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| 1 | <?php |
| 2 | /** |
| 3 | * @license GPL-2.0-or-later |
| 4 | * @file |
| 5 | */ |
| 6 | namespace Wikimedia\Rdbms; |
| 7 | |
| 8 | use InvalidArgumentException; |
| 9 | use LogicException; |
| 10 | use Psr\Log\LoggerInterface; |
| 11 | use Psr\Log\NullLogger; |
| 12 | use RuntimeException; |
| 13 | use Throwable; |
| 14 | use UnexpectedValueException; |
| 15 | use Wikimedia\ArrayUtils\ArrayUtils; |
| 16 | use Wikimedia\ObjectCache\BagOStuff; |
| 17 | use Wikimedia\ObjectCache\EmptyBagOStuff; |
| 18 | use Wikimedia\ObjectCache\WANObjectCache; |
| 19 | use Wikimedia\ScopedCallback; |
| 20 | use Wikimedia\Stats\StatsFactory; |
| 21 | use Wikimedia\Timestamp\ConvertibleTimestamp; |
| 22 | |
| 23 | /** |
| 24 | * @see ILoadBalancer |
| 25 | * @ingroup Database |
| 26 | */ |
| 27 | class LoadBalancer implements ILoadBalancerForOwner { |
| 28 | /** @var ILoadMonitor */ |
| 29 | private $loadMonitor; |
| 30 | /** @var BagOStuff */ |
| 31 | private $srvCache; |
| 32 | /** @var WANObjectCache */ |
| 33 | private $wanCache; |
| 34 | /** @var DatabaseFactory */ |
| 35 | private $databaseFactory; |
| 36 | |
| 37 | /** @var TransactionProfiler */ |
| 38 | private $trxProfiler; |
| 39 | /** @var StatsFactory */ |
| 40 | private $statsFactory; |
| 41 | /** @var LoggerInterface */ |
| 42 | private $logger; |
| 43 | /** @var callable Exception logger */ |
| 44 | private $errorLogger; |
| 45 | /** @var DatabaseDomain Local DB domain ID and default for new connections */ |
| 46 | private $localDomain; |
| 47 | /** @var bool Whether this PHP instance is for a CLI script */ |
| 48 | private $cliMode; |
| 49 | |
| 50 | /** @var array<string,array<int,Database[]>> Map of (connection pool => server index => Database[]) */ |
| 51 | private $conns; |
| 52 | |
| 53 | /** @var string The name of the DB cluster */ |
| 54 | private $clusterName; |
| 55 | /** @var ServerInfo */ |
| 56 | private $serverInfo; |
| 57 | /** @var array<int,int|float> Map of server index => weight */ |
| 58 | private $loads; |
| 59 | /** @var string|null Default query group to use with getConnection() */ |
| 60 | private $defaultGroup; |
| 61 | |
| 62 | /** @var array[] $aliases Map of (table => (dbname, schema, prefix) map) */ |
| 63 | private $tableAliases = []; |
| 64 | /** @var DatabaseDomain[]|string[] Map of (domain alias => DB domain) */ |
| 65 | private $domainAliases = []; |
| 66 | /** @var callable[] Map of (name => callable) */ |
| 67 | private $trxRecurringCallbacks = []; |
| 68 | /** @var bool[] Map of (domain => whether to use "temp tables only" mode) */ |
| 69 | private $tempTablesOnlyMode = []; |
| 70 | |
| 71 | /** @var string|null Active explicit transaction round owner or false if none */ |
| 72 | private $trxRoundFname = null; |
| 73 | /** @var string Stage of the current transaction round in the transaction round life-cycle */ |
| 74 | private $trxRoundStage = self::ROUND_CURSORY; |
| 75 | /** @var int[] The group replica server indexes keyed by group */ |
| 76 | private $readIndexByGroup = []; |
| 77 | /** @var DBPrimaryPos|null Replication sync position or false if not set */ |
| 78 | private $waitForPos; |
| 79 | /** @var bool Whether a lagged replica DB was used */ |
| 80 | private $laggedReplicaMode = false; |
| 81 | /** @var string|false Reason this instance is read-only or false if not */ |
| 82 | private $readOnlyReason = false; |
| 83 | /** @var int Total number of new connections ever made with this instance */ |
| 84 | private $connectionCounter = 0; |
| 85 | /** @var bool */ |
| 86 | private $disabled = false; |
| 87 | private ?ChronologyProtector $chronologyProtector = null; |
| 88 | /** @var bool Whether the session consistency callback already executed */ |
| 89 | private $chronologyProtectorCalled = false; |
| 90 | |
| 91 | /** @var IDatabaseForOwner|null The last connection handle that caused a problem */ |
| 92 | private $lastErrorConn; |
| 93 | |
| 94 | /** @var DatabaseDomain[] Map of (domain ID => domain instance) */ |
| 95 | private $nonLocalDomainCache = []; |
| 96 | private ?string $uniqueIdentifier = null; |
| 97 | |
| 98 | /** |
| 99 | * @var int Modification counter for invalidating connections held by |
| 100 | * DBConnRef instances. This is bumped by reconfigure(). |
| 101 | */ |
| 102 | private $modcount = 0; |
| 103 | |
| 104 | /** The "server index" LB info key; see {@link IDatabase::getLBInfo()} */ |
| 105 | private const INFO_SERVER_INDEX = 'serverIndex'; |
| 106 | /** The "connection category" LB info key; see {@link IDatabase::getLBInfo()} */ |
| 107 | private const INFO_CONN_CATEGORY = 'connCategory'; |
| 108 | |
| 109 | /** Warn when this many connection are held */ |
| 110 | private const CONN_HELD_WARN_THRESHOLD = 10; |
| 111 | |
| 112 | /** Default 'waitTimeout' when unspecified */ |
| 113 | private const MAX_WAIT_DEFAULT = 10; |
| 114 | /** Seconds to cache primary DB server read-only status */ |
| 115 | private const TTL_CACHE_READONLY = 5; |
| 116 | |
| 117 | /** A category of connections that are tracked and transaction round aware */ |
| 118 | private const CATEGORY_ROUND = 'round'; |
| 119 | /** A category of connections that are tracked and in autocommit-mode */ |
| 120 | private const CATEGORY_AUTOCOMMIT = 'auto-commit'; |
| 121 | /** A category of connections that are untracked and in gauge-mode */ |
| 122 | private const CATEGORY_GAUGE = 'gauge'; |
| 123 | |
| 124 | /** Transaction round, explicit or implicit, has not finished writing */ |
| 125 | private const ROUND_CURSORY = 'cursory'; |
| 126 | /** Transaction round writes are complete and ready for pre-commit checks */ |
| 127 | private const ROUND_FINALIZED = 'finalized'; |
| 128 | /** Transaction round passed final pre-commit checks */ |
| 129 | private const ROUND_APPROVED = 'approved'; |
| 130 | /** Transaction round was committed and post-commit callbacks must be run */ |
| 131 | private const ROUND_COMMIT_CALLBACKS = 'commit-callbacks'; |
| 132 | /** Transaction round was rolled back and post-rollback callbacks must be run */ |
| 133 | private const ROUND_ROLLBACK_CALLBACKS = 'rollback-callbacks'; |
| 134 | /** Transaction round encountered an error */ |
| 135 | private const ROUND_ERROR = 'error'; |
| 136 | |
| 137 | /** @var int Idiom for getExistingReaderIndex() meaning "no index selected" */ |
| 138 | private const READER_INDEX_NONE = -1; |
| 139 | |
| 140 | public function __construct( array $params ) { |
| 141 | $this->configure( $params ); |
| 142 | |
| 143 | $this->conns = self::newTrackedConnectionsArray(); |
| 144 | } |
| 145 | |
| 146 | /** |
| 147 | * @param array $params A database configuration array, see $wgLBFactoryConf. |
| 148 | * |
| 149 | * @return void |
| 150 | */ |
| 151 | protected function configure( array $params ): void { |
| 152 | $this->localDomain = isset( $params['localDomain'] ) |
| 153 | ? DatabaseDomain::newFromId( $params['localDomain'] ) |
| 154 | : DatabaseDomain::newUnspecified(); |
| 155 | |
| 156 | $this->serverInfo = new ServerInfo(); |
| 157 | $this->loads = []; |
| 158 | foreach ( $this->serverInfo->normalizeServerMaps( $params['servers'] ?? [] ) as $i => $server ) { |
| 159 | $this->serverInfo->addServer( $i, $server ); |
| 160 | $this->loads[$i] = $server['load']; |
| 161 | } |
| 162 | // If the cluster name is not specified, fallback to the current primary name |
| 163 | $this->clusterName = $params['clusterName'] |
| 164 | ?? $this->serverInfo->getServerName( ServerInfo::WRITER_INDEX ); |
| 165 | |
| 166 | if ( isset( $params['readOnlyReason'] ) && is_string( $params['readOnlyReason'] ) ) { |
| 167 | $this->readOnlyReason = $params['readOnlyReason']; |
| 168 | } |
| 169 | |
| 170 | $this->srvCache = $params['srvCache'] ?? new EmptyBagOStuff(); |
| 171 | $this->wanCache = $params['wanCache'] ?? WANObjectCache::newEmpty(); |
| 172 | |
| 173 | // Note: this parameter is normally absent. It is injectable for testing purposes only. |
| 174 | $this->databaseFactory = $params['databaseFactory'] ?? new DatabaseFactory( $params ); |
| 175 | |
| 176 | $this->errorLogger = $params['errorLogger'] ?? static function ( Throwable $e ) { |
| 177 | trigger_error( get_class( $e ) . ': ' . $e->getMessage(), E_USER_WARNING ); |
| 178 | }; |
| 179 | $this->logger = $params['logger'] ?? new NullLogger(); |
| 180 | |
| 181 | $this->trxProfiler = $params['trxProfiler'] ?? new TransactionProfiler(); |
| 182 | $this->statsFactory = $params['statsFactory'] ?? StatsFactory::newNull(); |
| 183 | |
| 184 | // Set up LoadMonitor |
| 185 | $loadMonitorConfig = $params['loadMonitor'] ?? [ 'class' => LoadMonitorNull::class ]; |
| 186 | $compat = [ |
| 187 | 'LoadMonitor' => LoadMonitor::class, |
| 188 | 'LoadMonitorNull' => LoadMonitorNull::class |
| 189 | ]; |
| 190 | $class = $loadMonitorConfig['class']; |
| 191 | // @phan-suppress-next-line PhanImpossibleCondition |
| 192 | if ( isset( $compat[$class] ) ) { |
| 193 | $class = $compat[$class]; |
| 194 | } |
| 195 | $this->loadMonitor = new $class( |
| 196 | $this, |
| 197 | $this->srvCache, |
| 198 | $this->wanCache, |
| 199 | $this->logger, |
| 200 | $this->statsFactory, |
| 201 | $loadMonitorConfig |
| 202 | ); |
| 203 | |
| 204 | if ( isset( $params['chronologyProtector'] ) ) { |
| 205 | $this->chronologyProtector = $params['chronologyProtector']; |
| 206 | } |
| 207 | |
| 208 | if ( isset( $params['roundStage'] ) ) { |
| 209 | if ( $params['roundStage'] === self::STAGE_POSTCOMMIT_CALLBACKS ) { |
| 210 | $this->trxRoundStage = self::ROUND_COMMIT_CALLBACKS; |
| 211 | } elseif ( $params['roundStage'] === self::STAGE_POSTROLLBACK_CALLBACKS ) { |
| 212 | $this->trxRoundStage = self::ROUND_ROLLBACK_CALLBACKS; |
| 213 | } |
| 214 | } |
| 215 | |
| 216 | $this->cliMode = $params['cliMode'] ?? ( PHP_SAPI === 'cli' || PHP_SAPI === 'phpdbg' ); |
| 217 | |
| 218 | $this->defaultGroup = $params['defaultGroup'] ?? self::GROUP_GENERIC; |
| 219 | if ( empty( $params['shuffleSharding'] ) ) { |
| 220 | $this->uniqueIdentifier = null; |
| 221 | } else { |
| 222 | $this->uniqueIdentifier = $params['uniqueIdentifier'] ?? null; |
| 223 | } |
| 224 | } |
| 225 | |
| 226 | private static function newTrackedConnectionsArray(): array { |
| 227 | // Note that CATEGORY_GAUGE connections are untracked |
| 228 | return [ |
| 229 | self::CATEGORY_ROUND => [], |
| 230 | self::CATEGORY_AUTOCOMMIT => [] |
| 231 | ]; |
| 232 | } |
| 233 | |
| 234 | public function getClusterName(): string { |
| 235 | return $this->clusterName; |
| 236 | } |
| 237 | |
| 238 | public function getLocalDomainID(): string { |
| 239 | return $this->localDomain->getId(); |
| 240 | } |
| 241 | |
| 242 | /** @inheritDoc */ |
| 243 | public function resolveDomainID( DatabaseDomain|string|false $domain ): string { |
| 244 | return $this->resolveDomainInstance( $domain )->getId(); |
| 245 | } |
| 246 | |
