3 * Database-backed job queue code.
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License along
16 * with this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
18 * http://www.gnu.org/copyleft/gpl.html
22 use Wikimedia\Rdbms\IDatabase
;
23 use Wikimedia\Rdbms\Database
;
24 use Wikimedia\Rdbms\DBConnectionError
;
25 use Wikimedia\Rdbms\DBError
;
26 use MediaWiki\MediaWikiServices
;
27 use Wikimedia\ScopedCallback
;
30 * Class to handle job queues stored in the DB
35 class JobQueueDB
extends JobQueue
{
36 const CACHE_TTL_SHORT
= 30; // integer; seconds to cache info without re-validating
37 const MAX_AGE_PRUNE
= 604800; // integer; seconds a job can live once claimed
38 const MAX_JOB_RANDOM
= 2147483647; // integer; 2^31 - 1, used for job_random
39 const MAX_OFFSET
= 255; // integer; maximum number of rows to skip
41 /** @var WANObjectCache */
43 /** @var IDatabase|DBError|null */
46 /** @var array|null Server configuration array */
48 /** @var string|null Name of an external DB cluster or null for the local DB cluster */
52 * Additional parameters include:
53 * - server : Server configuration array for Database::factory. Overrides "cluster".
54 * - cluster : The name of an external cluster registered via LBFactory.
55 * If not specified, the primary DB cluster for the wiki will be used.
56 * This can be overridden with a custom cluster so that DB handles will
57 * be retrieved via LBFactory::getExternalLB() and getConnection().
58 * - wanCache : An instance of WANObjectCache to use for caching.
59 * @param array $params
61 protected function __construct( array $params ) {
62 parent
::__construct( $params );
64 if ( isset( $params['server'] ) ) {
65 $this->server
= $params['server'];
66 } elseif ( isset( $params['cluster'] ) && is_string( $params['cluster'] ) ) {
67 $this->cluster
= $params['cluster'];
70 $this->cache
= $params['wanCache'] ?? WANObjectCache
::newEmpty();
73 protected function supportedOrders() {
74 return [ 'random', 'timestamp', 'fifo' ];
77 protected function optimalOrder() {
82 * @see JobQueue::doIsEmpty()
85 protected function doIsEmpty() {
86 $dbr = $this->getReplicaDB();
87 /** @noinspection PhpUnusedLocalVariableInspection */
88 $scope = $this->getScopedNoTrxFlag( $dbr );
90 $found = $dbr->selectField( // unclaimed job
91 'job', '1', [ 'job_cmd' => $this->type
, 'job_token' => '' ], __METHOD__
93 } catch ( DBError
$e ) {
94 $this->throwDBException( $e );
101 * @see JobQueue::doGetSize()
104 protected function doGetSize() {
105 $key = $this->getCacheKey( 'size' );
107 $size = $this->cache
->get( $key );
108 if ( is_int( $size ) ) {
112 $dbr = $this->getReplicaDB();
113 /** @noinspection PhpUnusedLocalVariableInspection */
114 $scope = $this->getScopedNoTrxFlag( $dbr );
116 $size = (int)$dbr->selectField( 'job', 'COUNT(*)',
117 [ 'job_cmd' => $this->type
, 'job_token' => '' ],
120 } catch ( DBError
$e ) {
121 $this->throwDBException( $e );
123 $this->cache
->set( $key, $size, self
::CACHE_TTL_SHORT
);
129 * @see JobQueue::doGetAcquiredCount()
132 protected function doGetAcquiredCount() {
133 if ( $this->claimTTL
<= 0 ) {
134 return 0; // no acknowledgements
137 $key = $this->getCacheKey( 'acquiredcount' );
139 $count = $this->cache
->get( $key );
140 if ( is_int( $count ) ) {
144 $dbr = $this->getReplicaDB();
145 /** @noinspection PhpUnusedLocalVariableInspection */
146 $scope = $this->getScopedNoTrxFlag( $dbr );
148 $count = (int)$dbr->selectField( 'job', 'COUNT(*)',
149 [ 'job_cmd' => $this->type
