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JobQueueRedis.php
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1 <?php
59 class JobQueueRedis extends JobQueue {
61  protected $redisPool;
62 
64  protected $server;
65 
67  protected $compression;
68 
69  const MAX_AGE_PRUNE = 604800; // integer; seconds a job can live once claimed (7 days)
70 
72  protected $key;
73 
79 
94  public function __construct( array $params ) {
95  parent::__construct( $params );
96  $params['redisConfig']['serializer'] = 'none'; // make it easy to use Lua
97  $this->server = $params['redisServer'];
98  $this->compression = isset( $params['compression'] ) ? $params['compression'] : 'none';
99  $this->redisPool = RedisConnectionPool::singleton( $params['redisConfig'] );
100  $this->maximumPeriodicTaskSeconds = isset( $params['maximumPeriodicTaskSeconds'] ) ?
101  $params['maximumPeriodicTaskSeconds'] : null;
102  }
103 
104  protected function supportedOrders() {
105  return array( 'timestamp', 'fifo' );
106  }
107 
108  protected function optimalOrder() {
109  return 'fifo';
110  }
111 
112  protected function supportsDelayedJobs() {
113  return true;
114  }
115 
121  protected function doIsEmpty() {
122  return $this->doGetSize() == 0;
123  }
124 
130  protected function doGetSize() {
131  $conn = $this->getConnection();
132  try {
133  return $conn->lSize( $this->getQueueKey( 'l-unclaimed' ) );
134  } catch ( RedisException $e ) {
135  $this->throwRedisException( $conn, $e );
136  }
137  }
138 
144  protected function doGetAcquiredCount() {
145  if ( $this->claimTTL <= 0 ) {
146  return 0; // no acknowledgements
147  }
148  $conn = $this->getConnection();
149  try {
150  $conn->multi( Redis::PIPELINE );
151  $conn->zSize( $this->getQueueKey( 'z-claimed' ) );
152  $conn->zSize( $this->getQueueKey( 'z-abandoned' ) );
153 
154  return array_sum( $conn->exec() );
155  } catch ( RedisException $e ) {
156  $this->throwRedisException( $conn, $e );
157  }
158  }
159 
165  protected function doGetDelayedCount() {
166  if ( !$this->checkDelay ) {
167  return 0; // no delayed jobs
168  }
169  $conn = $this->getConnection();
170  try {
171  return $conn->zSize( $this->getQueueKey( 'z-delayed' ) );
172  } catch ( RedisException $e ) {
173  $this->throwRedisException( $conn, $e );
174  }
175  }
176 
182  protected function doGetAbandonedCount() {
183  if ( $this->claimTTL <= 0 ) {
184  return 0; // no acknowledgements
185  }
186  $conn = $this->getConnection();
187  try {
188  return $conn->zSize( $this->getQueueKey( 'z-abandoned' ) );
189  } catch ( RedisException $e ) {
190  $this->throwRedisException( $conn, $e );
191  }
192  }
193 
201  protected function doBatchPush( array $jobs, $flags ) {
202  // Convert the jobs into field maps (de-duplicated against each other)
203  $items = array(); // (job ID => job fields map)
204  foreach ( $jobs as $job ) {
205  $item = $this->getNewJobFields( $job );
206  if ( strlen( $item['sha1'] ) ) { // hash identifier => de-duplicate
207  $items[$item['sha1']] = $item;
208  } else {
209  $items[$item['uuid']] = $item;
210  }
211  }
212 
213  if ( !count( $items ) ) {
214  return true; // nothing to do
215  }
216 
217  $conn = $this->getConnection();
218  try {
219  // Actually push the non-duplicate jobs into the queue...
220  if ( $flags & self::QOS_ATOMIC ) {
221  $batches = array( $items ); // all or nothing
222  } else {
223  $batches = array_chunk( $items, 500 ); // avoid tying up the server
224  }
225  $failed = 0;
226  $pushed = 0;
227  foreach ( $batches as $itemBatch ) {
228  $added = $this->pushBlobs( $conn, $itemBatch );
229  if ( is_int( $added ) ) {
230  $pushed += $added;
231  } else {
232  $failed += count( $itemBatch );
233  }
234  }
235  if ( $failed > 0 ) {
236  wfDebugLog( 'JobQueueRedis', "Could not insert {$failed} {$this->type} job(s)." );
237 
238  return false;
239  }
240  JobQueue::incrStats( 'job-insert', $this->type, count( $items ), $this->wiki );
241  JobQueue::incrStats( 'job-insert-duplicate', $this->type,
242  count( $items ) - $failed - $pushed, $this->wiki );
243  } catch ( RedisException $e ) {
244  $this->throwRedisException( $conn, $e );
245  }
246 
247  return true;
248  }
249 
256  protected function pushBlobs( RedisConnRef $conn, array $items ) {
257  $args = array(); // ([id, sha1, rtime, blob [, id, sha1, rtime, blob ... ] ] )
258  foreach ( $items as $item ) {
259  $args[] = (string)$item['uuid'];
260  $args[] = (string)$item['sha1'];
261  $args[] = (string)$item['rtimestamp'];
262  $args[] = (string)$this->serialize( $item );
263  }
264  static $script =
265 <<<LUA
266  local kUnclaimed, kSha1ById, kIdBySha1, kDelayed, kData = unpack(KEYS)
267  if #ARGV % 4 ~= 0 then return redis.error_reply('Unmatched arguments') end
268  local pushed = 0
269  for i = 1,#ARGV,4 do
270  local id,sha1,rtimestamp,blob = ARGV[i],ARGV[i+1],ARGV[i+2],ARGV[i+3]
271  if sha1 == '' or redis.call('hExists',kIdBySha1,sha1) == 0 then
272  if 1*rtimestamp > 0 then
273  -- Insert into delayed queue (release time as score)
274  redis.call('zAdd',kDelayed,rtimestamp,id)
275  else
276  -- Insert into unclaimed queue
277  redis.call('lPush',kUnclaimed,id)
278  end
279  if sha1 ~= '' then
280  redis.call('hSet',kSha1ById,id,sha1)
281  redis.call('hSet',kIdBySha1,sha1,id)
282  end
283  redis.call('hSet',kData,id,blob)
284  pushed = pushed + 1
285  end
286  end
287  return pushed
288 LUA;
289  return $conn->luaEval( $script,
290  array_merge(
291  array(
292  $this->getQueueKey( 'l-unclaimed' ), # KEYS[1]
293  $this->getQueueKey( 'h-sha1ById' ), # KEYS[2]
294  $this->getQueueKey( 'h-idBySha1' ), # KEYS[3]
295  $this->getQueueKey( 'z-delayed' ), # KEYS[4]
296  $this->getQueueKey( 'h-data' ), # KEYS[5]
297  ),
298  $args
299  ),
300  5 # number of first argument(s) that are keys
301  );
302  }
303 
309  protected function doPop() {
310  $job = false;
311 
312  // Push ready delayed jobs into the queue every 10 jobs to spread the load.
