MediaWiki REL1_35
RedisBagOStuff.php
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1<?php
35 protected $redisPool;
37 protected $servers;
39 protected $serverTagMap;
42
71 public function __construct( $params ) {
72 parent::__construct( $params );
73 $redisConf = [ 'serializer' => 'none' ]; // manage that in this class
74 foreach ( [ 'connectTimeout', 'persistent', 'password' ] as $opt ) {
75 if ( isset( $params[$opt] ) ) {
76 $redisConf[$opt] = $params[$opt];
77 }
78 }
79 $this->redisPool = RedisConnectionPool::singleton( $redisConf );
80
81 $this->servers = $params['servers'];
82 foreach ( $this->servers as $key => $server ) {
83 $this->serverTagMap[is_int( $key ) ? $server : $key] = $server;
84 }
85
86 $this->automaticFailover = $params['automaticFailover'] ?? true;
87
88 $this->attrMap[self::ATTR_SYNCWRITES] = self::QOS_SYNCWRITES_NONE;
89 }
90
91 protected function doGet( $key, $flags = 0, &$casToken = null ) {
92 $casToken = null;
93
94 $conn = $this->getConnection( $key );
95 if ( !$conn ) {
96 return false;
97 }
98
99 $e = null;
100 try {
101 $value = $conn->get( $key );
102 $casToken = $value;
103 $result = $this->unserialize( $value );
104 } catch ( RedisException $e ) {
105 $result = false;
106 $this->handleException( $conn, $e );
107 }
108
109 $this->logRequest( 'get', $key, $conn->getServer(), $e );
110
111 return $result;
112 }
113
114 protected function doSet( $key, $value, $exptime = 0, $flags = 0 ) {
115 $conn = $this->getConnection( $key );
116 if ( !$conn ) {
117 return false;
118 }
119
120 $ttl = $this->getExpirationAsTTL( $exptime );
121
122 $e = null;
123 try {
124 if ( $ttl ) {
125 $result = $conn->setex( $key, $ttl, $this->getSerialized( $value, $key ) );
126 } else {
127 $result = $conn->set( $key, $this->getSerialized( $value, $key ) );
128 }
129 } catch ( RedisException $e ) {
130 $result = false;
131 $this->handleException( $conn, $e );
132 }
133
134 $this->logRequest( 'set', $key, $conn->getServer(), $e );
135
136 return $result;
137 }
138
139 protected function doDelete( $key, $flags = 0 ) {
140 $conn = $this->getConnection( $key );
141 if ( !$conn ) {
142 return false;
143 }
144
145 $e = null;
146 try {
147 // Note that redis does not return false if the key was not there
148 $result = ( $conn->del( $key ) !== false );
149 } catch ( RedisException $e ) {
150 $result = false;
151 $this->handleException( $conn, $e );
152 }
153
154 $this->logRequest( 'delete', $key, $conn->getServer(), $e );
155
156 return $result;
157 }
158
159 protected function doGetMulti( array $keys, $flags = 0 ) {
161 $conns = [];
162 $batches = [];
163 foreach ( $keys as $key ) {
164 $conn = $this->getConnection( $key );
165 if ( $conn ) {
166 $server = $conn->getServer();
167 $conns[$server] = $conn;
168 $batches[$server][] = $key;
169 }
170 }
171
172 $result = [];
173 foreach ( $batches as $server => $batchKeys ) {
174 $conn = $conns[$server];
175
176 $e = null;
177 try {
178 // Avoid mget() to reduce CPU hogging from a single request
179 $conn->multi( Redis::PIPELINE );
180 foreach ( $batchKeys as $key ) {
181 $conn->get( $key );
182 }
183 $batchResult = $conn->exec();
184 if ( $batchResult === false ) {
185 $this->logRequest( 'get', implode( ',', $batchKeys ), $server, true );
186 continue;
187 }
188
189 foreach ( $batchResult as $i => $value ) {
190 if ( $value !== false ) {
191 $result[$batchKeys[$i]] = $this->unserialize( $value );
192 }
193 }
194 } catch ( RedisException $e ) {
195 $this->handleException( $conn, $e );
196 }
197
198 $this->logRequest( 'get', implode( ',', $batchKeys ), $server, $e );
199 }
200