, "job_token != {$dbr->addQuotes( '' )}" ],
152 } catch ( DBError
$e ) {
153 $this->throwDBException( $e );
155 $this->cache
->set( $key, $count, self
::CACHE_TTL_SHORT
);
161 * @see JobQueue::doGetAbandonedCount()
163 * @throws MWException
165 protected function doGetAbandonedCount() {
166 if ( $this->claimTTL
<= 0 ) {
167 return 0; // no acknowledgements
170 $key = $this->getCacheKey( 'abandonedcount' );
172 $count = $this->cache
->get( $key );
173 if ( is_int( $count ) ) {
177 $dbr = $this->getReplicaDB();
178 /** @noinspection PhpUnusedLocalVariableInspection */
179 $scope = $this->getScopedNoTrxFlag( $dbr );
181 $count = (int)$dbr->selectField( 'job', 'COUNT(*)',
183 'job_cmd' => $this->type
,
184 "job_token != {$dbr->addQuotes( '' )}",
185 "job_attempts >= " . $dbr->addQuotes( $this->maxTries
)
189 } catch ( DBError
$e ) {
190 $this->throwDBException( $e );
193 $this->cache
->set( $key, $count, self
::CACHE_TTL_SHORT
);
199 * @see JobQueue::doBatchPush()
200 * @param IJobSpecification[] $jobs
202 * @throws DBError|Exception
205 protected function doBatchPush( array $jobs, $flags ) {
206 $dbw = $this->getMasterDB();
207 /** @noinspection PhpUnusedLocalVariableInspection */
208 $scope = $this->getScopedNoTrxFlag( $dbw );
209 // In general, there will be two cases here:
210 // a) sqlite; DB connection is probably a regular round-aware handle.
211 // If the connection is busy with a transaction, then defer the job writes
212 // until right before the main round commit step. Any errors that bubble
213 // up will rollback the main commit round.
214 // b) mysql/postgres; DB connection is generally a separate CONN_TRX_AUTOCOMMIT handle.
215 // No transaction is active nor will be started by writes, so enqueue the jobs
216 // now so that any errors will show up immediately as the interface expects. Any
217 // errors that bubble up will rollback the main commit round.
219 $dbw->onTransactionPreCommitOrIdle(
220 function ( IDatabase
$dbw ) use ( $jobs, $flags, $fname ) {
221 $this->doBatchPushInternal( $dbw, $jobs, $flags, $fname );
228 * This function should *not* be called outside of JobQueueDB
230 * @suppress SecurityCheck-SQLInjection Bug in phan-taint-check handling bulk inserts
231 * @param IDatabase $dbw
232 * @param IJobSpecification[] $jobs
234 * @param string $method
238 public function doBatchPushInternal( IDatabase
$dbw, array $jobs, $flags, $method ) {
239 if ( $jobs === [] ) {
243 $rowSet = []; // (sha1 => job) map for jobs that are de-duplicated
244 $rowList = []; // list of jobs for jobs that are not de-duplicated
245 foreach ( $jobs as $job ) {
246 $row = $this->insertFields( $job, $dbw );
247 if ( $job->ignoreDuplicates() ) {
248 $rowSet[$row['job_sha1']] = $row;
254 if ( $flags & self
::QOS_ATOMIC
) {
255 $dbw->startAtomic( $method ); // wrap all the job additions in one transaction
258 // Strip out any duplicate jobs that are already in the queue...
259 if ( count( $rowSet ) ) {
260 $res = $dbw->select( 'job', 'job_sha1',
262 // No job_type condition since it's part of the job_sha1 hash
263 'job_sha1' => array_keys( $rowSet ),
264 'job_token' => '' // unclaimed
268 foreach ( $res as $row ) {
269 wfDebug( "Job with hash '{$row->job_sha1}' is a duplicate.\n" );
270 unset( $rowSet[$row->job_sha1
] ); // already enqueued
273 // Build the full list of job rows to insert
274 $rows = array_merge( $rowList, array_values( $rowSet ) );
275 // Insert the job rows in chunks to avoid replica DB lag...
