--- /dev/null
+<?php
+/**
+ * Redis client connection pooling manager.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @defgroup Redis Redis
+ */
+
+use Psr\Log\LoggerAwareInterface;
+use Psr\Log\LoggerInterface;
+
+/**
+ * Helper class to manage Redis connections.
+ *
+ * This can be used to get handle wrappers that free the handle when the wrapper
+ * leaves scope. The maximum number of free handles (connections) is configurable.
+ * This provides an easy way to cache connection handles that may also have state,
+ * such as a handle does between multi() and exec(), and without hoarding connections.
+ * The wrappers use PHP magic methods so that calling functions on them calls the
+ * function of the actual Redis object handle.
+ *
+ * @ingroup Redis
+ * @since 1.21
+ */
+class RedisConnectionPool implements LoggerAwareInterface {
+ /** @var string Connection timeout in seconds */
+ protected $connectTimeout;
+ /** @var string Read timeout in seconds */
+ protected $readTimeout;
+ /** @var string Plaintext auth password */
+ protected $password;
+ /** @var bool Whether connections persist */
+ protected $persistent;
+ /** @var int Serializer to use (Redis::SERIALIZER_*) */
+ protected $serializer;
+ /** @var string ID for persistent connections */
+ protected $id;
+
+ /** @var int Current idle pool size */
+ protected $idlePoolSize = 0;
+
+ /** @var array (server name => ((connection info array),...) */
+ protected $connections = [];
+ /** @var array (server name => UNIX timestamp) */
+ protected $downServers = [];
+
+ /** @var array (pool ID => RedisConnectionPool) */
+ protected static $instances = [];
+
+ /** integer; seconds to cache servers as "down". */
+ const SERVER_DOWN_TTL = 30;
+
+ /**
+ * @var LoggerInterface
+ */
+ protected $logger;
+
+ /**
+ * @param array $options
+ * @param string $id
+ * @throws Exception
+ */
+ protected function __construct( array $options, $id ) {
+ if ( !class_exists( 'Redis' ) ) {
+ throw new RuntimeException(
+ __CLASS__ . ' requires a Redis client library. ' .
+ 'See https://www.mediawiki.org/wiki/Redis#Setup' );
+ }
+ $this->logger = isset( $options['logger'] )
+ ? $options['logger']
+ : new \Psr\Log\NullLogger();
+ $this->connectTimeout = $options['connectTimeout'];
+ $this->readTimeout = $options['readTimeout'];
+ $this->persistent = $options['persistent'];
+ $this->password = $options['password'];
+ if ( !isset( $options['serializer'] ) || $options['serializer'] === 'php' ) {
+ $this->serializer = Redis::SERIALIZER_PHP;
+ } elseif ( $options['serializer'] === 'igbinary' ) {
+ $this->serializer = Redis::SERIALIZER_IGBINARY;
+ } elseif ( $options['serializer'] === 'none' ) {
+ $this->serializer = Redis::SERIALIZER_NONE;
+ } else {
+ throw new InvalidArgumentException( "Invalid serializer specified." );
+ }
+ $this->id = $id;
+ }
+
+ /**
+ * @param LoggerInterface $logger
+ * @return null
+ */
+ public function setLogger( LoggerInterface $logger ) {
+ $this->logger = $logger;
+ }
+
+ /**
+ * @param array $options
+ * @return array
+ */
+ protected static function applyDefaultConfig( array $options ) {
+ if ( !isset( $options['connectTimeout'] ) ) {
+ $options['connectTimeout'] = 1;
+ }
+ if ( !isset( $options['readTimeout'] ) ) {
+ $options['readTimeout'] = 1;
+ }
+ if ( !isset( $options['persistent'] ) ) {
+ $options['persistent'] = false;
+ }
+ if ( !isset( $options['password'] ) ) {
+ $options['password'] = null;
+ }
+
+ return $options;
+ }
+
+ /**
+ * @param array $options
+ * $options include:
+ * - connectTimeout : The timeout for new connections, in seconds.
+ * Optional, default is 1 second.
+ * - readTimeout : The timeout for operation reads, in seconds.
+ * Commands like BLPOP can fail if told to wait longer than this.
+ * Optional, default is 1 second.
+ * - persistent : Set this to true to allow connections to persist across
+ * multiple web requests. False by default.
+ * - password : The authentication password, will be sent to Redis in clear text.
+ * Optional, if it is unspecified, no AUTH command will be sent.
+ * - serializer : Set to "php", "igbinary", or "none". Default is "php".