201 return $result;
202 }
203
204 protected function doSetMulti( array $data, $exptime = 0, $flags = 0 ) {
206 $conns = [];
207 $batches = [];
208 foreach ( $data as $key => $value ) {
209 $conn = $this->getConnection( $key );
210 if ( $conn ) {
211 $server = $conn->getServer();
212 $conns[$server] = $conn;
213 $batches[$server][] = $key;
214 }
215 }
216
217 $ttl = $this->getExpirationAsTTL( $exptime );
218 $op = $ttl ? 'setex' : 'set';
219
220 $result = true;
221 foreach ( $batches as $server => $batchKeys ) {
222 $conn = $conns[$server];
223
224 $e = null;
225 try {
226 // Avoid mset() to reduce CPU hogging from a single request
227 $conn->multi( Redis::PIPELINE );
228 foreach ( $batchKeys as $key ) {
229 if ( $ttl ) {
230 $conn->setex( $key, $ttl, $this->getSerialized( $data[$key], $key ) );
231 } else {
232 $conn->set( $key, $this->getSerialized( $data[$key], $key ) );
233 }
234 }
235 $batchResult = $conn->exec();
236 if ( $batchResult === false ) {
237 $this->logRequest( $op, implode( ',', $batchKeys ), $server, true );
238 continue;
239 }
240 $result = $result && !in_array( false, $batchResult, true );
241 } catch ( RedisException $e ) {
242 $this->handleException( $conn, $e );
243 $result = false;
244 }
245
246 $this->logRequest( $op, implode( ',', $batchKeys ), $server, $e );
247 }
248
249 return $result;
250 }
251
252 protected function doDeleteMulti( array $keys, $flags = 0 ) {
254 $conns = [];
255 $batches = [];
256 foreach ( $keys as $key ) {
257 $conn = $this->getConnection( $key );
258 if ( $conn ) {
259 $server = $conn->getServer();
260 $conns[$server] = $conn;
261 $batches[$server][] = $key;
262 }
263 }
264
265 $result = true;
266 foreach ( $batches as $server => $batchKeys ) {
267 $conn = $conns[$server];
268
269 $e = null;
270 try {
271 // Avoid delete() with array to reduce CPU hogging from a single request
272 $conn->multi( Redis::PIPELINE );
273 foreach ( $batchKeys as $key ) {
274 $conn->del( $key );
275 }
276 $batchResult = $conn->exec();
277 if ( $batchResult === false ) {
278 $this->logRequest( 'delete', implode( ',', $batchKeys ), $server, true );
279 continue;
280 }
281 // Note that redis does not return false if the key was not there
282 $result = $result && !in_array( false, $batchResult, true );
283 } catch ( RedisException $e ) {
284 $this->handleException( $conn, $e );
285 $result = false;
286 }
287
288 $this->logRequest( 'delete', implode( ',', $batchKeys ), $server, $e );
289 }
290
291 return $result;
292 }
293
294 public function changeTTLMulti( array $keys, $exptime, $flags = 0 ) {
296 $conns = [];
297 $batches = [];
298 foreach ( $keys as $key ) {
299 $conn = $this->getConnection( $key );
300 if ( $conn ) {
301 $server = $conn->getServer();
302 $conns[$server] = $conn;
303 $batches[$server][] = $key;
304 }
305 }
306
307 $relative = $this->isRelativeExpiration( $exptime );
308 $op = ( $exptime == self::TTL_INDEFINITE )
309 ? 'persist'
310 : ( $relative ? 'expire' : 'expireAt' );
311
312 $result = true;
313 foreach ( $batches as $server => $batchKeys ) {
314 $conn = $conns[$server];
315
316 $e = null;
317 try {
318 $conn->multi( Redis::PIPELINE );
319 foreach ( $batchKeys as $key ) {
320 if ( $exptime == self::TTL_INDEFINITE ) {
321 $conn->persist( $key );
322 } elseif ( $relative ) {
323 $conn->expire( $key, $this->getExpirationAsTTL( $exptime ) );
324 } else {
325 $conn->expireAt( $key, $this->getExpirationAsTimestamp( $exptime ) );
326 }
327 }
328 $batchResult = $conn->exec();
329 if ( $batchResult === false ) {
330 $this->logRequest( $op, implode( ',', $batchKeys ), $server, true );
331 continue;
332 }
