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          * @params include:
  76          *   - redisConfig : An array of parameters to RedisConnectionPool::__construct().
  77          *                   Note that the serializer option is ignored as "none" is always used.
  78          *   - redisServer : A hostname/port combination or the absolute path of a UNIX socket.
  79          *                   If a hostname is specified but no port, the standard port number
  80          *                   6379 will be used. Required.
  81          *   - compression : The type of compression to use; one of (none,gzip).
  82          * @param array $params
  83          */
  84         public function __construct( array $params ) {
  85                 parent::__construct( $params );
  86                 $params['redisConfig']['serializer'] = 'none'; // make it easy to use Lua
  87                 $this->server = $params['redisServer'];
  88                 $this->compression = isset( $params['compression'] ) ? $params['compression'] : 'none';
  89                 $this->redisPool = RedisConnectionPool::singleton( $params['redisConfig'] );
  90         }
  91
  92         protected function supportedOrders() {
  93                 return array( 'timestamp', 'fifo' );
  94         }
  95
  96         protected function optimalOrder() {
  97                 return 'fifo';
  98         }
  99
 100         protected function supportsDelayedJobs() {
 101                 return true;
 102         }
 103
 104         /**
 105          * @see JobQueue::doIsEmpty()
 106          * @return bool
 107          * @throws MWException
 108          */
 109         protected function doIsEmpty() {
 110                 return $this->doGetSize() == 0;
 111         }
 112
 113         /**
 114          * @see JobQueue::doGetSize()
 115          * @return int
 116          * @throws MWException
 117          */
 118         protected function doGetSize() {
 119                 $conn = $this->getConnection();
 120                 try {
 121                         return $conn->lSize( $this->getQueueKey( 'l-unclaimed' ) );
 122                 } catch ( RedisException $e ) {
 123                         $this->throwRedisException( $this->server, $conn, $e );
 124                 }
 125         }
 126
 127         /**
 128          * @see JobQueue::doGetAcquiredCount()
 129          * @return int
 130          * @throws JobQueueError
 131          */
 132         protected function doGetAcquiredCount() {
 133                 if ( $this->claimTTL <= 0 ) {
 134                         return 0; // no acknowledgements
 135                 }
 136                 $conn = $this->getConnection();
 137                 try {
 138                         $conn->multi( Redis::PIPELINE );
 139                         $conn->zSize( $this->getQueueKey( 'z-claimed' ) );
 140                         $conn->zSize( $this->getQueueKey( 'z-abandoned' ) );
 141
 142                         return array_sum( $conn->exec() );
 143                 } catch ( RedisException $e ) {
 144                         $this->throwRedisException( $this->server, $conn, $e );
 145                 }
 146         }
 147
 148         /**
 149          * @see JobQueue::doGetDelayedCount()
 150          * @return int
 151          * @throws JobQueueError
 152          */
 153         protected function doGetDelayedCount() {
 154                 if ( !$this->checkDelay ) {
 155                         return 0; // no delayed jobs
 156                 }
 157                 $conn = $this->getConnection();
 158                 try {
 159                         return $conn->zSize( $this->getQueueKey( 'z-delayed' ) );
 160                 } catch ( RedisException $e ) {
 161                         $this->throwRedisException( $this->server, $conn, $e );
 162                 }
 163         }
 164
 165         /**
 166          * @see JobQueue::doGetAbandonedCount()
 167          * @return int
 168          * @throws JobQueueError
 169          */
 170         protected function doGetAbandonedCount() {
 171                 if ( $this->claimTTL <= 0 ) {
 172                         return 0; // no acknowledgements
 173                 }
 174                 $conn = $this->getConnection();
 175                 try {
 176                         return $conn->zSize( $this->getQueueKey( 'z-abandoned' ) );
 177                 } catch ( RedisException $e ) {
 178                         $this->throwRedisException( $this->server, $conn, $e );
 179                 }
 180         }
 181
 182         /**
 183          * @see JobQueue::doBatchPush()
 184          * @param array $jobs
 185          * @param $flags
 186          * @return bool
 187          * @throws JobQueueError
 188          */
 189         protected function doBatchPush( array $jobs, $flags ) {
 190                 // Convert the jobs into field maps (de-duplicated against each other)
 191                 $items = array(); // (job ID => job fields map)
 192                 foreach ( $jobs as $job ) {
 193                         $item = $this->getNewJobFields( $job );
 194                         if ( strlen( $item['sha1'] ) ) { // hash identifier => de-duplicate
 195                                 $items[$item['sha1']] = $item;
 196                         } else {
 197                                 $items[$item['uuid']] = $item;
 198                         }
 199                 }
 200
 201                 if ( !count( $items ) ) {
 202                         return true; // nothing to do
 203                 }
 204
 205                 $conn = $this->getConnection();
 206                 try {
 207                         // Actually push the non-duplicate jobs into the queue...
