wiki.techinc.nl/includes/libs/redis/RedisConnectionPool.php
Daimona Eaytoy 41ee2f2c61 Upgrade phan to 0.9.1
Released just now.

Many old suppressions can now be removed. Enabling the issue for
undeclared variables is left to do later, given that there are
roughly 200 warning.

Change-Id: I99462a1e9232d6e75022912e2df82bc2038476ef
2020-01-25 10:53:26 +00:00

411 lines
13 KiB
PHP

<?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;
use Psr\Log\NullLogger;
/**
* 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),...)
* @phan-var array<string,array{conn:Redis,free:bool}[]>
*/
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 = $options['logger'] ?? new 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' ) {
if ( !defined( 'Redis::SERIALIZER_IGBINARY' ) ) {
throw new InvalidArgumentException(
__CLASS__ . ': configured serializer "igbinary" not available' );
}
$this->serializer = Redis::SERIALIZER_IGBINARY;
} elseif ( $options['serializer'] === 'none' ) {
$this->serializer = Redis::SERIALIZER_NONE;
} else {
throw new InvalidArgumentException( "Invalid serializer specified." );
}
$this->id = $id;
}
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|null $logger PSR-3 logger intance. [optional]
* @return RedisConnRef|Redis|bool Returns false on failure
* @throws InvalidArgumentException
*/
public function getConnection( $server, LoggerInterface $logger = null ) {
// The above @return also documents 'Redis' for convenience with IDEs.
// RedisConnRef uses PHP magic methods, which wouldn't be recognised.
$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 ( ( $this->password !== null ) && !$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 ( $this->password !== null && !$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|null $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
*/
public 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.
}
}
}
}
}