313  // This is also done as a periodic task, but we don't want too much done at once.
314  if ( $this->checkDelay && mt_rand( 0, 9 ) == 0 ) {
316  }
317 
318  $conn = $this->getConnection();
319  try {
320  do {
321  if ( $this->claimTTL > 0 ) {
322  // Keep the claimed job list down for high-traffic queues
323  if ( mt_rand( 0, 99 ) == 0 ) {
325  }
326  $blob = $this->popAndAcquireBlob( $conn );
327  } else {
328  $blob = $this->popAndDeleteBlob( $conn );
329  }
330  if ( $blob === false ) {
331  break; // no jobs; nothing to do
332  }
333 
334  JobQueue::incrStats( 'job-pop', $this->type, 1, $this->wiki );
335  $item = $this->unserialize( $blob );
336  if ( $item === false ) {
337  wfDebugLog( 'JobQueueRedis', "Could not unserialize {$this->type} job." );
338  continue;
339  }
340 
341  // If $item is invalid, recyclePruneAndUndelayJobs() will cleanup as needed
342  $job = $this->getJobFromFields( $item ); // may be false
343  } while ( !$job ); // job may be false if invalid
344  } catch ( RedisException $e ) {
345  $this->throwRedisException( $conn, $e );
346  }
347 
348  return $job;
349  }
350 
356  protected function popAndDeleteBlob( RedisConnRef $conn ) {
357  static $script =
358 <<<LUA
359  local kUnclaimed, kSha1ById, kIdBySha1, kData = unpack(KEYS)
360  -- Pop an item off the queue
361  local id = redis.call('rpop',kUnclaimed)
362  if not id then return false end
363  -- Get the job data and remove it
364  local item = redis.call('hGet',kData,id)
365  redis.call('hDel',kData,id)
366  -- Allow new duplicates of this job
367  local sha1 = redis.call('hGet',kSha1ById,id)
368  if sha1 then redis.call('hDel',kIdBySha1,sha1) end
369  redis.call('hDel',kSha1ById,id)
370  -- Return the job data
371  return item
372 LUA;
373  return $conn->luaEval( $script,
374  array(
375  $this->getQueueKey( 'l-unclaimed' ), # KEYS[1]
376  $this->getQueueKey( 'h-sha1ById' ), # KEYS[2]
377  $this->getQueueKey( 'h-idBySha1' ), # KEYS[3]
378  $this->getQueueKey( 'h-data' ), # KEYS[4]
379  ),
380  4 # number of first argument(s) that are keys
381  );
382  }
383 
389  protected function popAndAcquireBlob( RedisConnRef $conn ) {
390  static $script =
391 <<<LUA
392  local kUnclaimed, kSha1ById, kIdBySha1, kClaimed, kAttempts, kData = unpack(KEYS)
393  -- Pop an item off the queue
394  local id = redis.call('rPop',kUnclaimed)
395  if not id then return false end
396  -- Allow new duplicates of this job
397  local sha1 = redis.call('hGet',kSha1ById,id)
398  if sha1 then redis.call('hDel',kIdBySha1,sha1) end
399  redis.call('hDel',kSha1ById,id)
400  -- Mark the jobs as claimed and return it
401  redis.call('zAdd',kClaimed,ARGV[1],id)
402  redis.call('hIncrBy',kAttempts,id,1)
403  return redis.call('hGet',kData,id)
404 LUA;
405  return $conn->luaEval( $script,
406  array(
407  $this->getQueueKey( 'l-unclaimed' ), # KEYS[1]
408  $this->getQueueKey( 'h-sha1ById' ), # KEYS[2]
409  $this->getQueueKey( 'h-idBySha1' ), # KEYS[3]
410  $this->getQueueKey( 'z-claimed' ), # KEYS[4]
411  $this->getQueueKey( 'h-attempts' ), # KEYS[5]
412  $this->getQueueKey( 'h-data' ), # KEYS[6]
413  time(), # ARGV[1] (injected to be replication-safe)
414  ),
415  6 # number of first argument(s) that are keys
416  );
417  }
418 
425  protected function doAck( Job $job ) {
426  if ( !isset( $job->metadata['uuid'] ) ) {
427  throw new MWException( "Job of type '{$job->getType()}' has no UUID." );
428  }
429  if ( $this->claimTTL > 0 ) {
430  $conn = $this->getConnection();
431  try {
432  static $script =
433 <<<LUA
434  local kClaimed, kAttempts, kData = unpack(KEYS)
435  -- Unmark the job as claimed
436  redis.call('zRem',kClaimed,ARGV[1])
437  redis.call('hDel',kAttempts,ARGV[1])
438  -- Delete the job data itself
439  return redis.call('hDel',kData,ARGV[1])
440 LUA;
441  $res = $conn->luaEval( $script,
442  array(
443  $this->getQueueKey( 'z-claimed' ), # KEYS[1]
444  $this->getQueueKey( 'h-attempts' ), # KEYS[2]
445  $this->getQueueKey( 'h-data' ), # KEYS[3]
446  $job->metadata['uuid'] # ARGV[1]
447  ),
448  3 # number of first argument(s) that are keys
449  );
450 
451  if ( !$res ) {
452  wfDebugLog( 'JobQueueRedis', "Could not acknowledge {$this->type} job." );
453 
454  return false;
455  }
456  } catch ( RedisException $e ) {
457  $this->throwRedisException( $conn, $e );
458  }
459  }
460 
461  return true;
462  }
463 
470  protected function doDeduplicateRootJob( Job $job ) {
471  if ( !$job->hasRootJobParams() ) {
472  throw new MWException( "Cannot register root job; missing parameters." );
473  }
474  $params = $job->getRootJobParams();
475 
476  $key = $this->getRootJobCacheKey( $params['rootJobSignature'] );
477 
478  $conn = $this->getConnection();
479  try {
480  $timestamp = $conn->get( $key ); // current last timestamp of this job
481  if ( $timestamp && $timestamp >= $params['rootJobTimestamp'] ) {
482  return true; // a newer version of this root job was enqueued
483  }
484 
485  // Update the timestamp of the last root job started at the location...