 208                         if ( $flags & self::QOS_ATOMIC ) {
 209                                 $batches = array( $items ); // all or nothing
 210                         } else {
 211                                 $batches = array_chunk( $items, 500 ); // avoid tying up the server
 212                         }
 213                         $failed = 0;
 214                         $pushed = 0;
 215                         foreach ( $batches as $itemBatch ) {
 216                                 $added = $this->pushBlobs( $conn, $itemBatch );
 217                                 if ( is_int( $added ) ) {
 218                                         $pushed += $added;
 219                                 } else {
 220                                         $failed += count( $itemBatch );
 221                                 }
 222                         }
 223                         if ( $failed > 0 ) {
 224                                 wfDebugLog( 'JobQueueRedis', "Could not insert {$failed} {$this->type} job(s)." );
 225
 226                                 return false;
 227                         }
 228                         JobQueue::incrStats( 'job-insert', $this->type, count( $items ) );
 229                         JobQueue::incrStats( 'job-insert-duplicate', $this->type,
 230                                 count( $items ) - $failed - $pushed );
 231                 } catch ( RedisException $e ) {
 232                         $this->throwRedisException( $this->server, $conn, $e );
 233                 }
 234
 235                 return true;
 236         }
 237
 238         /**
 239          * @param RedisConnRef $conn
 240          * @param array $items List of results from JobQueueRedis::getNewJobFields()
 241          * @return int Number of jobs inserted (duplicates are ignored)
 242          * @throws RedisException
 243          */
 244         protected function pushBlobs( RedisConnRef $conn, array $items ) {
 245                 $args = array(); // ([id, sha1, rtime, blob [, id, sha1, rtime, blob ... ] ] )
 246                 foreach ( $items as $item ) {
 247                         $args[] = (string)$item['uuid'];
 248                         $args[] = (string)$item['sha1'];
 249                         $args[] = (string)$item['rtimestamp'];
 250                         $args[] = (string)$this->serialize( $item );
 251                 }
 252                 static $script =
 253 <<<LUA
 254                 local kUnclaimed, kSha1ById, kIdBySha1, kDelayed, kData = unpack(KEYS)
 255                 if #ARGV % 4 ~= 0 then return redis.error_reply('Unmatched arguments') end
 256                 local pushed = 0
 257                 for i = 1,#ARGV,4 do
 258                         local id,sha1,rtimestamp,blob = ARGV[i],ARGV[i+1],ARGV[i+2],ARGV[i+3]
 259                         if sha1 == '' or redis.call('hExists',kIdBySha1,sha1) == 0 then
 260                                 if 1*rtimestamp > 0 then
 261                                         -- Insert into delayed queue (release time as score)
 262                                         redis.call('zAdd',kDelayed,rtimestamp,id)
 263                                 else
 264                                         -- Insert into unclaimed queue
 265                                         redis.call('lPush',kUnclaimed,id)
 266                                 end
 267                                 if sha1 ~= '' then
 268                                         redis.call('hSet',kSha1ById,id,sha1)
 269                                         redis.call('hSet',kIdBySha1,sha1,id)
 270                                 end
 271                                 redis.call('hSet',kData,id,blob)
 272                                 pushed = pushed + 1
 273                         end
 274                 end
 275                 return pushed
 276 LUA;
 277                 return $conn->luaEval( $script,
 278                         array_merge(
 279                                 array(
 280                                         $this->getQueueKey( 'l-unclaimed' ), # KEYS[1]
 281                                         $this->getQueueKey( 'h-sha1ById' ), # KEYS[2]
 282                                         $this->getQueueKey( 'h-idBySha1' ), # KEYS[3]
 283                                         $this->getQueueKey( 'z-delayed' ), # KEYS[4]
 284                                         $this->getQueueKey( 'h-data' ), # KEYS[5]
 285                                 ),
 286                                 $args
 287                         ),
 288                         5 # number of first argument(s) that are keys
 289                 );
 290         }
 291
 292         /**
 293          * @see JobQueue::doPop()
 294          * @return Job|bool
 295          * @throws JobQueueError
 296          */
 297         protected function doPop() {
 298                 $job = false;
 299
 300                 // Push ready delayed jobs into the queue every 10 jobs to spread the load.
