshots', [ $fname ] );
 217         }
 218
 219         final public function commitAll( $fname = __METHOD__, array $options = [] ) {
 220                 $this->commitMasterChanges( $fname, $options );
 221                 $this->forEachLBCallMethod( 'flushMasterSnapshots', [ $fname ] );
 222                 $this->forEachLBCallMethod( 'flushReplicaSnapshots', [ $fname ] );
 223         }
 224
 225         final public function beginMasterChanges( $fname = __METHOD__ ) {
 226                 $this->assertTransactionRoundStage( self::ROUND_CURSORY );
 227                 $this->trxRoundStage = self::ROUND_BEGINNING;
 228                 if ( $this->trxRoundId !== false ) {
 229                         throw new DBTransactionError(
 230                                 null,
 231                                 "$fname: transaction round '{$this->trxRoundId}' already started."
 232                         );
 233                 }
 234                 $this->trxRoundId = $fname;
 235                 // Set DBO_TRX flags on all appropriate DBs
 236                 $this->forEachLBCallMethod( 'beginMasterChanges', [ $fname ] );
 237                 $this->trxRoundStage = self::ROUND_CURSORY;
 238         }
 239
 240         final public function commitMasterChanges( $fname = __METHOD__, array $options = [] ) {
 241                 $this->assertTransactionRoundStage( self::ROUND_CURSORY );
 242                 $this->trxRoundStage = self::ROUND_COMMITTING;
 243                 if ( $this->trxRoundId !== false && $this->trxRoundId !== $fname ) {
 244                         throw new DBTransactionError(
 245                                 null,
 246                                 "$fname: transaction round '{$this->trxRoundId}' still running."
 247                         );
 248                 }
 249                 /** @noinspection PhpUnusedLocalVariableInspection */
 250                 $scope = $this->getScopedPHPBehaviorForCommit(); // try to ignore client aborts
 251                 // Run pre-commit callbacks and suppress post-commit callbacks, aborting on failure
 252                 do {
 253                         $count = 0; // number of callbacks executed this iteration
 254                         $this->forEachLB( function ( ILoadBalancer $lb ) use ( &$count ) {
 255                                 $count += $lb->finalizeMasterChanges();
 256                         } );
 257                 } while ( $count > 0 );
 258                 $this->trxRoundId = false;
 259                 // Perform pre-commit checks, aborting on failure
 260                 $this->forEachLBCallMethod( 'approveMasterChanges', [ $options ] );
 261                 // Log the DBs and methods involved in multi-DB transactions
 262                 $this->logIfMultiDbTransaction();
 263                 // Actually perform the commit on all master DB connections and revert DBO_TRX
 264                 $this->forEachLBCallMethod( 'commitMasterChanges', [ $fname ] );
 265                 // Run all post-commit callbacks in a separate step
 266                 $this->trxRoundStage = self::ROUND_COMMIT_CALLBACKS;
 267                 $e = $this->executePostTransactionCallbacks();
 268                 $this->trxRoundStage = self::ROUND_CURSORY;
 269                 // Throw any last post-commit callback error
 270                 if ( $e instanceof Exception ) {
 271                         throw $e;
 272                 }
 273         }
 274
 275         final public function rollbackMasterChanges( $fname = __METHOD__ ) {
 276                 $this->trxRoundStage = self::ROUND_ROLLING_BACK;
 277                 $this->trxRoundId = false;
 278                 // Actually perform the rollback on all master DB connections and revert DBO_TRX
 279                 $this->forEachLBCallMethod( 'rollbackMasterChanges', [ $fname ] );
 280                 // Run all post-commit callbacks in a separate step
 281                 $this->trxRoundStage = self::ROUND_ROLLBACK_CALLBACKS;
 282                 $this->executePostTransactionCallbacks();
 283                 $this->trxRoundStage = self::ROUND_CURSORY;
 284         }
 285
 286         /**
 287          * @return Exception|null
 288          */
 289         private function executePostTransactionCallbacks() {
 290                 // Run all post-commit callbacks until new ones stop getting added
 291                 $e = null; // first callback exception
 292                 do {