486  return $conn->set( $key, $params['rootJobTimestamp'], self::ROOTJOB_TTL ); // 2 weeks
487  } catch ( RedisException $e ) {
488  $this->throwRedisException( $conn, $e );
489  }
490  }
491 
498  protected function doIsRootJobOldDuplicate( Job $job ) {
499  if ( !$job->hasRootJobParams() ) {
500  return false; // job has no de-deplication info
501  }
502  $params = $job->getRootJobParams();
503 
504  $conn = $this->getConnection();
505  try {
506  // Get the last time this root job was enqueued
507  $timestamp = $conn->get( $this->getRootJobCacheKey( $params['rootJobSignature'] ) );
508  } catch ( RedisException $e ) {
509  $this->throwRedisException( $conn, $e );
510  }
511 
512  // Check if a new root job was started at the location after this one's...
513  return ( $timestamp && $timestamp > $params['rootJobTimestamp'] );
514  }
515 
521  protected function doDelete() {
522  static $props = array( 'l-unclaimed', 'z-claimed', 'z-abandoned',
523  'z-delayed', 'h-idBySha1', 'h-sha1ById', 'h-attempts', 'h-data' );
524 
525  $conn = $this->getConnection();
526  try {
527  $keys = array();
528  foreach ( $props as $prop ) {
529  $keys[] = $this->getQueueKey( $prop );
530  }
531 
532  return ( $conn->delete( $keys ) !== false );
533  } catch ( RedisException $e ) {
534  $this->throwRedisException( $conn, $e );
535  }
536  }
537 
542  public function getAllQueuedJobs() {
543  $conn = $this->getConnection();
544  try {
545  $that = $this;
546 
547  return new MappedIterator(
548  $conn->lRange( $this->getQueueKey( 'l-unclaimed' ), 0, -1 ),
549  function ( $uid ) use ( $that, $conn ) {
550  return $that->getJobFromUidInternal( $uid, $conn );
551  },
552  array( 'accept' => function ( $job ) {
553  return is_object( $job );
554  } )
555  );
556  } catch ( RedisException $e ) {
557  $this->throwRedisException( $conn, $e );
558  }
559  }
560 
565  public function getAllDelayedJobs() {
566  $conn = $this->getConnection();
567  try {
568  $that = $this;
569 
570  return new MappedIterator( // delayed jobs
571  $conn->zRange( $this->getQueueKey( 'z-delayed' ), 0, -1 ),
572  function ( $uid ) use ( $that, $conn ) {
573  return $that->getJobFromUidInternal( $uid, $conn );
574  },
575  array( 'accept' => function ( $job ) {
576  return is_object( $job );
577  } )
578  );
579  } catch ( RedisException $e ) {
580  $this->throwRedisException( $conn, $e );
581  }
582  }
583 
584  public function getCoalesceLocationInternal() {
585  return "RedisServer:" . $this->server;
586  }
587 
588  protected function doGetSiblingQueuesWithJobs( array $types ) {
589  return array_keys( array_filter( $this->doGetSiblingQueueSizes( $types ) ) );
590  }
591 
592  protected function doGetSiblingQueueSizes( array $types ) {
593  $sizes = array(); // (type => size)
594  $types = array_values( $types ); // reindex
595  $conn = $this->getConnection();
596  try {
597  $conn->multi( Redis::PIPELINE );
598  foreach ( $types as $type ) {
599  $conn->lSize( $this->getQueueKey( 'l-unclaimed', $type ) );
600  }
601  $res = $conn->exec();
602  if ( is_array( $res ) ) {
603  foreach ( $res as $i => $size ) {
604  $sizes[$types[$i]] = $size;
605  }
606  }
607  } catch ( RedisException $e ) {
608  $this->throwRedisException( $conn, $e );
609  }
610 
611  return $sizes;
612  }
613 
622  public function getJobFromUidInternal( $uid, RedisConnRef $conn ) {
623  try {
624  $data = $conn->hGet( $this->getQueueKey( 'h-data' ), $uid );
625  if ( $data === false ) {
626  return false; // not found
627  }
628  $item = $this->unserialize( $conn->hGet( $this->getQueueKey( 'h-data' ), $uid ) );
629  if ( !is_array( $item ) ) { // this shouldn't happen
630  throw new MWException( "Could not find job with ID '$uid'." );
631  }
632  $title = Title::makeTitle( $item['namespace'], $item['title'] );
633  $job = Job::factory( $item['type'], $title, $item['params'] );
634  $job->metadata['uuid'] = $item['uuid'];
635 
636  return $job;
637  } catch ( RedisException $e ) {
638  $this->throwRedisException( $conn, $e );
639  }
640  }
641 
649  public function recyclePruneAndUndelayJobs() {
650  $count = 0;
651  // For each job item that can be retried, we need to add it back to the
652  // main queue and remove it from the list of currenty claimed job items.
653  // For those that cannot, they are marked as dead and kept around for
654  // investigation and manual job restoration but are eventually deleted.
655  $conn = $this->getConnection();
656  try {
657  $now = time();
658  static $script =
659 <<<LUA
660  local kClaimed, kAttempts, kUnclaimed, kData, kAbandoned, kDelayed = unpack(KEYS)
661  local released,abandoned,pruned,undelayed = 0,0,0,0
662  -- Get all non-dead jobs that have an expired claim on them.
663  -- The score for each item is the last claim timestamp (UNIX).
