tests/phpunit/includes/db/LoadBalancerTest.php

   1 <?php
   2
   3 /**
   4  * Holds tests for LoadBalancer MediaWiki class.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  19  * http://www.gnu.org/copyleft/gpl.html
  20  *
  21  * @file
  22  */
  23
  24 use Wikimedia\Rdbms\DBError;
  25 use Wikimedia\Rdbms\DatabaseDomain;
  26 use Wikimedia\Rdbms\Database;
  27 use Wikimedia\Rdbms\LoadBalancer;
  28 use Wikimedia\Rdbms\LoadMonitorNull;
  29 use Wikimedia\TestingAccessWrapper;
  30
  31 /**
  32  * @group Database
  33  * @group medium
  34  * @covers \Wikimedia\Rdbms\LoadBalancer
  35  */
  36 class LoadBalancerTest extends MediaWikiTestCase {
  37         private function makeServerConfig( $flags = DBO_DEFAULT ) {
  38                 global $wgDBserver, $wgDBname, $wgDBuser, $wgDBpassword, $wgDBtype, $wgSQLiteDataDir;
  39
  40                 return [
  41                         'host' => $wgDBserver,
  42                         'dbname' => $wgDBname,
  43                         'tablePrefix' => $this->dbPrefix(),
  44                         'user' => $wgDBuser,
  45                         'password' => $wgDBpassword,
  46                         'type' => $wgDBtype,
  47                         'dbDirectory' => $wgSQLiteDataDir,
  48                         'load' => 0,
  49                         'flags' => $flags
  50                 ];
  51         }
  52
  53         /**
  54          * @covers LoadBalancer::getLocalDomainID()
  55          * @covers LoadBalancer::resolveDomainID()
  56          */
  57         public function testWithoutReplica() {
  58                 global $wgDBname;
  59
  60                 $called = false;
  61                 $lb = new LoadBalancer( [
  62                         // Simulate web request with DBO_TRX
  63                         'servers' => [ $this->makeServerConfig( DBO_TRX ) ],
  64                         'queryLogger' => MediaWiki\Logger\LoggerFactory::getInstance( 'DBQuery' ),
  65                         'localDomain' => new DatabaseDomain( $wgDBname, null, $this->dbPrefix() ),
  66                         'chronologyCallback' => function () use ( &$called ) {
  67                                 $called = true;
  68                         }
  69                 ] );
  70
  71                 $ld = DatabaseDomain::newFromId( $lb->getLocalDomainID() );
  72                 $this->assertEquals( $wgDBname, $ld->getDatabase(), 'local domain DB set' );
  73                 $this->assertEquals( $this->dbPrefix(), $ld->getTablePrefix(), 'local domain prefix set' );
  74                 $this->assertSame( 'my_test_wiki', $lb->resolveDomainID( 'my_test_wiki' ) );
  75                 $this->assertSame( $ld->getId(), $lb->resolveDomainID( false ) );
  76                 $this->assertSame( $ld->getId(), $lb->resolveDomainID( $ld ) );
  77                 $this->assertFalse( $called );
  78
  79                 $dbw = $lb->getConnection( DB_MASTER );
  80                 $this->assertTrue( $called );
  81                 $this->assertTrue( $dbw->getLBInfo( 'master' ), 'master shows as master' );
  82                 $this->assertTrue( $dbw->getFlag( $dbw::DBO_TRX ), "DBO_TRX set on master" );
  83                 $this->assertWriteAllowed( $dbw );
  84
  85                 $dbr = $lb->getConnection( DB_REPLICA );
  86                 $this->assertTrue( $dbr->getLBInfo( 'master' ), 'DB_REPLICA also gets the master' );
  87                 $this->assertTrue( $dbr->getFlag( $dbw::DBO_TRX ), "DBO_TRX set on replica" );
  88
  89                 if ( !$lb->getServerAttributes( $lb->getWriterIndex() )[$dbw::ATTR_DB_LEVEL_LOCKING] ) {
  90                         $dbwAuto = $lb->getConnection( DB_MASTER, [], false, $lb::CONN_TRX_AUTOCOMMIT );
  91                         $this->assertFalse(
  92                                 $dbwAuto->getFlag( $dbw::DBO_TRX ), "No DBO_TRX with CONN_TRX_AUTOCOMMIT" );
  93                         $this->assertTrue( $dbw->getFlag( $dbw::DBO_TRX ), "DBO_TRX still set on master" );
  94                         $this->assertNotEquals(
  95                                 $dbw, $dbwAuto, "CONN_TRX_AUTOCOMMIT uses separate connection" );