| 247 | final protected function resolveDomainInstance( DatabaseDomain|string|false $domain ): DatabaseDomain { |
| 248 | if ( $domain instanceof DatabaseDomain ) { |
| 249 | return $domain; // already a domain instance |
| 250 | } elseif ( $domain === false || $domain === $this->localDomain->getId() ) { |
| 251 | return $this->localDomain; |
| 252 | } elseif ( isset( $this->domainAliases[$domain] ) ) { |
| 253 | $this->domainAliases[$domain] = |
| 254 | DatabaseDomain::newFromId( $this->domainAliases[$domain] ); |
| 255 | |
| 256 | return $this->domainAliases[$domain]; |
| 257 | } |
| 258 | |
| 259 | $cachedDomain = $this->nonLocalDomainCache[$domain] ?? null; |
| 260 | if ( $cachedDomain === null ) { |
| 261 | $cachedDomain = DatabaseDomain::newFromId( $domain ); |
| 262 | $this->nonLocalDomainCache = [ $domain => $cachedDomain ]; |
| 263 | } |
| 264 | |
| 265 | return $cachedDomain; |
| 266 | } |
| 267 | |
| 268 | /** |
| 269 | * Sanitize connection flags provided by a call to getConnection() |
| 270 | * |
| 271 | * @param int $flags Bitfield of class CONN_* constants |
| 272 | * @param string $domain Database domain |
| 273 | * @return int Sanitized bitfield |
| 274 | */ |
| 275 | protected function sanitizeConnectionFlags( $flags, $domain ) { |
| 276 | if ( self::fieldHasBit( $flags, self::CONN_TRX_AUTOCOMMIT ) ) { |
| 277 | // Callers use CONN_TRX_AUTOCOMMIT to bypass REPEATABLE-READ staleness without |
| 278 | // resorting to row locks (e.g. FOR UPDATE) or to make small out-of-band commits |
| 279 | // during larger transactions. This is useful for avoiding lock contention. |
| 280 | // Assuming all servers are of the same type (or similar), which is overwhelmingly |
| 281 | // the case, use the primary server information to get the attributes. The information |
| 282 | // for $i cannot be used since it might be DB_REPLICA, which might require connection |
| 283 | // attempts in order to be resolved into a real server index. |
| 284 | $attributes = $this->getServerAttributes( ServerInfo::WRITER_INDEX ); |
| 285 | if ( $attributes[Database::ATTR_DB_LEVEL_LOCKING] ) { |
| 286 | // The RDBMS does not support concurrent writes (e.g. SQLite), so attempts |
| 287 | // to use separate connections would just cause self-deadlocks. Note that |
| 288 | // REPEATABLE-READ staleness is not an issue since DB-level locking means |
| 289 | // that transactions are Strict Serializable anyway. |
| 290 | $flags &= ~self::CONN_TRX_AUTOCOMMIT; |
| 291 | $type = $this->serverInfo->getServerType( ServerInfo::WRITER_INDEX ); |
| 292 | $this->logger->info( __METHOD__ . ": CONN_TRX_AUTOCOMMIT disallowed ($type)" ); |
| 293 | } elseif ( isset( $this->tempTablesOnlyMode[$domain] ) ) { |
| 294 | // T202116: integration tests are active and queries should be all be using |
| 295 | // temporary clone tables (via prefix). Such tables are not visible across |
| 296 | // different connections nor can there be REPEATABLE-READ snapshot staleness, |
| 297 | // so use the same connection for everything. |
| 298 | $flags &= ~self::CONN_TRX_AUTOCOMMIT; |
| 299 | } |
| 300 | } |
| 301 | |
| 302 | return $flags; |
| 303 | } |
| 304 | |
| 305 | /** |
| 306 | * @param IDatabase $conn |
| 307 | * @param int $flags |
| 308 | * @throws DBUnexpectedError |
| 309 | */ |
| 310 | private function enforceConnectionFlags( IDatabase $conn, $flags ) { |
| 311 | if ( |
| 312 | self::fieldHasBit( $flags, self::CONN_TRX_AUTOCOMMIT ) || |
| 313 | // Handles with open transactions are avoided since they might be subject |
| 314 | // to REPEATABLE-READ snapshots, which could affect the lag estimate query. |
| 315 | self::fieldHasBit( $flags, self::CONN_UNTRACKED_GAUGE ) |
| 316 | ) { |
| 317 | if ( $conn->trxLevel() ) { |
| 318 | throw new DBUnexpectedError( |
| 319 | $conn, |
| 320 | 'Handle requested with autocommit-mode yet it has a transaction' |
| 321 | ); |
| 322 | } |
| 323 | |
| 324 | $conn->clearFlag( $conn::DBO_TRX ); // auto-commit mode |
| 325 | } |
| 326 | } |
| 327 | |
| 328 | /** |
| 329 | * @param array<int,int|float> $loads Map of (server index => weight) for a load group |
| 330 | * @param int|float $sessionLagLimit Additional maximum lag threshold imposed by the session; |
| 331 | * use INF if none applies. Servers will count as lagged if their lag exceeds either this |
| 332 | * value or the configured "max lag" value. |
| 333 | * @return int|false Index of a non-lagged server with non-zero weight; false if none |
| 334 | */ |
| 335 | private function getRandomNonLagged( array $loads, $sessionLagLimit = INF ) { |
| 336 | $lags = $this->getLagTimes(); |
| 337 | |
| 338 | $dbs = []; |
| 339 | foreach ( $loads as $i => $load ) { |
| 340 | $srvName = $this->serverInfo->getServerName( $i ); |
| 341 | $dbs[$srvName] = $i; |
| 342 | } |
| 343 | // Unset excessively lagged servers from the load group |
| 344 | foreach ( $lags as $i => $lag ) { |
| 345 | if ( $i !== ServerInfo::WRITER_INDEX ) { |
| 346 | // How much lag normally counts as "excessive" for this server |
| 347 | $maxServerLag = $this->serverInfo->getServerMaxLag( $i ); |
| 348 | // How much lag counts as "excessive" for this server given the session |
| 349 | $maxServerLag = min( $maxServerLag, $sessionLagLimit ); |
| 350 | |
| 351 | $srvName = $this->serverInfo->getServerName( $i ); |
| 352 | if ( $lag === false && !is_infinite( $maxServerLag ) ) { |
| 353 | $this->logger->debug( |
| 354 | __METHOD__ . ": server {db_server} is not replicating?", |
| 355 | [ 'db_server' => $srvName ] |
| 356 | ); |
| 357 | unset( $loads[$i] ); |
| 358 | unset( $dbs[$srvName] ); |
| 359 | } elseif ( $lag > $maxServerLag ) { |
| 360 | $this->logger->debug( |
| 361 | __METHOD__ . |
| 362 | ": server {db_server} has {lag} seconds of lag (>= {maxlag})", |
| 363 | [ 'db_server' => $srvName, 'lag' => $lag, 'maxlag' => $maxServerLag ] |
| 364 | ); |
| 365 | unset( $loads[$i] ); |
| 366 | unset( $dbs[$srvName] ); |
| 367 | } |
| 368 | } |
| 369 | } |
| 370 | |
| 371 | if ( array_sum( $loads ) == 0 ) { |
| 372 | // All the replicas with non-zero weight are lagged and the primary has zero load. |
| 373 | // Inform caller so that it can use switch to read-only mode and use a lagged replica. |
| 374 | return false; |
| 375 | } |
| 376 | |
| 377 | // Return a server index based on weighted random selection |
| 378 | return $this->shuffleSharding( $dbs, $loads ); |
| 379 | } |
| 380 | |
| 381 | /** |
| 382 | * Apply shuffle sharding. Idea originally from Amazon's Route 53. |
| 383 | * |
| 384 | * It basically used a unique identifier from the request (IP is good enough) and uses hashing |
| 385 | * to pick a consistent set of 2 or 3 from the pool. Then using randomness, picks one at random. |
| 386 | * |
| 387 | * It provides many benefits and makes the system more robust against issues or attacks. |
| 388 | * |
| 389 | * @param array $dbs Map of server name => server index |
| 390 | * @param array $loads Map of (server index => weight) for a load group |
| 391 | * @return int Index of the server |
| 392 | */ |
| 393 | private function shuffleSharding( $dbs, $loads ) { |
| 394 | // shuffle sharding doesn't make sense in small groups |
| 395 | if ( count( $loads ) <= 3 || $this->uniqueIdentifier === null ) { |
| 396 | return ArrayUtils::pickRandom( $loads ); |
| 397 | } |
| 398 | |
| 399 | ArrayUtils::consistentHashSort( $dbs, $this->uniqueIdentifier ); |
| 400 | $keys = array_values( $dbs ); |
| 401 | return ArrayUtils::pickRandom( [ |
| 402 | $keys[0] => $loads[$keys[0]], |
| 403 | $keys[1] => $loads[$keys[1]], |
| 404 | $keys[2] => $loads[$keys[2]], |
| 405 | ] ); |
| 406 | } |
| 407 | |
| 408 | /** @inheritDoc */ |
| 409 | public function getReaderIndex( $group = false ) { |
| 410 | if ( !$this->serverInfo->hasReplicaServers() ) { |
| 411 | // There is only one possible server to use (the primary) |
| 412 | return ServerInfo::WRITER_INDEX; |
| 413 | } |
| 414 | |
| 415 | if ( |
| 416 | $group === 'dump' || |
| 417 | $group === 'vslow' || |
| 418 | $group === [ 'dump' ] || |
| 419 | $group === [ 'vslow' ] || |
| 420 | $this->defaultGroup === 'dump' || |
| 421 | $this->defaultGroup === 'vslow' |
| 422 | ) { |
| 423 | $group = 'vslow'; |
| 424 | } else { |
| 425 | $group = self::GROUP_GENERIC; |
| 426 | } |
| 427 | |
| 428 | $index = $this->getExistingReaderIndex( $group ); |
| 429 | if ( $index !== self::READER_INDEX_NONE ) { |
| 430 | // A reader index was already selected for this query group. Keep using it, |
| 431 | // since any session replication position was already waited on and any |
| 432 | // active transaction will be reused (e.g. for point-in-time snapshots). |
| 433 | return $index; |
| 434 | } |
| 435 | |
| 436 | // Get the server weight array for this load group |
| 437 | if ( $group === 'vslow' ) { |
| 438 | // pick the replica with the lowest weight above zero as the vslow |
| 439 | $lowestWeight = INF; |
| 440 | $loads = $this->loads; |
| 441 | foreach ( $this->loads as $index => $weight ) { |
| 442 | if ( $weight > 0 && $weight < $lowestWeight ) { |
| 443 | $loads = [ $index => $weight ]; |
| 444 | $lowestWeight = $weight; |
| 445 | } |
| 446 | } |
| 447 | } else { |
| 448 | $loads = $this->loads; |
| 449 | } |
| 450 | |
| 451 | if ( !$loads ) { |
| 452 | $this->logger->info( __METHOD__ . ": no loads for group $group" ); |
| 453 | return false; |
| 454 | } |
| 455 | |
| 456 | // Load any session replication positions, before any connection attempts, |
| 457 | // since reading them afterwards can only cause more delay due to possibly |
| 458 | // seeing even higher replication positions (e.g. from concurrent requests). |
| 459 | $this->loadSessionPrimaryPos(); |
| 460 | |
| 461 | // Scale the configured load weights according to each server's load/state. |
| 462 | // This can sometimes trigger server connections due to cache regeneration. |
| 463 | $this->loadMonitor->scaleLoads( $loads ); |
| 464 | |
| 465 | // Pick a server, accounting for load weights, lag, and session consistency |
| 466 | $i = $this->pickReaderIndex( $loads ); |
| 467 | if ( $i === false ) { |
| 468 | // Connection attempts failed |
| 469 | return false; |
| 470 | } |
| 471 | |
| 472 | // If data seen by queries is expected to reflect writes from a prior transaction, |
| 473 | // then wait for the chosen server to apply those changes. This is used to improve |
| 474 | // session consistency. |
| 475 | if ( !$this->awaitSessionPrimaryPos( $i ) ) { |
| 476 | // Data will be outdated compared to what was expected |
| 477 | $this->setLaggedReplicaMode(); |
| 478 | } |
| 479 | |
| 480 | // Keep using this server for DB_REPLICA handles for this group |
| 481 | if ( $i < 0 ) { |
| 482 | throw new UnexpectedValueException( "Cannot set a negative read server index" ); |
| 483 | } |
| 484 | $this->readIndexByGroup[$group] = $i; |
| 485 | |
| 486 | $serverName = $this->getServerName( $i ); |