664  local staleClaims = redis.call('zRangeByScore',kClaimed,0,ARGV[1])
665  for k,id in ipairs(staleClaims) do
666  local timestamp = redis.call('zScore',kClaimed,id)
667  local attempts = redis.call('hGet',kAttempts,id)
668  if attempts < ARGV[3] then
669  -- Claim expired and retries left: re-enqueue the job
670  redis.call('lPush',kUnclaimed,id)
671  redis.call('hIncrBy',kAttempts,id,1)
672  released = released + 1
673  else
674  -- Claim expired and no retries left: mark the job as dead
675  redis.call('zAdd',kAbandoned,timestamp,id)
676  abandoned = abandoned + 1
677  end
678  redis.call('zRem',kClaimed,id)
679  end
680  -- Get all of the dead jobs that have been marked as dead for too long.
681  -- The score for each item is the last claim timestamp (UNIX).
682  local deadClaims = redis.call('zRangeByScore',kAbandoned,0,ARGV[2])
683  for k,id in ipairs(deadClaims) do
684  -- Stale and out of retries: remove any traces of the job
685  redis.call('zRem',kAbandoned,id)
686  redis.call('hDel',kAttempts,id)
687  redis.call('hDel',kData,id)
688  pruned = pruned + 1
689  end
690  -- Get the list of ready delayed jobs, sorted by readiness (UNIX timestamp)
691  local ids = redis.call('zRangeByScore',kDelayed,0,ARGV[4])
692  -- Migrate the jobs from the "delayed" set to the "unclaimed" list
693  for k,id in ipairs(ids) do
694  redis.call('lPush',kUnclaimed,id)
695  redis.call('zRem',kDelayed,id)
696  end
697  undelayed = #ids
698  return {released,abandoned,pruned,undelayed}
699 LUA;
700  $res = $conn->luaEval( $script,
701  array(
702  $this->getQueueKey( 'z-claimed' ), # KEYS[1]
703  $this->getQueueKey( 'h-attempts' ), # KEYS[2]
704  $this->getQueueKey( 'l-unclaimed' ), # KEYS[3]
705  $this->getQueueKey( 'h-data' ), # KEYS[4]
706  $this->getQueueKey( 'z-abandoned' ), # KEYS[5]
707  $this->getQueueKey( 'z-delayed' ), # KEYS[6]
708  $now - $this->claimTTL, # ARGV[1]
709  $now - self::MAX_AGE_PRUNE, # ARGV[2]
710  $this->maxTries, # ARGV[3]
711  $now # ARGV[4]
712  ),
713  6 # number of first argument(s) that are keys
714  );
715  if ( $res ) {
716  list( $released, $abandoned, $pruned, $undelayed ) = $res;
717  $count += $released + $pruned + $undelayed;
718  JobQueue::incrStats( 'job-recycle', $this->type, $released, $this->wiki );
719  JobQueue::incrStats( 'job-abandon', $this->type, $abandoned, $this->wiki );
720  }
721  } catch ( RedisException $e ) {
722  $this->throwRedisException( $conn, $e );
723  }
724 
725  return $count;
726  }
727 
731  protected function doGetPeriodicTasks() {
732  $periods = array( 3600 ); // standard cleanup (useful on config change)
733  if ( $this->claimTTL > 0 ) {
734  $periods[] = ceil( $this->claimTTL / 2 ); // avoid bad timing
735  }
736  if ( $this->checkDelay ) {
737  $periods[] = 300; // 5 minutes
738  }
739  $period = min( $periods );
740  $period = max( $period, 30 ); // sanity
741  // Support override for faster testing
742  if ( $this->maximumPeriodicTaskSeconds !== null ) {
743  $period = min( $period, $this->maximumPeriodicTaskSeconds );
744  }
745  return array(
746  'recyclePruneAndUndelayJobs' => array(
747  'callback' => array( $this, 'recyclePruneAndUndelayJobs' ),
748  'period' => $period,
749  )
750  );
751  }
752 
757  protected function getNewJobFields( IJobSpecification $job ) {
758  return array(
759  // Fields that describe the nature of the job
760  'type' => $job->getType(),
761  'namespace' => $job->getTitle()->getNamespace(),
762  'title' => $job->getTitle()->getDBkey(),
763  'params' => $job->getParams(),
764  // Some jobs cannot run until a "release timestamp"
765  'rtimestamp' => $job->getReleaseTimestamp() ?: 0,
766  // Additional job metadata
768  'sha1' => $job->ignoreDuplicates()
769  ? wfBaseConvert( sha1( serialize( $job->getDeduplicationInfo() ) ), 16, 36, 31 )
770  : '',
771  'timestamp' => time() // UNIX timestamp
772  );
773  }
774 
779  protected function getJobFromFields( array $fields ) {
780  $title = Title::makeTitleSafe( $fields['namespace'], $fields['title'] );
781  if ( $title ) {
782  $job = Job::factory( $fields['type'], $title, $fields['params'] );
783  $job->metadata['uuid'] = $fields['uuid'];
784 
785  return $job;
786  }
787 
788  return false;
789  }
790 
795  protected function serialize( array $fields ) {
796  $blob = serialize( $fields );
797  if ( $this->compression === 'gzip'
798  && strlen( $blob ) >= 1024
799  && function_exists( 'gzdeflate' )
800  ) {
801  $object = (object)array( 'blob' => gzdeflate( $blob ), 'enc' => 'gzip' );
802  $blobz = serialize( $object );
803 
804  return ( strlen( $blobz ) < strlen( $blob ) ) ? $blobz : $blob;
805  } else {
806  return $blob;
807  }
808  }
809 
814  protected function unserialize( $blob ) {
815  $fields = unserialize( $blob );
816  if ( is_object( $fields ) ) {
817  if ( $fields->enc === 'gzip' && function_exists( 'gzinflate' ) ) {
818  $fields = unserialize( gzinflate( $fields->blob ) );
819  } else {
820  $fields = false;
821  }
822  }
823 
824  return is_array( $fields ) ? $fields : false;
825  }
826 
833  protected function getConnection() {
834  $conn = $this->redisPool->getConnection( $this->server );
835  if ( !$conn ) {
836  throw new JobQueueConnectionError( "Unable to connect to redis server." );
837  }
838 
839  return $conn;
840  }
841 
847  protected function throwRedisException( RedisConnRef $conn, $e ) {
848  $this->redisPool->handleError( $conn, $e );
849  throw new JobQueueError( "Redis server error: {$e->getMessage()}\n" );
850  }
851 
857  private function getQueueKey( $prop, $type = null ) {
858  $type = is_string( $type ) ? $type : $this->type;
859  list( $db, $prefix ) = wfSplitWikiID( $this->wiki );
860  if ( strlen( $this->key ) ) { // namespaced queue (for testing)
861  return wfForeignMemcKey( $db, $prefix, 'jobqueue', $type, $this->key, $prop );
862  } else {
863  return wfForeignMemcKey( $db, $prefix, 'jobqueue', $type, $prop );
864  }
865  }
866 
871  public function setTestingPrefix( $key ) {
872  $this->key = $key;
873  }
874 }
JobQueueRedis\doDeduplicateRootJob
doDeduplicateRootJob(Job $job)
Definition: JobQueueRedis.php:465
MappedIterator
Convenience class for generating iterators from iterators.