  96
  97                         $dbrAuto = $lb->getConnection( DB_REPLICA, [], false, $lb::CONN_TRX_AUTOCOMMIT );
  98                         $this->assertFalse(
  99                                 $dbrAuto->getFlag( $dbw::DBO_TRX ), "No DBO_TRX with CONN_TRX_AUTOCOMMIT" );
 100                         $this->assertTrue( $dbr->getFlag( $dbw::DBO_TRX ), "DBO_TRX still set on replica" );
 101                         $this->assertNotEquals(
 102                                 $dbr, $dbrAuto, "CONN_TRX_AUTOCOMMIT uses separate connection" );
 103
 104                         $dbwAuto2 = $lb->getConnection( DB_MASTER, [], false, $lb::CONN_TRX_AUTOCOMMIT );
 105                         $this->assertEquals( $dbwAuto2, $dbwAuto, "CONN_TRX_AUTOCOMMIT reuses connections" );
 106                 }
 107
 108                 $lb->closeAll();
 109         }
 110
 111         public function testWithReplica() {
 112                 global $wgDBserver;
 113
 114                 // Simulate web request with DBO_TRX
 115                 $lb = $this->newMultiServerLocalLoadBalancer( DBO_TRX );
 116
 117                 $this->assertEquals( 8, $lb->getServerCount() );
 118                 $this->assertTrue( $lb->hasReplicaServers() );
 119                 $this->assertTrue( $lb->hasStreamingReplicaServers() );
 120
 121                 $dbw = $lb->getConnection( DB_MASTER );
 122                 $this->assertTrue( $dbw->getLBInfo( 'master' ), 'master shows as master' );
 123                 $this->assertEquals(
 124                         ( $wgDBserver != '' ) ? $wgDBserver : 'localhost',
 125                         $dbw->getLBInfo( 'clusterMasterHost' ),
 126                         'cluster master set' );
 127                 $this->assertTrue( $dbw->getFlag( $dbw::DBO_TRX ), "DBO_TRX set on master" );
 128                 $this->assertWriteAllowed( $dbw );
 129
 130                 $dbr = $lb->getConnection( DB_REPLICA );
 131                 $this->assertTrue( $dbr->getLBInfo( 'replica' ), 'replica shows as replica' );
 132                 $this->assertEquals(
 133                         ( $wgDBserver != '' ) ? $wgDBserver : 'localhost',
 134                         $dbr->getLBInfo( 'clusterMasterHost' ),
 135                         'cluster master set' );
 136                 $this->assertTrue( $dbr->getFlag( $dbw::DBO_TRX ), "DBO_TRX set on replica" );
 137                 $this->assertWriteForbidden( $dbr );
 138
 139                 if ( !$lb->getServerAttributes( $lb->getWriterIndex() )[$dbw::ATTR_DB_LEVEL_LOCKING] ) {
 140                         $dbwAuto = $lb->getConnection( DB_MASTER, [], false, $lb::CONN_TRX_AUTOCOMMIT );
 141                         $this->assertFalse(
 142                                 $dbwAuto->getFlag( $dbw::DBO_TRX ), "No DBO_TRX with CONN_TRX_AUTOCOMMIT" );
 143                         $this->assertTrue( $dbw->getFlag( $dbw::DBO_TRX ), "DBO_TRX still set on master" );
 144                         $this->assertNotEquals(
 145                                 $dbw, $dbwAuto, "CONN_TRX_AUTOCOMMIT uses separate connection" );
 146
 147                         $dbrAuto = $lb->getConnection( DB_REPLICA, [], false, $lb::CONN_TRX_AUTOCOMMIT );
 148                         $this->assertFalse(
 149                                 $dbrAuto->getFlag( $dbw::DBO_TRX ), "No DBO_TRX with CONN_TRX_AUTOCOMMIT" );
 150                         $this->assertTrue( $dbr->getFlag( $dbw::DBO_TRX ), "DBO_TRX still set on replica" );
 151                         $this->assertNotEquals(
 152                                 $dbr, $dbrAuto, "CONN_TRX_AUTOCOMMIT uses separate connection" );
 153
 154                         $dbwAuto2 = $lb->getConnection( DB_MASTER, [], false, $lb::CONN_TRX_AUTOCOMMIT );
 155                         $this->assertEquals( $dbwAuto2, $dbwAuto, "CONN_TRX_AUTOCOMMIT reuses connections" );
 156                 }
 157
 158                 $lb->closeAll();
 159         }
 160
 161         private function newSingleServerLocalLoadBalancer() {
 162                 global $wgDBname;
 163
 164                 return new LoadBalancer( [
