includes/job/JobQueueRedis.php

   1 <?php
   2 /**
   3  * Redis-backed job queue code.
   4  *
   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.
   9  *
  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.
  14  *
  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
  19  *
  20  * @file
  21  * @author Aaron Schulz
  22  */
  23
  24 /**
  25  * Class to handle job queues stored in Redis
  26  *
  27  * This is faster, less resource intensive, queue that JobQueueDB.
  28  * All data for a queue using this class is placed into one redis server.
  29  *
  30  * There are eight main redis keys used to track jobs:
  31  *   - l-unclaimed  : A list of job IDs used for ready unclaimed jobs
  32  *   - z-claimed    : A sorted set of (job ID, UNIX timestamp as score) used for job retries
  33  *   - z-abandoned  : A sorted set of (job ID, UNIX timestamp as score) used for broken jobs
  34  *   - z-delayed    : A sorted set of (job ID, UNIX timestamp as score) used for delayed jobs
  35  *   - h-idBySha1   : A hash of (SHA1 => job ID) for unclaimed jobs used for de-duplication
  36  *   - h-sha1ById   : A hash of (job ID => SHA1) for unclaimed jobs used for de-duplication
  37  *   - h-attempts   : A hash of (job ID => attempt count) used for job claiming/retries
  38  *   - h-data       : A hash of (job ID => serialized blobs) for job storage
  39  * A job ID can be in only one of z-delayed, l-unclaimed, z-claimed, and z-abandoned.
  40  * If an ID appears in any of those lists, it should have a h-data entry for its ID.
  41  * If a job has a SHA1 de-duplication value and its ID is in l-unclaimed or z-delayed, then
  42  * there should be no other such jobs with that SHA1. Every h-idBySha1 entry has an h-sha1ById
  43  * entry and every h-sha1ById must refer to an ID that is l-unclaimed. If a job has its
  44  * ID in z-claimed or z-abandoned, then it must also have an h-attempts entry for its ID.
  45  *
  46  * Additionally, "rootjob:* keys track "root jobs" used for additional de-duplication.
  47  * Aside from root job keys, all keys have no expiry, and are only removed when jobs are run.
  48  * All the keys are prefixed with the relevant wiki ID information.
  49  *
  50  * This class requires Redis 2.6 as it makes use Lua scripts for fast atomic operations.
  51  * Additionally, it should be noted that redis has different persistence modes, such
  52  * as rdb snapshots, journaling, and no persistent. Appropriate configuration should be
  53  * made on the servers based on what queues are using it and what tolerance they have.
  54  *
  55  * @ingroup JobQueue
  56  * @ingroup Redis
  57  * @since 1.22
  58  */
  59 class JobQueueRedis extends JobQueue {
  60         /** @var RedisConnectionPool */
  61         protected $redisPool;
  62
  63         /** @var string Server address */
  64         protected $server;
  65
  66         /** @var string Compression method to use */
  67         protected $compression;
  68
  69         const MAX_AGE_PRUNE = 604800; // integer; seconds a job can live once claimed (7 days)
  70
  71         /** @var string Key to prefix the queue keys with (used for testing) */
  72         protected $key;
  73
  74         /**
  75          * @var null|int maximum seconds between execution of periodic tasks.  Used to speed up
  76          * testing but should otherwise be left unset.
  77          */
  78         protected $maximumPeriodicTaskSeconds;
  79
  80         /**
  81          * @params include:
  82          *   - redisConfig : An array of parameters to RedisConnectionPool::__construct().
  83          *                   Note that the serializer option is ignored as "none" is always used.
  84          *   - redisServer : A hostname/port combination or the absolute path of a UNIX socket.
  85          *                   If a hostname is specified but no port, the standard port number
  86          *                   6379 will be used. Required.
  87          *   - compression : The type of compression to use; one of (none,gzip).
  88          *   - maximumPeriodicTaskSeconds : Maximum seconds between check periodic tasks.  Set to
  89          *                   force faster execution of periodic tasks for inegration tests that
  90          *                   rely on checkDelay.  Without this the integration tests are very very
  91          *                   slow.  This really shouldn't be set in production.