 293                         $this->forEachLB( function ( ILoadBalancer $lb ) use ( &$e ) {
 294                                 $ex = $lb->runMasterTransactionIdleCallbacks();
 295                                 $e = $e ?: $ex;
 296                         } );
 297                 } while ( $this->hasMasterChanges() );
 298                 // Run all listener callbacks once
 299                 $this->forEachLB( function ( ILoadBalancer $lb ) use ( &$e ) {
 300                         $ex = $lb->runMasterTransactionListenerCallbacks();
 301                         $e = $e ?: $ex;
 302                 } );
 303
 304                 return $e;
 305         }
 306
 307         public function hasTransactionRound() {
 308                 return ( $this->trxRoundId !== false );
 309         }
 310
 311         public function isReadyForRoundOperations() {
 312                 return ( $this->trxRoundStage === self::ROUND_CURSORY );
 313         }
 314
 315         /**
 316          * Log query info if multi DB transactions are going to be committed now
 317          */
 318         private function logIfMultiDbTransaction() {
 319                 $callersByDB = [];
 320                 $this->forEachLB( function ( ILoadBalancer $lb ) use ( &$callersByDB ) {
 321                         $masterName = $lb->getServerName( $lb->getWriterIndex() );
 322                         $callers = $lb->pendingMasterChangeCallers();
 323                         if ( $callers ) {
 324                                 $callersByDB[$masterName] = $callers;
 325                         }
 326                 } );
 327
 328                 if ( count( $callersByDB ) >= 2 ) {
 329                         $dbs = implode( ', ', array_keys( $callersByDB ) );
 330                         $msg = "Multi-DB transaction [{$dbs}]:\n";
 331                         foreach ( $callersByDB as $db => $callers ) {
 332                                 $msg .= "$db: " . implode( '; ', $callers ) . "\n";
 333                         }
 334                         $this->queryLogger->info( $msg );
 335                 }
 336         }
 337
 338         public function hasMasterChanges() {
 339                 $ret = false;
 340                 $this->forEachLB( function ( ILoadBalancer $lb ) use ( &$ret ) {
 341                         $ret = $ret || $lb->hasMasterChanges();
 342                 } );
 343
 344                 return $ret;
 345         }
 346
 347         public function laggedReplicaUsed() {
 348                 $ret = false;
 349                 $this->forEachLB( function ( ILoadBalancer $lb ) use ( &$ret ) {
 350                         $ret = $ret || $lb->laggedReplicaUsed();
 351                 } );
 352
 353                 return $ret;
 354         }
 355
 356         public function hasOrMadeRecentMasterChanges( $age = null ) {
 357                 $ret = false;
 358                 $this->forEachLB( function ( ILoadBalancer $lb ) use ( $age, &$ret ) {
 359                         $ret = $ret || $lb->hasOrMadeRecentMasterChanges( $age );
 360                 } );
 361                 return $ret;
 362         }
 363
 364         public function waitForReplication( array $opts = [] ) {
 365                 $opts += [
 366                         'domain' => false,
 367                         'cluster' => false,
 368                         'timeout' => $this->cliMode ? 60 : 10,
 369                         'ifWritesSince' => null
 370                 ];
 371
 372                 if ( $opts['domain'] === false && isset( $opts['wiki'] ) ) {
 373                         $opts['domain'] = $opts['wiki']; // b/c
 374                 }
 375
 376                 // Figure out which clusters need to be checked
 377                 /** @var ILoadBalancer[] $lbs */
 378                 $lbs = [];
 379                 if ( $opts['cluster'] !== false ) {
 380                         $lbs[] = $this->getExternalLB( $opts['cluster'] );
 381                 } elseif ( $opts['domain'] !== false ) {
 382                         $lbs[] = $this->getMainLB( $opts['domain'] );
 383                 } else {
 384                         $this->forEachLB( function ( ILoadBalancer $lb ) use ( &$lbs ) {
 385                                 $lbs[] = $lb;
 386                         } );
 387                         if ( !$lbs ) {
 388                                 return; // nothing actually used
 389                         }
 390                 }
 391
 392                 // Get all the master positions of applicable DBs right now.