 301                 // This is also done as a periodic task, but we don't want too much done at once.
 302                 if ( $this->checkDelay && mt_rand( 0, 9 ) == 0 ) {
 303                         $this->releaseReadyDelayedJobs();
 304                 }
 305
 306                 $conn = $this->getConnection();
 307                 try {
 308                         do {
 309                                 if ( $this->claimTTL > 0 ) {
 310                                         // Keep the claimed job list down for high-traffic queues
 311                                         if ( mt_rand( 0, 99 ) == 0 ) {
 312                                                 $this->recycleAndDeleteStaleJobs();
 313                                         }
 314                                         $blob = $this->popAndAcquireBlob( $conn );
 315                                 } else {
 316                                         $blob = $this->popAndDeleteBlob( $conn );
 317                                 }
 318                                 if ( $blob === false ) {
 319                                         break; // no jobs; nothing to do
 320                                 }
 321
 322                                 JobQueue::incrStats( 'job-pop', $this->type );
 323                                 $item = $this->unserialize( $blob );
 324                                 if ( $item === false ) {
 325                                         wfDebugLog( 'JobQueueRedis', "Could not unserialize {$this->type} job." );
 326                                         continue;
 327                                 }
 328
 329                                 // If $item is invalid, recycleAndDeleteStaleJobs() will cleanup as needed
 330                                 $job = $this->getJobFromFields( $item ); // may be false
 331                         } while ( !$job ); // job may be false if invalid
 332                 } catch ( RedisException $e ) {
 333                         $this->throwRedisException( $this->server, $conn, $e );
 334                 }
 335
 336                 return $job;
 337         }
 338
 339         /**
 340          * @param RedisConnRef $conn
 341          * @return array serialized string or false
 342          * @throws RedisException
 343          */
 344         protected function popAndDeleteBlob( RedisConnRef $conn ) {
 345                 static $script =
 346 <<<LUA
 347                 local kUnclaimed, kSha1ById, kIdBySha1, kData = unpack(KEYS)
 348                 -- Pop an item off the queue
 349                 local id = redis.call('rpop',kUnclaimed)
 350                 if not id then return false end
 351                 -- Get the job data and remove it
 352                 local item = redis.call('hGet',kData,id)
 353                 redis.call('hDel',kData,id)
 354                 -- Allow new duplicates of this job
 355                 local sha1 = redis.call('hGet',kSha1ById,id)
 356                 if sha1 then redis.call('hDel',kIdBySha1,sha1) end
 357                 redis.call('hDel',kSha1ById,id)
 358                 -- Return the job data
 359                 return item
 360 LUA;
 361                 return $conn->luaEval( $script,
 362                         array(
 363                                 $this->getQueueKey( 'l-unclaimed' ), # KEYS[1]
 364                                 $this->getQueueKey( 'h-sha1ById' ), # KEYS[2]
 365                                 $this->getQueueKey( 'h-idBySha1' ), # KEYS[3]
 366                                 $this->getQueueKey( 'h-data' ), # KEYS[4]
 367                         ),
 368                         4 # number of first argument(s) that are keys
 369                 );
 370         }
 371
 372         /**
 373          * @param RedisConnRef $conn
 374          * @return array serialized string or false
 375          * @throws RedisException
 376          */
 377         protected function popAndAcquireBlob( RedisConnRef $conn ) {
 378                 static $script =
 379 <<<LUA
 380                 local kUnclaimed, kSha1ById, kIdBySha1, kClaimed, kAttempts, kData = unpack(KEYS)
 381                 -- Pop an item off the queue
 382                 local id = redis.call('rPop',kUnclaimed)
 383                 if not id then return false end
 384                 -- Allow new duplicates of this job
 385                 local sha1 = redis.call('hGet',kSha1ById,id)
 386                 if sha1 then redis.call('hDel',kIdBySha1,sha1) end