  92          * @param array $params
  93          */
  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
 116         /**
 117          * @see JobQueue::doIsEmpty()
 118          * @return bool
 119          * @throws MWException
 120          */
 121         protected function doIsEmpty() {
 122                 return $this->doGetSize() == 0;
 123         }
 124
 125         /**
 126          * @see JobQueue::doGetSize()
 127          * @return int
 128          * @throws MWException
 129          */
 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
 139         /**
 140          * @see JobQueue::doGetAcquiredCount()
 141          * @return int
 142          * @throws JobQueueError
 143          */
 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, $e );
 157                 }
 158         }
 159
 160         /**
 161          * @see JobQueue::doGetDelayedCount()
 162          * @return int
 163          * @throws JobQueueError
 164          */
 165         protected function doGetDelayedCount() {
 166                 if ( !$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
 177         /**
 178          * @see JobQueue::doGetAbandonedCount()
 179          * @return int
 180          * @throws JobQueueError
 181          */
 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
 194         /**
 195          * @see JobQueue::doBatchPush()
 196          * @param array $jobs
 197          * @param $flags
 198          * @return bool
 199          * @throws JobQueueError
 200          */
 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 ) );
 241                         JobQueue::incrStats( 'job-insert-duplicate', $this->type,
 242                                 count( $items ) - $failed - $pushed );
 243                 } catch ( RedisException $e ) {
 244                         $this->throwRedisException( $conn, $e );
 245                 }
 246
 247                 return true;
 248         }
 249
 250         /**
 251          * @param RedisConnRef $conn
 252          * @param array $items List of results from JobQueueRedis::getNewJobFields()
 253          * @return int Number of jobs inserted (duplicates are ignored)
 254          * @throws RedisException
 255          */
 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
 304         /**
 305          * @see JobQueue::doPop()
 306          * @return Job|bool
 307          * @throws JobQueueError
 308          */
 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 ) {
 315                         $this->recyclePruneAndUndelayJobs();
 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 ) {
 324                                                 $this->recyclePruneAndUndelayJobs();
 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 );
 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
 351         /**
 352          * @param RedisConnRef $conn
 353          * @return array serialized string or false
 354          * @throws RedisException
 355          */
 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
 384         /**
 385          * @param RedisConnRef $conn
 386          * @return array serialized string or false
 387          * @throws RedisException
 388          */
 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
 419         /**
 420          * @see JobQueue::doAck()
 421          * @param Job $job
 422          * @return Job|bool
 423          * @throws MWException|JobQueueError
 424          */
 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
 464         /**
 465          * @see JobQueue::doDeduplicateRootJob()
 466          * @param Job $job
 467          * @return bool
 468          * @throws MWException|JobQueueError
 469          */
 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
 492         /**
 493          * @see JobQueue::doIsRootJobOldDuplicate()
 494          * @param Job $job
 495          * @return bool
 496          * @throws JobQueueError
 497          */
 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
 516         /**
 517          * @see JobQueue::doDelete()
 518          * @return bool
 519          * @throws JobQueueError
 520          */
 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
 538         /**
 539          * @see JobQueue::getAllQueuedJobs()
 540          * @return Iterator
 541          */
 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
 561         /**
 562          * @see JobQueue::getAllQueuedJobs()
 563          * @return Iterator
 564          */
 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
 614         /**
 615          * This function should not be called outside JobQueueRedis
 616          *
 617          * @param $uid string
 618          * @param $conn RedisConnRef
 619          * @return Job|bool Returns false if the job does not exist
 620          * @throws MWException|JobQueueError
 621          */
 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
 642         /**
 643          * Recycle or destroy any jobs that have been claimed for too long
 644          * and release any ready delayed jobs into the queue
 645          *
 646          * @return int Number of jobs recycled/deleted/undelayed
 647          * @throws MWException|JobQueueError
 648          */
 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 );
 719                                 JobQueue::incrStats( 'job-abandon', $this->type, $abandoned );
 720                         }
 721                 } catch ( RedisException $e ) {
 722                         $this->throwRedisException( $conn, $e );
 723                 }
 724
 725                 return $count;
 726         }
 727
 728         /**
 729          * @return array
 730          */
 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
 753         /**
 754          * @param IJobSpecification $job
 755          * @return array
 756          */
 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
 767                         'uuid' => UIDGenerator::newRawUUIDv4( UIDGenerator::QUICK_RAND ),
 768                         'sha1' => $job->ignoreDuplicates()
 769                                 ? wfBaseConvert( sha1( serialize( $job->getDeduplicationInfo() ) ), 16, 36, 31 )
 770                                 : '',
 771                         'timestamp' => time() // UNIX timestamp
 772                 );
 773         }
 774
 775         /**
 776          * @param $fields array
 777          * @return Job|bool
 778          */
 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
 791         /**
 792          * @param array $fields
 793          * @return string Serialized and possibly compressed version of $fields
 794          */
 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
 810         /**
 811          * @param string $blob
 812          * @return array|bool Unserialized version of $blob or false
 813          */
 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
 827         /**
 828          * Get a connection to the server that handles all sub-queues for this queue
 829          *
 830          * @return RedisConnRef
 831          * @throws JobQueueConnectionError
 832          */
 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
 842         /**
 843          * @param $conn RedisConnRef
 844          * @param $e RedisException
 845          * @throws JobQueueError
 846          */
 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
 852         /**
 853          * @param $prop string
 854          * @param $type string|null
 855          * @return string
 856          */
 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
 867         /**
 868          * @param $key string
 869          * @return void
 870          */
 871         public function setTestingPrefix( $key ) {
 872                 $this->key = $key;
 873         }
 874 }