class LoadBalancer implements ILoadBalancer {
/** @var array[] Map of (server index => server config array) */
private $mServers;
- /** @var Database[][][] Map of local/foreignUsed/foreignFree => server index => IDatabase array */
+ /** @var Database[][][] Map of local/foreignUsed/foreignFree => server index => IDatabase[] */
private $mConns;
/** @var float[] Map of (server index => weight) */
private $mLoads;
/** @var integer Seconds to cache master server read-only status */
const TTL_CACHE_READONLY = 5;
+ const KEY_LOCAL = 'local';
+ const KEY_FOREIGN_FREE = 'foreignFree';
+ const KEY_FOREIGN_INUSE = 'foreignInUse';
+
public function __construct( array $params ) {
if ( !isset( $params['servers'] ) ) {
throw new InvalidArgumentException( __CLASS__ . ': missing servers parameter' );
$this->mReadIndex = -1;
$this->mConns = [
- 'local' => [],
- 'foreignUsed' => [],
- 'foreignFree' => []
+ self::KEY_LOCAL => [],
+ self::KEY_FOREIGN_INUSE => [],
+ self::KEY_FOREIGN_FREE => []
];
$this->mLoads = [];
$this->mWaitForPos = false;
}
$domain = $conn->getDomainID();
- if ( !isset( $this->mConns['foreignUsed'][$serverIndex][$domain] ) ) {
+ if ( !isset( $this->mConns[self::KEY_FOREIGN_INUSE][$serverIndex][$domain] ) ) {
throw new InvalidArgumentException( __METHOD__ .
": connection $serverIndex/$domain not found; it may have already been freed." );
- } elseif ( $this->mConns['foreignUsed'][$serverIndex][$domain] !== $conn ) {
+ } elseif ( $this->mConns[self::KEY_FOREIGN_INUSE][$serverIndex][$domain] !== $conn ) {
throw new InvalidArgumentException( __METHOD__ .
": connection $serverIndex/$domain mismatched; it may have already been freed." );
}
$conn->setLBInfo( 'foreignPoolRefCount', --$refCount );
if ( $refCount <= 0 ) {
- $this->mConns['foreignFree'][$serverIndex][$domain] = $conn;
- unset( $this->mConns['foreignUsed'][$serverIndex][$domain] );
- if ( !$this->mConns['foreignUsed'][$serverIndex] ) {
- unset( $this->mConns[ 'foreignUsed' ][$serverIndex] ); // clean up
+ $this->mConns[self::KEY_FOREIGN_FREE][$serverIndex][$domain] = $conn;
+ unset( $this->mConns[self::KEY_FOREIGN_INUSE][$serverIndex][$domain] );
+ if ( !$this->mConns[self::KEY_FOREIGN_INUSE][$serverIndex] ) {
+ unset( $this->mConns[ self::KEY_FOREIGN_INUSE ][$serverIndex] ); // clean up
}
$this->connLogger->debug( __METHOD__ . ": freed connection $serverIndex/$domain" );
} else {
if ( $domain !== false ) {
$conn = $this->openForeignConnection( $i, $domain );
- } elseif ( isset( $this->mConns['local'][$i][0] ) ) {
- $conn = $this->mConns['local'][$i][0];
+ } elseif ( isset( $this->mConns[self::KEY_LOCAL][$i][0] ) ) {
+ $conn = $this->mConns[self::KEY_LOCAL][$i][0];
} else {
if ( !isset( $this->mServers[$i] ) || !is_array( $this->mServers[$i] ) ) {
throw new InvalidArgumentException( "No server with index '$i'." );
$serverName = $this->getServerName( $i );
if ( $conn->isOpen() ) {
$this->connLogger->debug( "Connected to database $i at '$serverName'." );
- $this->mConns['local'][$i][0] = $conn;
+ $this->mConns[self::KEY_LOCAL][$i][0] = $conn;
} else {
$this->connLogger->warning( "Failed to connect to database $i at '$serverName'." );
$this->errorConnection = $conn;
$dbName = $domainInstance->getDatabase();
$prefix = $domainInstance->getTablePrefix();
- if ( isset( $this->mConns['foreignUsed'][$i][$domain] ) ) {
- // Reuse an already-used connection
- $conn = $this->mConns['foreignUsed'][$i][$domain];
+ if ( isset( $this->mConns[self::KEY_FOREIGN_INUSE][$i][$domain] ) ) {