276 foreach ( array_chunk( $rows, 50 ) as $rowBatch ) {
277 $dbw->insert( 'job', $rowBatch, $method );
279 $this->incrStats( 'inserts', $this->type
, count( $rows ) );
280 $this->incrStats( 'dupe_inserts', $this->type
,
281 count( $rowSet ) +
count( $rowList ) - count( $rows )
283 } catch ( DBError
$e ) {
284 $this->throwDBException( $e );
286 if ( $flags & self
::QOS_ATOMIC
) {
287 $dbw->endAtomic( $method );
292 * @see JobQueue::doPop()
293 * @return RunnableJob|bool
295 protected function doPop() {
296 $dbw = $this->getMasterDB();
297 /** @noinspection PhpUnusedLocalVariableInspection */
298 $scope = $this->getScopedNoTrxFlag( $dbw );
300 $job = false; // job popped off
302 $uuid = wfRandomString( 32 ); // pop attempt
303 do { // retry when our row is invalid or deleted as a duplicate
304 // Try to reserve a row in the DB...
305 if ( in_array( $this->order
, [ 'fifo', 'timestamp' ] ) ) {
306 $row = $this->claimOldest( $uuid );
307 } else { // random first
308 $rand = mt_rand( 0, self
::MAX_JOB_RANDOM
); // encourage concurrent UPDATEs
309 $gte = (bool)mt_rand( 0, 1 ); // find rows with rand before/after $rand
310 $row = $this->claimRandom( $uuid, $rand, $gte );
312 // Check if we found a row to reserve...
314 break; // nothing to do
316 $this->incrStats( 'pops', $this->type
);
318 // Get the job object from the row...
319 $params = self
::extractBlob( $row->job_params
);
320 $params = is_array( $params ) ?
$params : []; // sanity
321 $params +
= [ 'namespace' => $row->job_namespace
, 'title' => $row->job_title
];
322 $job = $this->factoryJob( $row->job_cmd
, $params );
323 $job->setMetadata( 'id', $row->job_id
);
324 $job->setMetadata( 'timestamp', $row->job_timestamp
);
328 if ( !$job ||
mt_rand( 0, 9 ) == 0 ) {
329 // Handled jobs that need to be recycled/deleted;
330 // any recycled jobs will be picked up next attempt
331 $this->recycleAndDeleteStaleJobs();
333 } catch ( DBError
$e ) {
334 $this->throwDBException( $e );
341 * Reserve a row with a single UPDATE without holding row locks over RTTs...
343 * @param string $uuid 32 char hex string
344 * @param int $rand Random unsigned integer (31 bits)
345 * @param bool $gte Search for job_random >= $random (otherwise job_random <= $random)
346 * @return stdClass|bool Row|false
348 protected function claimRandom( $uuid, $rand, $gte ) {
349 $dbw = $this->getMasterDB();
350 /** @noinspection PhpUnusedLocalVariableInspection */
351 $scope = $this->getScopedNoTrxFlag( $dbw );
352 // Check cache to see if the queue has <= OFFSET items
353 $tinyQueue = $this->cache
->get( $this->getCacheKey( 'small' ) );
355 $row = false; // the row acquired
356 $invertedDirection = false; // whether one job_random direction was already scanned
357 // This uses a replication safe method for acquiring jobs. One could use UPDATE+LIMIT
358 // instead, but that either uses ORDER BY (in which case it deadlocks in MySQL) or is
359 // not replication safe. Due to https://bugs.mysql.com/bug.php?id=6980, subqueries cannot
360 // be used here with MySQL.
362 if ( $tinyQueue ) { // queue has <= MAX_OFFSET rows
363 // For small queues, using OFFSET will overshoot and return no rows more often.
364 // Instead, this uses job_random to pick a row (possibly checking both directions).
365 $ineq = $gte ?
'>=' : '<=';
366 $dir = $gte ?
'ASC' : 'DESC';
367 $row = $dbw->selectRow( 'job', self
::selectFields(), // find a random job
369 'job_cmd' => $this->type
,
370 'job_token' => '', // unclaimed
371 "job_random {$ineq} {$dbw->addQuotes( $rand )}" ],
373 [ 'ORDER BY' => "job_random {$dir}" ]
375 if ( !$row && !$invertedDirection ) {
377 $invertedDirection = true;
378 continue; // try the other direction
380 } else { // table *may* have >= MAX_OFFSET rows
381 // T44614: "ORDER BY job_random" with a job_random inequality causes high CPU
382 // in MySQL if there are many rows for some reason. This uses a small OFFSET
383 // instead of job_random for reducing excess claim retries.