| 487 | $this->logger->debug( __METHOD__ . ": using server $serverName for group '$group'" ); |
| 488 | |
| 489 | return $i; |
| 490 | } |
| 491 | |
| 492 | /** |
| 493 | * Get the server index chosen for DB_REPLICA connections for the given query group |
| 494 | * |
| 495 | * @param string $group Query group; use false for the generic group |
| 496 | * @return int Specific server index or LoadBalancer::READER_INDEX_NONE if none was chosen |
| 497 | */ |
| 498 | protected function getExistingReaderIndex( $group ) { |
| 499 | return $this->readIndexByGroup[$group] ?? self::READER_INDEX_NONE; |
| 500 | } |
| 501 | |
| 502 | /** |
| 503 | * Pick a server that is reachable and preferably non-lagged based on the load weights |
| 504 | * |
| 505 | * This will leave the server connection open within the pool for reuse |
| 506 | * |
| 507 | * @param array<int,int|float> $loads Map of (server index => weight) for a load group |
| 508 | * @return int|false Server index to use as the load group reader index; false on failure |
| 509 | */ |
| 510 | private function pickReaderIndex( array $loads ) { |
| 511 | if ( $loads === [] ) { |
| 512 | throw new InvalidArgumentException( "Load group array is empty" ); |
| 513 | } |
| 514 | |
| 515 | $i = false; |
| 516 | // Quickly look through the available servers for a server that meets criteria... |
| 517 | $currentLoads = $loads; |
| 518 | while ( count( $currentLoads ) ) { |
| 519 | if ( $this->waitForPos && $this->waitForPos->asOfTime() ) { |
| 520 | $this->logger->debug( __METHOD__ . ": session has replication position" ); |
| 521 | // ChronologyProtector::getSessionPrimaryPos called in loadSessionPrimaryPos() |
| 522 | // sets "waitForPos" for session consistency. This triggers doWait() after |
| 523 | // connect, so it's especially good to avoid lagged servers so as to avoid |
| 524 | // excessive delay in that method. |
| 525 | $ago = microtime( true ) - $this->waitForPos->asOfTime(); |
| 526 | // Aim for <= 1 second of waiting (being too picky can backfire) |
| 527 | $i = $this->getRandomNonLagged( $currentLoads, $ago + 1 ); |
| 528 | } else { |
| 529 | // Any server with less lag than it's 'max lag' param is preferable |
| 530 | $i = $this->getRandomNonLagged( $currentLoads ); |
| 531 | } |
| 532 | |
| 533 | if ( $i === false && count( $currentLoads ) ) { |
| 534 | $this->setLaggedReplicaMode(); |
| 535 | // All replica DBs lagged, just pick anything. |
| 536 | $i = ArrayUtils::pickRandom( $currentLoads ); |
| 537 | } |
| 538 | |
| 539 | if ( $i === false ) { |
| 540 | // pickRandom() returned false. |
| 541 | // This is permanent and means the configuration or LoadMonitor |
| 542 | // wants us to return false. |
| 543 | $this->logger->debug( __METHOD__ . ": no suitable server found" ); |
| 544 | return false; |
| 545 | } |
| 546 | |
| 547 | $serverName = $this->getServerName( $i ); |
| 548 | $this->logger->debug( __METHOD__ . ": connecting to $serverName..." ); |
| 549 | |
| 550 | // Get a connection to this server without triggering complementary connections |
| 551 | // to other servers (due to things like lag or read-only checks). We want to avoid |
| 552 | // the risk of overhead and recursion here. |
| 553 | $conn = $this->getServerConnection( $i, self::DOMAIN_ANY, self::CONN_SILENCE_ERRORS ); |
| 554 | if ( !$conn ) { |
| 555 | $this->logger->warning( __METHOD__ . ": failed connecting to $serverName" ); |
| 556 | unset( $currentLoads[$i] ); // avoid this server next iteration |
| 557 | continue; |
| 558 | } |
| 559 | |
| 560 | // Return this server |
| 561 | break; |
| 562 | } |
| 563 | |
| 564 | // If all servers were down, quit now |
| 565 | if ( $currentLoads === [] ) { |
| 566 | $this->logger->error( __METHOD__ . ": all servers down" ); |
| 567 | } |
| 568 | |
| 569 | return $i; |
| 570 | } |
| 571 | |
| 572 | /** @inheritDoc */ |
| 573 | public function waitForAll( DBPrimaryPos $pos, $timeout = null ) { |
| 574 | $timeout = $timeout ?: self::MAX_WAIT_DEFAULT; |
| 575 | |
| 576 | $oldPos = $this->waitForPos; |
| 577 | try { |
| 578 | $this->waitForPos = $pos; |
| 579 | |
| 580 | $failedReplicas = []; |
| 581 | foreach ( $this->serverInfo->getStreamingReplicaIndexes() as $i ) { |
| 582 | if ( isset( $this->loads[$i] ) && $this->loads[$i] > 0 ) { |
| 583 | $start = ConvertibleTimestamp::hrtime(); |
| 584 | $ok = $this->awaitSessionPrimaryPos( $i, $timeout ); |
| 585 | if ( !$ok ) { |
| 586 | $failedReplicas[] = $this->getServerName( $i ); |
| 587 | } |
| 588 | $timeout -= intval( ( ConvertibleTimestamp::hrtime() - $start ) / 1e9 ); |
| 589 | } |
| 590 | } |
| 591 | |
| 592 | // Stop spamming logs when only one replica is lagging and we have 5+ replicas. |
| 593 | // Mediawiki automatically stops sending queries to the lagged one. |
| 594 | $failed = $failedReplicas && ( count( $failedReplicas ) > 1 || $this->getServerCount() < 5 ); |
| 595 | if ( $failed ) { |
| 596 | $this->logger->error( |
| 597 | "Timed out waiting for replication to reach {raw_pos}", |
| 598 | [ |
| 599 | 'raw_pos' => $pos->__toString(), |
| 600 | 'failed_hosts' => $failedReplicas, |
| 601 | 'timeout' => $timeout, |
| 602 | 'exception' => new RuntimeException() |
| 603 | ] |
| 604 | ); |
| 605 | } |
| 606 | |
| 607 | return !$failed; |
| 608 | } finally { |
| 609 | // Restore the old position; this is used for throttling, not lag-protection |
| 610 | $this->waitForPos = $oldPos; |
| 611 | } |
| 612 | } |
| 613 | |
| 614 | /** |
| 615 | * @param int $i |
| 616 | * @param int $flags |
| 617 | * @return IDatabaseForOwner|false |
| 618 | */ |
| 619 | public function getAnyOpenConnection( $i, $flags = 0 ) { |
| 620 | $i = ( $i === self::DB_PRIMARY ) ? ServerInfo::WRITER_INDEX : $i; |
| 621 | $conn = false; |
| 622 | foreach ( $this->conns as $type => $poolConnsByServer ) { |
| 623 | if ( $i === self::DB_REPLICA ) { |
| 624 | // Consider all existing connections to any server |
| 625 | $applicableConnsByServer = $poolConnsByServer; |
| 626 | } else { |
| 627 | // Consider all existing connections to a specific server |
| 628 | $applicableConnsByServer = isset( $poolConnsByServer[$i] ) |
| 629 | ? [ $i => $poolConnsByServer[$i] ] |
| 630 | : []; |
| 631 | } |
| 632 | |
| 633 | $conn = $this->pickAnyOpenConnection( $applicableConnsByServer ); |
| 634 | if ( $conn ) { |
| 635 | $this->logger->debug( __METHOD__ . ": found '$type' connection to #$i." ); |
| 636 | break; |
| 637 | } |
| 638 | } |
| 639 | |
| 640 | if ( $conn ) { |
| 641 | $this->enforceConnectionFlags( $conn, $flags ); |
| 642 | } |
| 643 | |
| 644 | return $conn; |
| 645 | } |
| 646 | |
| 647 | /** |
| 648 | * @param Database[][] $connsByServer Map of (server index => array of DB handles) |
| 649 | * @return IDatabaseForOwner|false An appropriate open connection or false if none found |
| 650 | */ |
| 651 | private function pickAnyOpenConnection( array $connsByServer ) { |
| 652 | foreach ( $connsByServer as $i => $conns ) { |
| 653 | foreach ( $conns as $conn ) { |
| 654 | if ( !$conn->isOpen() ) { |
| 655 | $this->logger->warning( |
| 656 | __METHOD__ . |
| 657 | ": pooled DB handle for {db_server} (#$i) has no open connection.", |
| 658 | $this->getConnLogContext( $conn ) |
| 659 | ); |
| 660 | continue; // some sort of error occurred? |
| 661 | } |
| 662 | return $conn; |
| 663 | } |
| 664 | } |
| 665 | |
| 666 | return false; |
| 667 | } |
| 668 | |
| 669 | /** |
| 670 | * Wait for a given replica DB to catch up to the primary DB pos stored in "waitForPos" |
| 671 | * |
| 672 | * @see loadSessionPrimaryPos() |
| 673 | * |
| 674 | * @param int $index Specific server index |
| 675 | * @param int|null $timeout Max seconds to wait; default is "waitTimeout" |
| 676 | * @return bool Success |
| 677 | */ |
| 678 | private function awaitSessionPrimaryPos( $index, $timeout = null ) { |
| 679 | $timeout = max( 1, intval( $timeout ?: self::MAX_WAIT_DEFAULT ) ); |
| 680 | |
| 681 | if ( !$this->waitForPos || $index === ServerInfo::WRITER_INDEX ) { |
| 682 | return true; |
| 683 | } |
| 684 | |
| 685 | $srvName = $this->getServerName( $index ); |
| 686 | |
| 687 | // Check if we already know that the DB has reached this point |
| 688 | $key = $this->srvCache->makeGlobalKey( __CLASS__, 'last-known-pos', $srvName, 'v2' ); |
| 689 | |
| 690 | /** @var DBPrimaryPos $knownReachedPos */ |
| 691 | $position = $this->srvCache->get( $key ); |
| 692 | if ( !is_array( $position ) ) { |
| 693 | $knownReachedPos = null; |
| 694 | } else { |
| 695 | $class = $position['_type_']; |
| 696 | $knownReachedPos = $class::newFromArray( $position ); |
| 697 | } |
| 698 | if ( |
| 699 | $knownReachedPos instanceof DBPrimaryPos && |
| 700 | $knownReachedPos->hasReached( $this->waitForPos ) |
| 701 | ) { |
| 702 | $this->logger->debug( |
| 703 | __METHOD__ . |
| 704 | ": replica DB {db_server} known to be caught up (pos >= $knownReachedPos).", |
| 705 | [ 'db_server' => $srvName ] |
| 706 | ); |
| 707 | |
| 708 | return true; |
| 709 | } |
| 710 | |
| 711 | $close = false; // close the connection afterwards |
| 712 | $flags = self::CONN_SILENCE_ERRORS; |
| 713 | // Check if there is an existing connection that can be used |
| 714 | $conn = $this->getAnyOpenConnection( $index, $flags ); |
| 715 | if ( !$conn ) { |
| 716 | // Get a connection to this server without triggering complementary connections |
| 717 | // to other servers (due to things like lag or read-only checks). We want to avoid |
| 718 | // the risk of overhead and recursion here. |
| 719 | $conn = $this->getServerConnection( $index, self::DOMAIN_ANY, $flags ); |
| 720 | if ( !$conn ) { |
| 721 | $this->logger->warning( |
| 722 | __METHOD__ . ': failed to connect to {db_server}', |
| 723 | [ 'db_server' => $srvName ] |
| 724 | ); |
| 725 | |
| 726 | return false; |
| 727 | } |
| 728 | // Avoid connection spam in waitForAll() when connections |
| 729 | // are made just for the sake of doing this lag check. |
| 730 | $close = true; |
| 731 | } |
| 732 | |
| 733 | $this->logger->info( |
| 734 | __METHOD__ . |
| 735 | ': waiting for replica DB {db_server} to catch up...', |
| 736 | $this->getConnLogContext( $conn ) |
| 737 | ); |
| 738 | |
| 739 | $result = $conn->primaryPosWait( $this->waitForPos, $timeout ); |
| 740 | |
| 741 | $ok = ( $result !== null && $result != -1 ); |
| 742 | if ( $ok ) { |
| 743 | // Remember that the DB reached this point |
| 744 | $this->srvCache->set( $key, $this->waitForPos->toArray(), BagOStuff::TTL_DAY ); |
| 745 | } |
| 746 | |
| 747 | if ( $close ) { |
| 748 | $this->closeConnection( $conn ); |
| 749 | } |
| 750 | |
| 751 | return $ok; |
| 752 | } |
| 753 | |
| 754 | /** @inheritDoc */ |
| 755 | public function getConnection( $i, $groups = [], string|false $domain = false, $flags = 0 ) { |
| 756 | if ( self::fieldHasBit( $flags, self::CONN_SILENCE_ERRORS ) ) { |
| 757 | throw new UnexpectedValueException( |