Definition: MappedIterator.php:29
Title\makeTitle
static & makeTitle( $ns, $title, $fragment='', $interwiki='')
Create a new Title from a namespace index and a DB key.
Definition: Title.php:398
object
globals will be eliminated from MediaWiki replaced by an application object which would be passed to constructors Whether that would be an convenient solution remains to be but certainly PHP makes such object oriented programming models easier than they were in previous versions For the time being MediaWiki programmers will have to work in an environment with some global context At the time of globals were initialised on startup by MediaWiki of these were configuration which are documented in DefaultSettings php There is no comprehensive documentation for the remaining however some of the most important ones are listed below They are typically initialised either in index php or in Setup php For a description of the see design txt $wgTitle Title object created from the request URL $wgOut OutputPage object for HTTP response $wgUser User object for the user associated with the current request $wgLang Language object selected by user preferences $wgContLang Language object associated with the wiki being viewed $wgParser Parser object Parser extensions register their hooks here $wgRequest WebRequest object
Definition: globals.txt:25
UIDGenerator\QUICK_RAND
const QUICK_RAND
Definition: UIDGenerator.php:42
data
and how to run hooks for an and one after Each event has a preferably in CamelCase For ArticleDelete hook A clump of code and data that should be run when an event happens This can be either a function and a chunk of data
Definition: hooks.txt:6
of
globals txt Globals are evil The original MediaWiki code relied on globals for processing context far too often MediaWiki development since then has been a story of slowly moving context out of global variables and into objects Storing processing context in object member variables allows those objects to be reused in a much more flexible way Consider the elegance of
Definition: globals.txt:10
RedisConnectionPool\singleton
static singleton(array $options)
Definition: RedisConnectionPool.php:115
php
skin txt MediaWiki includes four core it has been set as the default in MediaWiki since the replacing Monobook it had been been the default skin since before being replaced by Vector largely rewritten in while keeping its appearance Several legacy skins were removed in the as the burden of supporting them became too heavy to bear Those in etc for skin dependent CSS etc for skin dependent JavaScript These can also be customised on a per user by etc This feature has led to a wide variety of user styles becoming that gallery is a good place to ending in php
Definition: skin.txt:62
JobQueue\incrStats
static incrStats( $key, $type, $delta=1, $wiki=null)
Call wfIncrStats() for the queue overall and for the queue type.
Definition: JobQueue.php:714
JobQueueRedis\doGetAcquiredCount
doGetAcquiredCount()
Definition: JobQueueRedis.php:139
is
We use the convention $dbr for read and $dbw for write to help you keep track of whether the database object is a the world will explode Or to be a subsequent write query which succeeded on the master may fail when replicated to the slave due to a unique key collision Replication on the slave will stop and it may take hours to repair the database and get it back online Setting read_only in my cnf on the slave will avoid this but given the dire we prefer to have as many checks as possible We provide a but the wrapper functions like please read the documentation for except in special pages derived from QueryPage It s a common pitfall for new developers to submit code containing SQL queries which examine huge numbers of rows Remember that COUNT * is(N), counting rows in atable is like counting beans in a bucket.------------------------------------------------------------------------ Replication------------------------------------------------------------------------The largest installation of MediaWiki, Wikimedia, uses a large set ofslave MySQL servers replicating writes made to a master MySQL server. Itis important to understand the issues associated with this setup if youwant to write code destined for Wikipedia.It 's often the case that the best algorithm to use for a given taskdepends on whether or not replication is in use. Due to our unabashedWikipedia-centrism, we often just use the replication-friendly version, but if you like, you can use wfGetLB() ->getServerCount() > 1 tocheck to see if replication is in use.===Lag===Lag primarily occurs when large write queries are sent to the master.Writes on the master are executed in parallel, but they are executed inserial when they are replicated to the slaves. The master writes thequery to the binlog when the transaction is committed. The slaves pollthe binlog and start executing the query as soon as it appears. They canservice reads while they are performing a write query, but will not readanything more from the binlog and thus will perform no more writes. Thismeans that if the write query runs for a long time, the slaves will lagbehind the master for the time it takes for the write query to complete.Lag can be exacerbated by high read load. MediaWiki 's load balancer willstop sending reads to a slave when it is lagged by more than 30 seconds.If the load ratios are set incorrectly, or if there is too much loadgenerally, this may lead to a slave permanently hovering around 30seconds lag.If all slaves are lagged by more than 30 seconds, MediaWiki will stopwriting to the database. All edits and other write operations will berefused, with an error returned to the user. This gives the slaves achance to catch up. Before we had this mechanism, the slaves wouldregularly lag by several minutes, making review of recent editsdifficult.In addition to this, MediaWiki attempts to ensure that the user seesevents occurring on the wiki in chronological order. A few seconds of lagcan be tolerated, as long as the user sees a consistent picture fromsubsequent requests. This is done by saving the master binlog positionin the session, and then at the start of each request, waiting for theslave to catch up to that position before doing any reads from it. Ifthis wait times out, reads are allowed anyway, but the request isconsidered to be in "lagged slave mode". Lagged slave mode can bechecked by calling wfGetLB() ->getLaggedSlaveMode(). The onlypractical consequence at present is a warning displayed in the pagefooter.===Lag avoidance===To avoid excessive lag, queries which write large numbers of rows shouldbe split up, generally to write one row at a time. Multi-row INSERT ...SELECT queries are the worst offenders should be avoided altogether.Instead do the select first and then the insert.===Working with lag===Despite our best efforts, it 's not practical to guarantee a low-lagenvironment. Lag will usually be less than one second, but mayoccasionally be up to 30 seconds. For scalability, it 's very importantto keep load on the master low, so simply sending all your queries tothe master is not the answer. So when you have a genuine need forup-to-date data, the following approach is advised:1) Do a quick query to the master for a sequence number or timestamp 2) Run the full query on the slave and check if it matches the data you gotfrom the master 3) If it doesn 't, run the full query on the masterTo avoid swamping the master every time the slaves lag, use of thisapproach should be kept to a minimum. In most cases you should just readfrom the slave and let the user deal with the delay.------------------------------------------------------------------------ Lock contention------------------------------------------------------------------------Due to the high write rate on Wikipedia(and some other wikis), MediaWiki developers need to be very careful to structure their writesto avoid long-lasting locks. By default, MediaWiki opens a transactionat the first query, and commits it before the output is sent. Locks willbe held from the time when the query is done until the commit. So youcan reduce lock time by doing as much processing as possible before youdo your write queries.Often this approach is not good enough, and it becomes necessary toenclose small groups of queries in their own transaction. Use thefollowing syntax:$dbw=wfGetDB(DB_MASTER
JobQueueRedis\__construct
__construct(array $params)
@params include:
Definition: JobQueueRedis.php:89
JobQueueRedis\$server
string $server
Server address *.