384 $row = $dbw->selectRow( 'job', self
::selectFields(), // find a random job
386 'job_cmd' => $this->type
,
387 'job_token' => '', // unclaimed
390 [ 'OFFSET' => mt_rand( 0, self
::MAX_OFFSET
) ]
393 $tinyQueue = true; // we know the queue must have <= MAX_OFFSET rows
394 $this->cache
->set( $this->getCacheKey( 'small' ), 1, 30 );
395 continue; // use job_random
399 if ( $row ) { // claim the job
400 $dbw->update( 'job', // update by PK
402 'job_token' => $uuid,
403 'job_token_timestamp' => $dbw->timestamp(),
404 'job_attempts = job_attempts+1' ],
405 [ 'job_cmd' => $this->type
, 'job_id' => $row->job_id
, 'job_token' => '' ],
408 // This might get raced out by another runner when claiming the previously
409 // selected row. The use of job_random should minimize this problem, however.
410 if ( !$dbw->affectedRows() ) {
411 $row = false; // raced out
414 break; // nothing to do
422 * Reserve a row with a single UPDATE without holding row locks over RTTs...
424 * @param string $uuid 32 char hex string
425 * @return stdClass|bool Row|false
427 protected function claimOldest( $uuid ) {
428 $dbw = $this->getMasterDB();
429 /** @noinspection PhpUnusedLocalVariableInspection */
430 $scope = $this->getScopedNoTrxFlag( $dbw );
432 $row = false; // the row acquired
434 if ( $dbw->getType() === 'mysql' ) {
435 // Per https://bugs.mysql.com/bug.php?id=6980, we can't use subqueries on the
436 // same table being changed in an UPDATE query in MySQL (gives Error: 1093).
437 // Oracle and Postgre have no such limitation. However, MySQL offers an
438 // alternative here by supporting ORDER BY + LIMIT for UPDATE queries.
439 $dbw->query( "UPDATE {$dbw->tableName( 'job' )} " .
441 "job_token = {$dbw->addQuotes( $uuid ) }, " .
442 "job_token_timestamp = {$dbw->addQuotes( $dbw->timestamp() )}, " .
443 "job_attempts = job_attempts+1 " .
445 "job_cmd = {$dbw->addQuotes( $this->type )} " .
446 "AND job_token = {$dbw->addQuotes( '' )} " .
447 ") ORDER BY job_id ASC LIMIT 1",
451 // Use a subquery to find the job, within an UPDATE to claim it.
452 // This uses as much of the DB wrapper functions as possible.
455 'job_token' => $uuid,
456 'job_token_timestamp' => $dbw->timestamp(),
457 'job_attempts = job_attempts+1' ],
459 $dbw->selectSQLText( 'job', 'job_id',
460 [ 'job_cmd' => $this->type
, 'job_token' => '' ],
462 [ 'ORDER BY' => 'job_id ASC', 'LIMIT' => 1 ] ) .
468 // Fetch any row that we just reserved...
469 if ( $dbw->affectedRows() ) {
470 $row = $dbw->selectRow( 'job', self
::selectFields(),
471 [ 'job_cmd' => $this->type
, 'job_token' => $uuid ], __METHOD__
473 if ( !$row ) { // raced out by duplicate job removal
474 wfDebug( "Row deleted as duplicate by another process.\n" );
477 break; // nothing to do
485 * @see JobQueue::doAck()
486 * @param RunnableJob $job
487 * @throws MWException
489 protected function doAck( RunnableJob
$job ) {
490 $id = $job->getMetadata( 'id' );
491 if ( $id === null ) {
492 throw new MWException( "Job of type '{$job->getType()}' has no ID." );
495 $dbw = $this->getMasterDB();
496 /** @noinspection PhpUnusedLocalVariableInspection */
497 $scope = $this->getScopedNoTrxFlag( $dbw );
499 // Delete a row with a single DELETE without holding row locks over RTTs...
