3 * Redis client connection pooling manager.
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License along
16 * with this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
18 * http://www.gnu.org/copyleft/gpl.html
21 * @defgroup Redis Redis
24 use Psr\Log\LoggerAwareInterface
;
25 use Psr\Log\LoggerInterface
;
28 * Helper class to manage Redis connections.
30 * This can be used to get handle wrappers that free the handle when the wrapper
31 * leaves scope. The maximum number of free handles (connections) is configurable.
32 * This provides an easy way to cache connection handles that may also have state,
33 * such as a handle does between multi() and exec(), and without hoarding connections.
34 * The wrappers use PHP magic methods so that calling functions on them calls the
35 * function of the actual Redis object handle.
40 class RedisConnectionPool
implements LoggerAwareInterface
{
41 /** @var string Connection timeout in seconds */
42 protected $connectTimeout;
43 /** @var string Read timeout in seconds */
44 protected $readTimeout;
45 /** @var string Plaintext auth password */
47 /** @var bool Whether connections persist */
48 protected $persistent;
49 /** @var int Serializer to use (Redis::SERIALIZER_*) */
50 protected $serializer;
51 /** @var string ID for persistent connections */
54 /** @var int Current idle pool size */
55 protected $idlePoolSize = 0;
57 /** @var array (server name => ((connection info array),...) */
58 protected $connections = [];
59 /** @var array (server name => UNIX timestamp) */
60 protected $downServers = [];
62 /** @var array (pool ID => RedisConnectionPool) */
63 protected static $instances = [];
65 /** integer; seconds to cache servers as "down". */
66 const SERVER_DOWN_TTL
= 30;
69 * @var LoggerInterface
74 * @param array $options
78 protected function __construct( array $options, $id ) {
79 if ( !class_exists( 'Redis' ) ) {
80 throw new RuntimeException(
81 __CLASS__
. ' requires a Redis client library. ' .
82 'See https://www.mediawiki.org/wiki/Redis#Setup' );
84 $this->logger
= $options['logger'] ??
new \Psr\Log\
NullLogger();
85 $this->connectTimeout
= $options['connectTimeout'];
86 $this->readTimeout
= $options['readTimeout'];
87 $this->persistent
= $options['persistent'];
88 $this->password
= $options['password'];
89 if ( !isset( $options['serializer'] ) ||
$options['serializer'] === 'php' ) {
90 $this->serializer
= Redis
::SERIALIZER_PHP
;
91 } elseif ( $options['serializer'] === 'igbinary' ) {
92 $this->serializer
= Redis
::SERIALIZER_IGBINARY
;
93 } elseif ( $options['serializer'] === 'none' ) {
94 $this->serializer
= Redis
::SERIALIZER_NONE
;
96 throw new InvalidArgumentException( "Invalid serializer specified." );
102 * @param LoggerInterface $logger
105 public function setLogger( LoggerInterface
$logger ) {
106 $this->logger
= $logger;
110 * @param array $options
113 protected static function applyDefaultConfig( array $options ) {
114 if ( !isset( $options['connectTimeout'] ) ) {
115 $options['connectTimeout'] = 1;
117 if ( !isset( $options['readTimeout'] ) ) {
118 $options['readTimeout'] = 1;
120 if ( !isset( $options['persistent'] ) ) {
121 $options['persistent'] = false;
123 if ( !isset( $options['password'] ) ) {
124 $options['password'] = null;
131 * @param array $options
133 * - connectTimeout : The timeout for new connections, in seconds.
134 * Optional, default is 1 second.
135 * - readTimeout : The timeout for operation reads, in seconds.
136 * Commands like BLPOP can fail if told to wait longer than this.
137 * Optional, default is 1 second.
138 * - persistent : Set this to true to allow connections to persist across
139 * multiple web requests. False by default.
140 * - password : The authentication password, will be sent to Redis in clear text.
141 * Optional, if it is unspecified, no AUTH command will be sent.
142 * - serializer : Set to "php", "igbinary", or "none". Default is "php".
143 * @return RedisConnectionPool
145 public static function singleton( array $options ) {
146 $options = self
::applyDefaultConfig( $options );
147 // Map the options to a unique hash...
148 ksort( $options ); // normalize to avoid pool fragmentation
149 $id = sha1( serialize( $options ) );
150 // Initialize the object at the hash as needed...
151 if ( !isset( self
::$instances[$id] ) ) {
152 self
::$instances[$id] = new self( $options, $id );
155 return self
::$instances[$id];
159 * Destroy all singleton() instances
162 public static function destroySingletons() {
163 self
::$instances = [];
167 * Get a connection to a redis server. Based on code in RedisBagOStuff.php.
169 * @param string $server A hostname/port combination or the absolute path of a UNIX socket.
170 * If a hostname is specified but no port, port 6379 will be used.
171 * @param LoggerInterface|null $logger PSR-3 logger intance. [optional]
172 * @return RedisConnRef|bool Returns false on failure
173 * @throws MWException
175 public function getConnection( $server, LoggerInterface
$logger = null ) {
176 $logger = $logger ?
: $this->logger
;
177 // Check the listing "dead" servers which have had a connection errors.
178 // Servers are marked dead for a limited period of time, to
179 // avoid excessive overhead from repeated connection timeouts.
180 if ( isset( $this->downServers
[$server] ) ) {
182 if ( $now > $this->downServers
[$server] ) {
184 unset( $this->downServers
[$server] );
188 'Server "{redis_server}" is marked down for another ' .