+ * @return RedisConnectionPool
+ */
+ public static function singleton( array $options ) {
+ $options = self::applyDefaultConfig( $options );
+ // Map the options to a unique hash...
+ ksort( $options ); // normalize to avoid pool fragmentation
+ $id = sha1( serialize( $options ) );
+ // Initialize the object at the hash as needed...
+ if ( !isset( self::$instances[$id] ) ) {
+ self::$instances[$id] = new self( $options, $id );
+ }
+
+ return self::$instances[$id];
+ }
+
+ /**
+ * Destroy all singleton() instances
+ * @since 1.27
+ */
+ public static function destroySingletons() {
+ self::$instances = [];
+ }
+
+ /**
+ * Get a connection to a redis server. Based on code in RedisBagOStuff.php.
+ *
+ * @param string $server A hostname/port combination or the absolute path of a UNIX socket.
+ * If a hostname is specified but no port, port 6379 will be used.
+ * @param LoggerInterface $logger PSR-3 logger intance. [optional]
+ * @return RedisConnRef|bool Returns false on failure
+ * @throws MWException
+ */
+ public function getConnection( $server, LoggerInterface $logger = null ) {
+ $logger = $logger ?: $this->logger;
+ // Check the listing "dead" servers which have had a connection errors.
+ // Servers are marked dead for a limited period of time, to
+ // avoid excessive overhead from repeated connection timeouts.
+ if ( isset( $this->downServers[$server] ) ) {
+ $now = time();
+ if ( $now > $this->downServers[$server] ) {
+ // Dead time expired
+ unset( $this->downServers[$server] );
+ } else {
+ // Server is dead
+ $logger->debug(
+ 'Server "{redis_server}" is marked down for another ' .
+ ( $this->downServers[$server] - $now ) . 'seconds',
+ [ 'redis_server' => $server ]
+ );
+
+ return false;
+ }
+ }
+
+ // Check if a connection is already free for use
+ if ( isset( $this->connections[$server] ) ) {
+ foreach ( $this->connections[$server] as &$connection ) {
+ if ( $connection['free'] ) {
+ $connection['free'] = false;
+ --$this->idlePoolSize;
+
+ return new RedisConnRef(
+ $this, $server, $connection['conn'], $logger
+ );
+ }
+ }
+ }
+
+ if ( !$server ) {
+ throw new InvalidArgumentException(
+ __CLASS__ . ": invalid configured server \"$server\"" );
+ } elseif ( substr( $server, 0, 1 ) === '/' ) {
+ // UNIX domain socket
+ // These are required by the redis extension to start with a slash, but
+ // we still need to set the port to a special value to make it work.
+ $host = $server;
+ $port = 0;
+ } else {
+ // TCP connection
+ if ( preg_match( '/^\[(.+)\]:(\d+)$/', $server, $m ) ) {
+ list( $host, $port ) = [ $m[1], (int)$m[2] ]; // (ip, port)
+ } elseif ( preg_match( '/^([^:]+):(\d+)$/', $server, $m ) ) {
+ list( $host, $port ) = [ $m[1], (int)$m[2] ]; // (ip or path, port)
+ } else {
+ list( $host, $port ) = [ $server, 6379 ]; // (ip or path, port)
+ }
+ }
+
+ $conn = new Redis();
+ try {
+ if ( $this->persistent ) {
+ $result = $conn->pconnect( $host, $port, $this->connectTimeout, $this->id );
+ } else {
+ $result = $conn->connect( $host, $port, $this->connectTimeout );
+ }
+ if ( !$result ) {
+ $logger->error(
+ 'Could not connect to server "{redis_server}"',
+ [ 'redis_server' => $server ]
+ );
+ // Mark server down for some time to avoid further timeouts
+ $this->downServers[$server] = time() + self::SERVER_DOWN_TTL;
+
+ return false;
+ }
+ if ( $this->password !== null ) {
+ if ( !$conn->auth( $this->password ) ) {
+ $logger->error(
+ 'Authentication error connecting to "{redis_server}"',
+ [ 'redis_server' => $server ]
+ );
+ }
+ }
+ } catch ( RedisException $e ) {
+ $this->downServers[$server] = time() + self::SERVER_DOWN_TTL;
+ $logger->error(
+ 'Redis exception connecting to "{redis_server}"',
+ [
+ 'redis_server' => $server,
+ 'exception' => $e,
+ ]
+ );
+
+ return false;
+ }
+
+ if ( $conn ) {
+ $conn->setOption( Redis::OPT_READ_TIMEOUT, $this->readTimeout );