 387                 redis.call('hDel',kSha1ById,id)
 388                 -- Mark the jobs as claimed and return it
 389                 redis.call('zAdd',kClaimed,ARGV[1],id)
 390                 redis.call('hIncrBy',kAttempts,id,1)
 391                 return redis.call('hGet',kData,id)
 392 LUA;
 393                 return $conn->luaEval( $script,
 394                         array(
 395                                 $this->getQueueKey( 'l-unclaimed' ), # KEYS[1]
 396                                 $this->getQueueKey( 'h-sha1ById' ), # KEYS[2]
 397                                 $this->getQueueKey( 'h-idBySha1' ), # KEYS[3]
 398                                 $this->getQueueKey( 'z-claimed' ), # KEYS[4]
 399                                 $this->getQueueKey( 'h-attempts' ), # KEYS[5]
 400                                 $this->getQueueKey( 'h-data' ), # KEYS[6]
 401                                 time(), # ARGV[1] (injected to be replication-safe)
 402                         ),
 403                         6 # number of first argument(s) that are keys
 404                 );
 405         }
 406
 407         /**
 408          * @see JobQueue::doAck()
 409          * @param Job $job
 410          * @return Job|bool
 411          * @throws MWException|JobQueueError
 412          */
 413         protected function doAck( Job $job ) {
 414                 if ( !isset( $job->metadata['uuid'] ) ) {
 415                         throw new MWException( "Job of type '{$job->getType()}' has no UUID." );
 416                 }
 417                 if ( $this->claimTTL > 0 ) {
 418                         $conn = $this->getConnection();
 419                         try {
 420                                 static $script =
 421 <<<LUA
 422                                 local kClaimed, kAttempts, kData = unpack(KEYS)
 423                                 -- Unmark the job as claimed
 424                                 redis.call('zRem',kClaimed,ARGV[1])
 425                                 redis.call('hDel',kAttempts,ARGV[1])
 426                                 -- Delete the job data itself
 427                                 return redis.call('hDel',kData,ARGV[1])
 428 LUA;
 429                                 $res = $conn->luaEval( $script,
 430                                         array(
 431                                                 $this->getQueueKey( 'z-claimed' ), # KEYS[1]
 432                                                 $this->getQueueKey( 'h-attempts' ), # KEYS[2]
 433                                                 $this->getQueueKey( 'h-data' ), # KEYS[3]
 434                                                 $job->metadata['uuid'] # ARGV[1]
 435                                         ),
 436                                         3 # number of first argument(s) that are keys
 437                                 );
 438
 439                                 if ( !$res ) {
 440                                         wfDebugLog( 'JobQueueRedis', "Could not acknowledge {$this->type} job." );
 441
 442                                         return false;
 443                                 }
 444                         } catch ( RedisException $e ) {
 445                                 $this->throwRedisException( $this->server, $conn, $e );
 446                         }
 447                 }
 448
 449                 return true;
 450         }
 451
 452         /**
 453          * @see JobQueue::doDeduplicateRootJob()
 454          * @param Job $job
 455          * @return bool
 456          * @throws MWException|JobQueueError
 457          */
 458         protected function doDeduplicateRootJob( Job $job ) {
 459                 if ( !$job->hasRootJobParams() ) {
 460                         throw new MWException( "Cannot register root job; missing parameters." );
 461                 }
 462                 $params = $job->getRootJobParams();
 463
 464                 $key = $this->getRootJobCacheKey( $params['rootJobSignature'] );
 465
 466                 $conn = $this->getConnection();
 467                 try {
 468                         $timestamp = $conn->get( $key ); // current last timestamp of this job
 469                         if ( $timestamp && $timestamp >= $params['rootJobTimestamp'] ) {
 470                                 return true; // a newer version of this root job was enqueued
 471                         }
 472
 473                         // Update the timestamp of the last root job started at the location...