333 $result = in_array( false, $batchResult, true ) ? false : $result;
334 } catch ( RedisException $e ) {
335 $this->handleException( $conn, $e );
336 $result = false;
337 }
338
339 $this->logRequest( $op, implode( ',', $batchKeys ), $server, $e );
340 }
341
342 return $result;
343 }
344
345 protected function doAdd( $key, $value, $expiry = 0, $flags = 0 ) {
346 $conn = $this->getConnection( $key );
347 if ( !$conn ) {
348 return false;
349 }
350
351 $ttl = $this->getExpirationAsTTL( $expiry );
352 try {
353 $result = $conn->set(
354 $key,
355 $this->getSerialized( $value, $key ),
356 $ttl ? [ 'nx', 'ex' => $ttl ] : [ 'nx' ]
357 );
358 } catch ( RedisException $e ) {
359 $result = false;
360 $this->handleException( $conn, $e );
361 }
362
363 $this->logRequest( 'add', $key, $conn->getServer(), $result );
364
365 return $result;
366 }
367
368 public function incr( $key, $value = 1, $flags = 0 ) {
369 $conn = $this->getConnection( $key );
370 if ( !$conn ) {
371 return false;
372 }
373
374 try {
375 if ( !$conn->exists( $key ) ) {
376 return false;
377 }
378 // @FIXME: on races, the key may have a 0 TTL
379 $result = $conn->incrBy( $key, $value );
380 } catch ( RedisException $e ) {
381 $result = false;
382 $this->handleException( $conn, $e );
383 }
384
385 $this->logRequest( 'incr', $key, $conn->getServer(), $result );
386
387 return $result;
388 }
389
390 public function decr( $key, $value = 1, $flags = 0 ) {
391 $conn = $this->getConnection( $key );
392 if ( !$conn ) {
393 return false;
394 }
395
396 try {
397 if ( !$conn->exists( $key ) ) {
398 return false;
399 }
400 // @FIXME: on races, the key may have a 0 TTL
401 $result = $conn->decrBy( $key, $value );
402 } catch ( RedisException $e ) {
403 $result = false;
404 $this->handleException( $conn, $e );
405 }
406
407 $this->logRequest( 'decr', $key, $conn->getServer(), $result );
408
409 return $result;
410 }
411
412 protected function doChangeTTL( $key, $exptime, $flags ) {
413 $conn = $this->getConnection( $key );
414 if ( !$conn ) {
415 return false;
416 }
417
418 $relative = $this->isRelativeExpiration( $exptime );
419 try {
420 if ( $exptime == self::TTL_INDEFINITE ) {
421 $result = $conn->persist( $key );
422 $this->logRequest( 'persist', $key, $conn->getServer(), $result );
423 } elseif ( $relative ) {
424 $result = $conn->expire( $key, $this->getExpirationAsTTL( $exptime ) );
425 $this->logRequest( 'expire', $key, $conn->getServer(), $result );
426 } else {
427 $result = $conn->expireAt( $key, $this->getExpirationAsTimestamp( $exptime ) );
428 $this->logRequest( 'expireAt', $key, $conn->getServer(), $result );
429 }
430 } catch ( RedisException $e ) {
431 $result = false;
432 $this->handleException( $conn, $e );
433 }
434
435 return $result;
436 }
437
442 protected function getConnection( $key ) {
443 $candidates = array_keys( $this->serverTagMap );
444
445 if ( count( $this->servers ) > 1 ) {
446 ArrayUtils::consistentHashSort( $candidates, $key, '/' );
447 if ( !$this->automaticFailover ) {
448 $candidates = array_slice( $candidates, 0, 1 );
449 }
450 }
451
452 while ( ( $tag = array_shift( $candidates ) ) !== null ) {
453 $server = $this->serverTagMap[$tag];
454 $conn = $this->redisPool->getConnection( $server, $this->logger );
455 if ( !$conn ) {
456 continue;
457 }
458
459 // If automatic failover is enabled, check that the server's link
460 // to its master (if any) is up -- but only if there are other
461 // viable candidates left to consider. Also, getMasterLinkStatus()
462 // does not work with twemproxy, though $candidates will be empty
463 // by now in such cases.