502 [ 'job_cmd' => $this->type
, 'job_id' => $id ],
506 $this->incrStats( 'acks', $this->type
);
507 } catch ( DBError
$e ) {
508 $this->throwDBException( $e );
513 * @see JobQueue::doDeduplicateRootJob()
514 * @param IJobSpecification $job
515 * @throws MWException
518 protected function doDeduplicateRootJob( IJobSpecification
$job ) {
519 $params = $job->getParams();
520 if ( !isset( $params['rootJobSignature'] ) ) {
521 throw new MWException( "Cannot register root job; missing 'rootJobSignature'." );
522 } elseif ( !isset( $params['rootJobTimestamp'] ) ) {
523 throw new MWException( "Cannot register root job; missing 'rootJobTimestamp'." );
525 $key = $this->getRootJobCacheKey( $params['rootJobSignature'] );
526 // Callers should call JobQueueGroup::push() before this method so that if the insert
527 // fails, the de-duplication registration will be aborted. Since the insert is
528 // deferred till "transaction idle", do the same here, so that the ordering is
529 // maintained. Having only the de-duplication registration succeed would cause
530 // jobs to become no-ops without any actual jobs that made them redundant.
531 $dbw = $this->getMasterDB();
532 /** @noinspection PhpUnusedLocalVariableInspection */
533 $scope = $this->getScopedNoTrxFlag( $dbw );
535 $cache = $this->dupCache
;
536 $dbw->onTransactionCommitOrIdle(
537 function () use ( $cache, $params, $key ) {
538 $timestamp = $cache->get( $key ); // current last timestamp of this job
539 if ( $timestamp && $timestamp >= $params['rootJobTimestamp'] ) {
540 return true; // a newer version of this root job was enqueued
543 // Update the timestamp of the last root job started at the location...
544 return $cache->set( $key, $params['rootJobTimestamp'], JobQueueDB
::ROOTJOB_TTL
);
553 * @see JobQueue::doDelete()
556 protected function doDelete() {
557 $dbw = $this->getMasterDB();
558 /** @noinspection PhpUnusedLocalVariableInspection */
559 $scope = $this->getScopedNoTrxFlag( $dbw );
561 $dbw->delete( 'job', [ 'job_cmd' => $this->type
] );
562 } catch ( DBError
$e ) {
563 $this->throwDBException( $e );
570 * @see JobQueue::doWaitForBackups()
573 protected function doWaitForBackups() {
574 if ( $this->server
) {
575 return; // not using LBFactory instance
578 $lbFactory = MediaWikiServices
::getInstance()->getDBLoadBalancerFactory();
579 $lbFactory->waitForReplication( [
580 'domain' => $this->domain
,
581 'cluster' => is_string( $this->cluster
) ?
$this->cluster
: false
588 protected function doFlushCaches() {
589 foreach ( [ 'size', 'acquiredcount' ] as $type ) {
590 $this->cache
->delete( $this->getCacheKey( $type ) );
595 * @see JobQueue::getAllQueuedJobs()
598 public function getAllQueuedJobs() {
599 return $this->getJobIterator( [ 'job_cmd' => $this->getType(), 'job_token' => '' ] );
603 * @see JobQueue::getAllAcquiredJobs()
606 public function getAllAcquiredJobs() {
607 return $this->getJobIterator( [ 'job_cmd' => $this->getType(), "job_token > ''" ] );
611 * @param array $conds Query conditions
614 protected function getJobIterator( array $conds ) {
615 $dbr = $this->getReplicaDB();
616 /** @noinspection PhpUnusedLocalVariableInspection */
617 $scope = $this->getScopedNoTrxFlag( $dbr );
619 return new MappedIterator(
620 $dbr->select( 'job', self
::selectFields(), $conds ),
622 $params = strlen( $row->job_params
) ?
unserialize( $row->job_params
) : [];
623 $params = is_array( $params ) ?
$params : []; // sanity
625 'namespace' => $row->job_namespace
,
626 'title' => $row->job_title
629 $job = $this->factoryJob( $row->job_cmd
, $params );
630 $job->setMetadata( 'id', $row->job_id
);
631 $job->setMetadata( 'timestamp', $row->job_timestamp
);
636 } catch ( DBError
$e ) {
637 $this->throwDBException( $e );
641 public function getCoalesceLocationInternal() {
642 if ( $this->server
) {
643 return null; // not using the LBFactory instance
646 return is_string( $this->cluster
)
647 ?