 474                         return $conn->set( $key, $params['rootJobTimestamp'], self::ROOTJOB_TTL ); // 2 weeks
 475                 } catch ( RedisException $e ) {
 476                         $this->throwRedisException( $this->server, $conn, $e );
 477                 }
 478         }
 479
 480         /**
 481          * @see JobQueue::doIsRootJobOldDuplicate()
 482          * @param Job $job
 483          * @return bool
 484          * @throws JobQueueError
 485          */
 486         protected function doIsRootJobOldDuplicate( Job $job ) {
 487                 if ( !$job->hasRootJobParams() ) {
 488                         return false; // job has no de-deplication info
 489                 }
 490                 $params = $job->getRootJobParams();
 491
 492                 $conn = $this->getConnection();
 493                 try {
 494                         // Get the last time this root job was enqueued
 495                         $timestamp = $conn->get( $this->getRootJobCacheKey( $params['rootJobSignature'] ) );
 496                 } catch ( RedisException $e ) {
 497                         $this->throwRedisException( $this->server, $conn, $e );
 498                 }
 499
 500                 // Check if a new root job was started at the location after this one's...
 501                 return ( $timestamp && $timestamp > $params['rootJobTimestamp'] );
 502         }
 503
 504         /**
 505          * @see JobQueue::doDelete()
 506          * @return bool
 507          * @throws JobQueueError
 508          */
 509         protected function doDelete() {
 510                 static $props = array( 'l-unclaimed', 'z-claimed', 'z-abandoned',
 511                         'z-delayed', 'h-idBySha1', 'h-sha1ById', 'h-attempts', 'h-data' );
 512
 513                 $conn = $this->getConnection();
 514                 try {
 515                         $keys = array();
 516                         foreach ( $props as $prop ) {
 517                                 $keys[] = $this->getQueueKey( $prop );
 518                         }
 519
 520                         return ( $conn->delete( $keys ) !== false );
 521                 } catch ( RedisException $e ) {
 522                         $this->throwRedisException( $this->server, $conn, $e );
 523                 }
 524         }
 525
 526         /**
 527          * @see JobQueue::getAllQueuedJobs()
 528          * @return Iterator
 529          */
 530         public function getAllQueuedJobs() {
 531                 $conn = $this->getConnection();
 532                 try {
 533                         $that = $this;
 534
 535                         return new MappedIterator(
 536                                 $conn->lRange( $this->getQueueKey( 'l-unclaimed' ), 0, -1 ),
 537                                 function ( $uid ) use ( $that, $conn ) {
 538                                         return $that->getJobFromUidInternal( $uid, $conn );
 539                                 },
 540                                 array( 'accept' => function ( $job ) {
 541                                         return is_object( $job );
 542                                 } )
 543                         );
 544                 } catch ( RedisException $e ) {
 545                         $this->throwRedisException( $this->server, $conn, $e );
 546                 }
 547         }
 548
 549         /**
 550          * @see JobQueue::getAllQueuedJobs()
 551          * @return Iterator
 552          */
 553         public function getAllDelayedJobs() {
 554                 $conn = $this->getConnection();
 555                 try {
 556                         $that = $this;
 557
 558                         return new MappedIterator( // delayed jobs
 559                                 $conn->zRange( $this->getQueueKey( 'z-delayed' ), 0, -1 ),
 560                                 function ( $uid ) use ( $that, $conn ) {
 561                                         return $that->getJobFromUidInternal( $uid, $conn );
 562                                 },
 563                                 array( 'accept' => function ( $job ) {
 564                                         return is_object( $job );
 565                                 } )
 566                         );
 567                 } catch ( RedisException $e ) {
 568                         $this->throwRedisException( $this->server, $conn, $e );
 569                 }
 570         }
 571
 572         public function getCoalesceLocationInternal() {
 573                 return "RedisServer:" . $this->server;
 574         }
 575
 576         protected function doGetSiblingQueuesWithJobs( array $types ) {
 577                 return array_keys( array_filter( $this->doGetSiblingQueueSizes( $types ) ) );
 578         }
 579
 580         protected function doGetSiblingQueueSizes( array $types ) {
 581                 $sizes = array(); // (type => size)
 582                 $types = array_values( $types ); // reindex
 583                 try {
 584                         $conn = $this->getConnection();
 585                         $conn->multi( Redis::PIPELINE );
 586                         foreach ( $types as $type ) {
