X-Git-Url: https://git.heureux-cyclage.org/?p=lhc%2Fweb%2Fwiklou.git;a=blobdiff_plain;f=includes%2Flibs%2Frdbms%2Floadbalancer%2FLoadBalancer.php;h=e95e23f9465d6e97603199c93c3d2231319ae327;hp=b01b23f4ddd1126c80143ef1cbcae3ba6bbf3e41;hb=a5723f66d687b3817655ef927fecc8ca829e0d21;hpb=9bf44d08f938cc9a85dc647b8a00665d5bd01fb6 diff --git a/includes/libs/rdbms/loadbalancer/LoadBalancer.php b/includes/libs/rdbms/loadbalancer/LoadBalancer.php index b01b23f4dd..e95e23f946 100644 --- a/includes/libs/rdbms/loadbalancer/LoadBalancer.php +++ b/includes/libs/rdbms/loadbalancer/LoadBalancer.php @@ -39,17 +39,17 @@ use Exception; */ class LoadBalancer implements ILoadBalancer { /** @var array[] Map of (server index => server config array) */ - private $mServers; + private $servers; /** @var Database[][][] Map of (connection category => server index => IDatabase[]) */ - private $mConns; + private $conns; /** @var float[] Map of (server index => weight) */ - private $mLoads; + private $loads; /** @var array[] Map of (group => server index => weight) */ - private $mGroupLoads; + private $groupLoads; /** @var bool Whether to disregard replica DB lag as a factor in replica DB selection */ - private $mAllowLagged; + private $allowLagged; /** @var int Seconds to spend waiting on replica DB lag to resolve */ - private $mWaitTimeout; + private $waitTimeout; /** @var array The LoadMonitor configuration */ private $loadMonitorConfig; /** @var array[] $aliases Map of (table => (dbname, schema, prefix) map) */ @@ -79,15 +79,15 @@ class LoadBalancer implements ILoadBalancer { /** @var Database DB connection object that caused a problem */ private $errorConnection; /** @var int The generic (not query grouped) replica DB index (of $mServers) */ - private $mReadIndex; + private $readIndex; /** @var bool|DBMasterPos False if not set */ - private $mWaitForPos; + private $waitForPos; /** @var bool Whether the generic reader fell back to a lagged replica DB */ private $laggedReplicaMode = false; /** @var bool Whether the generic reader fell back to a lagged replica DB */ private $allReplicasDownMode = false; /** @var string The last DB selection or connection error */ - private $mLastError = 'Unknown error'; + private $lastError = 'Unknown error'; /** @var string|bool Reason the LB is read-only or false if not */ private $readOnlyReason = false; /** @var int Total connections opened */ @@ -122,6 +122,8 @@ class LoadBalancer implements ILoadBalancer { /** @var int Default 'maxLag' when unspecified */ const MAX_LAG_DEFAULT = 10; + /** @var int Default 'waitTimeout' when unspecified */ + const MAX_WAIT_DEFAULT = 10; /** @var int Seconds to cache master server read-only status */ const TTL_CACHE_READONLY = 5; @@ -137,12 +139,12 @@ class LoadBalancer implements ILoadBalancer { if ( !isset( $params['servers'] ) ) { throw new InvalidArgumentException( __CLASS__ . ': missing servers parameter' ); } - $this->mServers = $params['servers']; - foreach ( $this->mServers as $i => $server ) { + $this->servers = $params['servers']; + foreach ( $this->servers as $i => $server ) { if ( $i == 0 ) { - $this->mServers[$i]['master'] = true; + $this->servers[$i]['master'] = true; } else { - $this->mServers[$i]['replica'] = true; + $this->servers[$i]['replica'] = true; } } @@ -151,10 +153,12 @@ class LoadBalancer implements ILoadBalancer { : DatabaseDomain::newUnspecified(); $this->setLocalDomain( $localDomain ); - $this->mWaitTimeout = isset( $params['waitTimeout'] ) ? $params['waitTimeout'] : 10; + $this->waitTimeout = isset( $params['waitTimeout'] ) + ? $params['waitTimeout'] + : self::MAX_WAIT_DEFAULT; - $this->mReadIndex = -1; - $this->mConns = [ + $this->readIndex = -1; + $this->conns = [ // Connection were transaction rounds may be applied self::KEY_LOCAL => [], self::KEY_FOREIGN_INUSE => [], @@ -164,9 +168,9 @@ class LoadBalancer implements ILoadBalancer { self::KEY_FOREIGN_INUSE_NOROUND => [], self::KEY_FOREIGN_FREE_NOROUND => [] ]; - $this->mLoads = []; - $this->mWaitForPos = false; - $this->mAllowLagged = false; + $this->loads = []; + $this->waitForPos = false; + $this->allowLagged = false; if ( isset( $params['readOnlyReason'] ) && is_string( $params['readOnlyReason'] ) ) { $this->readOnlyReason = $params['readOnlyReason']; @@ -184,13 +188,13 @@ class LoadBalancer implements ILoadBalancer { $this->loadMonitorConfig += [ 'lagWarnThreshold' => $this->maxLag ]; foreach ( $params['servers'] as $i => $server ) { - $this->mLoads[$i] = $server['load']; + $this->loads[$i] = $server['load']; if ( isset( $server['groupLoads'] ) ) { foreach ( $server['groupLoads'] as $group => $ratio ) { - if ( !isset( $this->mGroupLoads[$group] ) ) { - $this->mGroupLoads[$group] = []; + if ( !isset( $this->groupLoads[$group] ) ) { + $this->groupLoads[$group] = []; } - $this->mGroupLoads[$group][$i] = $ratio; + $this->groupLoads[$group][$i] = $ratio; } } } @@ -285,8 +289,8 @@ class LoadBalancer implements ILoadBalancer { foreach ( $lags as $i => $lag ) { if ( $i != 0 ) { # How much lag this server nominally is allowed to have - $maxServerLag = isset( $this->mServers[$i]['max lag'] ) - ? $this->mServers[$i]['max lag'] + $maxServerLag = isset( $this->servers[$i]['max lag'] ) + ? $this->servers[$i]['max lag'] : $this->maxLag; // default # Constrain that futher by $maxLag argument $maxServerLag = min( $maxServerLag, $maxLag ); @@ -294,11 +298,13 @@ class LoadBalancer implements ILoadBalancer { $host = $this->getServerName( $i ); if ( $lag === false && !is_infinite( $maxServerLag ) ) { $this->replLogger->error( - "Server {host} is not replicating?", [ 'host' => $host ] ); + __METHOD__ . + ": server {host} is not replicating?", [ 'host' => $host ] ); unset( $loads[$i] ); } elseif ( $lag > $maxServerLag ) { $this->replLogger->info( - "Server {host} has {lag} seconds of lag (>= {maxlag})", + __METHOD__ . + ": server {host} has {lag} seconds of lag (>= {maxlag})", [ 'host' => $host, 'lag' => $lag, 'maxlag' => $maxServerLag ] ); unset( $loads[$i] ); @@ -328,18 +334,18 @@ class LoadBalancer implements ILoadBalancer { } public function getReaderIndex( $group = false, $domain = false ) { - if ( count( $this->mServers ) == 1 ) { + if ( count( $this->servers ) == 1 ) { // Skip the load balancing if there's only one server return $this->getWriterIndex(); - } elseif ( $group === false && $this->mReadIndex >= 0 ) { + } elseif ( $group === false && $this->readIndex >= 0 ) { // Shortcut if the generic reader index was already cached - return $this->mReadIndex; + return $this->readIndex; } if ( $group !== false ) { // Use the server weight array for this load group - if ( isset( $this->mGroupLoads[$group] ) ) { - $loads = $this->mGroupLoads[$group]; + if ( isset( $this->groupLoads[$group] ) ) { + $loads = $this->groupLoads[$group]; } else { // No loads for this group, return false and the caller can use some other group $this->connLogger->info( __METHOD__ . ": no loads for group $group" ); @@ -348,7 +354,7 @@ class LoadBalancer implements ILoadBalancer { } } else { // Use the generic load group - $loads = $this->mLoads; + $loads = $this->loads; } // Scale the configured load ratios according to each server's load and state @@ -361,7 +367,7 @@ class LoadBalancer implements ILoadBalancer { return false; } - if ( $this->mWaitForPos && $i != $this->getWriterIndex() ) { + if ( $this->waitForPos && $i != $this->getWriterIndex() ) { // Before any data queries are run, wait for the server to catch up to the // specified position. This is used to improve session consistency. Note that // when LoadBalancer::waitFor() sets mWaitForPos, the waiting triggers here, @@ -371,9 +377,9 @@ class LoadBalancer implements ILoadBalancer { } } - if ( $this->mReadIndex <= 0 && $this->mLoads[$i] > 0 && $group === false ) { + if ( $this->readIndex <= 0 && $this->loads[$i] > 0 && $group === false ) { // Cache the generic reader index for future ungrouped DB_REPLICA handles - $this->mReadIndex = $i; + $this->readIndex = $i; // Record if the generic reader index is in "lagged replica DB" mode if ( $laggedReplicaMode ) { $this->laggedReplicaMode = true; @@ -404,15 +410,15 @@ class LoadBalancer implements ILoadBalancer { // Quickly look through the available servers for a server that meets criteria... $currentLoads = $loads; while ( count( $currentLoads ) ) { - if ( $this->mAllowLagged || $laggedReplicaMode ) { + if ( $this->allowLagged || $laggedReplicaMode ) { $i = ArrayUtils::pickRandom( $currentLoads ); } else { $i = false; - if ( $this->mWaitForPos && $this->mWaitForPos->asOfTime() ) { + if ( $this->waitForPos && $this->waitForPos->asOfTime() ) { // ChronologyProtecter sets mWaitForPos for session consistency. // This triggers doWait() after connect, so it's especially good to // avoid lagged servers so as to avoid excessive delay in that method. - $ago = microtime( true ) - $this->mWaitForPos->asOfTime(); + $ago = microtime( true ) - $this->waitForPos->asOfTime(); // Aim for <= 1 second of waiting (being too picky can backfire) $i = $this->getRandomNonLagged( $currentLoads, $domain, $ago + 1 ); } @@ -422,7 +428,8 @@ class LoadBalancer implements ILoadBalancer { } if ( $i === false && count( $currentLoads ) != 0 ) { // All replica DBs lagged. Switch to read-only mode - $this->replLogger->error( "All replica DBs lagged. Switch to read-only mode" ); + $this->replLogger->error( + __METHOD__ . ": all replica DBs lagged. Switch to read-only mode" ); $i = ArrayUtils::pickRandom( $currentLoads ); $laggedReplicaMode = true; } @@ -460,18 +467,18 @@ class LoadBalancer implements ILoadBalancer { // If all servers were down, quit now if ( !count( $currentLoads ) ) { - $this->connLogger->error( "All servers down" ); + $this->connLogger->error( __METHOD__ . ": all servers down" ); } return [ $i, $laggedReplicaMode ]; } public function waitFor( $pos ) { - $oldPos = $this->mWaitForPos; + $oldPos = $this->waitForPos; try { - $this->mWaitForPos = $pos; + $this->waitForPos = $pos; // If a generic reader connection was already established, then wait now - $i = $this->mReadIndex; + $i = $this->readIndex; if ( $i > 0 ) { if ( !$this->doWait( $i ) ) { $this->laggedReplicaMode = true; @@ -484,14 +491,14 @@ class LoadBalancer implements ILoadBalancer { } public function waitForOne( $pos, $timeout = null ) { - $oldPos = $this->mWaitForPos; + $oldPos = $this->waitForPos; try { - $this->mWaitForPos = $pos; + $this->waitForPos = $pos; - $i = $this->mReadIndex; + $i = $this->readIndex; if ( $i <= 0 ) { // Pick a generic replica DB if there isn't one yet - $readLoads = $this->mLoads; + $readLoads = $this->loads; unset( $readLoads[$this->getWriterIndex()] ); // replica DBs only $readLoads = array_filter( $readLoads ); // with non-zero load $i = ArrayUtils::pickRandom( $readLoads ); @@ -504,27 +511,34 @@ class LoadBalancer implements ILoadBalancer { } } finally { # Restore the old position, as this is not used for lag-protection but for throttling - $this->mWaitForPos = $oldPos; + $this->waitForPos = $oldPos; } return $ok; } public function waitForAll( $pos, $timeout = null ) { - $oldPos = $this->mWaitForPos; + $timeout = $timeout ?: $this->waitTimeout; + + $oldPos = $this->waitForPos; try { - $this->mWaitForPos = $pos; - $serverCount = count( $this->mServers ); + $this->waitForPos = $pos; + $serverCount = count( $this->servers ); $ok = true; for ( $i = 1; $i < $serverCount; $i++ ) { - if ( $this->mLoads[$i] > 0 ) { + if ( $this->loads[$i] > 0 ) { + $start = microtime( true ); $ok = $this->doWait( $i, true, $timeout ) && $ok; + $timeout -= ( microtime( true ) - $start ); + if ( $timeout <= 0 ) { + break; // timeout reached + } } } } finally { # Restore the old position, as this is not used for lag-protection but for throttling - $this->mWaitForPos = $oldPos; + $this->waitForPos = $oldPos; } return $ok; @@ -538,8 +552,8 @@ class LoadBalancer implements ILoadBalancer { return; } - if ( !$this->mWaitForPos || $pos->hasReached( $this->mWaitForPos ) ) { - $this->mWaitForPos = $pos; + if ( !$this->waitForPos || $pos->hasReached( $this->waitForPos ) ) { + $this->waitForPos = $pos; } } @@ -548,7 +562,7 @@ class LoadBalancer implements ILoadBalancer { * @return IDatabase|bool */ public function getAnyOpenConnection( $i ) { - foreach ( $this->mConns as $connsByServer ) { + foreach ( $this->conns as $connsByServer ) { if ( !empty( $connsByServer[$i] ) ) { /** @var IDatabase[] $serverConns */ $serverConns = $connsByServer[$i]; @@ -564,11 +578,11 @@ class LoadBalancer implements ILoadBalancer { * Wait for a given replica DB to catch up to the master pos stored in $this * @param int $index Server index * @param bool $open Check the server even if a new connection has to be made - * @param int $timeout Max seconds to wait; default is mWaitTimeout + * @param int $timeout Max seconds to wait; default is "waitTimeout" given to __construct() * @return bool */ protected function doWait( $index, $open = false, $timeout = null ) { - $close = false; // close the connection afterwards + $timeout = max( 1, $timeout ?: $this->waitTimeout ); // Check if we already know that the DB has reached this point $server = $this->getServerName( $index ); @@ -577,27 +591,34 @@ class LoadBalancer implements ILoadBalancer { $knownReachedPos = $this->srvCache->get( $key ); if ( $knownReachedPos instanceof DBMasterPos && - $knownReachedPos->hasReached( $this->mWaitForPos ) + $knownReachedPos->hasReached( $this->waitForPos ) ) { - $this->replLogger->debug( __METHOD__ . + $this->replLogger->debug( + __METHOD__ . ': replica DB {dbserver} known to be caught up (pos >= $knownReachedPos).', - [ 'dbserver' => $server ] ); + [ 'dbserver' => $server ] + ); return true; } // Find a connection to wait on, creating one if needed and allowed + $close = false; // close the connection afterwards $conn = $this->getAnyOpenConnection( $index ); if ( !$conn ) { if ( !$open ) { - $this->replLogger->debug( __METHOD__ . ': no connection open for {dbserver}', - [ 'dbserver' => $server ] ); + $this->replLogger->debug( + __METHOD__ . ': no connection open for {dbserver}', + [ 'dbserver' => $server ] + ); return false; } else { $conn = $this->openConnection( $index, self::DOMAIN_ANY ); if ( !$conn ) { - $this->replLogger->warning( __METHOD__ . ': failed to connect to {dbserver}', - [ 'dbserver' => $server ] ); + $this->replLogger->warning( + __METHOD__ . ': failed to connect to {dbserver}', + [ 'dbserver' => $server ] + ); return false; } @@ -607,23 +628,39 @@ class LoadBalancer implements ILoadBalancer { } } - $this->replLogger->info( __METHOD__ . ': Waiting for replica DB {dbserver} to catch up...', - [ 'dbserver' => $server ] ); - $timeout = $timeout ?: $this->mWaitTimeout; - $result = $conn->masterPosWait( $this->mWaitForPos, $timeout ); + $this->replLogger->info( + __METHOD__ . + ': waiting for replica DB {dbserver} to catch up...', + [ 'dbserver' => $server ] + ); + + $result = $conn->masterPosWait( $this->waitForPos, $timeout ); - if ( $result == -1 || is_null( $result ) ) { - // Timed out waiting for replica DB, use master instead + if ( $result === null ) { + $this->replLogger->warning( + __METHOD__ . ': Errored out waiting on {host} pos {pos}', + [ + 'host' => $server, + 'pos' => $this->waitForPos, + 'trace' => ( new RuntimeException() )->getTraceAsString() + ] + ); + $ok = false; + } elseif ( $result == -1 ) { $this->replLogger->warning( __METHOD__ . ': Timed out waiting on {host} pos {pos}', - [ 'host' => $server, 'pos' => $this->mWaitForPos ] + [ + 'host' => $server, + 'pos' => $this->waitForPos, + 'trace' => ( new RuntimeException() )->getTraceAsString() + ] ); $ok = false; } else { - $this->replLogger->info( __METHOD__ . ": Done" ); + $this->replLogger->debug( __METHOD__ . ": done waiting" ); $ok = true; // Remember that the DB reached this point - $this->srvCache->set( $key, $this->mWaitForPos, BagOStuff::TTL_DAY ); + $this->srvCache->set( $key, $this->waitForPos, BagOStuff::TTL_DAY ); } if ( $close ) { @@ -665,14 +702,14 @@ class LoadBalancer implements ILoadBalancer { # Operation-based index if ( $i == self::DB_REPLICA ) { - $this->mLastError = 'Unknown error'; // reset error string + $this->lastError = 'Unknown error'; // reset error string # Try the general server pool if $groups are unavailable. $i = ( $groups === [ false ] ) ? false // don't bother with this if that is what was tried above : $this->getReaderIndex( false, $domain ); # Couldn't find a working server in getReaderIndex()? if ( $i === false ) { - $this->mLastError = 'No working replica DB server: ' . $this->mLastError; + $this->lastError = 'No working replica DB server: ' . $this->lastError; // Throw an exception $this->reportConnectionError(); return null; // not reached @@ -720,7 +757,8 @@ class LoadBalancer implements ILoadBalancer { } elseif ( $conn instanceof DBConnRef ) { // DBConnRef already handles calling reuseConnection() and only passes the live // Database instance to this method. Any caller passing in a DBConnRef is broken. - $this->connLogger->error( __METHOD__ . ": got DBConnRef instance.