 393                 // This can be faster since waiting on one cluster reduces the
 394                 // time needed to wait on the next clusters.
 395                 $masterPositions = array_fill( 0, count( $lbs ), false );
 396                 foreach ( $lbs as $i => $lb ) {
 397                         if ( $lb->getServerCount() <= 1 ) {
 398                                 // T29975 - Don't try to wait for replica DBs if there are none
 399                                 // Prevents permission error when getting master position
 400                                 continue;
 401                         } elseif ( $opts['ifWritesSince']
 402                                 && $lb->lastMasterChangeTimestamp() < $opts['ifWritesSince']
 403                         ) {
 404                                 continue; // no writes since the last wait
 405                         }
 406                         $masterPositions[$i] = $lb->getMasterPos();
 407                 }
 408
 409                 // Run any listener callbacks *after* getting the DB positions. The more
 410                 // time spent in the callbacks, the less time is spent in waitForAll().
 411                 foreach ( $this->replicationWaitCallbacks as $callback ) {
 412                         $callback();
 413                 }
 414
 415                 $failed = [];
 416                 foreach ( $lbs as $i => $lb ) {
 417                         if ( $masterPositions[$i] ) {
 418                                 // The RDBMS may not support getMasterPos()
 419                                 if ( !$lb->waitForAll( $masterPositions[$i], $opts['timeout'] ) ) {
 420                                         $failed[] = $lb->getServerName( $lb->getWriterIndex() );
 421                                 }
 422                         }
 423                 }
 424
 425                 if ( $failed ) {
 426                         throw new DBReplicationWaitError(
 427                                 null,
 428                                 "Could not wait for replica DBs to catch up to " .
 429                                 implode( ', ', $failed )
 430                         );
 431                 }
 432         }
 433
 434         public function setWaitForReplicationListener( $name, callable $callback = null ) {
 435                 if ( $callback ) {
 436                         $this->replicationWaitCallbacks[$name] = $callback;
 437                 } else {
 438                         unset( $this->replicationWaitCallbacks[$name] );
 439                 }
 440         }
 441
 442         public function getEmptyTransactionTicket( $fname ) {
 443                 if ( $this->hasMasterChanges() ) {
 444                         $this->queryLogger->error( __METHOD__ . ": $fname does not have outer scope.\n" .
 445                                 ( new RuntimeException() )->getTraceAsString() );
 446
 447                         return null;
 448                 }
 449
 450                 return $this->ticket;
 451         }
 452
 453         final public function commitAndWaitForReplication( $fname, $ticket, array $opts = [] ) {
 454                 if ( $ticket !== $this->ticket ) {
 455                         $this->perfLogger->error( __METHOD__ . ": $fname does not have outer scope.\n" .
 456                                 ( new RuntimeException() )->getTraceAsString() );
 457
 458                         return;
 459                 }
 460
 461                 // The transaction owner and any caller with the empty transaction ticket can commit
 462                 // so that getEmptyTransactionTicket() callers don't risk seeing DBTransactionError.
 463                 if ( $this->trxRoundId !== false && $fname !== $this->trxRoundId ) {
 464                         $this->queryLogger->info( "$fname: committing on behalf of {$this->trxRoundId}." );
 465                         $fnameEffective = $this->trxRoundId;
 466                 } else {
 467                         $fnameEffective = $fname;
 468                 }
 469
 470                 $this->commitMasterChanges( $fnameEffective );
 471                 $this->waitForReplication( $opts );
 472                 // If a nested caller committed on behalf of $fname, start another empty $fname
 473                 // transaction, leaving the caller with the same empty transaction state as before.