Definition: JobQueueRedis.php:62
JobQueueRedis\$compression
string $compression
Compression method to use *.
Definition: JobQueueRedis.php:64
JobQueueRedis\$maximumPeriodicTaskSeconds
null int $maximumPeriodicTaskSeconds
maximum seconds between execution of periodic tasks.
Definition: JobQueueRedis.php:73
$timestamp
if( $limit) $timestamp
Definition: importImages.php:104
wiki
Prior to maintenance scripts were a hodgepodge of code that had no cohesion or formal method of action Beginning maintenance scripts have been cleaned up to use a unified class Directory structure How to run a script How to write your own DIRECTORY STRUCTURE The maintenance directory of a MediaWiki installation contains several all of which have unique purposes HOW TO RUN A SCRIPT Ridiculously just call php someScript php that s in the top level maintenance directory if not default wiki
Definition: maintenance.txt:1
wfDebugLog
wfDebugLog( $logGroup, $text, $dest='all')
Send a line to a supplementary debug log file, if configured, or main debug log if not.
Definition: GlobalFunctions.php:1087
JobQueueRedis\doBatchPush
doBatchPush(array $jobs, $flags)
Definition: JobQueueRedis.php:196
JobQueueRedis\setTestingPrefix
setTestingPrefix( $key)
Definition: JobQueueRedis.php:866
release
skin txt MediaWiki includes four core it has been set as the default in MediaWiki since the replacing Monobook it had been been the default skin since before being replaced by Vector largely rewritten in while keeping its appearance Several legacy skins were removed in the release
Definition: skin.txt:10
JobQueueRedis\doGetSiblingQueuesWithJobs
doGetSiblingQueuesWithJobs(array $types)
Definition: JobQueueRedis.php:583
$params
$params
Definition: styleTest.css.php:40
JobQueueRedis\getJobFromFields
getJobFromFields(array $fields)
Definition: JobQueueRedis.php:774
wfSplitWikiID
wfSplitWikiID( $wiki)
Split a wiki ID into DB name and table prefix.
Definition: GlobalFunctions.php:3684
JobQueueRedis\MAX_AGE_PRUNE
const MAX_AGE_PRUNE
Definition: JobQueueRedis.php:66
$flags
it s the revision text itself In either if gzip is the revision text is gzipped $flags
Definition: hooks.txt:2124
JobQueueRedis\getAllQueuedJobs
getAllQueuedJobs()
Definition: JobQueueRedis.php:537
JobQueueRedis\recyclePruneAndUndelayJobs
recyclePruneAndUndelayJobs()
Recycle or destroy any jobs that have been claimed for too long and release any ready delayed jobs in...
Definition: JobQueueRedis.php:644
JobQueueRedis\doPop
doPop()
Definition: JobQueueRedis.php:304
JobQueueRedis\getJobFromUidInternal
getJobFromUidInternal( $uid, RedisConnRef $conn)
This function should not be called outside JobQueueRedis.
Definition: JobQueueRedis.php:617
key
design txt This is a brief overview of the new design More thorough and up to date information is available on the documentation wiki at etc Handles the details of getting and saving to the user table of the and dealing with sessions and cookies OutputPage Encapsulates the entire HTML page that will be sent in response to any server request It is used by calling its functions to add in any and then calling but I prefer the flexibility This should also do the output encoding The system allocates a global one in $wgOut Title Represents the title of an and does all the work of translating among various forms such as plain database key
Definition: design.txt:25
UIDGenerator\newRawUUIDv4
static newRawUUIDv4( $flags=0)
Return an RFC4122 compliant v4 UUID.
Definition: UIDGenerator.php:217
Job
Class to both describe a background job and handle jobs.
Definition: Job.php:31
JobQueueRedis\getAllDelayedJobs
getAllDelayedJobs()
Definition: JobQueueRedis.php:560
MWException
MediaWiki exception.
Definition: MWException.php:26
$blob
$blob
Definition: testCompression.php:61
JobQueue\$type
string $type
Job type *.
Definition: JobQueue.php:34
JobQueueRedis\getNewJobFields
getNewJobFields(IJobSpecification $job)
Definition: JobQueueRedis.php:752
array
the array() calling protocol came about after MediaWiki 1.4rc1.
List of Api Query prop modules.
JobQueueRedis\doGetAbandonedCount
doGetAbandonedCount()
Definition: JobQueueRedis.php:177
JobQueueRedis\optimalOrder
optimalOrder()
Get the default queue order to use if configuration does not specify one.
Definition: JobQueueRedis.php:103
JobQueueError
Definition: JobQueue.php:738
wfForeignMemcKey
wfForeignMemcKey( $db, $prefix)
Get a cache key for a foreign DB.