| 758 | __METHOD__ . ' got CONN_SILENCE_ERRORS; connection is already deferred' |
| 759 | ); |
| 760 | } |
| 761 | |
| 762 | $domain = $this->resolveDomainID( $domain ); |
| 763 | $role = ( $i === self::DB_PRIMARY || $i === ServerInfo::WRITER_INDEX ) |
| 764 | ? self::DB_PRIMARY |
| 765 | : self::DB_REPLICA; |
| 766 | |
| 767 | return new DBConnRef( $this, [ $i, $groups, $domain, $flags ], $role, $this->modcount ); |
| 768 | } |
| 769 | |
| 770 | /** @inheritDoc */ |
| 771 | public function getConnectionInternal( $i, $groups = [], $domain = false, $flags = 0 ): IDatabase { |
| 772 | $domain = $this->resolveDomainID( $domain ); |
| 773 | $flags = $this->sanitizeConnectionFlags( $flags, $domain ); |
| 774 | // If given DB_PRIMARY/DB_REPLICA, resolve it to a specific server index. Resolving |
| 775 | // DB_REPLICA might trigger getServerConnection() calls due to the getReaderIndex() |
| 776 | // connectivity checks or LoadMonitor::scaleLoads() server state cache regeneration. |
| 777 | // The use of getServerConnection() instead of getConnection() avoids infinite loops. |
| 778 | $serverIndex = $i; |
| 779 | if ( $i === self::DB_PRIMARY ) { |
| 780 | $serverIndex = ServerInfo::WRITER_INDEX; |
| 781 | } elseif ( $i === self::DB_REPLICA ) { |
| 782 | $groupIndex = $this->getReaderIndex( $groups ); |
| 783 | if ( $groupIndex !== false ) { |
| 784 | // Group connection succeeded |
| 785 | $serverIndex = $groupIndex; |
| 786 | } |
| 787 | if ( $serverIndex < 0 ) { |
| 788 | $this->reportConnectionError( 'could not connect to any replica DB server' ); |
| 789 | } |
| 790 | } elseif ( !$this->serverInfo->hasServerIndex( $i ) ) { |
| 791 | throw new UnexpectedValueException( "Invalid server index index #$i" ); |
| 792 | } |
| 793 | // Get an open connection to that server (might trigger a new connection) |
| 794 | return $this->getServerConnection( $serverIndex, $domain, $flags ); |
| 795 | } |
| 796 | |
| 797 | /** @inheritDoc */ |
| 798 | public function getServerConnection( $i, $domain, $flags = 0 ) { |
| 799 | $domainInstance = DatabaseDomain::newFromId( $domain ); |
| 800 | // Number of connections made before getting the server index and handle |
| 801 | $priorConnectionsMade = $this->connectionCounter; |
| 802 | // Get an open connection to this server (might trigger a new connection) |
| 803 | $conn = $this->reuseOrOpenConnectionForNewRef( $i, $domainInstance, $flags ); |
| 804 | // Throw an error or otherwise bail out if the connection attempt failed |
| 805 | if ( !( $conn instanceof IDatabaseForOwner ) ) { |
| 806 | if ( !self::fieldHasBit( $flags, self::CONN_SILENCE_ERRORS ) ) { |
| 807 | $this->reportConnectionError(); |
| 808 | } |
| 809 | |
| 810 | return false; |
| 811 | } |
| 812 | |
| 813 | // Profile any new connections caused by this method |
| 814 | if ( $this->connectionCounter > $priorConnectionsMade ) { |
| 815 | $this->trxProfiler->recordConnection( |
| 816 | $conn->getServerName(), |
| 817 | $conn->getDBname(), |
| 818 | ( $i === ServerInfo::WRITER_INDEX && $this->hasStreamingReplicaServers() ) |
| 819 | ); |
| 820 | } |
| 821 | |
| 822 | if ( !$conn->isOpen() ) { |
| 823 | $this->lastErrorConn = $conn; |
| 824 | // Connection was made but later unrecoverably lost for some reason. |
| 825 | // Do not return a handle that will just throw exceptions on use, but |
| 826 | // let the calling code, e.g. getReaderIndex(), try another server. |
| 827 | if ( !self::fieldHasBit( $flags, self::CONN_SILENCE_ERRORS ) ) { |
| 828 | $this->reportConnectionError(); |
| 829 | } |
| 830 | return false; |
| 831 | } |
| 832 | |
| 833 | return $conn; |
| 834 | } |
| 835 | |
| 836 | /** @inheritDoc */ |
| 837 | public function getMaintenanceConnectionRef( |
| 838 | $i, |
| 839 | $groups = [], |
| 840 | $domain = false, |
| 841 | $flags = 0 |
| 842 | ): DBConnRef { |
| 843 | if ( self::fieldHasBit( $flags, self::CONN_SILENCE_ERRORS ) ) { |
| 844 | throw new UnexpectedValueException( |
| 845 | __METHOD__ . ' CONN_SILENCE_ERRORS is not supported' |
| 846 | ); |
| 847 | } |
| 848 | |
| 849 | $domain = $this->resolveDomainID( $domain ); |
| 850 | $role = ( $i === self::DB_PRIMARY || $i === ServerInfo::WRITER_INDEX ) |
| 851 | ? self::DB_PRIMARY |
| 852 | : self::DB_REPLICA; |
| 853 | |
| 854 | return new DBConnRef( $this, [ $i, $groups, $domain, $flags ], $role, $this->modcount ); |
| 855 | } |
| 856 | |
| 857 | /** |
| 858 | * Get a live connection handle to the given domain |
| 859 | * |
| 860 | * This will reuse an existing tracked connection when possible. In some cases, this |
| 861 | * involves switching the DB domain of an existing handle in order to reuse it. If no |
| 862 | * existing handles can be reused, then a new connection will be made. |
| 863 | * |
| 864 | * @param int $i Specific server index |
| 865 | * @param DatabaseDomain $domain Database domain ID required by the reference |
| 866 | * @param int $flags Bit field of class CONN_* constants |
| 867 | * @return IDatabase|null Database or null on error |
| 868 | * @throws DBError When database selection fails |
| 869 | * @throws InvalidArgumentException When the server index is invalid |
| 870 | * @throws UnexpectedValueException When the DB domain of the connection is corrupted |
| 871 | * @throws DBAccessError If disable() was called |
| 872 | */ |
| 873 | private function reuseOrOpenConnectionForNewRef( $i, DatabaseDomain $domain, $flags = 0 ) { |
| 874 | // Figure out which connection pool to use based on the flags |
| 875 | if ( $this->fieldHasBit( $flags, self::CONN_UNTRACKED_GAUGE ) ) { |
| 876 | // Use low timeouts, use autocommit mode, ignore transaction rounds |
| 877 | $category = self::CATEGORY_GAUGE; |
| 878 | } elseif ( self::fieldHasBit( $flags, self::CONN_TRX_AUTOCOMMIT ) ) { |
| 879 | // Use autocommit mode, ignore transaction rounds |
| 880 | $category = self::CATEGORY_AUTOCOMMIT; |
| 881 | } else { |
| 882 | // Respect DBO_DEFAULT, respect transaction rounds |
| 883 | $category = self::CATEGORY_ROUND; |
| 884 | } |
| 885 | |
| 886 | $conn = null; |
| 887 | // Reuse a free connection in the pool from any domain if possible. There should only |
| 888 | // be one connection in this pool unless either: |
| 889 | // - a) IDatabase::databasesAreIndependent() returns true (e.g. postgres) and two |
| 890 | // or more database domains have been used during the load balancer's lifetime |
| 891 | // - b) Two or more nested function calls used getConnection() on different domains. |
| 892 | foreach ( ( $this->conns[$category][$i] ?? [] ) as $poolConn ) { |
| 893 | // Check if any required DB domain changes for the new reference are possible |
| 894 | // Calling selectDomain() would trigger a reconnect, which will break if a |
| 895 | // transaction is active or if there is any other meaningful session state. |
| 896 | $isShareable = !( |
| 897 | $poolConn->databasesAreIndependent() && |
| 898 | $domain->getDatabase() !== null && |
| 899 | $domain->getDatabase() !== $poolConn->getDBname() |
| 900 | ); |
| 901 | if ( $isShareable ) { |
| 902 | $conn = $poolConn; |
| 903 | // Make any required DB domain changes for the new reference |
| 904 | if ( !$domain->isUnspecified() ) { |
| 905 | $conn->selectDomain( $domain ); |
| 906 | } |
| 907 | $this->logger->debug( __METHOD__ . ": reusing connection for $i/$domain" ); |
| 908 | break; |
| 909 | } |
| 910 | } |
| 911 | |
| 912 | // If necessary, try to open a new connection and add it to the pool |
| 913 | if ( !$conn ) { |
| 914 | $conn = $this->reallyOpenConnection( |
| 915 | $i, |
| 916 | $domain, |
| 917 | [ self::INFO_CONN_CATEGORY => $category ] |
| 918 | ); |
| 919 | if ( $conn->isOpen() ) { |
| 920 | // Make Database::isReadOnly() respect server-side and configuration-based |
| 921 | // read-only mode. Note that replica handles are always seen as read-only |
| 922 | // in Database::isReadOnly() and Database::assertIsWritablePrimary(). |
| 923 | if ( $i === ServerInfo::WRITER_INDEX ) { |
| 924 | if ( $this->readOnlyReason !== false ) { |
| 925 | $readOnlyReason = $this->readOnlyReason; |
| 926 | } elseif ( $this->isPrimaryRunningReadOnly( $conn ) ) { |
| 927 | $readOnlyReason = 'The primary database server is running in read-only mode.'; |
| 928 | } else { |
| 929 | $readOnlyReason = false; |
| 930 | } |
| 931 | $conn->setLBInfo( $conn::LB_READ_ONLY_REASON, $readOnlyReason ); |
| 932 | } |
| 933 | // Connection obtained; check if it belongs to a tracked connection category |
| 934 | if ( isset( $this->conns[$category] ) ) { |
| 935 | // Track this connection for future reuse |
| 936 | $this->conns[$category][$i][] = $conn; |
| 937 | } |
| 938 | } else { |
| 939 | $this->logger->warning( __METHOD__ . ": connection error for $i/$domain" ); |
| 940 | $this->lastErrorConn = $conn; |
| 941 | $conn = null; |
| 942 | } |
| 943 | } |
| 944 | |
| 945 | if ( $conn instanceof IDatabaseForOwner ) { |
| 946 | // Check to make sure that the right domain is selected |
| 947 | $this->assertConnectionDomain( $conn, $domain ); |
| 948 | // Check to make sure that the CONN_* flags are respected |
| 949 | $this->enforceConnectionFlags( $conn, $flags ); |
| 950 | } |
| 951 | |
| 952 | return $conn; |
| 953 | } |
| 954 | |
| 955 | /** |
| 956 | * Sanity check to make sure that the right domain is selected |
| 957 | * |
| 958 | * @param Database $conn |
| 959 | * @param DatabaseDomain $domain |
| 960 | * @throws DBUnexpectedError |
| 961 | */ |
| 962 | private function assertConnectionDomain( Database $conn, DatabaseDomain $domain ) { |
| 963 | if ( !$domain->isCompatible( $conn->getDomainID() ) ) { |
| 964 | throw new UnexpectedValueException( |
| 965 | "Got connection to '{$conn->getDomainID()}', but expected one for '{$domain}'" |
| 966 | ); |
| 967 | } |
| 968 | } |
| 969 | |
| 970 | /** @inheritDoc */ |
| 971 | public function getServerAttributes( $i ) { |
| 972 | return $this->databaseFactory->attributesFromType( |
| 973 | $this->getServerType( $i ), |
| 974 | $this->serverInfo->getServerDriver( $i ) |
| 975 | ); |
| 976 | } |
| 977 | |
| 978 | /** |
| 979 | * Open a new network connection to a server (uncached) |
| 980 | * |
| 981 | * Returns a Database object whether or not the connection was successful. |
| 982 | * |
| 983 | * @param int $i Specific server index |
| 984 | * @param DatabaseDomain $domain Domain the connection is for, possibly unspecified |
| 985 | * @param array $lbInfo Additional information for setLBInfo() |
| 986 | * @return Database |
| 987 | * @throws DBAccessError |
| 988 | * @throws InvalidArgumentException |
| 989 | */ |
| 990 | protected function reallyOpenConnection( $i, DatabaseDomain $domain, array $lbInfo ) { |
| 991 | if ( $this->disabled ) { |
| 992 | throw new DBAccessError(); |
| 993 | } |
| 994 | |
| 995 | $server = $this->serverInfo->getServerInfoStrict( $i ); |
| 996 | if ( $lbInfo[self::INFO_CONN_CATEGORY] === self::CATEGORY_GAUGE ) { |