464 if ( $this->automaticFailover && $candidates ) {
465 try {
467 $info = $conn->info();
468 if ( ( $info['master_link_status'] ?? null ) === 'down' ) {
469 // If the master cannot be reached, fail-over to the next server.
470 // If masters are in data-center A, and replica DBs in data-center B,
471 // this helps avoid the case were fail-over happens in A but not
472 // to the corresponding server in B (e.g. read/write mismatch).
473 continue;
474 }
475 } catch ( RedisException $e ) {
476 // Server is not accepting commands
477 $this->redisPool->handleError( $conn, $e );
478 continue;
479 }
480 }
481
482 return $conn;
483 }
484
485 $this->setLastError( BagOStuff::ERR_UNREACHABLE );
486
487 return null;
488 }
489
494 protected function logError( $msg ) {
495 $this->logger->error( "Redis error: $msg" );
496 }
497
506 protected function handleException( RedisConnRef $conn, RedisException $e ) {
507 $this->setLastError( BagOStuff::ERR_UNEXPECTED );
508 $this->redisPool->handleError( $conn, $e );
509 }
510
518 public function logRequest( $op, $keys, $server, $e = null ) {
519 $this->debug( "$op($keys) on $server: " . ( $e ? "failure" : "success" ) );
520 }
521}
Storage medium specific cache for storing items (e.g.
getExpirationAsTimestamp( $exptime)
Convert an optionally relative timestamp to an absolute time.
getSerialized( $value, $key)
Get the serialized form a value, using any applicable prepared value.
getExpirationAsTTL( $exptime)
Convert an optionally absolute expiry time to a relative time.
setLastError( $err)
Set the "last error" registry.
Redis-based caching module for redis server >= 2.6.12 and phpredis >= 2.2.4.
RedisConnectionPool $redisPool
incr( $key, $value=1, $flags=0)
Increase stored value of $key by $value while preserving its TTL.
changeTTLMulti(array $keys, $exptime, $flags=0)
Change the expiration of multiple keys that exist.
handleException(RedisConnRef $conn, RedisException $e)
The redis extension throws an exception in response to various read, write and protocol errors.
array $servers
List of server names.
doSetMulti(array $data, $exptime=0, $flags=0)
doChangeTTL( $key, $exptime, $flags)
logRequest( $op, $keys, $server, $e=null)
Send information about a single request to the debug log.
doDelete( $key, $flags=0)
Delete an item.
logError( $msg)
Log a fatal error.
doAdd( $key, $value, $expiry=0, $flags=0)
Insert an item if it does not already exist.
__construct( $params)
Construct a RedisBagOStuff object.
doGet( $key, $flags=0, &$casToken=null)
array $serverTagMap
Map of (tag => server name)
doGetMulti(array $keys, $flags=0)
Get an associative array containing the item for each of the keys that have items.
doSet( $key, $value, $exptime=0, $flags=0)
Set an item.
doDeleteMulti(array $keys, $flags=0)
decr( $key, $value=1, $flags=0)
Decrease stored value of $key by $value while preserving its TTL.
Helper class to handle automatically marking connectons as reusable (via RAII pattern)
Helper class to manage Redis connections.
static singleton(array $options)