Definition: GlobalFunctions.php:3652
list
deferred txt A few of the database updates required by various functions here can be deferred until after the result page is displayed to the user For updating the view updating the linked to tables after a etc PHP does not yet have any way to tell the server to actually return and disconnect while still running these but it might have such a feature in the future We handle these by creating a deferred update object and putting those objects on a global list
Definition: deferred.txt:11
false
processing should stop and the error should be shown to the user * false
Definition: hooks.txt:188
JobQueueRedis\getCoalesceLocationInternal
getCoalesceLocationInternal()
Do not use this function outside of JobQueue/JobQueueGroup.
Definition: JobQueueRedis.php:579
Title\makeTitleSafe
static makeTitleSafe( $ns, $title, $fragment='', $interwiki='')
Create a new Title from a namespace index and a DB key.
Definition: Title.php:422
RedisConnectionPool
Helper class to manage Redis connections.
Definition: RedisConnectionPool.php:38
JobQueueRedis\$key
string $key
Key to prefix the queue keys with (used for testing) *.
Definition: JobQueueRedis.php:68
$title
presenting them properly to the user as errors is done by the caller $title
Definition: hooks.txt:1324
$size
$size
Definition: RandomTest.php:75
JobQueueRedis\getConnection
getConnection()
Get a connection to the server that handles all sub-queues for this queue.
Definition: JobQueueRedis.php:828
too
I won t presume to tell you how to I m just describing the methods I chose to use for myself If you do choose to follow these it will probably be easier for you to collaborate with others on the but if you want to contribute without by all means do which work well I also use K &R brace matching style I know that s a religious issue for so if you want to use a style that puts opening braces on the next that s OK too
Definition: design.txt:79
JobQueueRedis\pushBlobs
pushBlobs(RedisConnRef $conn, array $items)
Definition: JobQueueRedis.php:251
RedisConnRef\luaEval
luaEval( $script, array $params, $numKeys)
Definition: RedisConnectionPool.php:406
JobQueueRedis\supportedOrders
supportedOrders()
Get the allowed queue orders for configuration validation.
Definition: JobQueueRedis.php:99
JobQueueRedis\getQueueKey
getQueueKey( $prop, $type=null)
Definition: JobQueueRedis.php:852
Job\factory
static factory( $command, Title $title, $params=false)
Create the appropriate object to handle a specific job.
Definition: Job.php:67
JobQueueRedis\throwRedisException
throwRedisException(RedisConnRef $conn, $e)
Definition: JobQueueRedis.php:842
JobQueueConnectionError
Definition: JobQueue.php:741
off
Use of locking define a new flag for $wgAntiLockFlags which allows them to be turned off
Definition: database.txt:164
JobQueueRedis\doGetDelayedCount
doGetDelayedCount()
Definition: JobQueueRedis.php:160
$count
$count
Definition: UtfNormalTest2.php:96
it
=Architecture==Two class hierarchies are used to provide the functionality associated with the different content models:*Content interface(and AbstractContent base class) define functionality that acts on the concrete content of a page, and *ContentHandler base class provides functionality specific to a content model, but not acting on concrete content. The most important function of ContentHandler is to act as a factory for the appropriate implementation of Content. These Content objects are to be used by MediaWiki everywhere, instead of passing page content around as text. All manipulation and analysis of page content must be done via the appropriate methods of the Content object. For each content model, a subclass of ContentHandler has to be registered with $wgContentHandlers. The ContentHandler object for a given content model can be obtained using ContentHandler::getForModelID($id). Also Title, WikiPage and Revision now have getContentHandler() methods for convenience. ContentHandler objects are singletons that provide functionality specific to the content type, but not directly acting on the content of some page. ContentHandler::makeEmptyContent() and ContentHandler::unserializeContent() can be used to create a Content object of the appropriate type. However, it is recommended to instead use WikiPage::getContent() resp. Revision::getContent() to get a page 's content as a Content object. These two methods should be the ONLY way in which page content is accessed. Another important function of ContentHandler objects is to define custom action handlers for a content model, see ContentHandler::getActionOverrides(). This is similar to what WikiPage::getActionOverrides() was already doing.==Serialization==With the ContentHandler facility, page content no longer has to be text based. Objects implementing the Content interface are used to represent and handle the content internally. For storage and data exchange, each content model supports at least one serialization format via ContentHandler::serializeContent($content). The list of supported formats for a given content model can be accessed using ContentHandler::getSupportedFormats(). Content serialization formats are identified using MIME type like strings. The following formats are built in:*text/x-wiki - wikitext *text/javascript - for js pages *text/css - for css pages *text/plain - for future use, e.g. with plain text messages. *text/html - for future use, e.g. with plain html messages. *application/vnd.php.serialized - for future use with the api and for extensions *application/json - for future use with the api, and for use by extensions *application/xml - for future use with the api, and for use by extensions In PHP, use the corresponding CONTENT_FORMAT_XXX constant. Note that when using the API to access page content, especially action=edit, action=parse and action=query &prop=revisions, the model and format of the content should always be handled explicitly. Without that information, interpretation of the provided content is not reliable. The same applies to XML dumps generated via maintenance/dumpBackup.php or Special:Export. Also note that the API will provide encapsulated, serialized content - so if the API was called with format=json, and contentformat is also json(or rather, application/json), the page content is represented as a string containing an escaped json structure. Extensions that use JSON to serialize some types of page content may provide specialized API modules that allow access to that content in a more natural form.==Compatibility==The ContentHandler facility is introduced in a way that should allow all existing code to keep functioning at least for pages that contain wikitext or other text based content. However, a number of functions and hooks have been deprecated in favor of new versions that are aware of the page 's content model, and will now generate warnings when used. Most importantly, the following functions have been deprecated:*Revisions::getText() and Revisions::getRawText() is deprecated in favor Revisions::getContent() *WikiPage::getText() is deprecated in favor WikiPage::getContent() Also, the old Article::getContent()(which returns text) is superceded by Article::getContentObject(). However, both methods should be avoided since they do not provide clean access to the page 's actual content. For instance, they may return a system message for non-existing pages. Use WikiPage::getContent() instead. Code that relies on a textual representation of the page content should eventually be rewritten. However, ContentHandler::getContentText() provides a stop-gap that can be used to get text for a page. Its behavior is controlled by $wgContentHandlerTextFallback it