| 997 | // Use low connection/read timeouts for connection used for gauging server health. |
| 998 | // Gauge information should be cached and used to avoid outages. Indefinite hanging |
| 999 | // while gauging servers would do the opposite. |
| 1000 | $server['connectTimeout'] = min( 1, $server['connectTimeout'] ?? INF ); |
| 1001 | $server['receiveTimeout'] = min( 1, $server['receiveTimeout'] ?? INF ); |
| 1002 | // Avoid implicit transactions and avoid any SET query for session variables during |
| 1003 | // Database::open(). If a server becomes slow, every extra query can cause significant |
| 1004 | // delays, even with low connect/receive timeouts. |
| 1005 | $server['flags'] ??= 0; |
| 1006 | $server['flags'] &= ~IDatabase::DBO_DEFAULT; |
| 1007 | $server['flags'] |= IDatabase::DBO_GAUGE; |
| 1008 | } else { |
| 1009 | // Use implicit transactions unless explicitly configured otherwise |
| 1010 | $server['flags'] ??= IDatabase::DBO_DEFAULT; |
| 1011 | } |
| 1012 | |
| 1013 | if ( !empty( $server['is static'] ) ) { |
| 1014 | $topologyRole = IDatabase::ROLE_STATIC_CLONE; |
| 1015 | } else { |
| 1016 | $topologyRole = ( $i === ServerInfo::WRITER_INDEX ) |
| 1017 | ? IDatabase::ROLE_STREAMING_MASTER |
| 1018 | : IDatabase::ROLE_STREAMING_REPLICA; |
| 1019 | } |
| 1020 | |
| 1021 | $conn = $this->databaseFactory->create( |
| 1022 | $server['type'], |
| 1023 | array_merge( $server, [ |
| 1024 | // Basic replication role information |
| 1025 | 'topologyRole' => $topologyRole, |
| 1026 | // Use the database specified in $domain (null means "none or entrypoint DB"); |
| 1027 | // fallback to the $server default if the RDBMs is an embedded library using a |
| 1028 | // file on disk since there would be nothing to access to without a DB/file name. |
| 1029 | 'dbname' => $this->getServerAttributes( $i )[Database::ATTR_DB_IS_FILE] |
| 1030 | ? ( $domain->getDatabase() ?? $server['dbname'] ?? null ) |
| 1031 | : $domain->getDatabase(), |
| 1032 | // Override the $server default schema with that of $domain if specified |
| 1033 | 'schema' => $domain->getSchema(), |
| 1034 | // Use the table prefix specified in $domain |
| 1035 | 'tablePrefix' => $domain->getTablePrefix(), |
| 1036 | 'srvCache' => $this->srvCache, |
| 1037 | 'logger' => $this->logger, |
| 1038 | 'errorLogger' => $this->errorLogger, |
| 1039 | 'trxProfiler' => $this->trxProfiler, |
| 1040 | 'lbInfo' => [ self::INFO_SERVER_INDEX => $i ] + $lbInfo |
| 1041 | ] ), |
| 1042 | Database::NEW_UNCONNECTED |
| 1043 | ); |
| 1044 | // Set alternative table names before any queries can be issued |
| 1045 | $conn->setTableAliases( $this->tableAliases ); |
| 1046 | // Account for any active transaction round and listeners |
| 1047 | $this->syncConnectionRoundState( $conn ); |
| 1048 | if ( $i === ServerInfo::WRITER_INDEX ) { |
| 1049 | foreach ( $this->trxRecurringCallbacks as $name => $callback ) { |
| 1050 | $conn->setTransactionListener( $name, $callback ); |
| 1051 | } |
| 1052 | } |
| 1053 | |
| 1054 | // Make the connection handle live |
| 1055 | try { |
| 1056 | $conn->initConnection(); |
| 1057 | ++$this->connectionCounter; |
| 1058 | } catch ( DBConnectionError ) { |
| 1059 | $this->lastErrorConn = $conn; |
| 1060 | // ignore; let the DB handle the logging |
| 1061 | } |
| 1062 | |
| 1063 | if ( $conn->isOpen() ) { |
| 1064 | $this->logger->debug( __METHOD__ . ": opened new connection for $i/$domain" ); |
| 1065 | } else { |
| 1066 | $this->logger->warning( |
| 1067 | __METHOD__ . ": connection error for $i/{db_domain}", |
| 1068 | [ 'db_domain' => $domain->getId() ] |
| 1069 | ); |
| 1070 | } |
| 1071 | |
| 1072 | // Log when many connection are made during a single request/script |
| 1073 | $count = 0; |
| 1074 | foreach ( $this->conns as $poolConnsByServer ) { |
| 1075 | foreach ( $poolConnsByServer as $serverConns ) { |
| 1076 | $count += count( $serverConns ); |
| 1077 | } |
| 1078 | } |
| 1079 | if ( $count >= self::CONN_HELD_WARN_THRESHOLD ) { |
| 1080 | $this->logger->warning( |
| 1081 | __METHOD__ . ": {connections}+ connections made (primary={primarydb})", |
| 1082 | $this->getConnLogContext( |
| 1083 | $conn, |
| 1084 | [ |
| 1085 | 'connections' => $count, |
| 1086 | 'primarydb' => $this->serverInfo->getPrimaryServerName(), |
| 1087 | 'db_domain' => $domain->getId() |
| 1088 | ] |
| 1089 | ) |
| 1090 | ); |
| 1091 | } |
| 1092 | |
| 1093 | $this->assertConnectionDomain( $conn, $domain ); |
| 1094 | |
| 1095 | return $conn; |
| 1096 | } |
| 1097 | |
| 1098 | /** |
| 1099 | * Make sure that any "waitForPos" replication positions are loaded and available |
| 1100 | * |
| 1101 | * Each load balancer cluster has up to one replication position for the session. |
| 1102 | * These are used when data read by queries is expected to reflect writes caused |
| 1103 | * by a prior request/script from the same client. |
| 1104 | * |
| 1105 | * @see awaitSessionPrimaryPos() |
| 1106 | */ |
| 1107 | private function loadSessionPrimaryPos() { |
| 1108 | if ( !$this->chronologyProtectorCalled && $this->chronologyProtector ) { |
| 1109 | $this->chronologyProtectorCalled = true; |
| 1110 | $pos = $this->chronologyProtector->getSessionPrimaryPos( $this ); |
| 1111 | $this->logger->debug( __METHOD__ . ': executed chronology callback.' ); |
| 1112 | if ( $pos ) { |
| 1113 | if ( !$this->waitForPos || $pos->hasReached( $this->waitForPos ) ) { |
| 1114 | $this->waitForPos = $pos; |
| 1115 | } |
| 1116 | } |
| 1117 | } |
| 1118 | } |
| 1119 | |
| 1120 | /** |
| 1121 | * @param string $extraLbError Separate load balancer error |
| 1122 | * @throws DBConnectionError |
| 1123 | * @return never |
| 1124 | */ |
| 1125 | private function reportConnectionError( $extraLbError = '' ): never { |
| 1126 | if ( $this->lastErrorConn instanceof IDatabaseForOwner ) { |
| 1127 | $srvName = $this->lastErrorConn->getServerName(); |
| 1128 | $lastDbError = $this->lastErrorConn->lastError() ?: 'unknown error'; |
| 1129 | |
| 1130 | $exception = new DBConnectionError( |
| 1131 | $this->lastErrorConn, |
| 1132 | $extraLbError |
| 1133 | ? "{$extraLbError}; {$lastDbError} ({$srvName})" |
| 1134 | : "{$lastDbError} ({$srvName})" |
| 1135 | ); |
| 1136 | |
| 1137 | if ( $extraLbError ) { |
| 1138 | $this->logger->warning( |
| 1139 | __METHOD__ . ": $extraLbError; {last_error} ({db_server})", |
| 1140 | $this->getConnLogContext( |
| 1141 | $this->lastErrorConn, |
| 1142 | [ |
| 1143 | 'method' => __METHOD__, |
| 1144 | 'last_error' => $lastDbError |
| 1145 | ] |
| 1146 | ) |
| 1147 | ); |
| 1148 | } |
| 1149 | } else { |
| 1150 | $exception = new DBConnectionError( |
| 1151 | null, |
| 1152 | $extraLbError ?: 'could not connect to the DB server' |
| 1153 | ); |
| 1154 | |
| 1155 | if ( $extraLbError ) { |
| 1156 | $this->logger->error( |
| 1157 | __METHOD__ . ": $extraLbError", |
| 1158 | [ |
| 1159 | 'method' => __METHOD__, |
| 1160 | 'last_error' => '(last connection error missing)' |
| 1161 | ] |
| 1162 | ); |
| 1163 | } |
| 1164 | } |
| 1165 | |
| 1166 | throw $exception; |
| 1167 | } |
| 1168 | |
| 1169 | /** @inheritDoc */ |
| 1170 | public function getServerCount() { |
| 1171 | return $this->serverInfo->getServerCount(); |
| 1172 | } |
| 1173 | |
| 1174 | /** @inheritDoc */ |
| 1175 | public function hasReplicaServers() { |
| 1176 | return $this->serverInfo->hasReplicaServers(); |
| 1177 | } |
| 1178 | |
| 1179 | /** @inheritDoc */ |
| 1180 | public function hasStreamingReplicaServers() { |
| 1181 | return $this->serverInfo->hasStreamingReplicaServers(); |
| 1182 | } |
| 1183 | |
| 1184 | /** @inheritDoc */ |
| 1185 | public function getServerName( $i ): string { |
| 1186 | return $this->serverInfo->getServerName( $i ); |
| 1187 | } |
| 1188 | |
| 1189 | /** @inheritDoc */ |
| 1190 | public function getServerInfo( $i ) { |
| 1191 | return $this->serverInfo->getServerInfo( $i ); |
| 1192 | } |
| 1193 | |
| 1194 | /** @inheritDoc */ |
| 1195 | public function getServerType( $i ) { |
| 1196 | return $this->serverInfo->getServerType( $i ); |
| 1197 | } |
| 1198 | |
| 1199 | /** @inheritDoc */ |
| 1200 | public function getPrimaryPos() { |
| 1201 | $conn = $this->getAnyOpenConnection( ServerInfo::WRITER_INDEX ); |
| 1202 | if ( $conn ) { |
| 1203 | return $conn->getPrimaryPos(); |
| 1204 | } |
| 1205 | |
| 1206 | /** @var IDatabaseForOwner|null $conn */ |
| 1207 | $conn = $this->getConnectionInternal( ServerInfo::WRITER_INDEX, [], false, self::CONN_SILENCE_ERRORS ); |
| 1208 | // @phan-suppress-next-line PhanRedundantCondition |
| 1209 | if ( !$conn ) { |
| 1210 | $this->reportConnectionError(); |
| 1211 | } |
| 1212 | |
| 1213 | // ::getConnectionInternal() should return IDatabaseForOwner but changing signature |
| 1214 | // is not straightforward (being implemented in Wikibase) |
| 1215 | '@phan-var IDatabaseForOwner $conn'; |
| 1216 | try { |
| 1217 | return $conn->getPrimaryPos(); |
| 1218 | } finally { |
| 1219 | $this->closeConnection( $conn ); |
| 1220 | } |
| 1221 | } |
| 1222 | |
| 1223 | /** |
| 1224 | * Apply updated configuration. |
| 1225 | * |
| 1226 | * This only unregisters servers that were removed in the new configuration. |
| 1227 | * It does not register new servers nor update the group load weights. |
| 1228 | * |
| 1229 | * This invalidates any open connections. However, existing connections may continue to be |
| 1230 | * used while they are in an active transaction. In that case, the old connection will be |
| 1231 | * discarded on the first operation after the transaction is complete. The next operation |
| 1232 | * will use a new connection based on the new configuration. |
| 1233 | * |
| 1234 | * @internal for use by LBFactory::reconfigure() |
| 1235 | * |
| 1236 | * @see DBConnRef::ensureConnection() |
| 1237 | * @see LBFactory::reconfigure() |
| 1238 | * |
| 1239 | * @param array $params A database configuration array, see $wgLBFactoryConf. |
| 1240 | * |
| 1241 | * @return void |
| 1242 | */ |
| 1243 | public function reconfigure( array $params ) { |
| 1244 | $anyServerDepooled = false; |
| 1245 | |
| 1246 | $paramServers = $params['servers']; |
| 1247 | $newIndexByServerIndex = $this->serverInfo->reconfigureServers( $paramServers ); |
| 1248 | foreach ( $newIndexByServerIndex as $i => $ni ) { |
| 1249 | if ( $ni === null ) { |
| 1250 | // Server no longer exists in the new config |
| 1251 | $anyServerDepooled = true; |
| 1252 | // Note that if the primary server is depooled and a replica server promoted |
| 1253 | // to new primary, then DB_PRIMARY handles will fail with server index errors |
| 1254 | unset( $this->loads[$i] ); |
| 1255 | } |
| 1256 | } |
| 1257 | |
| 1258 | if ( $anyServerDepooled ) { |
| 1259 | // NOTE: We could close all connection here, but some may be in the middle of |
| 1260 | // a transaction. So instead, we leave it to DBConnRef to close the |