"DBCluster:{$this->cluster}:{$this->domain}"
648 : "LBFactory:{$this->domain}";
651 protected function doGetSiblingQueuesWithJobs( array $types ) {
652 $dbr = $this->getReplicaDB();
653 /** @noinspection PhpUnusedLocalVariableInspection */
654 $scope = $this->getScopedNoTrxFlag( $dbr );
655 // @note: this does not check whether the jobs are claimed or not.
656 // This is useful so JobQueueGroup::pop() also sees queues that only
657 // have stale jobs. This lets recycleAndDeleteStaleJobs() re-enqueue
658 // failed jobs so that they can be popped again for that edge case.
659 $res = $dbr->select( 'job', 'DISTINCT job_cmd',
660 [ 'job_cmd' => $types ], __METHOD__
);
663 foreach ( $res as $row ) {
664 $types[] = $row->job_cmd
;
670 protected function doGetSiblingQueueSizes( array $types ) {
671 $dbr = $this->getReplicaDB();
672 /** @noinspection PhpUnusedLocalVariableInspection */
673 $scope = $this->getScopedNoTrxFlag( $dbr );
675 $res = $dbr->select( 'job', [ 'job_cmd', 'COUNT(*) AS count' ],
676 [ 'job_cmd' => $types ], __METHOD__
, [ 'GROUP BY' => 'job_cmd' ] );
679 foreach ( $res as $row ) {
680 $sizes[$row->job_cmd
] = (int)$row->count
;
687 * Recycle or destroy any jobs that have been claimed for too long
689 * @return int Number of jobs recycled/deleted
691 public function recycleAndDeleteStaleJobs() {
693 $count = 0; // affected rows
694 $dbw = $this->getMasterDB();
695 /** @noinspection PhpUnusedLocalVariableInspection */
696 $scope = $this->getScopedNoTrxFlag( $dbw );
699 if ( !$dbw->lock( "jobqueue-recycle-{$this->type}", __METHOD__
, 1 ) ) {
700 return $count; // already in progress
703 // Remove claims on jobs acquired for too long if enabled...
704 if ( $this->claimTTL
> 0 ) {
705 $claimCutoff = $dbw->timestamp( $now - $this->claimTTL
);
706 // Get the IDs of jobs that have be claimed but not finished after too long.
707 // These jobs can be recycled into the queue by expiring the claim. Selecting
708 // the IDs first means that the UPDATE can be done by primary key (less deadlocks).
709 $res = $dbw->select( 'job', 'job_id',
711 'job_cmd' => $this->type
,
712 "job_token != {$dbw->addQuotes( '' )}", // was acquired
713 "job_token_timestamp < {$dbw->addQuotes( $claimCutoff )}", // stale
714 "job_attempts < {$dbw->addQuotes( $this->maxTries )}" ], // retries left
720 }, iterator_to_array( $res )
722 if ( count( $ids ) ) {
723 // Reset job_token for these jobs so that other runners will pick them up.
724 // Set the timestamp to the current time, as it is useful to now that the job
725 // was already tried before (the timestamp becomes the "released" time).
729 'job_token_timestamp' => $dbw->timestamp( $now ) ], // time of release
734 $affected = $dbw->affectedRows();
736 $this->incrStats( 'recycles', $this->type
, $affected );
740 // Just destroy any stale jobs...
741 $pruneCutoff = $dbw->timestamp( $now - self
::MAX_AGE_PRUNE
);
743 'job_cmd' => $this->type
,
744 "job_token != {$dbw->addQuotes( '' )}", // was acquired
745 "job_token_timestamp < {$dbw->addQuotes( $pruneCutoff )}" // stale
747 if ( $this->claimTTL
> 0 ) { // only prune jobs attempted too many times...
748 $conds[] = "job_attempts >= {$dbw->addQuotes( $this->maxTries )}";
750 // Get the IDs of jobs that are considered stale and should be removed. Selecting
751 // the IDs first means that the UPDATE can be done by primary key (less deadlocks).