 165                         'servers' => [ $this->makeServerConfig() ],
 166                         'localDomain' => new DatabaseDomain( $wgDBname, null, $this->dbPrefix() )
 167                 ] );
 168         }
 169
 170         private function newMultiServerLocalLoadBalancer( $flags = DBO_DEFAULT ) {
 171                 global $wgDBserver, $wgDBname, $wgDBuser, $wgDBpassword, $wgDBtype, $wgSQLiteDataDir;
 172
 173                 $servers = [
 174                         // Master DB
 175                         0 => [
 176                                 'host' => $wgDBserver,
 177                                 'dbname' => $wgDBname,
 178                                 'tablePrefix' => $this->dbPrefix(),
 179                                 'user' => $wgDBuser,
 180                                 'password' => $wgDBpassword,
 181                                 'type' => $wgDBtype,
 182                                 'dbDirectory' => $wgSQLiteDataDir,
 183                                 'load' => 0,
 184                                 'flags' => $flags
 185                         ],
 186                         // Main replica DBs
 187                         1 => [
 188                                 'host' => $wgDBserver,
 189                                 'dbname' => $wgDBname,
 190                                 'tablePrefix' => $this->dbPrefix(),
 191                                 'user' => $wgDBuser,
 192                                 'password' => $wgDBpassword,
 193                                 'type' => $wgDBtype,
 194                                 'dbDirectory' => $wgSQLiteDataDir,
 195                                 'load' => 100,
 196                                 'flags' => $flags
 197                         ],
 198                         2 => [
 199                                 'host' => $wgDBserver,
 200                                 'dbname' => $wgDBname,
 201                                 'tablePrefix' => $this->dbPrefix(),
 202                                 'user' => $wgDBuser,
 203                                 'password' => $wgDBpassword,
 204                                 'type' => $wgDBtype,
 205                                 'dbDirectory' => $wgSQLiteDataDir,
 206                                 'load' => 100,
 207                                 'flags' => $flags
 208                         ],
 209                         // RC replica DBs
 210                         3 => [
 211                                 'host' => $wgDBserver,
 212                                 'dbname' => $wgDBname,
 213                                 'tablePrefix' => $this->dbPrefix(),
 214                                 'user' => $wgDBuser,
 215                                 'password' => $wgDBpassword,
 216                                 'type' => $wgDBtype,
 217                                 'dbDirectory' => $wgSQLiteDataDir,
 218                                 'load' => 0,
 219                                 'groupLoads' => [
 220                                         'recentchanges' => 100,
 221                                         'watchlist' => 100
 222                                 ],
 223                                 'flags' => $flags
 224                         ],
 225                         // Logging replica DBs
 226                         4 => [
 227                                 'host' => $wgDBserver,
 228                                 'dbname' => $wgDBname,
 229                                 'tablePrefix' => $this->dbPrefix(),
 230                                 'user' => $wgDBuser,
 231                                 'password' => $wgDBpassword,
 232                                 'type' => $wgDBtype,
 233                                 'dbDirectory' => $wgSQLiteDataDir,
 234                                 'load' => 0,
 235                                 'groupLoads' => [
 236                                         'logging' => 100
 237                                 ],
 238                                 'flags' => $flags
 239                         ],
 240                         5 => [