 474                 if ( $fnameEffective !== $fname ) {
 475                         $this->beginMasterChanges( $fnameEffective );
 476                 }
 477         }
 478
 479         public function getChronologyProtectorTouched( $dbName ) {
 480                 return $this->getChronologyProtector()->getTouched( $dbName );
 481         }
 482
 483         public function disableChronologyProtection() {
 484                 $this->getChronologyProtector()->setEnabled( false );
 485         }
 486
 487         /**
 488          * @return ChronologyProtector
 489          */
 490         protected function getChronologyProtector() {
 491                 if ( $this->chronProt ) {
 492                         return $this->chronProt;
 493                 }
 494
 495                 $this->chronProt = new ChronologyProtector(
 496                         $this->memStash,
 497                         [
 498                                 'ip' => $this->requestInfo['IPAddress'],
 499                                 'agent' => $this->requestInfo['UserAgent'],
 500                         ],
 501                         $this->requestInfo['ChronologyPositionIndex']
 502                 );
 503                 $this->chronProt->setLogger( $this->replLogger );
 504
 505                 if ( $this->cliMode ) {
 506                         $this->chronProt->setEnabled( false );
 507                 } elseif ( $this->requestInfo['ChronologyProtection'] === 'false' ) {
 508                         // Request opted out of using position wait logic. This is useful for requests
 509                         // done by the job queue or background ETL that do not have a meaningful session.
 510                         $this->chronProt->setWaitEnabled( false );
 511                 }
 512
 513                 $this->replLogger->debug( __METHOD__ . ': using request info ' .
 514                         json_encode( $this->requestInfo, JSON_PRETTY_PRINT ) );
 515
 516                 return $this->chronProt;
 517         }
 518
 519         /**
 520          * Get and record all of the staged DB positions into persistent memory storage
 521          *
 522          * @param ChronologyProtector $cp
 523          * @param callable|null $workCallback Work to do instead of waiting on syncing positions
 524          * @param string $mode One of (sync, async); whether to wait on remote datacenters
 525          * @param int|null &$cpIndex DB position key write counter; incremented on update
 526          */
 527         protected function shutdownChronologyProtector(
 528                 ChronologyProtector $cp, $workCallback, $mode, &$cpIndex = null
 529         ) {
 530                 // Record all the master positions needed
 531                 $this->forEachLB( function ( ILoadBalancer $lb ) use ( $cp ) {
 532                         $cp->shutdownLB( $lb );
 533                 } );
 534                 // Write them to the persistent stash. Try to do something useful by running $work
 535                 // while ChronologyProtector waits for the stash write to replicate to all DCs.
 536                 $unsavedPositions = $cp->shutdown( $workCallback, $mode, $cpIndex );
 537                 if ( $unsavedPositions && $workCallback ) {
 538                         // Invoke callback in case it did not cache the result yet
 539                         $workCallback(); // work now to block for less time in waitForAll()
 540                 }
 541                 // If the positions failed to write to the stash, at least wait on local datacenter
 542                 // replica DBs to catch up before responding. Even if there are several DCs, this increases
 543                 // the chance that the user will see their own changes immediately afterwards. As long
 544                 // as the sticky DC cookie applies (same domain), this is not even an issue.
 545                 $this->forEachLB( function ( ILoadBalancer $lb ) use ( $unsavedPositions ) {
 546                         $masterName = $lb->getServerName( $lb->getWriterIndex() );
 547                         if ( isset( $unsavedPositions[$masterName] ) ) {
 548                                 $lb->waitForAll( $unsavedPositions[$masterName] );
 549                         }
 550                 } );
 551         }
 552
 553         /**
 554          * Base parameters to ILoadBalancer::__construct()
 555          * @return array
 556          */
 557         final protected function baseLoadBalancerParams() {
 558                 if ( $this->trxRoundStage === self::ROUND_COMMIT_CALLBACKS ) {
 559                         $initStage = ILoadBalancer::STAGE_POSTCOMMIT_CALLBACKS;
 560                 } elseif ( $this->trxRoundStage === self::ROUND_ROLLBACK_CALLBACKS ) {
 561                         $initStage = ILoadBalancer::STAGE_POSTROLLBACK_CALLBACKS;
 562                 } else {
 563                         $initStage = null;
 564                 }
 565
 566                 return [
 567                         'localDomain' => $this->localDomain,
 568                         'readOnlyReason' => $this->readOnlyReason,