752 $res = $dbw->select( 'job', 'job_id', $conds, __METHOD__
);
756 }, iterator_to_array( $res )
758 if ( count( $ids ) ) {
759 $dbw->delete( 'job', [ 'job_id' => $ids ], __METHOD__
);
760 $affected = $dbw->affectedRows();
762 $this->incrStats( 'abandons', $this->type
, $affected );
765 $dbw->unlock( "jobqueue-recycle-{$this->type}", __METHOD__
);
766 } catch ( DBError
$e ) {
767 $this->throwDBException( $e );
774 * @param IJobSpecification $job
775 * @param IDatabase $db
778 protected function insertFields( IJobSpecification
$job, IDatabase
$db ) {
780 // Fields that describe the nature of the job
781 'job_cmd' => $job->getType(),
782 'job_namespace' => $job->getParams()['namespace'] ?? NS_SPECIAL
,
783 'job_title' => $job->getParams()['title'] ??
'',
784 'job_params' => self
::makeBlob( $job->getParams() ),
785 // Additional job metadata
786 'job_timestamp' => $db->timestamp(),
787 'job_sha1' => Wikimedia\base_convert
(
788 sha1( serialize( $job->getDeduplicationInfo() ) ),
791 'job_random' => mt_rand( 0, self
::MAX_JOB_RANDOM
)
796 * @throws JobQueueConnectionError
799 protected function getReplicaDB() {
801 return $this->getDB( DB_REPLICA
);
802 } catch ( DBConnectionError
$e ) {
803 throw new JobQueueConnectionError( "DBConnectionError:" . $e->getMessage() );
808 * @throws JobQueueConnectionError
811 protected function getMasterDB() {
813 return $this->getDB( DB_MASTER
);
814 } catch ( DBConnectionError
$e ) {
815 throw new JobQueueConnectionError( "DBConnectionError:" . $e->getMessage() );
820 * @param int $index (DB_REPLICA/DB_MASTER)
823 protected function getDB( $index ) {
824 if ( $this->server
) {
825 if ( $this->conn
instanceof IDatabase
) {
827 } elseif ( $this->conn
instanceof DBError
) {
832 $this->conn
= Database
::factory( $this->server
['type'], $this->server
);
833 } catch ( DBError
$e ) {
840 $lbFactory = MediaWikiServices
::getInstance()->getDBLoadBalancerFactory();
841 $lb = is_string( $this->cluster
)
842 ?
$lbFactory->getExternalLB( $this->cluster
)
843 : $lbFactory->getMainLB( $this->domain
);
845 return ( $lb->getServerType( $lb->getWriterIndex() ) !== 'sqlite' )
846 // Keep a separate connection to avoid contention and deadlocks;
847 // However, SQLite has the opposite behavior due to DB-level locking.
848 ?
$lb->getConnectionRef( $index, [], $this->domain
, $lb::CONN_TRX_AUTOCOMMIT
)
849 // Jobs insertion will be defered until the PRESEND stage to reduce contention.
850 : $lb->getConnectionRef( $index, [], $this->domain
);
855 * @param IDatabase $db
856 * @return ScopedCallback
858 private function getScopedNoTrxFlag( IDatabase
$db ) {
859 $autoTrx = $db->getFlag( DBO_TRX
); // get current setting
860 $db->clearFlag( DBO_TRX
); // make each query its own transaction
862 return new ScopedCallback( function () use ( $db, $autoTrx ) {
864 $db->setFlag( DBO_TRX
); // restore old setting
870 * @param string $property
873 private function getCacheKey( $property ) {
874 $cluster = is_string( $this->cluster
) ?
$this->cluster
: 'main';
876 return $this->cache
->makeGlobalKey(
886 * @param array|bool $params
889 protected static function makeBlob( $params ) {
890 if ( $params !== false ) {
891 return serialize( $params );
898 * @param string $blob
901 protected static function extractBlob( $blob ) {
902 if ( (string)$blob !== '' ) {
903 return unserialize( $blob );
911 * @throws JobQueueError
913 protected function throwDBException( DBError
$e ) {
914 throw new JobQueueError( get_class( $e ) . ": " . $e->getMessage() );
918 * Return the list of job fields that should be selected.
922 public static function selectFields() {
933 'job_token_timestamp',