 241                                 'host' => $wgDBserver,
 242                                 'dbname' => $wgDBname,
 243                                 'tablePrefix' => $this->dbPrefix(),
 244                                 'user' => $wgDBuser,
 245                                 'password' => $wgDBpassword,
 246                                 'type' => $wgDBtype,
 247                                 'dbDirectory' => $wgSQLiteDataDir,
 248                                 'load' => 0,
 249                                 'groupLoads' => [
 250                                         'logging' => 100
 251                                 ],
 252                                 'flags' => $flags
 253                         ],
 254                         // Maintenance query replica DBs
 255                         6 => [
 256                                 'host' => $wgDBserver,
 257                                 'dbname' => $wgDBname,
 258                                 'tablePrefix' => $this->dbPrefix(),
 259                                 'user' => $wgDBuser,
 260                                 'password' => $wgDBpassword,
 261                                 'type' => $wgDBtype,
 262                                 'dbDirectory' => $wgSQLiteDataDir,
 263                                 'load' => 0,
 264                                 'groupLoads' => [
 265                                         'vslow' => 100
 266                                 ],
 267                                 'flags' => $flags
 268                         ],
 269                         // Replica DB that only has a copy of some static tables
 270                         7 => [
 271                                 'host' => $wgDBserver,
 272                                 'dbname' => $wgDBname,
 273                                 'tablePrefix' => $this->dbPrefix(),
 274                                 'user' => $wgDBuser,
 275                                 'password' => $wgDBpassword,
 276                                 'type' => $wgDBtype,
 277                                 'dbDirectory' => $wgSQLiteDataDir,
 278                                 'load' => 0,
 279                                 'groupLoads' => [
 280                                         'archive' => 100
 281                                 ],
 282                                 'flags' => $flags,
 283                                 'is static' => true
 284                         ]
 285                 ];
 286
 287                 return new LoadBalancer( [
 288                         'servers' => $servers,
 289                         'localDomain' => new DatabaseDomain( $wgDBname, null, $this->dbPrefix() ),
 290                         'queryLogger' => MediaWiki\Logger\LoggerFactory::getInstance( 'DBQuery' ),
 291                         'loadMonitorClass' => LoadMonitorNull::class
 292                 ] );
 293         }
 294
 295         private function assertWriteForbidden( Database $db ) {
 296                 try {
 297                         $db->delete( 'some_table', [ 'id' => 57634126 ], __METHOD__ );
 298                         $this->fail( 'Write operation should have failed!' );
 299                 } catch ( DBError $ex ) {
 300                         // check that the exception message contains "Write operation"
 301                         $constraint = new PHPUnit_Framework_Constraint_StringContains( 'Write operation' );
 302
 303                         if ( !$constraint->evaluate( $ex->getMessage(), '', true ) ) {
 304                                 // re-throw original error, to preserve stack trace
 305                                 throw $ex;
 306                         }
 307                 }
 308         }
 309
 310         private function assertWriteAllowed( Database $db ) {
 311                 $table = $db->tableName( 'some_table' );
 312                 // Trigger a transaction so that rollback() will remove all the tables.
 313                 // Don't do this for MySQL/Oracle as they auto-commit transactions for DDL
 314                 // statements such as CREATE TABLE.