Definition: contenthandler.txt:107
$args
if( $line===false) $args
Definition: cdb.php:62
JobQueue\getRootJobCacheKey
getRootJobCacheKey( $signature)
Definition: JobQueue.php:526
JobQueueRedis\doDelete
doDelete()
Definition: JobQueueRedis.php:516
JobQueueRedis\popAndDeleteBlob
popAndDeleteBlob(RedisConnRef $conn)
Definition: JobQueueRedis.php:351
type
This document describes the state of Postgres support in and is fairly well maintained The main code is very well while extensions are very hit and miss it is probably the most supported database after MySQL Much of the work in making MediaWiki database agnostic came about through the work of creating Postgres as and are nearing end of but without copying over all the usage comments General notes on the but these can almost always be programmed around *Although Postgres has a true BOOLEAN type
Definition: postgres.txt:22
JobQueueRedis\$redisPool
RedisConnectionPool $redisPool
Definition: JobQueueRedis.php:60
JobQueueRedis\serialize
serialize(array $fields)
Definition: JobQueueRedis.php:790
JobQueueRedis\doGetSize
doGetSize()
Definition: JobQueueRedis.php:125
in
Prior to maintenance scripts were a hodgepodge of code that had no cohesion or formal method of action Beginning in
Definition: maintenance.txt:1
on
We ve cleaned up the code here by removing clumps of infrequently used code and moving them off somewhere else It s much easier for someone working with this code to see what s _really_ going on
Definition: hooks.txt:86
are
The ContentHandler facility adds support for arbitrary content types on wiki instead of relying on wikitext for everything It was introduced in MediaWiki Each kind of and so on Built in content types are
Definition: contenthandler.txt:5
JobQueueRedis\doIsEmpty
doIsEmpty()
Definition: JobQueueRedis.php:116
wfBaseConvert
wfBaseConvert( $input, $sourceBase, $destBase, $pad=1, $lowercase=true, $engine='auto')
Convert an arbitrarily-long digit string from one numeric base to another, optionally zero-padding to...
Definition: GlobalFunctions.php:3432
JobQueueRedis\supportsDelayedJobs
supportsDelayedJobs()
Find out if delayed jobs are supported for configuration validation.
Definition: JobQueueRedis.php:107
$job
if(count( $args)< 1) $job
Definition: recompressTracked.php:42
then
skin txt MediaWiki includes four core it has been set as the default in MediaWiki since the replacing Monobook it had been been the default skin since then
Definition: skin.txt:10
JobQueueRedis\doIsRootJobOldDuplicate
doIsRootJobOldDuplicate(Job $job)
Definition: JobQueueRedis.php:493
as
This document is intended to provide useful advice for parties seeking to redistribute MediaWiki to end users It s targeted particularly at maintainers for Linux since it s been observed that distribution packages of MediaWiki often break We ve consistently had to recommend that users seeking support use official tarballs instead of their distribution s and this often solves whatever problem the user is having It would be nice if this could such as
Definition: distributors.txt:9
JobQueue
Class to handle enqueueing and running of background jobs.
Definition: JobQueue.php:31
RedisConnRef
Helper class to handle automatically marking connectons as reusable (via RAII pattern)
Definition: RedisConnectionPool.php:348
$keys
$keys
Definition: testCompression.php:63
JobQueueRedis\doAck
doAck(Job $job)
Definition: JobQueueRedis.php:420
from
Please log in again after you receive it</td >< td > s a saved copy from
Definition: All_system_messages.txt:3297
JobQueueRedis\unserialize
unserialize( $blob)
Definition: JobQueueRedis.php:809
that
deferred txt A few of the database updates required by various functions here can be deferred until after the result page is displayed to the user For updating the view updating the linked to tables after a etc PHP does not yet have any way to tell the server to actually return and disconnect while still running these but it might have such a feature in the future We handle these by creating a deferred update object and putting those objects on a global then executing the whole list after the page is displayed We don t do anything smart like collating updates to the same table or such because the list is almost always going to have just one item on if that
Definition: deferred.txt:11
JobQueueRedis\doGetSiblingQueueSizes
doGetSiblingQueueSizes(array $types)
Definition: JobQueueRedis.php:587
JobQueueRedis\popAndAcquireBlob
popAndAcquireBlob(RedisConnRef $conn)
Definition: JobQueueRedis.php:384
$failed
$failed
Definition: Utf8Test.php:90
$res
$res
Definition: database.txt:21
server
This document is intended to provide useful advice for parties seeking to redistribute MediaWiki to end users It s targeted particularly at maintainers for Linux since it s been observed that distribution packages of MediaWiki often break We ve consistently had to recommend that users seeking support use official tarballs instead of their distribution s and this often solves whatever problem the user is having It would be nice if this could such and we might be restricted by PHP settings such as safe mode or open_basedir We cannot assume that the software even has read access anywhere useful Many shared hosts run all users web applications under the same so they can t rely on Unix and must forbid reads to even standard directories like tmp lest users read each others files We cannot assume that the user has the ability to install or run any programs not written as web accessible PHP scripts Since anything that works on cheap shared hosting will work if you have shell or root access MediaWiki s design is based around catering to the lowest common denominator Although we support higher end setups as the way many things work by default is tailored toward shared hosting These defaults are unconventional from the point of view of and they certainly aren t ideal for someone who s installing MediaWiki as MediaWiki does not conform to normal Unix filesystem layout Hopefully we ll offer direct support for standard layouts in the but for now *any change to the location of files is unsupported *Moving things and leaving symlinks will *probably *not break but it is *strongly *advised not to try any more intrusive changes to get MediaWiki to conform more closely to your filesystem hierarchy Any such attempt will almost certainly result in unnecessary bugs The standard recommended location to install relative to the web is it should be possible to enable the appropriate rewrite rules by if you can reconfigure the web server
Definition: distributors.txt:53
JobQueueRedis\doGetPeriodicTasks
doGetPeriodicTasks()
Definition: JobQueueRedis.php:726
IJobSpecification
Job queue task description interface.
Definition: JobSpecification.php:30
JobQueueRedis
Class to handle job queues stored in Redis.
Definition: JobQueueRedis.php:59
$e
div flags Integer display flags(NO_ACTION_LINK, NO_EXTRA_USER_LINKS) 'LogException' returning false will NOT prevent logging $e
Definition: hooks.txt:1632