| 1261 | // connection when it detects that the modcount has changed and no |
| 1262 | // transaction is open. |
| 1263 | $this->logger->info( 'Reconfiguring dbs!' ); |
| 1264 | // Unpin DB_REPLICA connection groups from server indexes |
| 1265 | $this->readIndexByGroup = []; |
| 1266 | // We could close all connection here, but some may be in the middle of a |
| 1267 | // transaction. So instead, we leave it to DBConnRef to close the connection |
| 1268 | // when it detects that the modcount has changed and no transaction is open. |
| 1269 | $this->conns = self::newTrackedConnectionsArray(); |
| 1270 | // Bump modification counter to invalidate the connections held by DBConnRef |
| 1271 | // instances. This will cause the next call to a method on the DBConnRef |
| 1272 | // to get a new connection from getConnectionInternal() |
| 1273 | $this->modcount++; |
| 1274 | } |
| 1275 | } |
| 1276 | |
| 1277 | /** @inheritDoc */ |
| 1278 | public function disable( $fname = __METHOD__ ) { |
| 1279 | $this->closeAll( $fname ); |
| 1280 | $this->disabled = true; |
| 1281 | } |
| 1282 | |
| 1283 | /** @inheritDoc */ |
| 1284 | public function closeAll( $fname = __METHOD__ ) { |
| 1285 | /** @noinspection PhpUnusedLocalVariableInspection */ |
| 1286 | $scope = ScopedCallback::newScopedIgnoreUserAbort(); |
| 1287 | foreach ( $this->getOpenConnections() as $conn ) { |
| 1288 | $conn->close( $fname ); |
| 1289 | } |
| 1290 | |
| 1291 | $this->conns = self::newTrackedConnectionsArray(); |
| 1292 | } |
| 1293 | |
| 1294 | /** |
| 1295 | * Close a connection |
| 1296 | * |
| 1297 | * Using this function makes sure the LoadBalancer knows the connection is closed. |
| 1298 | * If you use $conn->close() directly, the load balancer won't update its state. |
| 1299 | */ |
| 1300 | private function closeConnection( IDatabaseForOwner $conn ) { |
| 1301 | if ( $conn instanceof DBConnRef ) { |
| 1302 | // Avoid calling close() but still leaving the handle in the pool |
| 1303 | throw new RuntimeException( 'Cannot close DBConnRef instance; it must be shareable' ); |
| 1304 | } |
| 1305 | |
| 1306 | $domain = $conn->getDomainID(); |
| 1307 | $serverIndex = $conn->getLBInfo( self::INFO_SERVER_INDEX ); |
| 1308 | if ( $serverIndex === null ) { |
| 1309 | throw new UnexpectedValueException( "Handle on '$domain' missing server index" ); |
| 1310 | } |
| 1311 | |
| 1312 | $srvName = $this->serverInfo->getServerName( $serverIndex ); |
| 1313 | |
| 1314 | $found = false; |
| 1315 | foreach ( $this->conns as $type => $poolConnsByServer ) { |
| 1316 | $key = array_search( $conn, $poolConnsByServer[$serverIndex] ?? [], true ); |
| 1317 | if ( $key !== false ) { |
| 1318 | $found = true; |
| 1319 | unset( $this->conns[$type][$serverIndex][$key] ); |
| 1320 | } |
| 1321 | } |
| 1322 | |
| 1323 | if ( !$found ) { |
| 1324 | $this->logger->warning( |
| 1325 | __METHOD__ . |
| 1326 | ": orphaned connection to database {$this->stringifyConn( $conn )} at '$srvName'." |
| 1327 | ); |
| 1328 | } |
| 1329 | |
| 1330 | $this->logger->debug( |
| 1331 | __METHOD__ . |
| 1332 | ": closing connection to database {$this->stringifyConn( $conn )} at '$srvName'." |
| 1333 | ); |
| 1334 | |
| 1335 | $conn->close( __METHOD__ ); |
| 1336 | } |
| 1337 | |
| 1338 | /** @inheritDoc */ |
| 1339 | public function finalizePrimaryChanges( $fname = __METHOD__ ) { |
| 1340 | $this->assertTransactionRoundStage( [ self::ROUND_CURSORY, self::ROUND_FINALIZED ] ); |
| 1341 | /** @noinspection PhpUnusedLocalVariableInspection */ |
| 1342 | $scope = ScopedCallback::newScopedIgnoreUserAbort(); |
| 1343 | |
| 1344 | $this->trxRoundStage = self::ROUND_ERROR; // "failed" until proven otherwise |
| 1345 | // Loop until callbacks stop adding callbacks on other connections |
| 1346 | $total = 0; |
| 1347 | do { |
| 1348 | $count = 0; // callbacks execution attempts |
| 1349 | foreach ( $this->getOpenPrimaryConnections() as $conn ) { |
| 1350 | // Run any pre-commit callbacks while leaving the post-commit ones suppressed. |
| 1351 | // Any error should cause all (peer) transactions to be rolled back together. |
| 1352 | $count += $conn->runOnTransactionPreCommitCallbacks(); |
| 1353 | } |
| 1354 | $total += $count; |
| 1355 | } while ( $count > 0 ); |
| 1356 | // Defer post-commit callbacks until after COMMIT/ROLLBACK happens on all handles |
| 1357 | foreach ( $this->getOpenPrimaryConnections() as $conn ) { |
| 1358 | $conn->setTrxEndCallbackSuppression( true ); |
| 1359 | } |
| 1360 | $this->trxRoundStage = self::ROUND_FINALIZED; |
| 1361 | |
| 1362 | return $total; |
| 1363 | } |
| 1364 | |
| 1365 | /** @inheritDoc */ |
| 1366 | public function approvePrimaryChanges( int $maxWriteDuration, $fname = __METHOD__ ) { |
| 1367 | $this->assertTransactionRoundStage( self::ROUND_FINALIZED ); |
| 1368 | /** @noinspection PhpUnusedLocalVariableInspection */ |
| 1369 | $scope = ScopedCallback::newScopedIgnoreUserAbort(); |
| 1370 | |
| 1371 | $this->trxRoundStage = self::ROUND_ERROR; // "failed" until proven otherwise |
| 1372 | foreach ( $this->getOpenPrimaryConnections() as $conn ) { |
| 1373 | // Any atomic sections should have been closed by now and there definitely should |
| 1374 | // not be any open transactions started by begin() from callers outside Database. |
| 1375 | if ( $conn->explicitTrxActive() ) { |
| 1376 | throw new DBTransactionError( |
| 1377 | $conn, |
| 1378 | "Explicit transaction still active; a caller might have failed to call " . |
| 1379 | "endAtomic() or cancelAtomic()." |
| 1380 | ); |
| 1381 | } |
| 1382 | // Assert that the time to replicate the transaction will be reasonable. |
| 1383 | // If this fails, then all DB transactions will be rollback back together. |
| 1384 | $time = $conn->pendingWriteQueryDuration( $conn::ESTIMATE_DB_APPLY ); |
| 1385 | if ( $maxWriteDuration > 0 ) { |
| 1386 | if ( $time > $maxWriteDuration ) { |
| 1387 | $humanTimeSec = round( $time, 3 ); |
| 1388 | throw new DBTransactionSizeError( |
| 1389 | $conn, |
| 1390 | "Transaction spent {time}s in writes, exceeding the {$maxWriteDuration}s limit", |
| 1391 | // Message parameters for: transaction-duration-limit-exceeded |
| 1392 | [ $time, $maxWriteDuration ], |
| 1393 | null, |
| 1394 | [ 'time' => $humanTimeSec ] |
| 1395 | ); |
| 1396 | } elseif ( $time > 0 ) { |
| 1397 | $timeMs = $time * 1000; |
| 1398 | $humanTimeMs = round( $timeMs, $timeMs > 1 ? 0 : 3 ); |
| 1399 | $this->logger->debug( |
| 1400 | "Transaction spent {time_ms}ms in writes, under the {$maxWriteDuration}s limit", |
| 1401 | [ 'time_ms' => $humanTimeMs ] |
| 1402 | ); |
| 1403 | } |
| 1404 | } |
| 1405 | // If a connection sits idle for too long it might be dropped, causing transaction |
| 1406 | // writes and session locks to be lost. Ping all the server connections before making |
| 1407 | // any attempt to commit the transactions belonging to the active transaction round. |
| 1408 | if ( $conn->writesOrCallbacksPending() || $conn->sessionLocksPending() ) { |
| 1409 | if ( !$conn->ping() ) { |
| 1410 | throw new DBTransactionError( |
| 1411 | $conn, |
| 1412 | "Pre-commit ping failed on server {$conn->getServerName()}" |
| 1413 | ); |
| 1414 | } |
| 1415 | } |
| 1416 | } |
| 1417 | $this->trxRoundStage = self::ROUND_APPROVED; |
| 1418 | } |
| 1419 | |
| 1420 | /** @inheritDoc */ |
| 1421 | public function beginPrimaryChanges( $fname = __METHOD__ ) { |
| 1422 | if ( $this->trxRoundFname !== null ) { |
| 1423 | throw new DBTransactionError( |
| 1424 | null, |
| 1425 | "Transaction round '{$this->trxRoundFname}' already started" |
| 1426 | ); |
| 1427 | } |
| 1428 | $this->assertTransactionRoundStage( self::ROUND_CURSORY ); |
| 1429 | /** @noinspection PhpUnusedLocalVariableInspection */ |
| 1430 | $scope = ScopedCallback::newScopedIgnoreUserAbort(); |
| 1431 | |
| 1432 | // Clear any empty transactions (no writes/callbacks) from the implicit round |
| 1433 | $this->flushPrimarySnapshots( $fname ); |
| 1434 | |
| 1435 | $this->trxRoundFname = $fname; |
| 1436 | $this->trxRoundStage = self::ROUND_ERROR; // "failed" until proven otherwise |
| 1437 | // Mark applicable handles as participating in this explicit transaction round. |
| 1438 | // For each of these handles, any writes and callbacks will be tied to a single |
| 1439 | // transaction. The (peer) handles will reject begin()/commit() calls unless they |
| 1440 | // are part of an en masse commit or an en masse rollback. |
| 1441 | foreach ( $this->getOpenConnections() as $conn ) { |
| 1442 | $this->syncConnectionRoundState( $conn ); |
| 1443 | } |
| 1444 | $this->trxRoundStage = self::ROUND_CURSORY; |
| 1445 | } |
| 1446 | |
| 1447 | /** @inheritDoc */ |
| 1448 | public function commitPrimaryChanges( $fname = __METHOD__ ) { |
| 1449 | $this->assertTransactionRoundStage( self::ROUND_APPROVED ); |
| 1450 | /** @noinspection PhpUnusedLocalVariableInspection */ |
| 1451 | $scope = ScopedCallback::newScopedIgnoreUserAbort(); |
| 1452 | |
| 1453 | $failures = []; |
| 1454 | |
| 1455 | $this->trxRoundFname = null; |
| 1456 | $this->trxRoundStage = self::ROUND_ERROR; // "failed" until proven otherwise |
| 1457 | // Commit any writes and clear any snapshots as well (callbacks require AUTOCOMMIT). |
| 1458 | // Note that callbacks should already be suppressed due to finalizePrimaryChanges(). |
| 1459 | foreach ( $this->getOpenPrimaryConnections() as $conn ) { |
| 1460 | try { |
| 1461 | $conn->commit( $fname, $conn::FLUSHING_ALL_PEERS ); |
| 1462 | } catch ( DBError $e ) { |
| 1463 | ( $this->errorLogger )( $e ); |
| 1464 | $failures[] = "{$conn->getServerName()}: {$e->getMessage()}"; |
| 1465 | } |
| 1466 | } |
| 1467 | if ( $failures ) { |
| 1468 | throw new DBTransactionError( |
| 1469 | null, |
| 1470 | "Commit failed on server(s) " . implode( "\n", array_unique( $failures ) ) |
| 1471 | ); |
| 1472 | } |
| 1473 | // Unmark handles as participating in this explicit transaction round |
| 1474 | foreach ( $this->getOpenConnections() as $conn ) { |
| 1475 | $this->syncConnectionRoundState( $conn ); |
| 1476 | } |
| 1477 | $this->trxRoundStage = self::ROUND_COMMIT_CALLBACKS; |
| 1478 | } |
| 1479 | |
| 1480 | /** @inheritDoc */ |
| 1481 | public function runPrimaryTransactionIdleCallbacks( $fname = __METHOD__ ) { |
| 1482 | if ( $this->trxRoundStage === self::ROUND_COMMIT_CALLBACKS ) { |
| 1483 | $type = IDatabase::TRIGGER_COMMIT; |
| 1484 | } elseif ( $this->trxRoundStage === self::ROUND_ROLLBACK_CALLBACKS ) { |
| 1485 | $type = IDatabase::TRIGGER_ROLLBACK; |
| 1486 | } else { |
| 1487 | throw new DBTransactionError( |
| 1488 | null, |
| 1489 | "Transaction should be in the callback stage (not '{$this->trxRoundStage}')" |
| 1490 | ); |
| 1491 | } |
| 1492 | /** @noinspection PhpUnusedLocalVariableInspection */ |
| 1493 | $scope = ScopedCallback::newScopedIgnoreUserAbort(); |
| 1494 | |