189 ( $this->downServers
[$server] - $now ) . 'seconds',
190 [ 'redis_server' => $server ]
197 // Check if a connection is already free for use
198 if ( isset( $this->connections
[$server] ) ) {
199 foreach ( $this->connections
[$server] as &$connection ) {
200 if ( $connection['free'] ) {
201 $connection['free'] = false;
202 --$this->idlePoolSize
;
204 return new RedisConnRef(
205 $this, $server, $connection['conn'], $logger
212 throw new InvalidArgumentException(
213 __CLASS__
. ": invalid configured server \"$server\"" );
214 } elseif ( substr( $server, 0, 1 ) === '/' ) {
215 // UNIX domain socket
216 // These are required by the redis extension to start with a slash, but
217 // we still need to set the port to a special value to make it work.
222 if ( preg_match( '/^\[(.+)\]:(\d+)$/', $server, $m ) ) {
223 list( $host, $port ) = [ $m[1], (int)$m[2] ]; // (ip, port)
224 } elseif ( preg_match( '/^([^:]+):(\d+)$/', $server, $m ) ) {
225 list( $host, $port ) = [ $m[1], (int)$m[2] ]; // (ip or path, port)
227 list( $host, $port ) = [ $server, 6379 ]; // (ip or path, port)
233 if ( $this->persistent
) {
234 $result = $conn->pconnect( $host, $port, $this->connectTimeout
, $this->id
);
236 $result = $conn->connect( $host, $port, $this->connectTimeout
);
240 'Could not connect to server "{redis_server}"',
241 [ 'redis_server' => $server ]
243 // Mark server down for some time to avoid further timeouts
244 $this->downServers
[$server] = time() + self
::SERVER_DOWN_TTL
;
248 if ( $this->password
!== null ) {
249 if ( !$conn->auth( $this->password
) ) {
251 'Authentication error connecting to "{redis_server}"',
252 [ 'redis_server' => $server ]
256 } catch ( RedisException
$e ) {
257 $this->downServers
[$server] = time() + self
::SERVER_DOWN_TTL
;
259 'Redis exception connecting to "{redis_server}"',
261 'redis_server' => $server,
270 $conn->setOption( Redis
::OPT_READ_TIMEOUT
, $this->readTimeout
);
271 $conn->setOption( Redis
::OPT_SERIALIZER
, $this->serializer
);
272 $this->connections
[$server][] = [ 'conn' => $conn, 'free' => false ];
274 return new RedisConnRef( $this, $server, $conn, $logger );
281 * Mark a connection to a server as free to return to the pool
283 * @param string $server
287 public function freeConnection( $server, Redis
$conn ) {
290 foreach ( $this->connections
[$server] as &$connection ) {
291 if ( $connection['conn'] === $conn && !$connection['free'] ) {
292 $connection['free'] = true;
293 ++
$this->idlePoolSize
;
298 $this->closeExcessIdleConections();
304 * Close any extra idle connections if there are more than the limit
306 protected function closeExcessIdleConections() {
307 if ( $this->idlePoolSize
<= count( $this->connections
) ) {
308 return; // nothing to do (no more connections than servers)
311 foreach ( $this->connections
as &$serverConnections ) {
312 foreach ( $serverConnections as $key => &$connection ) {
313 if ( $connection['free'] ) {
314 unset( $serverConnections[$key] );
315 if ( --$this->idlePoolSize
<= count( $this->connections
) ) {
316 return; // done (no more connections than servers)
324 * The redis extension throws an exception in response to various read, write
325 * and protocol errors. Sometimes it also closes the connection, sometimes
326 * not. The safest response for us is to explicitly destroy the connection
327 * object and let it be reopened during the next request.
329 * @param RedisConnRef $cref
330 * @param RedisException $e
332 public function handleError( RedisConnRef
$cref, RedisException
$e ) {
333 $server = $cref->getServer();
334 $this->logger
->error(
335 'Redis exception on server "{redis_server}"',
337 'redis_server' => $server,
341 foreach ( $this->connections
[$server] as $key => $connection ) {
342 if ( $cref->isConnIdentical( $connection['conn'] ) ) {
343 $this->idlePoolSize
-= $connection['free'] ?
1 : 0;
344 unset( $this->connections
[$server][$key] );
351 * Re-send an AUTH request to the redis server (useful after disconnects).
353 * This works around an upstream bug in phpredis. phpredis hides disconnects by transparently
354 * reconnecting, but it neglects to re-authenticate the new connection. To the user of the
355 * phpredis client API this manifests as a seemingly random tendency of connections to lose
356 * their authentication status.
358 * This method is for internal use only.
360 * @see https://github.com/nicolasff/phpredis/issues/403
362 * @param string $server
364 * @return bool Success
366 public function reauthenticateConnection( $server, Redis
$conn ) {
367 if ( $this->password
!== null ) {
368 if ( !$conn->auth( $this->password
) ) {
369 $this->logger
->error(
370 'Authentication error connecting to "{redis_server}"',
371 [ 'redis_server' => $server ]
382 * Adjust or reset the connection handle read timeout value
385 * @param int|null $timeout Optional
387 public function resetTimeout( Redis
$conn, $timeout = null ) {
388 $conn->setOption( Redis
::OPT_READ_TIMEOUT
, $timeout ?
: $this->readTimeout
);
392 * Make sure connections are closed for sanity
394 function __destruct() {
395 foreach ( $this->connections
as $server => &$serverConnections ) {
396 foreach ( $serverConnections as $key => &$connection ) {
398 /** @var Redis $conn */
399 $conn = $connection['conn'];
401 } catch ( RedisException
$e ) {
402 // The destructor can be called on shutdown when random parts of the system
403 // have been destructed already, causing weird errors. Ignore them.