+ // Reuse an in-use connection for the same domain that is not in-use
+ $conn = $this->mConns[self::KEY_FOREIGN_INUSE][$i][$domain];
$this->connLogger->debug( __METHOD__ . ": reusing connection $i/$domain" );
- } elseif ( isset( $this->mConns['foreignFree'][$i][$domain] ) ) {
- // Reuse a free connection for the same domain
- $conn = $this->mConns['foreignFree'][$i][$domain];
- unset( $this->mConns['foreignFree'][$i][$domain] );
- $this->mConns['foreignUsed'][$i][$domain] = $conn;
+ } elseif ( isset( $this->mConns[self::KEY_FOREIGN_FREE][$i][$domain] ) ) {
+ // Reuse a free connection for the same domain that is not in-use
+ $conn = $this->mConns[self::KEY_FOREIGN_FREE][$i][$domain];
+ unset( $this->mConns[self::KEY_FOREIGN_FREE][$i][$domain] );
+ $this->mConns[self::KEY_FOREIGN_INUSE][$i][$domain] = $conn;
$this->connLogger->debug( __METHOD__ . ": reusing free connection $i/$domain" );
- } elseif ( !empty( $this->mConns['foreignFree'][$i] ) ) {
+ } elseif ( !empty( $this->mConns[self::KEY_FOREIGN_FREE][$i] ) ) {
// Reuse a connection from another domain
- $conn = reset( $this->mConns['foreignFree'][$i] );
- $oldDomain = key( $this->mConns['foreignFree'][$i] );
+ $conn = reset( $this->mConns[self::KEY_FOREIGN_FREE][$i] );
+ $oldDomain = key( $this->mConns[self::KEY_FOREIGN_FREE][$i] );
// The empty string as a DB name means "don't care".
// DatabaseMysqlBase::open() already handle this on connection.
if ( strlen( $dbName ) && !$conn->selectDB( $dbName ) ) {
$conn = false;
} else {
$conn->tablePrefix( $prefix );
- unset( $this->mConns['foreignFree'][$i][$oldDomain] );
- $this->mConns['foreignUsed'][$i][$domain] = $conn;
+ unset( $this->mConns[self::KEY_FOREIGN_FREE][$i][$oldDomain] );
+ $this->mConns[self::KEY_FOREIGN_INUSE][$i][$domain] = $conn;
$this->connLogger->debug( __METHOD__ .
": reusing free connection from $oldDomain for $domain" );
}
$conn = false;
} else {
$conn->tablePrefix( $prefix );
- $this->mConns['foreignUsed'][$i][$domain] = $conn;
+ $this->mConns[self::KEY_FOREIGN_INUSE][$i][$domain] = $conn;
$this->connLogger->debug( __METHOD__ . ": opened new connection for $i/$domain" );
}
}
} );
$this->mConns = [
- 'local' => [],
- 'foreignFree' => [],
- 'foreignUsed' => [],
+ self::KEY_LOCAL => [],
+ self::KEY_FOREIGN_FREE => [],
+ self::KEY_FOREIGN_INUSE => [],
];
$this->connsOpened = 0;
}
}
public function setDomainPrefix( $prefix ) {
- if ( $this->mConns['foreignUsed'] ) {
- // Do not switch connections to explicit foreign domains unless marked as free
- $domains = [];
- foreach ( $this->mConns['foreignUsed'] as $i => $connsByDomain ) {
- $domains = array_merge( $domains, array_keys( $connsByDomain ) );
+ // Find connections to explicit foreign domains still marked as in-use...
+ $domainsInUse = [];
+ $this->forEachOpenConnection( function ( IDatabase $conn ) use ( &$domainsInUse ) {
+ // Once reuseConnection() is called on a handle, its reference count goes from 1 to 0.
+ // Until then, it is still in use by the caller (explicitly or via DBConnRef scope).
+ if ( $conn->getLBInfo( 'foreignPoolRefCount' ) > 0 ) {
+ $domainsInUse[] = $conn->getDomainID();
}
- $domains = implode( ', ', $domains );
+ } );
+
+ // Do not switch connections to explicit foreign domains unless marked as safe
+ if ( $domainsInUse ) {
+ $domains = implode( ', ', $domainsInUse );
throw new DBUnexpectedError( null,
"Foreign domain connections are still in use ($domains)." );
}
dépôts / lhc / web / wiklou.git / blobdiff