 587                                 $conn->lSize( $this->getQueueKey( 'l-unclaimed', $type ) );
 588                         }
 589                         $res = $conn->exec();
 590                         if ( is_array( $res ) ) {
 591                                 foreach ( $res as $i => $size ) {
 592                                         $sizes[$types[$i]] = $size;
 593                                 }
 594                         }
 595                 } catch ( RedisException $e ) {
 596                         $this->throwRedisException( $this->server, $conn, $e );
 597                 }
 598
 599                 return $sizes;
 600         }
 601
 602         /**
 603          * This function should not be called outside JobQueueRedis
 604          *
 605          * @param $uid string
 606          * @param $conn RedisConnRef
 607          * @return Job|bool Returns false if the job does not exist
 608          * @throws MWException|JobQueueError
 609          */
 610         public function getJobFromUidInternal( $uid, RedisConnRef $conn ) {
 611                 try {
 612                         $data = $conn->hGet( $this->getQueueKey( 'h-data' ), $uid );
 613                         if ( $data === false ) {
 614                                 return false; // not found
 615                         }
 616                         $item = $this->unserialize( $conn->hGet( $this->getQueueKey( 'h-data' ), $uid ) );
 617                         if ( !is_array( $item ) ) { // this shouldn't happen
 618                                 throw new MWException( "Could not find job with ID '$uid'." );
 619                         }
 620                         $title = Title::makeTitle( $item['namespace'], $item['title'] );
 621                         $job = Job::factory( $item['type'], $title, $item['params'] );
 622                         $job->metadata['uuid'] = $item['uuid'];
 623
 624                         return $job;
 625                 } catch ( RedisException $e ) {
 626                         $this->throwRedisException( $this->server, $conn, $e );
 627                 }
 628         }
 629
 630         /**
 631          * Release any ready delayed jobs into the queue
 632          *
 633          * @return int Number of jobs released
 634          * @throws JobQueueError
 635          */
 636         public function releaseReadyDelayedJobs() {
 637                 $count = 0;
 638
 639                 $conn = $this->getConnection();
 640                 try {
 641                         static $script =
 642 <<<LUA
 643                         local kDelayed, kUnclaimed = unpack(KEYS)
 644                         -- Get the list of ready delayed jobs, sorted by readiness
 645                         local ids = redis.call('zRangeByScore',kDelayed,0,ARGV[1])
 646                         -- Migrate the jobs from the "delayed" set to the "unclaimed" list
 647                         for k,id in ipairs(ids) do
 648                                 redis.call('lPush',kUnclaimed,id)
 649                                 redis.call('zRem',kDelayed,id)
 650                         end
 651                         return #ids
 652 LUA;
 653                         $count += (int)$conn->luaEval( $script,
 654                                 array(
 655                                         $this->getQueueKey( 'z-delayed' ), // KEYS[1]
 656                                         $this->getQueueKey( 'l-unclaimed' ), // KEYS[2]
 657                                         time() // ARGV[1]; max "delay until" UNIX timestamp
 658                                 ),
 659                                 2 # first two arguments are keys
 660                         );
 661                 } catch ( RedisException $e ) {
 662                         $this->throwRedisException( $this->server, $conn, $e );
 663                 }
 664
 665                 return $count;
 666         }
 667
 668         /**
 669          * Recycle or destroy any jobs that have been claimed for too long
 670          *
 671          * @return int Number of jobs recycled/deleted
 672          * @throws MWException|JobQueueError
 673          */
 674         public function recycleAndDeleteStaleJobs() {
 675                 if ( $this->claimTTL <= 0 ) { // sanity
 676                         throw new MWException( "Cannot recycle jobs since acknowledgements are disabled." );
 677                 }
 678                 $count = 0;
 679                 // For each job item that can be retried, we need to add it back to the
 680                 // main queue and remove it from the list of currenty claimed job items.
 681                 // For those that cannot, they are marked as dead and kept around for
 682                 // investigation and manual job restoration but are eventually deleted.
 683                 $conn = $this->getConnection();
 684                 try {
 685                         $now = time();
 686                         static $script =
 687 <<<LUA
 688                         local kClaimed, kAttempts, kUnclaimed, kData, kAbandoned = unpack(KEYS)
 689                         local released,abandoned,pruned = 0,0,0
 690                         -- Get all non-dead jobs that have an expired claim on them.