+ $conn->setOption( Redis::OPT_SERIALIZER, $this->serializer );
+ $this->connections[$server][] = [ 'conn' => $conn, 'free' => false ];
+
+ return new RedisConnRef( $this, $server, $conn, $logger );
+ } else {
+ return false;
+ }
+ }
+
+ /**
+ * Mark a connection to a server as free to return to the pool
+ *
+ * @param string $server
+ * @param Redis $conn
+ * @return bool
+ */
+ public function freeConnection( $server, Redis $conn ) {
+ $found = false;
+
+ foreach ( $this->connections[$server] as &$connection ) {
+ if ( $connection['conn'] === $conn && !$connection['free'] ) {
+ $connection['free'] = true;
+ ++$this->idlePoolSize;
+ break;
+ }
+ }
+
+ $this->closeExcessIdleConections();
+
+ return $found;
+ }
+
+ /**
+ * Close any extra idle connections if there are more than the limit
+ */
+ protected function closeExcessIdleConections() {
+ if ( $this->idlePoolSize <= count( $this->connections ) ) {
+ return; // nothing to do (no more connections than servers)
+ }
+
+ foreach ( $this->connections as &$serverConnections ) {
+ foreach ( $serverConnections as $key => &$connection ) {
+ if ( $connection['free'] ) {
+ unset( $serverConnections[$key] );
+ if ( --$this->idlePoolSize <= count( $this->connections ) ) {
+ return; // done (no more connections than servers)
+ }
+ }
+ }
+ }
+ }
+
+ /**
+ * The redis extension throws an exception in response to various read, write
+ * and protocol errors. Sometimes it also closes the connection, sometimes
+ * not. The safest response for us is to explicitly destroy the connection
+ * object and let it be reopened during the next request.
+ *
+ * @param RedisConnRef $cref
+ * @param RedisException $e
+ */
+ public function handleError( RedisConnRef $cref, RedisException $e ) {
+ $server = $cref->getServer();
+ $this->logger->error(
+ 'Redis exception on server "{redis_server}"',
+ [
+ 'redis_server' => $server,
+ 'exception' => $e,
+ ]
+ );
+ foreach ( $this->connections[$server] as $key => $connection ) {
+ if ( $cref->isConnIdentical( $connection['conn'] ) ) {
+ $this->idlePoolSize -= $connection['free'] ? 1 : 0;
+ unset( $this->connections[$server][$key] );
+ break;
+ }
+ }
+ }
+
+ /**
+ * Re-send an AUTH request to the redis server (useful after disconnects).
+ *
+ * This works around an upstream bug in phpredis. phpredis hides disconnects by transparently
+ * reconnecting, but it neglects to re-authenticate the new connection. To the user of the
+ * phpredis client API this manifests as a seemingly random tendency of connections to lose
+ * their authentication status.
+ *
+ * This method is for internal use only.
+ *
+ * @see https://github.com/nicolasff/phpredis/issues/403
+ *
+ * @param string $server
+ * @param Redis $conn
+ * @return bool Success
+ */
+ public function reauthenticateConnection( $server, Redis $conn ) {
+ if ( $this->password !== null ) {
+ if ( !$conn->auth( $this->password ) ) {
+ $this->logger->error(
+ 'Authentication error connecting to "{redis_server}"',
+ [ 'redis_server' => $server ]
+ );
+
+ return false;
+ }
+ }
+
+ return true;
+ }
+
+ /**
+ * Adjust or reset the connection handle read timeout value
+ *
+ * @param Redis $conn
+ * @param int $timeout Optional
+ */
+ public function resetTimeout( Redis $conn, $timeout = null ) {
+ $conn->setOption( Redis::OPT_READ_TIMEOUT, $timeout ?: $this->readTimeout );
+ }
+
+ /**
+ * Make sure connections are closed for sanity
+ */
+ function __destruct() {
+ foreach ( $this->connections as $server => &$serverConnections ) {
+ foreach ( $serverConnections as $key => &$connection ) {
+ try {
+ /** @var Redis $conn */
+ $conn = $connection['conn'];
+ $conn->close();
+ } catch ( RedisException $e ) {
+ // The destructor can be called on shutdown when random parts of the system
+ // have been destructed already, causing weird errors. Ignore them.
+ }
+ }
+ }
+ }
+}
scripts.mit.edu / autoinstallsdev / mediawiki.git / blobdiff