 315                 $useAtomicSection = in_array( $db->getType(), [ 'sqlite', 'postgres', 'mssql' ], true );
 316                 try {
 317                         $db->dropTable( 'some_table' ); // clear for sanity
 318                         $this->assertNotEquals( $db::STATUS_TRX_ERROR, $db->trxStatus() );
 319
 320                         if ( $useAtomicSection ) {
 321                                 $db->startAtomic( __METHOD__ );
 322                         }
 323                         // Use only basic SQL and trivial types for these queries for compatibility
 324                         $this->assertNotSame(
 325                                 false,
 326                                 $db->query( "CREATE TABLE $table (id INT, time INT)", __METHOD__ ),
 327                                 "table created"
 328                         );
 329                         $this->assertNotEquals( $db::STATUS_TRX_ERROR, $db->trxStatus() );
 330                         $this->assertNotSame(
 331                                 false,
 332                                 $db->query( "DELETE FROM $table WHERE id=57634126", __METHOD__ ),
 333                                 "delete query"
 334                         );
 335                         $this->assertNotEquals( $db::STATUS_TRX_ERROR, $db->trxStatus() );
 336                 } finally {
 337                         if ( !$useAtomicSection ) {
 338                                 // Drop the table to clean up, ignoring any error.
 339                                 $db->dropTable( 'some_table' );
 340                         }
 341                         // Rollback the atomic section for sqlite's benefit.
 342                         $db->rollback( __METHOD__, 'flush' );
 343                         $this->assertNotEquals( $db::STATUS_TRX_ERROR, $db->trxStatus() );
 344                 }
 345         }
 346
 347         public function testServerAttributes() {
 348                 $servers = [
 349                         [ // master
 350                                 'dbname'      => 'my_unittest_wiki',
 351                                 'tablePrefix' => 'unittest_',
 352                                 'type'        => 'sqlite',
 353                                 'dbDirectory' => "some_directory",
 354                                 'load'        => 0
 355                         ]
 356                 ];
 357
 358                 $lb = new LoadBalancer( [
 359                         'servers' => $servers,
 360                         'localDomain' => new DatabaseDomain( 'my_unittest_wiki', null, 'unittest_' ),
 361                         'loadMonitorClass' => LoadMonitorNull::class
 362                 ] );
 363
 364                 $this->assertTrue( $lb->getServerAttributes( 0 )[Database::ATTR_DB_LEVEL_LOCKING] );
 365
 366                 $servers = [
 367                         [ // master
 368                                 'host'        => 'db1001',
 369                                 'user'        => 'wikiuser',
 370                                 'password'    => 'none',
 371                                 'dbname'      => 'my_unittest_wiki',
 372                                 'tablePrefix' => 'unittest_',
 373                                 'type'        => 'mysql',
 374                                 'load'        => 100
 375                         ],
 376                         [ // emulated replica
 377                                 'host'        => 'db1002',
 378                                 'user'        => 'wikiuser',
 379                                 'password'    => 'none',
 380                                 'dbname'      => 'my_unittest_wiki',
 381                                 'tablePrefix' => 'unittest_',
 382                                 'type'        => 'mysql',
 383                                 'load'        => 100
 384                         ]
 385                 ];
 386
 387                 $lb = new LoadBalancer( [
 388                         'servers' => $servers,
 389                         'localDomain' => new DatabaseDomain( 'my_unittest_wiki', null, 'unittest_' ),
