3 * Object caching using Redis (http://redis.io/).
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
23 class RedisBagOStuff
extends BagOStuff
{
24 /** @var RedisConnectionPool */
26 /** @var array List of server names */
29 protected $automaticFailover;
32 * Construct a RedisBagOStuff object. Parameters are:
34 * - servers: An array of server names. A server name may be a hostname,
35 * a hostname/port combination or the absolute path of a UNIX socket.
36 * If a hostname is specified but no port, the standard port number
37 * 6379 will be used. Required.
39 * - connectTimeout: The timeout for new connections, in seconds. Optional,
40 * default is 1 second.
42 * - persistent: Set this to true to allow connections to persist across
43 * multiple web requests. False by default.
45 * - password: The authentication password, will be sent to Redis in
46 * clear text. Optional, if it is unspecified, no AUTH command will be
49 * - automaticFailover: If this is false, then each key will be mapped to
50 * a single server, and if that server is down, any requests for that key
51 * will fail. If this is true, a connection failure will cause the client
52 * to immediately try the next server in the list (as determined by a
53 * consistent hashing algorithm). True by default. This has the
54 * potential to create consistency issues if a server is slow enough to
55 * flap, for example if it is in swap death.
56 * @param array $params
58 function __construct( $params ) {
59 $redisConf = array( 'serializer' => 'none' ); // manage that in this class
60 foreach ( array( 'connectTimeout', 'persistent', 'password' ) as $opt ) {
61 if ( isset( $params[$opt] ) ) {
62 $redisConf[$opt] = $params[$opt];
65 $this->redisPool
= RedisConnectionPool
::singleton( $redisConf );
67 $this->servers
= $params['servers'];
68 if ( isset( $params['automaticFailover'] ) ) {
69 $this->automaticFailover
= $params['automaticFailover'];
71 $this->automaticFailover
= true;
75 public function get( $key, &$casToken = null ) {
76 $section = new ProfileSection( __METHOD__
);
78 list( $server, $conn ) = $this->getConnection( $key );
83 $value = $conn->get( $key );
85 $result = $this->unserialize( $value );
86 } catch ( RedisException
$e ) {
88 $this->handleException( $conn, $e );
91 $this->logRequest( 'get', $key, $server, $result );
95 public function set( $key, $value, $expiry = 0 ) {
96 $section = new ProfileSection( __METHOD__
);
98 list( $server, $conn ) = $this->getConnection( $key );
102 $expiry = $this->convertToRelative( $expiry );
105 $result = $conn->setex( $key, $expiry, $this->serialize( $value ) );
107 // No expiry, that is very different from zero expiry in Redis
108 $result = $conn->set( $key, $this->serialize( $value ) );
110 } catch ( RedisException
$e ) {
112 $this->handleException( $conn, $e );
115 $this->logRequest( 'set', $key, $server, $result );
119 public function cas( $casToken, $key, $value, $expiry = 0 ) {
120 $section = new ProfileSection( __METHOD__
);
122 list( $server, $conn ) = $this->getConnection( $key );
126 $expiry = $this->convertToRelative( $expiry );
128 $conn->watch( $key );
130 if ( $this->serialize( $this->get( $key ) ) !== $casToken ) {
135 // multi()/exec() will fail atomically if the key changed since watch()
138 $conn->setex( $key, $expiry, $this->serialize( $value ) );
140 // No expiry, that is very different from zero expiry in Redis
141 $conn->set( $key, $this->serialize( $value ) );
143 $result = ( $conn->exec() == array( true ) );
144 } catch ( RedisException
$e ) {
146 $this->handleException( $conn, $e );
149 $this->logRequest( 'cas', $key, $server, $result );
153 public function delete( $key, $time = 0 ) {
154 $section = new ProfileSection( __METHOD__
);
156 list( $server, $conn ) = $this->getConnection( $key );
161 $conn->delete( $key );
162 // Return true even if the key didn't exist
164 } catch ( RedisException
$e ) {
166 $this->handleException( $conn, $e );
169 $this->logRequest( 'delete', $key, $server, $result );
173 public function getMulti( array $keys ) {
174 $section = new ProfileSection( __METHOD__
);
178 foreach ( $keys as $key ) {
179 list( $server, $conn ) = $this->getConnection( $key );
183 $conns[$server] = $conn;
184 $batches[$server][] = $key;
187 foreach ( $batches as $server => $batchKeys ) {
188 $conn = $conns[$server];
190 $conn->multi( Redis
::PIPELINE
);
191 foreach ( $batchKeys as $key ) {
194 $batchResult = $conn->exec();
195 if ( $batchResult === false ) {
196 $this->debug( "multi request to $server failed" );
199 foreach ( $batchResult as $i => $value ) {
200 if ( $value !== false ) {
201 $result[$batchKeys[$i]] = $this->unserialize( $value );
204 } catch ( RedisException
$e ) {
205 $this->handleException( $conn, $e );
209 $this->debug( "getMulti for " . count( $keys ) . " keys " .