\n" . + $this->connLogger->error( + __METHOD__ . ": got DBConnRef instance.\n" . ( new RuntimeException() )->getTraceAsString() ); return; @@ -739,20 +777,20 @@ class LoadBalancer implements ILoadBalancer { } $domain = $conn->getDomainID(); - if ( !isset( $this->mConns[$connInUseKey][$serverIndex][$domain] ) ) { + if ( !isset( $this->conns[$connInUseKey][$serverIndex][$domain] ) ) { throw new InvalidArgumentException( __METHOD__ . ": connection $serverIndex/$domain not found; it may have already been freed." ); - } elseif ( $this->mConns[$connInUseKey][$serverIndex][$domain] !== $conn ) { + } elseif ( $this->conns[$connInUseKey][$serverIndex][$domain] !== $conn ) { throw new InvalidArgumentException( __METHOD__ . ": connection $serverIndex/$domain mismatched; it may have already been freed." ); } $conn->setLBInfo( 'foreignPoolRefCount', --$refCount ); if ( $refCount <= 0 ) { - $this->mConns[$connFreeKey][$serverIndex][$domain] = $conn; - unset( $this->mConns[$connInUseKey][$serverIndex][$domain] ); - if ( !$this->mConns[$connInUseKey][$serverIndex] ) { - unset( $this->mConns[$connInUseKey][$serverIndex] ); // clean up + $this->conns[$connFreeKey][$serverIndex][$domain] = $conn; + unset( $this->conns[$connInUseKey][$serverIndex][$domain] ); + if ( !$this->conns[$connInUseKey][$serverIndex] ) { + unset( $this->conns[$connInUseKey][$serverIndex] ); // clean up } $this->connLogger->debug( __METHOD__ . ": freed connection $serverIndex/$domain" ); } else { @@ -804,27 +842,29 @@ class LoadBalancer implements ILoadBalancer { } else { // Connection is to the local domain $connKey = $autoCommit ? self::KEY_LOCAL_NOROUND : self::KEY_LOCAL; - if ( isset( $this->mConns[$connKey][$i][0] ) ) { - $conn = $this->mConns[$connKey][$i][0]; + if ( isset( $this->conns[$connKey][$i][0] ) ) { + $conn = $this->conns[$connKey][$i][0]; } else { - if ( !isset( $this->mServers[$i] ) || !is_array( $this->mServers[$i] ) ) { + if ( !isset( $this->servers[$i] ) || !is_array( $this->servers[$i] ) ) { throw new InvalidArgumentException( "No server with index '$i'." ); } // Open a new connection - $server = $this->mServers[$i]; + $server = $this->servers[$i]; $server['serverIndex'] = $i; $server['autoCommitOnly'] = $autoCommit; if ( $this->localDomain->getDatabase() !== null ) { // Use the local domain table prefix if the local domain is specified $server['tablePrefix'] = $this->localDomain->getTablePrefix(); } - $conn = $this->reallyOpenConnection( $server, $this->localDomain->getDatabase() ); + $conn = $this->reallyOpenConnection( $server, $this->localDomain ); $host = $this->getServerName( $i ); if ( $conn->isOpen() ) { - $this->connLogger->debug( "Connected to database $i at '$host'." ); - $this->mConns[$connKey][$i][0] = $conn; + $this->connLogger->debug( + __METHOD__ . ": connected to database $i at '$host'." ); + $this->conns[$connKey][$i][0] = $conn; } else { - $this->connLogger->warning( "Failed to connect to database $i at '$host'." ); + $this->connLogger->warning( + __METHOD__ . ": failed to connect to database $i at '$host'." ); $this->errorConnection = $conn; $conn = false; } @@ -882,44 +922,44 @@ class LoadBalancer implements ILoadBalancer { $connInUseKey = self::KEY_FOREIGN_INUSE; } - if ( isset( $this->mConns[$connInUseKey][$i][$domain] ) ) { + if ( isset( $this->conns[$connInUseKey][$i][$domain] ) ) { // Reuse an in-use connection for the same domain - $conn = $this->mConns[$connInUseKey][$i][$domain]; + $conn = $this->conns[$connInUseKey][$i][$domain]; $this->connLogger->debug( __METHOD__ . ": reusing connection $i/$domain" ); - } elseif ( isset( $this->mConns[$connFreeKey][$i][$domain] ) ) { + } elseif ( isset( $this->conns[$connFreeKey][$i][$domain] ) ) { // Reuse a free connection for the same domain - $conn = $this->mConns[$connFreeKey][$i][$domain]; - unset( $this->mConns[$connFreeKey][$i][$domain] ); - $this->mConns[$connInUseKey][$i][$domain] = $conn; + $conn = $this->conns[$connFreeKey][$i][$domain]; + unset( $this->conns[$connFreeKey][$i][$domain] ); + $this->conns[$connInUseKey][$i][$domain] = $conn; $this->connLogger->debug( __METHOD__ . ": reusing free connection $i/$domain" ); - } elseif ( !empty( $this->mConns[$connFreeKey][$i] ) ) { + } elseif ( !empty( $this->conns[$connFreeKey][$i] ) ) { // Reuse a free connection from another domain - $conn = reset( $this->mConns[$connFreeKey][$i] ); - $oldDomain = key( $this->mConns[$connFreeKey][$i] ); + $conn = reset( $this->conns[$connFreeKey][$i] ); + $oldDomain = key( $this->conns[$connFreeKey][$i] ); if ( strlen( $dbName ) && !