 691                         -- The score for each item is the last claim timestamp (UNIX).
 692                         local staleClaims = redis.call('zRangeByScore',kClaimed,0,ARGV[1])
 693                         for k,id in ipairs(staleClaims) do
 694                                 local timestamp = redis.call('zScore',kClaimed,id)
 695                                 local attempts = redis.call('hGet',kAttempts,id)
 696                                 if attempts < ARGV[3] then
 697                                         -- Claim expired and retries left: re-enqueue the job
 698                                         redis.call('lPush',kUnclaimed,id)
 699                                         redis.call('hIncrBy',kAttempts,id,1)
 700                                         released = released + 1
 701                                 else
 702                                         -- Claim expired and no retries left: mark the job as dead
 703                                         redis.call('zAdd',kAbandoned,timestamp,id)
 704                                         abandoned = abandoned + 1
 705                                 end
 706                                 redis.call('zRem',kClaimed,id)
 707                         end
 708                         -- Get all of the dead jobs that have been marked as dead for too long.
 709                         -- The score for each item is the last claim timestamp (UNIX).
 710                         local deadClaims = redis.call('zRangeByScore',kAbandoned,0,ARGV[2])
 711                         for k,id in ipairs(deadClaims) do
 712                                 -- Stale and out of retries: remove any traces of the job
 713                                 redis.call('zRem',kAbandoned,id)
 714                                 redis.call('hDel',kAttempts,id)
 715                                 redis.call('hDel',kData,id)
 716                                 pruned = pruned + 1
 717                         end
 718                         return {released,abandoned,pruned}
 719 LUA;
 720                         $res = $conn->luaEval( $script,
 721                                 array(
 722                                         $this->getQueueKey( 'z-claimed' ), # KEYS[1]
 723                                         $this->getQueueKey( 'h-attempts' ), # KEYS[2]
 724                                         $this->getQueueKey( 'l-unclaimed' ), # KEYS[3]
 725                                         $this->getQueueKey( 'h-data' ), # KEYS[4]
 726                                         $this->getQueueKey( 'z-abandoned' ), # KEYS[5]
 727                                         $now - $this->claimTTL, # ARGV[1]
 728                                         $now - self::MAX_AGE_PRUNE, # ARGV[2]
 729                                         $this->maxTries # ARGV[3]
 730                                 ),
 731                                 5 # number of first argument(s) that are keys
 732                         );
 733                         if ( $res ) {
 734                                 list( $released, $abandoned, $pruned ) = $res;
 735                                 $count += $released + $pruned;
 736                                 JobQueue::incrStats( 'job-recycle', $this->type, $released );
 737                                 JobQueue::incrStats( 'job-abandon', $this->type, $abandoned );
 738                         }
 739                 } catch ( RedisException $e ) {
 740                         $this->throwRedisException( $this->server, $conn, $e );
 741                 }
 742
 743                 return $count;
 744         }
 745
 746         /**
 747          * @return array
 748          */
 749         protected function doGetPeriodicTasks() {
 750                 $tasks = array();
 751                 if ( $this->claimTTL > 0 ) {
 752                         $tasks['recycleAndDeleteStaleJobs'] = array(
 753                                 'callback' => array( $this, 'recycleAndDeleteStaleJobs' ),
 754                                 'period' => ceil( $this->claimTTL / 2 )
 755                         );
 756                 }
 757                 if ( $this->checkDelay ) {
 758                         $tasks['releaseReadyDelayedJobs'] = array(
 759                                 'callback' => array( $this, 'releaseReadyDelayedJobs' ),
 760                                 'period' => 300 // 5 minutes
 761                         );
 762                 }
 763
 764                 return $tasks;
 765         }
 766
 767         /**
 768          * @param Job $job
 769          * @return array
 770          */
 771         protected function getNewJobFields( Job $job ) {
 772                 return array(
 773                         // Fields that describe the nature of the job
 774                         'type' => $job->getType(),
 775                         'namespace' => $job->getTitle()->getNamespace(),