 569                         'srvCache' => $this->srvCache,
 570                         'wanCache' => $this->wanCache,
 571                         'profiler' => $this->profiler,
 572                         'trxProfiler' => $this->trxProfiler,
 573                         'queryLogger' => $this->queryLogger,
 574                         'connLogger' => $this->connLogger,
 575                         'replLogger' => $this->replLogger,
 576                         'errorLogger' => $this->errorLogger,
 577                         'deprecationLogger' => $this->deprecationLogger,
 578                         'hostname' => $this->hostname,
 579                         'cliMode' => $this->cliMode,
 580                         'agent' => $this->agent,
 581                         'chronologyCallback' => function ( ILoadBalancer $lb ) {
 582                                 // Defer ChronologyProtector construction in case setRequestInfo() ends up
 583                                 // being called later (but before the first connection attempt) (T192611)
 584                                 $this->getChronologyProtector()->initLB( $lb );
 585                         },
 586                         'roundStage' => $initStage
 587                 ];
 588         }
 589
 590         /**
 591          * @param ILoadBalancer $lb
 592          */
 593         protected function initLoadBalancer( ILoadBalancer $lb ) {
 594                 if ( $this->trxRoundId !== false ) {
 595                         $lb->beginMasterChanges( $this->trxRoundId ); // set DBO_TRX
 596                 }
 597
 598                 $lb->setTableAliases( $this->tableAliases );
 599                 $lb->setIndexAliases( $this->indexAliases );
 600         }
 601
 602         public function setTableAliases( array $aliases ) {
 603                 $this->tableAliases = $aliases;
 604         }
 605
 606         public function setIndexAliases( array $aliases ) {
 607                 $this->indexAliases = $aliases;
 608         }
 609
 610         public function setDomainPrefix( $prefix ) {
 611                 $this->localDomain = new DatabaseDomain(
 612                         $this->localDomain->getDatabase(),
 613                         null,
 614                         $prefix
 615                 );
 616
 617                 $this->forEachLB( function ( ILoadBalancer $lb ) use ( $prefix ) {
 618                         $lb->setDomainPrefix( $prefix );
 619                 } );
 620         }
 621
 622         public function closeAll() {
 623                 $this->forEachLBCallMethod( 'closeAll', [] );
 624         }
 625
 626         public function setAgentName( $agent ) {
 627                 $this->agent = $agent;
 628         }
 629
 630         public function appendShutdownCPIndexAsQuery( $url, $index ) {
 631                 $usedCluster = 0;
 632                 $this->forEachLB( function ( ILoadBalancer $lb ) use ( &$usedCluster ) {
 633                         $usedCluster |= ( $lb->getServerCount() > 1 );
 634                 } );
 635
 636                 if ( !$usedCluster ) {
 637                         return $url; // no master/replica clusters touched
 638                 }
 639
 640                 return strpos( $url, '?' ) === false ? "$url?cpPosIndex=$index" : "$url&cpPosIndex=$index";
 641         }
 642
 643         public function setRequestInfo( array $info ) {
 644                 if ( $this->chronProt ) {
 645                         throw new LogicException( 'ChronologyProtector already initialized.' );
 646                 }
 647
 648                 $this->requestInfo = $info + $this->requestInfo;
 649         }
 650
 651         /**
 652          * @param string $stage
 653          */
 654         private function assertTransactionRoundStage( $stage ) {
 655                 if ( $this->trxRoundStage !== $stage ) {
 656                         throw new DBTransactionError(
 657                                 null,
 658                                 "Transaction round stage must be '$stage' (not '{$this->trxRoundStage}')"
 659                         );
 660                 }
 661         }
 662
 663         /**
 664          * Make PHP ignore user aborts/disconnects until the returned
 665          * value leaves scope. This returns null and does nothing in CLI mode.
 666          *
 667          * @return ScopedCallback|null
 668          */
 669         final protected function getScopedPHPBehaviorForCommit() {
 670                 if ( PHP_SAPI != 'cli' ) { // https://bugs.php.net/bug.php?id=47540
 671                         $old = ignore_user_abort( true ); // avoid half-finished operations
 672                         return new ScopedCallback( function () use ( $old ) {
 673                                 ignore_user_abort( $old );
 674                         } );
 675                 }
 676
 677                 return null;
 678         }
 679
 680         function __destruct() {
 681                 $this->destroy();
 682         }
 683 }
 684
 685 class_alias( LBFactory::class, 'LBFactory' );