$conn->selectDB( $dbName ) ) { - $this->mLastError = "Error selecting database '$dbName' on server " . + $this->lastError = "Error selecting database '$dbName' on server " . $conn->getServer() . " from client host {$this->host}"; $this->errorConnection = $conn; $conn = false; } else { $conn->tablePrefix( $prefix ); - unset( $this->mConns[$connFreeKey][$i][$oldDomain] ); + unset( $this->conns[$connFreeKey][$i][$oldDomain] ); // Note that if $domain is an empty string, getDomainID() might not match it - $this->mConns[$connInUseKey][$i][$conn->getDomainId()] = $conn; + $this->conns[$connInUseKey][$i][$conn->getDomainId()] = $conn; $this->connLogger->debug( __METHOD__ . ": reusing free connection from $oldDomain for $domain" ); } } else { - if ( !isset( $this->mServers[$i] ) || !is_array( $this->mServers[$i] ) ) { + if ( !isset( $this->servers[$i] ) || !is_array( $this->servers[$i] ) ) { throw new InvalidArgumentException( "No server with index '$i'." ); } // Open a new connection - $server = $this->mServers[$i]; + $server = $this->servers[$i]; $server['serverIndex'] = $i; $server['foreignPoolRefCount'] = 0; $server['foreign'] = true; $server['autoCommitOnly'] = $autoCommit; - $conn = $this->reallyOpenConnection( $server, $dbName ); + $conn = $this->reallyOpenConnection( $server, $domainInstance ); if ( !$conn->isOpen() ) { $this->connLogger->warning( __METHOD__ . ": connection error for $i/$domain" ); $this->errorConnection = $conn; @@ -927,7 +967,7 @@ class LoadBalancer implements ILoadBalancer { } else { $conn->tablePrefix( $prefix ); // as specified // Note that if $domain is an empty string, getDomainID() might not match it - $this->mConns[$connInUseKey][$i][$conn->getDomainID()] = $conn; + $this->conns[$connInUseKey][$i][$conn->getDomainID()] = $conn; $this->connLogger->debug( __METHOD__ . ": opened new connection for $i/$domain" ); } } @@ -962,18 +1002,29 @@ class LoadBalancer implements ILoadBalancer { * Returns a Database object whether or not the connection was successful. * * @param array $server - * @param string|null $dbNameOverride Use "" to not select any database + * @param DatabaseDomain $domainOverride Use an unspecified domain to not select any database * @return Database * @throws DBAccessError * @throws InvalidArgumentException */ - protected function reallyOpenConnection( array $server, $dbNameOverride ) { + protected function reallyOpenConnection( array $server, DatabaseDomain $domainOverride ) { if ( $this->disabled ) { throw new DBAccessError(); } - if ( $dbNameOverride !== null ) { - $server['dbname'] = $dbNameOverride; + // Handle $domainOverride being a specified or an unspecified domain + if ( $domainOverride->getDatabase() === null ) { + // Normally, an RDBMS requires a DB name specified on connection and the $server + // configuration array is assumed to already specify an appropriate DB name. + if ( $server['type'] === 'mysql' ) { + // For MySQL, DATABASE and SCHEMA are synonyms, connections need not specify a DB, + // and the DB name in $server might not exist due to legacy reasons (the default + // domain used to ignore the local LB domain, even when mismatched). + $server['dbname'] = null; + } + } else { + $server['dbname'] = $domainOverride->getDatabase(); + $server['schema'] = $domainOverride->getSchema(); } // Let the handle know what the cluster master is (e.g. "db1052") @@ -1034,27 +1085,28 @@ class LoadBalancer implements ILoadBalancer { $conn = $this->errorConnection; // the connection which caused the error $context = [ 'method' => __METHOD__, - 'last_error' => $this->mLastError, + 'last_error' => $this->lastError, ]; if ( $conn instanceof IDatabase ) { $context['db_server'] = $conn->getServer(); $this->connLogger->warning( - "Connection error: {last_error} ({db_server})", + __METHOD__ . ": connection error: {last_error} ({db_server})", $context ); // throws DBConnectionError - $conn->reportConnectionError( "{$this->mLastError} ({$context['db_server']})" ); + $conn->reportConnectionError( "{$this->lastError} ({$context['db_server']})" ); } else { // No last connection, probably due to all servers being too busy $this->connLogger->error( - "LB failure with no last connection. Connection error: {last_error}", + __METHOD__ . + ": LB failure with no last connection. Connection error: {last_error}", $context ); // If all servers were busy, mLastError will contain something sensible - throw new DBConnectionError( null, $this->mLastError ); + throw new DBConnectionError( null, $this->lastError ); } } @@ -1063,22 +1115,22 @@ class LoadBalancer implements ILoadBalancer { } public function haveIndex( $i ) { - return array_key_exists( $i, $this->mServers ); + return array_key_exists( $i, $this->servers ); } public function isNonZeroLoad( $i ) { - return array_key_exists( $i, $this->mServers ) && $this->mLoads[$i] != 0; + return array_key_exists( $i, $this->servers ) && $this->loads[$i] != 0; } public function getServerCount() { - return count( $this->mServers ); + return count( $this->servers ); } public function getServerName( $i ) { - if ( isset( $this->mServers[$i]['hostName'] ) ) { - $name = $this->mServers[$i]['hostName']; - } elseif ( isset( $this->mServers[$i]['host'] ) ) { - $name = $this->mServers[$i]['host']; + if ( isset( $this->servers[$i]['hostName'] ) ) { + $name = $this->servers[$i]['hostName']; + } elseif ( isset( $this->servers[$i]['host'] ) ) { + $name = $this->servers[$i]['host']; } else { $name = ''; } @@ -1087,7 +1139,7 @@ class LoadBalancer implements ILoadBalancer { } public function getServerType( $i ) { - return isset( $this->mServers[$i]['type'] ) ? $this->mServers[$i]['type'] : 'unknown'; + return isset( $this->servers[$i]['type'] ) ? $this->servers[$i]['type'] : 'unknown'; } public function getMasterPos() { @@ -1095,7 +1147,7 @@ class LoadBalancer implements ILoadBalancer { # master (however unlikely that may be), then we can fetch the position from the replica DB. $masterConn = $this->getAnyOpenConnection( $this->getWriterIndex() ); if ( !$masterConn ) { - $serverCount = count( $this->mServers ); + $serverCount = count( $this->servers ); for ( $i = 1; $i < $serverCount; $i++ ) { $conn = $this->getAnyOpenConnection( $i ); if ( $conn ) { @@ -1117,11 +1169,12 @@ class LoadBalancer implements ILoadBalancer { public function closeAll() { $this->forEachOpenConnection( function ( IDatabase $conn ) { $host = $conn->getServer(); - $this->connLogger->debug( "Closing connection to database '$host'." ); + $this->connLogger->debug( + __METHOD__ . ": closing connection to database '$host'." ); $conn->close(); } ); - $this->mConns = [ + $this->conns = [ self::KEY_LOCAL => [], self::KEY_FOREIGN_INUSE => [], self::KEY_FOREIGN_FREE => [], @@ -1134,7 +1187,7 @@ class LoadBalancer implements ILoadBalancer { public function closeConnection( IDatabase $conn ) { $serverIndex = $conn->getLBInfo( 'serverIndex' ); // second index level of mConns - foreach ( $this->mConns as $type => $connsByServer ) { + foreach ( $this->conns as $type => $connsByServer ) { if ( !isset( $connsByServer[$serverIndex] ) ) { continue; } @@ -1142,8 +1195,9 @@ class LoadBalancer implements ILoadBalancer { foreach ( $connsByServer[$serverIndex] as $i => $trackedConn ) { if ( $conn === $trackedConn ) { $host = $this->getServerName( $i ); - $this->connLogger->debug( "Closing connection to database $i at '$host'." ); - unset( $this->mConns[$type][$serverIndex][$i] ); + $this->connLogger->debug( + __METHOD__ . ": closing connection to database $i at '$host'." ); + unset( $this->conns[$type][$serverIndex][$i] ); --$this->connsOpened; break 2; } @@ -1327,7 +1381,7 @@ class LoadBalancer implements ILoadBalancer { $this->trxRoundId = false; $this->forEachOpenMasterConnection( function ( IDatabase $conn ) use ( $fname, $restore ) { - if ( $conn->writesOrCallbacksPending() ) { + if ( $conn->writesOrCallbacksPending() || $conn->explicitTrxActive() ) { $conn->rollback( $fname, $conn::FLUSHING_ALL_PEERS ); } if ( $restore ) { @@ -1403,7 +1457,7 @@ class LoadBalancer implements ILoadBalancer { } public function hasOrMadeRecentMasterChanges( $age = null ) { - $age = ( $age === null ) ? $this->mWaitTimeout : $age; + $age = ( $age === null ) ? $this->waitTimeout : $age; return ( $this->hasMasterChanges() || $this->lastMasterChangeTimestamp() > microtime( true ) - $age ); @@ -1507,11 +1561,11 @@ class LoadBalancer implements ILoadBalancer { public function allowLagged( $mode = null ) { if ( $mode === null ) { - return $this->mAllowLagged; + return $this->allowLagged; } - $this->mAllowLagged = $mode; + $this->allowLagged = $mode; - return $this->mAllowLagged; + return $this->allowLagged; } public function pingAll() { @@ -1526,7 +1580,7 @@ class LoadBalancer implements ILoadBalancer { } public function forEachOpenConnection( $callback, array $params = [] ) { - foreach ( $this->mConns as $connsByServer ) { + foreach ( $this->conns as $connsByServer ) { foreach ( $connsByServer as $serverConns ) { foreach ( $serverConns as $conn ) { $mergedParams = array_merge( [ $conn ], $params ); @@ -1538,7 +1592,7 @@ class LoadBalancer implements ILoadBalancer { public function forEachOpenMasterConnection( $callback, array $params = [] ) { $masterIndex = $this->getWriterIndex(); - foreach ( $this->mConns as $connsByServer ) { + foreach ( $this->conns as $connsByServer ) { if ( isset( $connsByServer[$masterIndex] ) ) { /** @var IDatabase $conn */ foreach ( $connsByServer[$masterIndex] as $conn ) { @@ -1550,7 +1604,7 @@ class LoadBalancer implements ILoadBalancer { } public function forEachOpenReplicaConnection( $callback, array $params = [] ) { - foreach ( $this->mConns as $connsByServer ) { + foreach ( $this->conns as $connsByServer ) { foreach ( $connsByServer as $i => $serverConns ) { if ( $i === $this->getWriterIndex() ) { continue; // skip master @@ -1574,9 +1628,9 @@ class LoadBalancer implements ILoadBalancer { $lagTimes = $this->getLagTimes( $domain ); foreach ( $lagTimes as $i => $lag ) { - if ( $this->mLoads[$i] > 0 && $lag > $maxLag ) { + if ( $this->loads[$i] > 0 && $lag > $maxLag ) { $maxLag = $lag; - $host = $this->mServers[$i]['host']; + $host = $this->servers[$i]['host']; $maxIndex = $i; } } @@ -1591,7 +1645,7 @@ class LoadBalancer implements ILoadBalancer { $knownLagTimes = []; // map of (server index => 0 seconds) $indexesWithLag = []; - foreach ( $this->mServers as $i => $server ) { + foreach ( $this->servers as $i => $server ) { if ( empty( $server['is static'] ) ) { $indexesWithLag[] = $i; // DB server might have replication lag } else { @@ -1613,10 +1667,12 @@ class LoadBalancer implements ILoadBalancer { /** * @param IDatabase $conn * @param DBMasterPos|bool $pos - * @param int $timeout + * @param int|null $timeout * @return bool */ - public function safeWaitForMasterPos( IDatabase $conn, $pos = false, $timeout = 10 ) { + public function safeWaitForMasterPos( IDatabase $conn, $pos = false, $timeout = null ) { + $timeout = max( 1, $timeout ?: $this->waitTimeout ); + if ( $this->getServerCount() <= 1 || !$conn->getLBInfo( 'replica' ) ) { return true; // server is not a replica DB } @@ -1636,18 +1692,26 @@ class LoadBalancer implements ILoadBalancer { if ( $pos instanceof DBMasterPos ) { $result = $conn->masterPosWait( $pos, $timeout ); if ( $result == -1 || is_null( $result ) ) { - $msg = __METHOD__ . ': Timed out waiting on {host} pos {pos}'; - $this->replLogger->warning( $msg, - [ 'host' => $conn->getServer(), 'pos' => $pos ] ); + $msg = __METHOD__ . ': timed out waiting on {host} pos {pos}'; + $this->replLogger->warning( $msg, [ + 'host' => $conn->getServer(), + 'pos' => $pos, + 'trace' => ( new RuntimeException() )->getTraceAsString() + ] ); $ok = false; } else { - $this->replLogger->info( __METHOD__ . ': Done' ); + $this->replLogger->debug( __METHOD__ . ': done waiting' ); $ok = true; } } else { $ok = false; // something is misconfigured - $this->replLogger->error( 'Could not get master pos for {host}', - [ 'host' => $conn->getServer() ] ); + $this->replLogger->error( + __METHOD__ . ': could not get master pos for {host}', + [ + 'host' => $conn->getServer(), + 'trace' => ( new RuntimeException() )->getTraceAsString() + ] + ); } return $ok; @@ -1691,7 +1755,7 @@ class LoadBalancer implements ILoadBalancer { $oldDomain = $this->localDomain->getId(); $this->setLocalDomain( new DatabaseDomain( $this->localDomain->getDatabase(), - null, + $this->localDomain->getSchema(), $prefix ) );