 390                         'loadMonitorClass' => LoadMonitorNull::class
 391                 ] );
 392
 393                 $this->assertFalse( $lb->getServerAttributes( 1 )[Database::ATTR_DB_LEVEL_LOCKING] );
 394         }
 395
 396         /**
 397          * @covers LoadBalancer::openConnection()
 398          * @covers LoadBalancer::getAnyOpenConnection()
 399          */
 400         function testOpenConnection() {
 401                 $lb = $this->newSingleServerLocalLoadBalancer();
 402
 403                 $i = $lb->getWriterIndex();
 404                 $this->assertEquals( null, $lb->getAnyOpenConnection( $i ) );
 405
 406                 $conn1 = $lb->getConnection( $i );
 407                 $this->assertNotEquals( null, $conn1 );
 408                 $this->assertEquals( $conn1, $lb->getAnyOpenConnection( $i ) );
 409                 $this->assertFalse( $conn1->getFlag( DBO_TRX ) );
 410
 411                 $conn2 = $lb->getConnection( $i, [], false, $lb::CONN_TRX_AUTOCOMMIT );
 412                 $this->assertNotEquals( null, $conn2 );
 413                 $this->assertFalse( $conn2->getFlag( DBO_TRX ) );
 414
 415                 if ( $lb->getServerAttributes( $i )[Database::ATTR_DB_LEVEL_LOCKING] ) {
 416                         $this->assertEquals( null,
 417                                 $lb->getAnyOpenConnection( $i, $lb::CONN_TRX_AUTOCOMMIT ) );
 418                         $this->assertEquals( $conn1,
 419                                 $lb->getConnection(
 420                                         $i, [], false, $lb::CONN_TRX_AUTOCOMMIT ), $lb::CONN_TRX_AUTOCOMMIT );
 421                 } else {
 422                         $this->assertEquals( $conn2,
 423                                 $lb->getAnyOpenConnection( $i, $lb::CONN_TRX_AUTOCOMMIT ) );
 424                         $this->assertEquals( $conn2,
 425                                 $lb->getConnection( $i, [], false, $lb::CONN_TRX_AUTOCOMMIT ) );
 426
 427                         $conn2->startAtomic( __METHOD__ );
 428                         try {
 429                                 $lb->getConnection( $i, [], false, $lb::CONN_TRX_AUTOCOMMIT );
 430                                 $conn2->endAtomic( __METHOD__ );
 431                                 $this->fail( "No exception thrown." );
 432                         } catch ( DBUnexpectedError $e ) {
 433                                 $this->assertEquals(
 434                                         'Handle requested with CONN_TRX_AUTOCOMMIT yet it has a transaction',
 435                                         $e->getMessage()
 436                                 );
 437                         }
 438                         $conn2->endAtomic( __METHOD__ );
 439                 }
 440
 441                 $lb->closeAll();
 442         }
 443
 444         public function testTransactionCallbackChains() {
 445                 global $wgDBserver, $wgDBname, $wgDBuser, $wgDBpassword, $wgDBtype, $wgSQLiteDataDir;
 446
 447                 $servers = [
 448                         [
 449                                 'host' => $wgDBserver,
 450                                 'dbname' => $wgDBname,
 451                                 'tablePrefix' => $this->dbPrefix(),
 452                                 'user' => $wgDBuser,
 453                                 'password' => $wgDBpassword,
 454                                 'type' => $wgDBtype,
 455                                 'dbDirectory' => $wgSQLiteDataDir,
 456                                 'load' => 0,
 457                                 'flags' => DBO_TRX // simulate a web request with DBO_TRX
 458                         ],
 459                 ];
 460
 461                 $lb = new LoadBalancer( [
 462                         'servers' => $servers,
 463                         'localDomain' => new DatabaseDomain( $wgDBname, null, $this->dbPrefix() )
 464                 ] );
 465
 466                 $conn1 = $lb->openConnection( $lb->getWriterIndex(), false );
 467                 $conn2 = $lb->openConnection( $lb->getWriterIndex(), '' );