| 1495 | $oldStage = $this->trxRoundStage; |
| 1496 | $this->trxRoundStage = self::ROUND_ERROR; // "failed" until proven otherwise |
| 1497 | |
| 1498 | // Now that the COMMIT/ROLLBACK step is over, enable post-commit callback runs |
| 1499 | foreach ( $this->getOpenPrimaryConnections() as $conn ) { |
| 1500 | $conn->setTrxEndCallbackSuppression( false ); |
| 1501 | } |
| 1502 | |
| 1503 | $errors = []; |
| 1504 | $fname = __METHOD__; |
| 1505 | // Loop until callbacks stop adding callbacks on other connections |
| 1506 | do { |
| 1507 | // Run any pending callbacks for each connection... |
| 1508 | $count = 0; // callback execution attempts |
| 1509 | foreach ( $this->getOpenPrimaryConnections() as $conn ) { |
| 1510 | if ( $conn->trxLevel() ) { |
| 1511 | continue; // retry in the next iteration, after commit() is called |
| 1512 | } |
| 1513 | $count += $conn->runOnTransactionIdleCallbacks( $type, $errors ); |
| 1514 | } |
| 1515 | // Clear out any active transactions left over from callbacks... |
| 1516 | foreach ( $this->getOpenPrimaryConnections() as $conn ) { |
| 1517 | if ( $conn->writesPending() ) { |
| 1518 | // A callback from another handle wrote to this one and DBO_TRX is set |
| 1519 | $fnames = implode( ', ', $conn->pendingWriteCallers() ); |
| 1520 | $this->logger->info( |
| 1521 | "$fname: found writes pending ($fnames).", |
| 1522 | $this->getConnLogContext( |
| 1523 | $conn, |
| 1524 | [ 'exception' => new RuntimeException() ] |
| 1525 | ) |
| 1526 | ); |
| 1527 | $this->statsFactory->getCounter( 'rdbms_callback_writes_found_total' ) |
| 1528 | ->setLabel( 'db_cluster', $this->getClusterName() ) |
| 1529 | ->setLabel( 'db_server', $conn->getServerName() ) |
| 1530 | ->increment(); |
| 1531 | } elseif ( $conn->trxLevel() ) { |
| 1532 | // A callback from another handle read from this one and DBO_TRX is set, |
| 1533 | // which can easily happen if there is only one DB (no replicas) |
| 1534 | $this->logger->debug( "$fname: found empty transaction." ); |
| 1535 | } |
| 1536 | try { |
| 1537 | $conn->commit( $fname, $conn::FLUSHING_ALL_PEERS ); |
| 1538 | } catch ( DBError $ex ) { |
| 1539 | $errors[] = $ex; |
| 1540 | } |
| 1541 | } |
| 1542 | } while ( $count > 0 ); |
| 1543 | |
| 1544 | $this->trxRoundStage = $oldStage; |
| 1545 | |
| 1546 | return $errors[0] ?? null; |
| 1547 | } |
| 1548 | |
| 1549 | /** @inheritDoc */ |
| 1550 | public function runPrimaryTransactionListenerCallbacks( $fname = __METHOD__ ) { |
| 1551 | if ( $this->trxRoundStage === self::ROUND_COMMIT_CALLBACKS ) { |
| 1552 | $type = IDatabase::TRIGGER_COMMIT; |
| 1553 | } elseif ( $this->trxRoundStage === self::ROUND_ROLLBACK_CALLBACKS ) { |
| 1554 | $type = IDatabase::TRIGGER_ROLLBACK; |
| 1555 | } else { |
| 1556 | throw new DBTransactionError( |
| 1557 | null, |
| 1558 | "Transaction should be in the callback stage (not '{$this->trxRoundStage}')" |
| 1559 | ); |
| 1560 | } |
| 1561 | /** @noinspection PhpUnusedLocalVariableInspection */ |
| 1562 | $scope = ScopedCallback::newScopedIgnoreUserAbort(); |
| 1563 | |
| 1564 | $errors = []; |
| 1565 | $this->trxRoundStage = self::ROUND_ERROR; // "failed" until proven otherwise |
| 1566 | foreach ( $this->getOpenPrimaryConnections() as $conn ) { |
| 1567 | $conn->runTransactionListenerCallbacks( $type, $errors ); |
| 1568 | } |
| 1569 | $this->trxRoundStage = self::ROUND_CURSORY; |
| 1570 | |
| 1571 | return $errors[0] ?? null; |
| 1572 | } |
| 1573 | |
| 1574 | /** @inheritDoc */ |
| 1575 | public function rollbackPrimaryChanges( $fname = __METHOD__ ) { |
| 1576 | /** @noinspection PhpUnusedLocalVariableInspection */ |
| 1577 | $scope = ScopedCallback::newScopedIgnoreUserAbort(); |
| 1578 | |
| 1579 | $this->trxRoundFname = null; |
| 1580 | $this->trxRoundStage = self::ROUND_ERROR; // "failed" until proven otherwise |
| 1581 | foreach ( $this->getOpenPrimaryConnections() as $conn ) { |
| 1582 | $conn->rollback( $fname, $conn::FLUSHING_ALL_PEERS ); |
| 1583 | } |
| 1584 | // Unmark handles as participating in this explicit transaction round |
| 1585 | foreach ( $this->getOpenConnections() as $conn ) { |
| 1586 | $this->syncConnectionRoundState( $conn ); |
| 1587 | } |
| 1588 | $this->trxRoundStage = self::ROUND_ROLLBACK_CALLBACKS; |
| 1589 | } |
| 1590 | |
| 1591 | /** @inheritDoc */ |
| 1592 | public function flushPrimarySessions( $fname = __METHOD__ ) { |
| 1593 | $this->assertTransactionRoundStage( [ self::ROUND_CURSORY ] ); |
| 1594 | if ( $this->hasPrimaryChanges() ) { |
| 1595 | // Any transaction should have been rolled back beforehand |
| 1596 | throw new DBTransactionError( null, "Cannot reset session while writes are pending" ); |
| 1597 | } |
| 1598 | |
| 1599 | foreach ( $this->getOpenPrimaryConnections() as $conn ) { |
| 1600 | $conn->flushSession( $fname, $conn::FLUSHING_ALL_PEERS ); |
| 1601 | } |
| 1602 | } |
| 1603 | |
| 1604 | /** |
| 1605 | * @param string|string[] $stage |
| 1606 | * @throws DBTransactionError |
| 1607 | */ |
| 1608 | private function assertTransactionRoundStage( $stage ) { |
| 1609 | $stages = (array)$stage; |
| 1610 | |
| 1611 | if ( !in_array( $this->trxRoundStage, $stages, true ) ) { |
| 1612 | $stageList = implode( |
| 1613 | '/', |
| 1614 | array_map( static fn ( $v ) => "'$v'", $stages ) |
| 1615 | ); |
| 1616 | $transactionName = $this->trxRoundFname ?? '<unknown>'; |
| 1617 | throw new DBTransactionError( |
| 1618 | null, |
| 1619 | "Transaction '$transactionName' round stage must be '$stageList' (not '{$this->trxRoundStage}')" |
| 1620 | ); |
| 1621 | } |
| 1622 | } |
| 1623 | |
| 1624 | /** |
| 1625 | * Make connections with DBO_DEFAULT/DBO_TRX set join any active transaction round |
| 1626 | * |
| 1627 | * Some servers may have neither flag enabled, meaning that they opt out of such |
| 1628 | * transaction rounds and remain in auto-commit mode. Such behavior might be desired |
| 1629 | * when a DB server is used for something like simple key/value storage. |
| 1630 | * |
| 1631 | * @param Database $conn |
| 1632 | */ |
| 1633 | private function syncConnectionRoundState( Database $conn ) { |
| 1634 | if ( $conn->getLBInfo( self::INFO_CONN_CATEGORY ) !== self::CATEGORY_ROUND ) { |
| 1635 | return; // transaction rounds do not apply to these connections |
| 1636 | } |
| 1637 | |
| 1638 | if ( $this->trxRoundFname !== null ) { |
| 1639 | // Explicit transaction round |
| 1640 | $trxRoundLevel = 1; |
| 1641 | } else { |
| 1642 | // Implicit auto-commit round (cli mode) or implicit transaction round (web mode) |
| 1643 | $trxRoundLevel = ( $this->cliMode ? 0 : 1 ); |
| 1644 | } |
| 1645 | |
| 1646 | // CATEGORY_ROUND DB handles with DBO_DEFAULT are considered "round aware" and the |
| 1647 | // load balancer will take over the logic of when DBO_TRX is set for such DB handles. |
| 1648 | // DBO_TRX will be set only when a transaction round is active (explicit or implicit). |
| 1649 | if ( $conn->getFlag( $conn::DBO_DEFAULT ) ) { |
| 1650 | if ( $trxRoundLevel ) { |
| 1651 | // Wrap queries in a transaction joined to the active transaction round |
| 1652 | $conn->setFlag( $conn::DBO_TRX ); |
| 1653 | } else { |
| 1654 | // Do not wrap queries in a transaction (no active transaction round) |
| 1655 | $conn->clearFlag( $conn::DBO_TRX ); |
| 1656 | } |
| 1657 | } |
| 1658 | |
| 1659 | // Note that DBO_TRX is normally only set above or by DatabaseFactory applying |
| 1660 | // DBO_DEFAULT. However, integration tests might directly force DBO_TRX in the |
| 1661 | // server configuration arrays. Such handles will still be flushed during calls |
| 1662 | // to {@link LoadBalancer::commitPrimaryChanges()}. |
| 1663 | if ( $conn->getFlag( $conn::DBO_TRX ) ) { |
| 1664 | // DB handle is participating in the active transaction round |
| 1665 | $conn->setLBInfo( $conn::LB_TRX_ROUND_LEVEL, $trxRoundLevel ); |
| 1666 | $conn->setLBInfo( $conn::LB_TRX_ROUND_FNAME, $this->trxRoundFname ); |
| 1667 | } else { |
| 1668 | // DB handle is not participating in any transaction rounds |
| 1669 | $conn->setLBInfo( $conn::LB_TRX_ROUND_LEVEL, 0 ); |
| 1670 | $conn->setLBInfo( $conn::LB_TRX_ROUND_FNAME, null ); |
| 1671 | } |
| 1672 | } |
| 1673 | |
| 1674 | /** @inheritDoc */ |
| 1675 | public function flushReplicaSnapshots( $fname = __METHOD__ ) { |
| 1676 | foreach ( $this->conns as $poolConnsByServer ) { |
| 1677 | foreach ( $poolConnsByServer as $serverIndex => $serverConns ) { |
| 1678 | if ( $serverIndex === ServerInfo::WRITER_INDEX ) { |
| 1679 | continue; // skip primary |
| 1680 | } |
| 1681 | foreach ( $serverConns as $conn ) { |
| 1682 | $conn->flushSnapshot( $fname ); |
| 1683 | } |
| 1684 | } |
| 1685 | } |
| 1686 | } |
| 1687 | |
| 1688 | /** @inheritDoc */ |
| 1689 | public function flushPrimarySnapshots( $fname = __METHOD__ ) { |
| 1690 | foreach ( $this->getOpenPrimaryConnections() as $conn ) { |
| 1691 | $conn->flushSnapshot( $fname ); |
| 1692 | } |
| 1693 | } |
| 1694 | |
| 1695 | /** @inheritDoc */ |
| 1696 | public function hasPrimaryConnection() { |
| 1697 | return (bool)$this->getAnyOpenConnection( ServerInfo::WRITER_INDEX ); |
| 1698 | } |
| 1699 | |
| 1700 | /** @inheritDoc */ |
| 1701 | public function hasPrimaryChanges() { |
| 1702 | foreach ( $this->getOpenPrimaryConnections() as $conn ) { |
| 1703 | if ( $conn->writesOrCallbacksPending() ) { |
| 1704 | return true; |
| 1705 | } |
| 1706 | } |
| 1707 | |
| 1708 | return false; |
| 1709 | } |
| 1710 | |
| 1711 | /** @inheritDoc */ |
| 1712 | public function lastPrimaryChangeTimestamp() { |
| 1713 | $lastTime = null; |
| 1714 | foreach ( $this->getOpenPrimaryConnections() as $conn ) { |
| 1715 | $lastTime = max( $lastTime, $conn->lastDoneWrites() ); |
| 1716 | } |
| 1717 | |
| 1718 | return $lastTime; |
| 1719 | } |
| 1720 | |
| 1721 | /** @inheritDoc */ |
| 1722 | public function hasOrMadeRecentPrimaryChanges( $age = null ) { |
| 1723 | $age ??= self::MAX_WAIT_DEFAULT; |
| 1724 | |
| 1725 | return ( $this->hasPrimaryChanges() |
| 1726 | || $this->lastPrimaryChangeTimestamp() > microtime( true ) - $age ); |
| 1727 | } |
| 1728 | |
| 1729 | /** @inheritDoc */ |
| 1730 | public function pendingPrimaryChangeCallers() { |
| 1731 | $fnames = []; |
| 1732 | foreach ( $this->getOpenPrimaryConnections() as $conn ) { |
| 1733 | $fnames = array_merge( $fnames, $conn->pendingWriteCallers() ); |
| 1734 | } |
| 1735 | |
| 1736 | return $fnames; |
| 1737 | } |
| 1738 | |
| 1739 | /** @inheritDoc */ |
| 1740 | public function explicitTrxActive() { |
| 1741 | foreach ( $this->getOpenPrimaryConnections() as $conn ) { |
| 1742 | if ( $conn->explicitTrxActive() ) { |
| 1743 | return true; |
| 1744 | } |
| 1745 | } |
| 1746 | return false; |
| 1747 | } |
| 1748 | |
| 1749 | private function setLaggedReplicaMode(): void { |
| 1750 | $this->laggedReplicaMode = true; |
| 1751 | $this->logger->warning( __METHOD__ . ": setting lagged replica mode" ); |
| 1752 | } |