210 "returned " . count( $result ) . " results" );
219 public function setMulti( array $data, $expiry = 0 ) {
220 $section = new ProfileSection( __METHOD__
);
224 foreach ( $data as $key => $value ) {
225 list( $server, $conn ) = $this->getConnection( $key );
229 $conns[$server] = $conn;
230 $batches[$server][] = $key;
233 $expiry = $this->convertToRelative( $expiry );
235 foreach ( $batches as $server => $batchKeys ) {
236 $conn = $conns[$server];
238 $conn->multi( Redis
::PIPELINE
);
239 foreach ( $batchKeys as $key ) {
241 $conn->setex( $key, $expiry, $this->serialize( $data[$key] ) );
243 $conn->set( $key, $this->serialize( $data[$key] ) );
246 $batchResult = $conn->exec();
247 if ( $batchResult === false ) {
248 $this->debug( "setMulti request to $server failed" );
251 foreach ( $batchResult as $value ) {
252 if ( $value === false ) {
256 } catch ( RedisException
$e ) {
257 $this->handleException( $server, $conn, $e );
267 public function add( $key, $value, $expiry = 0 ) {
268 $section = new ProfileSection( __METHOD__
);
270 list( $server, $conn ) = $this->getConnection( $key );
274 $expiry = $this->convertToRelative( $expiry );
278 $conn->setnx( $key, $this->serialize( $value ) );
279 $conn->expire( $key, $expiry );
280 $result = ( $conn->exec() == array( true, true ) );
282 $result = $conn->setnx( $key, $this->serialize( $value ) );
284 } catch ( RedisException
$e ) {
286 $this->handleException( $conn, $e );
289 $this->logRequest( 'add', $key, $server, $result );
294 * Non-atomic implementation of incr().
296 * Probably all callers actually want incr() to atomically initialise
297 * values to zero if they don't exist, as provided by the Redis INCR
298 * command. But we are constrained by the memcached-like interface to
299 * return null in that case. Once the key exists, further increments are
301 * @param string $key Key to increase
302 * @param int $value Value to add to $key (Default 1)
303 * @return int|bool New value or false on failure
305 public function incr( $key, $value = 1 ) {
306 $section = new ProfileSection( __METHOD__
);
308 list( $server, $conn ) = $this->getConnection( $key );
312 if ( !$conn->exists( $key ) ) {
316 $result = $conn->incrBy( $key, $value );
317 } catch ( RedisException
$e ) {
319 $this->handleException( $conn, $e );
322 $this->logRequest( 'incr', $key, $server, $result );
329 protected function serialize( $data ) {
330 // Serialize anything but integers so INCR/DECR work
331 // Do not store integer-like strings as integers to avoid type confusion (bug 60563)
332 return is_int( $data ) ?
$data : serialize( $data );
336 * @param string $data
339 protected function unserialize( $data ) {
340 return ctype_digit( $data ) ?
intval( $data ) : unserialize( $data );
344 * Get a Redis object with a connection suitable for fetching the specified key
345 * @return array (server, RedisConnRef) or (false, false)
347 protected function getConnection( $key ) {
348 if ( count( $this->servers
) === 1 ) {
349 $candidates = $this->servers
;
351 $candidates = $this->servers
;
352 ArrayUtils
::consistentHashSort( $candidates, $key, '/' );
353 if ( !$this->automaticFailover
) {
354 $candidates = array_slice( $candidates, 0, 1 );
358 foreach ( $candidates as $server ) {
359 $conn = $this->redisPool
->getConnection( $server );
361 return array( $server, $conn );
364 $this->setLastError( BagOStuff
::ERR_UNREACHABLE
);
365 return array( false, false );
372 protected function logError( $msg ) {
373 wfDebugLog( 'redis', "Redis error: $msg" );
377 * The redis extension throws an exception in response to various read, write
378 * and protocol errors. Sometimes it also closes the connection, sometimes
379 * not. The safest response for us is to explicitly destroy the connection
380 * object and let it be reopened during the next request.
381 * @param RedisConnRef $conn
382 * @param Exception $e
384 protected function handleException( RedisConnRef
$conn, $e ) {
385 $this->setLastError( BagOStuff
::ERR_UNEXPECTED
);
386 $this->redisPool
->handleError( $conn, $e );
390 * Send information about a single request to the debug log
391 * @param string $method
393 * @param string $server
394 * @param bool $result
396 public function logRequest( $method, $key, $server, $result ) {
397 $this->debug( "$method $key on $server: " .
398 ( $result === false ?
"failure" : "success" ) );