 776                         'title' => $job->getTitle()->getDBkey(),
 777                         'params' => $job->getParams(),
 778                         // Some jobs cannot run until a "release timestamp"
 779                         'rtimestamp' => $job->getReleaseTimestamp() ?: 0,
 780                         // Additional job metadata
 781                         'uuid' => UIDGenerator::newRawUUIDv4( UIDGenerator::QUICK_RAND ),
 782                         'sha1' => $job->ignoreDuplicates()
 783                                         ? wfBaseConvert( sha1( serialize( $job->getDeduplicationInfo() ) ), 16, 36, 31 )
 784                                         : '',
 785                         'timestamp' => time() // UNIX timestamp
 786                 );
 787         }
 788
 789         /**
 790          * @param $fields array
 791          * @return Job|bool
 792          */
 793         protected function getJobFromFields( array $fields ) {
 794                 $title = Title::makeTitleSafe( $fields['namespace'], $fields['title'] );
 795                 if ( $title ) {
 796                         $job = Job::factory( $fields['type'], $title, $fields['params'] );
 797                         $job->metadata['uuid'] = $fields['uuid'];
 798
 799                         return $job;
 800                 }
 801
 802                 return false;
 803         }
 804
 805         /**
 806          * @param array $fields
 807          * @return string Serialized and possibly compressed version of $fields
 808          */
 809         protected function serialize( array $fields ) {
 810                 $blob = serialize( $fields );
 811                 if ( $this->compression === 'gzip'
 812                         && strlen( $blob ) >= 1024
 813                         && function_exists( 'gzdeflate' )
 814                 ) {
 815                         $object = (object)array( 'blob' => gzdeflate( $blob ), 'enc' => 'gzip' );
 816                         $blobz = serialize( $object );
 817
 818                         return ( strlen( $blobz ) < strlen( $blob ) ) ? $blobz : $blob;
 819                 } else {
 820                         return $blob;
 821                 }
 822         }
 823
 824         /**
 825          * @param string $blob
 826          * @return array|bool Unserialized version of $blob or false
 827          */
 828         protected function unserialize( $blob ) {
 829                 $fields = unserialize( $blob );
 830                 if ( is_object( $fields ) ) {
 831                         if ( $fields->enc === 'gzip' && function_exists( 'gzinflate' ) ) {
 832                                 $fields = unserialize( gzinflate( $fields->blob ) );
 833                         } else {
 834                                 $fields = false;
 835                         }
 836                 }
 837
 838                 return is_array( $fields ) ? $fields : false;
 839         }
 840
 841         /**
 842          * Get a connection to the server that handles all sub-queues for this queue
 843          *
 844          * @return RedisConnRef
 845          * @throws JobQueueConnectionError
 846          */
 847         protected function getConnection() {
 848                 $conn = $this->redisPool->getConnection( $this->server );
 849                 if ( !$conn ) {
 850                         throw new JobQueueConnectionError( "Unable to connect to redis server." );
 851                 }
 852
 853                 return $conn;
 854         }
 855
 856         /**
 857          * @param $server string
 858          * @param $conn RedisConnRef
 859          * @param $e RedisException
 860          * @throws JobQueueError
 861          */
 862         protected function throwRedisException( $server, RedisConnRef $conn, $e ) {
 863                 $this->redisPool->handleException( $server, $conn, $e );
 864                 throw new JobQueueError( "Redis server error: {$e->getMessage()}\n" );
 865         }
 866
 867         /**
 868          * @param $prop string
 869          * @param $type string|null
 870          * @return string
 871          */
 872         private function getQueueKey( $prop, $type = null ) {
 873                 $type = is_string( $type ) ? $type : $this->type;
 874                 list( $db, $prefix ) = wfSplitWikiID( $this->wiki );
 875                 if ( strlen( $this->key ) ) { // namespaced queue (for testing)
 876                         return wfForeignMemcKey( $db, $prefix, 'jobqueue', $type, $this->key, $prop );
 877                 } else {
 878                         return wfForeignMemcKey( $db, $prefix, 'jobqueue', $type, $prop );
 879                 }
 880         }
 881
 882         /**
 883          * @param $key string
 884          * @return void
 885          */
 886         public function setTestingPrefix( $key ) {
 887                 $this->key = $key;
 888         }
 889 }