| 1753 | |
| 1754 | /** @inheritDoc */ |
| 1755 | public function laggedReplicaUsed() { |
| 1756 | return $this->laggedReplicaMode; |
| 1757 | } |
| 1758 | |
| 1759 | /** @inheritDoc */ |
| 1760 | public function getReadOnlyReason() { |
| 1761 | if ( $this->readOnlyReason !== false ) { |
| 1762 | return $this->readOnlyReason; |
| 1763 | } elseif ( $this->isPrimaryRunningReadOnly() ) { |
| 1764 | return 'The primary database server is running in read-only mode.'; |
| 1765 | } |
| 1766 | |
| 1767 | return false; |
| 1768 | } |
| 1769 | |
| 1770 | /** |
| 1771 | * @note This method suppresses DBError exceptions in order to avoid severe downtime |
| 1772 | * @param IDatabaseForOwner|null $conn Recently acquired primary connection; null if not applicable |
| 1773 | * @return bool Whether the entire primary DB server or the local domain DB is read-only |
| 1774 | */ |
| 1775 | private function isPrimaryRunningReadOnly( ?IDatabaseForOwner $conn = null ) { |
| 1776 | // Context will often be HTTP GET/HEAD; heavily cache the results |
| 1777 | return (bool)$this->wanCache->getWithSetCallback( |
| 1778 | // Note that table prefixes are not related to server-side read-only mode |
| 1779 | $this->wanCache->makeGlobalKey( |
| 1780 | 'rdbms-server-readonly', |
| 1781 | $this->serverInfo->getPrimaryServerName() |
| 1782 | ), |
| 1783 | self::TTL_CACHE_READONLY, |
| 1784 | function ( $oldValue ) use ( $conn ) { |
| 1785 | $scope = $this->trxProfiler->silenceForScope(); |
| 1786 | $conn ??= $this->getServerConnection( |
| 1787 | ServerInfo::WRITER_INDEX, |
| 1788 | self::DOMAIN_ANY, |
| 1789 | self::CONN_SILENCE_ERRORS |
| 1790 | ); |
| 1791 | if ( $conn ) { |
| 1792 | try { |
| 1793 | $value = (int)$conn->serverIsReadOnly(); |
| 1794 | } catch ( DBError ) { |
| 1795 | $value = is_int( $oldValue ) ? $oldValue : 0; |
| 1796 | } |
| 1797 | } else { |
| 1798 | $value = 0; |
| 1799 | } |
| 1800 | ScopedCallback::consume( $scope ); |
| 1801 | |
| 1802 | return $value; |
| 1803 | }, |
| 1804 | [ |
| 1805 | 'busyValue' => 0, |
| 1806 | 'pcTTL' => WANObjectCache::TTL_PROC_LONG |
| 1807 | ] |
| 1808 | ); |
| 1809 | } |
| 1810 | |
| 1811 | /** @inheritDoc */ |
| 1812 | public function pingAll() { |
| 1813 | $success = true; |
| 1814 | foreach ( $this->getOpenConnections() as $conn ) { |
| 1815 | if ( !$conn->ping() ) { |
| 1816 | $success = false; |
| 1817 | } |
| 1818 | } |
| 1819 | |
| 1820 | return $success; |
| 1821 | } |
| 1822 | |
| 1823 | /** |
| 1824 | * Get all open connections |
| 1825 | * @return \Generator|Database[] |
| 1826 | */ |
| 1827 | private function getOpenConnections() { |
| 1828 | foreach ( $this->conns as $poolConnsByServer ) { |
| 1829 | foreach ( $poolConnsByServer as $serverConns ) { |
| 1830 | foreach ( $serverConns as $conn ) { |
| 1831 | yield $conn; |
| 1832 | } |
| 1833 | } |
| 1834 | } |
| 1835 | } |
| 1836 | |
| 1837 | /** |
| 1838 | * Get all open primary connections |
| 1839 | * @return \Generator|Database[] |
| 1840 | */ |
| 1841 | private function getOpenPrimaryConnections() { |
| 1842 | foreach ( $this->conns as $poolConnsByServer ) { |
| 1843 | /** @var IDatabaseForOwner $conn */ |
| 1844 | foreach ( ( $poolConnsByServer[ServerInfo::WRITER_INDEX] ?? [] ) as $conn ) { |
| 1845 | yield $conn; |
| 1846 | } |
| 1847 | } |
| 1848 | } |
| 1849 | |
| 1850 | /** @inheritDoc */ |
| 1851 | public function getMaxLag() { |
| 1852 | $host = ''; |
| 1853 | $maxLag = -1; |
| 1854 | $maxIndex = 0; |
| 1855 | |
| 1856 | if ( $this->serverInfo->hasReplicaServers() ) { |
| 1857 | $lagTimes = $this->getLagTimes(); |
| 1858 | foreach ( $lagTimes as $i => $lag ) { |
| 1859 | // Allowing the value to be unset due to stale cache (T361824) |
| 1860 | $load = $this->loads[$i] ?? 0; |
| 1861 | if ( $load > 0 && $lag > $maxLag ) { |
| 1862 | $maxLag = $lag; |
| 1863 | $host = $this->serverInfo->getServerInfoStrict( $i, 'host' ); |
| 1864 | $maxIndex = $i; |
| 1865 | } |
| 1866 | } |
| 1867 | } |
| 1868 | |
| 1869 | return [ $host, $maxLag, $maxIndex ]; |
| 1870 | } |
| 1871 | |
| 1872 | /** @inheritDoc */ |
| 1873 | public function getLagTimes() { |
| 1874 | if ( !$this->hasReplicaServers() ) { |
| 1875 | return [ ServerInfo::WRITER_INDEX => 0 ]; // no replication = no lag |
| 1876 | } |
| 1877 | $fname = __METHOD__; |
| 1878 | return $this->wanCache->getWithSetCallback( |
| 1879 | $this->wanCache->makeGlobalKey( 'rdbms-lags', $this->getClusterName() ), |
| 1880 | // Add jitter to avoid stampede |
| 1881 | 10 + mt_rand( 1, 10 ), |
| 1882 | function () use ( $fname ) { |
| 1883 | $lags = []; |
| 1884 | foreach ( $this->serverInfo->getStreamingReplicaIndexes() as $i ) { |
| 1885 | $conn = $this->getServerConnection( |
| 1886 | $i, |
| 1887 | self::DOMAIN_ANY, |
| 1888 | self::CONN_SILENCE_ERRORS | self::CONN_UNTRACKED_GAUGE |
| 1889 | ); |
| 1890 | if ( $conn ) { |
| 1891 | $lags[$i] = $conn->getLag(); |
| 1892 | $conn->close( $fname ); |
| 1893 | } else { |
| 1894 | $lags[$i] = false; |
| 1895 | } |
| 1896 | } |
| 1897 | return $lags; |
| 1898 | }, |
| 1899 | [ 'lockTSE' => 30 ] |
| 1900 | ); |
| 1901 | } |
| 1902 | |
| 1903 | /** @inheritDoc */ |
| 1904 | public function waitForPrimaryPos( IDatabase $conn ) { |
| 1905 | if ( $conn->getLBInfo( self::INFO_SERVER_INDEX ) === ServerInfo::WRITER_INDEX ) { |
| 1906 | return true; // not a replica DB server |
| 1907 | } |
| 1908 | |
| 1909 | // Get the current primary DB position, opening a connection only if needed |
| 1910 | $flags = self::CONN_SILENCE_ERRORS; |
| 1911 | $primaryConn = $this->getAnyOpenConnection( ServerInfo::WRITER_INDEX, $flags ); |
| 1912 | if ( $primaryConn ) { |
| 1913 | $pos = $primaryConn->getPrimaryPos(); |
| 1914 | } else { |
| 1915 | $primaryConn = $this->getServerConnection( ServerInfo::WRITER_INDEX, self::DOMAIN_ANY, $flags ); |
| 1916 | if ( !$primaryConn ) { |
| 1917 | throw new DBReplicationWaitError( |
| 1918 | null, |
| 1919 | "Could not obtain a primary database connection to get the position" |
| 1920 | ); |
| 1921 | } |
| 1922 | $pos = $primaryConn->getPrimaryPos(); |
| 1923 | $this->closeConnection( $primaryConn ); |
| 1924 | } |
| 1925 | |
| 1926 | if ( $pos instanceof DBPrimaryPos && $conn instanceof IDatabaseForOwner ) { |
| 1927 | $this->logger->debug( __METHOD__ . ': waiting' ); |
| 1928 | $result = $conn->primaryPosWait( $pos, self::MAX_WAIT_DEFAULT ); |
| 1929 | $ok = ( $result !== null && $result != -1 ); |
| 1930 | if ( $ok ) { |
| 1931 | $this->logger->debug( __METHOD__ . ': done waiting (success)' ); |
| 1932 | } else { |
| 1933 | $this->logger->debug( __METHOD__ . ': done waiting (failure)' ); |
| 1934 | } |
| 1935 | } else { |
| 1936 | $ok = false; // something is misconfigured |
| 1937 | $this->logger->error( |
| 1938 | __METHOD__ . ': could not get primary pos for {db_server}', |
| 1939 | $this->getConnLogContext( $conn, [ 'exception' => new RuntimeException() ] ) |
| 1940 | ); |
| 1941 | } |
| 1942 | |
| 1943 | return $ok; |
| 1944 | } |
| 1945 | |
| 1946 | /** @inheritDoc */ |
| 1947 | public function setTransactionListener( $name, ?callable $callback = null ) { |
| 1948 | if ( $callback ) { |
| 1949 | $this->trxRecurringCallbacks[$name] = $callback; |
| 1950 | } else { |
| 1951 | unset( $this->trxRecurringCallbacks[$name] ); |
| 1952 | } |
| 1953 | foreach ( $this->getOpenPrimaryConnections() as $conn ) { |
| 1954 | $conn->setTransactionListener( $name, $callback ); |
| 1955 | } |
| 1956 | } |
| 1957 | |
| 1958 | public function setTableAliases( array $aliases ) { |
| 1959 | $this->tableAliases = $aliases; |
| 1960 | } |
| 1961 | |
| 1962 | public function setDomainAliases( array $aliases ) { |
| 1963 | $this->domainAliases = $aliases; |
| 1964 | } |
| 1965 | |
| 1966 | /** @inheritDoc */ |
| 1967 | public function setLocalDomainPrefix( $prefix ) { |
| 1968 | $oldLocalDomain = $this->localDomain; |
| 1969 | $this->localDomain = new DatabaseDomain( |
| 1970 | $this->localDomain->getDatabase(), |
| 1971 | $this->localDomain->getSchema(), |
| 1972 | $prefix |
| 1973 | ); |
| 1974 | |
| 1975 | // Update the prefix for existing connections. |
| 1976 | // Existing DBConnRef handles will not be affected. |
| 1977 | foreach ( $this->getOpenConnections() as $conn ) { |
| 1978 | if ( $oldLocalDomain->equals( $conn->getDomainID() ) ) { |
| 1979 | $conn->tablePrefix( $prefix ); |
| 1980 | } |
| 1981 | } |
| 1982 | } |
| 1983 | |
| 1984 | /** @inheritDoc */ |
| 1985 | public function redefineLocalDomain( $domain ) { |
| 1986 | $this->closeAll( __METHOD__ ); |
| 1987 | $this->localDomain = DatabaseDomain::newFromId( $domain ); |
| 1988 | } |
| 1989 | |
| 1990 | /** @inheritDoc */ |
| 1991 | public function setTempTablesOnlyMode( $value, $domain ) { |
| 1992 | $old = $this->tempTablesOnlyMode[$domain] ?? false; |
| 1993 | if ( $value ) { |
| 1994 | $this->tempTablesOnlyMode[$domain] = true; |
| 1995 | } else { |
| 1996 | unset( $this->tempTablesOnlyMode[$domain] ); |
| 1997 | } |
| 1998 | |
| 1999 | return $old; |
| 2000 | } |
| 2001 | |
| 2002 | /** |
| 2003 | * @param IDatabase $conn |
| 2004 | * @return string Description of a connection handle for log messages |
| 2005 | * @throws InvalidArgumentException |
| 2006 | */ |
| 2007 | private function stringifyConn( IDatabase $conn ) { |
| 2008 | return $conn->getLBInfo( self::INFO_SERVER_INDEX ) . '/' . $conn->getDomainID(); |
| 2009 | } |
| 2010 | |
| 2011 | /** |
| 2012 | * @param int $flags A bitfield of flags |
| 2013 | * @param int $bit Bit flag constant |
| 2014 | * @return bool Whether the bit field has the specified bit flag set |
| 2015 | */ |
| 2016 | private function fieldHasBit( int $flags, int $bit ) { |
| 2017 | return ( ( $flags & $bit ) === $bit ); |
| 2018 | } |
| 2019 | |
| 2020 | /** |
| 2021 | * Create a log context to pass to PSR-3 logger functions. |
| 2022 | * |
| 2023 | * @param IDatabase $conn |
| 2024 | * @param array $extras Additional data to add to context |
| 2025 | * @return array |
| 2026 | */ |
| 2027 | protected function getConnLogContext( IDatabase $conn, array $extras = [] ) { |
| 2028 | return $extras + [ |
| 2029 | 'db_server' => $conn->getServerName(), |
| 2030 | 'db_domain' => $conn->getDomainID(), |
| 2031 | ]; |
| 2032 | } |
| 2033 | |
| 2034 | /** |
| 2035 | * @param float|null &$time Mock UNIX timestamp for testing |
| 2036 | * @internal |
| 2037 | * @codeCoverageIgnore |
| 2038 | */ |
| 2039 | public function setMockTime( &$time ) { |
| 2040 | if ( !$this->loadMonitor instanceof LoadMonitor ) { |
| 2041 | throw new LogicException( 'Cannot set mock time on ' . $this::class . ' (consider adding ' . |
| 2042 | 'setMockTime to ILoadMonitor).' ); |
| 2043 | } |
| 2044 | $this->loadMonitor->setMockTime( $time ); |
| 2045 | } |
| 2046 | |
| 2047 | public function setDefaultGroupName( string $defaultGroup ): void { |
| 2048 | $this->defaultGroup = $defaultGroup; |
| 2049 | } |
| 2050 | } |