 468
 469                 $count = 0;
 470                 $lb->forEachOpenMasterConnection( function () use ( &$count ) {
 471                         ++$count;
 472                 } );
 473                 $this->assertEquals( 2, $count, 'Connection handle count' );
 474
 475                 $tlCalls = 0;
 476                 $lb->setTransactionListener( 'test-listener', function () use ( &$tlCalls ) {
 477                         ++$tlCalls;
 478                 } );
 479
 480                 $lb->beginMasterChanges( __METHOD__ );
 481                 $bc = array_fill_keys( [ 'a', 'b', 'c', 'd' ], 0 );
 482                 $conn1->onTransactionPreCommitOrIdle( function () use ( &$bc, $conn1, $conn2 ) {
 483                         $bc['a'] = 1;
 484                         $conn2->onTransactionPreCommitOrIdle( function () use ( &$bc, $conn1, $conn2 ) {
 485                                 $bc['b'] = 1;
 486                                 $conn1->onTransactionPreCommitOrIdle( function () use ( &$bc, $conn1, $conn2 ) {
 487                                         $bc['c'] = 1;
 488                                         $conn1->onTransactionPreCommitOrIdle( function () use ( &$bc, $conn1, $conn2 ) {
 489                                                 $bc['d'] = 1;
 490                                         } );
 491                                 } );
 492                         } );
 493                 } );
 494                 $lb->finalizeMasterChanges();
 495                 $lb->approveMasterChanges( [] );
 496                 $lb->commitMasterChanges( __METHOD__ );
 497                 $lb->runMasterTransactionIdleCallbacks();
 498                 $lb->runMasterTransactionListenerCallbacks();
 499
 500                 $this->assertEquals( array_fill_keys( [ 'a', 'b', 'c', 'd' ], 1 ), $bc );
 501                 $this->assertEquals( 2, $tlCalls );
 502
 503                 $tlCalls = 0;
 504                 $lb->beginMasterChanges( __METHOD__ );
 505                 $ac = array_fill_keys( [ 'a', 'b', 'c', 'd' ], 0 );
 506                 $conn1->onTransactionCommitOrIdle( function () use ( &$ac, $conn1, $conn2 ) {
 507                         $ac['a'] = 1;
 508                         $conn2->onTransactionCommitOrIdle( function () use ( &$ac, $conn1, $conn2 ) {
 509                                 $ac['b'] = 1;
 510                                 $conn1->onTransactionCommitOrIdle( function () use ( &$ac, $conn1, $conn2 ) {
 511                                         $ac['c'] = 1;
 512                                         $conn1->onTransactionCommitOrIdle( function () use ( &$ac, $conn1, $conn2 ) {
 513                                                 $ac['d'] = 1;
 514                                         } );
 515                                 } );
 516                         } );
 517                 } );
 518                 $lb->finalizeMasterChanges();
 519                 $lb->approveMasterChanges( [] );
 520                 $lb->commitMasterChanges( __METHOD__ );
 521                 $lb->runMasterTransactionIdleCallbacks();
 522                 $lb->runMasterTransactionListenerCallbacks();
 523
 524                 $this->assertEquals( array_fill_keys( [ 'a', 'b', 'c', 'd' ], 1 ), $ac );
 525                 $this->assertEquals( 2, $tlCalls );
 526
 527                 $conn1->close();
 528                 $conn2->close();
 529         }
 530
 531         public function testDBConnRefReadsMasterAndReplicaRoles() {
 532                 $lb = $this->newSingleServerLocalLoadBalancer();
 533
 534                 $rConn = $lb->getConnectionRef( DB_REPLICA );
 535                 $wConn = $lb->getConnectionRef( DB_MASTER );
 536                 $wConn2 = $lb->getConnectionRef( 0 );
 537
 538                 $v = [ 'value' => '1', '1' ];
 539                 $sql = 'SELECT MAX(1) AS value';
 540                 foreach ( [ $rConn, $wConn, $wConn2 ] as $conn ) {
 541                         $conn->clearFlag( $conn::DBO_TRX );
 542
 543                         $res = $conn->query( $sql, __METHOD__ );
 544                         $this->assertEquals( $v, $conn->fetchRow( $res ) );
 545
 546                         $res = $conn->query( $sql, __METHOD__, $conn::QUERY_REPLICA_ROLE );
 547                         $this->assertEquals( $v, $conn->fetchRow( $res ) );
 548                 }
 549
 550                 $wConn->getScopedLockAndFlush( 'key', __METHOD__, 1 );
 551                 $wConn2->getScopedLockAndFlush( 'key2', __METHOD__, 1 );
 552         }
 553
 554         /**
 555          * @expectedException \Wikimedia\Rdbms\DBReadOnlyRoleError
 556          */
 557         public function testDBConnRefWritesReplicaRole() {
 558                 $lb = $this->newSingleServerLocalLoadBalancer();
 559
 560                 $rConn = $lb->getConnectionRef( DB_REPLICA );
 561
 562                 $rConn->query( 'DELETE FROM sometesttable WHERE 1=0' );
 563         }
 564
 565         /**
 566          * @expectedException \Wikimedia\Rdbms\DBReadOnlyRoleError
 567          */
 568         public function testDBConnRefWritesReplicaRoleIndex() {
 569                 $lb = $this->newMultiServerLocalLoadBalancer();
 570
 571                 $rConn = $lb->getConnectionRef( 1 );
 572
 573                 $rConn->query( 'DELETE FROM sometesttable WHERE 1=0' );
 574         }
 575
 576         /**
 577          * @expectedException \Wikimedia\Rdbms\DBReadOnlyRoleError
 578          */
 579         public function testDBConnRefWritesReplicaRoleInsert() {
 580                 $lb = $this->newMultiServerLocalLoadBalancer();
 581
 582                 $rConn = $lb->getConnectionRef( DB_REPLICA );
 583
 584                 $rConn->insert( 'test', [ 't' => 1 ], __METHOD__ );
 585         }
 586
 587         public function testQueryGroupIndex() {
 588                 $lb = $this->newMultiServerLocalLoadBalancer();
 589                 /** @var LoadBalancer $lbWrapper */
 590                 $lbWrapper = TestingAccessWrapper::newFromObject( $lb );
 591
 592                 $rGeneric = $lb->getConnectionRef( DB_REPLICA );
 593                 $mainIndexPicked = $rGeneric->getLBInfo( 'serverIndex' );
 594
 595                 $this->assertEquals( $mainIndexPicked, $lbWrapper->getExistingReaderIndex( false ) );
 596                 $this->assertTrue( in_array( $mainIndexPicked, [ 1, 2 ] ) );
 597                 for ( $i = 0; $i < 300; ++$i ) {
 598                         $rLog = $lb->getConnectionRef( DB_REPLICA, [] );
 599                         $this->assertEquals(
 600                                 $mainIndexPicked,
 601                                 $rLog->getLBInfo( 'serverIndex' ),
 602                                 "Main index unchanged" );
 603                 }
 604
 605                 $rRC = $lb->getConnectionRef( DB_REPLICA, [ 'recentchanges' ] );
 606                 $rWL = $lb->getConnectionRef( DB_REPLICA, [ 'watchlist' ] );
 607
 608                 $this->assertEquals( 3, $rRC->getLBInfo( 'serverIndex' ) );
 609                 $this->assertEquals( 3, $rWL->getLBInfo( 'serverIndex' ) );
 610
 611                 $rLog = $lb->getConnectionRef( DB_REPLICA, [ 'logging', 'watchlist' ] );
 612                 $logIndexPicked = $rLog->getLBInfo( 'serverIndex' );
 613
 614                 $this->assertEquals( $logIndexPicked, $lbWrapper->getExistingReaderIndex( 'logging' ) );
 615                 $this->assertTrue( in_array( $logIndexPicked, [ 4, 5 ] ) );
 616
 617                 for ( $i = 0; $i < 300; ++$i ) {
 618                         $rLog = $lb->getConnectionRef( DB_REPLICA, [ 'logging', 'watchlist' ] );
 619                         $this->assertEquals(
 620                                 $logIndexPicked, $rLog->getLBInfo( 'serverIndex' ), "Index unchanged" );
 621                 }
 622
 623                 $rVslow = $lb->getConnectionRef( DB_REPLICA, [ 'vslow', 'logging' ] );
 624                 $vslowIndexPicked = $rVslow->getLBInfo( 'serverIndex' );
 625
 626                 $this->assertEquals( $vslowIndexPicked, $lbWrapper->getExistingReaderIndex( 'vslow' ) );
 627                 $this->assertEquals( 6, $vslowIndexPicked );
 628         }
 629 }