=== Error ===
Request URL: N/A (job runner)
Request ID: `XSMHqwpAAEwAAGXdU9AAAADV`
```name=message
/rpc/RunSingleJob.php PHP Fatal Error from line 79 of /srv/mediawiki/php-1.34.0-wmf.11/vendor/wikibase/data-model/src/Entity/ItemId.php: request has exceeded memory limit
```
```name=trace,lines=10
#0 /srv/mediawiki/php-1.34.0-wmf.11/vendor/wikibase/data-model/src/Entity/ItemId.php(79): NO_FUNCTION_GIVEN()
#1 [internal function]: Wikibase\DataModel\Entity\ItemId->unserialize(string)
#2 /srv/mediawiki/php-1.34.0-wmf.11/vendor/wikibase/data-model/src/Entity/EntityIdValue.php(50): unserialize(string)
#3 [internal function]: Wikibase\DataModel\Entity\EntityIdValue->unserialize(string)
#4 /srv/mediawiki/php-1.34.0-wmf.11/vendor/wikibase/data-model/src/Snak/PropertyValueSnak.php(67): unserialize(string)
#5 [internal function]: Wikibase\DataModel\Snak\PropertyValueSnak->unserialize(string)
#6 [internal function]: Memcached->getByKey(string, string, NULL, NULL)
#7 /srv/mediawiki/php-1.34.0-wmf.11/includes/libs/objectcache/MemcachedPeclBagOStuff.php(154): Memcached->get(string, NULL, NULL)
#8 /srv/mediawiki/php-1.34.0-wmf.11/includes/libs/objectcache/BagOStuff.php(206): MemcachedPeclBagOStuff->doGet(string, integer)
#9 /srv/mediawiki/php-1.34.0-wmf.11/extensions/Wikibase/lib/includes/Store/EntityRevisionCache.php(74): BagOStuff->get(string)
#10 /srv/mediawiki/php-1.34.0-wmf.11/extensions/Wikibase/lib/includes/Store/CacheRetrievingEntityRevisionLookup.php(104): Wikibase\Lib\Store\EntityRevisionCache->get(Wikibase\DataModel\Entity\ItemId)
#11 /srv/mediawiki/php-1.34.0-wmf.11/extensions/Wikibase/lib/includes/Store/CachingEntityRevisionLookup.php(84): Wikibase\Lib\Store\CacheRetrievingEntityRevisionLookup->getEntityRevisionFromCache(Wikibase\DataModel\Entity\ItemId, integer, string)
#12 /srv/mediawiki/php-1.34.0-wmf.11/extensions/Wikibase/lib/includes/Store/CachingEntityRevisionLookup.php(104): Wikibase\Lib\Store\CachingEntityRevisionLookup->getEntityRevision(Wikibase\DataModel\Entity\ItemId, integer, string)
#13 /srv/mediawiki/php-1.34.0-wmf.11/extensions/Wikibase/lib/includes/Store/CachingEntityRevisionLookup.php(87): Wikibase\Lib\Store\CachingEntityRevisionLookup->fetchEntityRevision(Wikibase\DataModel\Entity\ItemId, integer, string)
#14 /srv/mediawiki/php-1.34.0-wmf.11/extensions/Wikibase/lib/includes/Store/RevisionBasedEntityLookup.php(39): Wikibase\Lib\Store\CachingEntityRevisionLookup->getEntityRevision(Wikibase\DataModel\Entity\ItemId)
#15 /srv/mediawiki/php-1.34.0-wmf.11/vendor/wikibase/data-model-services/src/Lookup/RedirectResolvingEntityLookup.php(51): Wikibase\Lib\Store\RevisionBasedEntityLookup->getEntity(Wikibase\DataModel\Entity\ItemId)
#16 /srv/mediawiki/php-1.34.0-wmf.11/extensions/WikibaseQualityConstraints/src/ConstraintCheck/Helper/ExceptionIgnoringEntityLookup.php(37): Wikibase\DataModel\Services\Lookup\RedirectResolvingEntityLookup->getEntity(Wikibase\DataModel\Entity\ItemId)
#17 /srv/mediawiki/php-1.34.0-wmf.11/extensions/WikibaseQualityConstraints/src/ConstraintCheck/Checker/SymmetricChecker.php(106): WikibaseQuality\ConstraintReport\ConstraintCheck\Helper\ExceptionIgnoringEntityLookup->getEntity(Wikibase\DataModel\Entity\ItemId)
#18 /srv/mediawiki/php-1.34.0-wmf.11/extensions/WikibaseQualityConstraints/src/ConstraintCheck/DelegatingConstraintChecker.php(566): WikibaseQuality\ConstraintReport\ConstraintCheck\Checker\SymmetricChecker->checkConstraint(WikibaseQuality\ConstraintReport\ConstraintCheck\Context\MainSnakContext, WikibaseQuality\ConstraintReport\Constraint)
#19 /srv/mediawiki/php-1.34.0-wmf.11/extensions/WikibaseQualityConstraints/src/ConstraintCheck/DelegatingConstraintChecker.php(460): WikibaseQuality\ConstraintReport\ConstraintCheck\DelegatingConstraintChecker->getCheckResultFor(WikibaseQuality\ConstraintReport\ConstraintCheck\Context\MainSnakContext, WikibaseQuality\ConstraintReport\Constraint)
#20 /srv/mediawiki/php-1.34.0-wmf.11/extensions/WikibaseQualityConstraints/src/ConstraintCheck/DelegatingConstraintChecker.php(375): WikibaseQuality\ConstraintReport\ConstraintCheck\DelegatingConstraintChecker->checkConstraintsForMainSnak(Wikibase\DataModel\Entity\Item, Wikibase\DataModel\Statement\Statement, NULL, array)
#21 /srv/mediawiki/php-1.34.0-wmf.11/extensions/WikibaseQualityConstraints/src/ConstraintCheck/DelegatingConstraintChecker.php(347): WikibaseQuality\ConstraintReport\ConstraintCheck\DelegatingConstraintChecker->checkStatement(Wikibase\DataModel\Entity\Item, Wikibase\DataModel\Statement\Statement, NULL, array)
#22 /srv/mediawiki/php-1.34.0-wmf.11/extensions/WikibaseQualityConstraints/src/ConstraintCheck/DelegatingConstraintChecker.php(156): WikibaseQuality\ConstraintReport\ConstraintCheck\DelegatingConstraintChecker->checkEveryStatement(Wikibase\DataModel\Entity\Item, NULL, array)
#23 /srv/mediawiki/php-1.34.0-wmf.11/extensions/WikibaseQualityConstraints/src/Api/CheckingResultsSource.php(54): WikibaseQuality\ConstraintReport\ConstraintCheck\DelegatingConstraintChecker->checkAgainstConstraintsOnEntityId(Wikibase\DataModel\Entity\ItemId, NULL, array, array)
#24 /srv/mediawiki/php-1.34.0-wmf.11/extensions/WikibaseQualityConstraints/src/Api/CachingResultsSource.php(247): WikibaseQuality\ConstraintReport\Api\CheckingResultsSource->getResults(array, array, NULL, array)
#25 /srv/mediawiki/php-1.34.0-wmf.11/extensions/WikibaseQualityConstraints/src/Api/CachingResultsSource.php(179): WikibaseQuality\ConstraintReport\Api\CachingResultsSource->getAndStoreResults(array, array, NULL, array)
#26 /srv/mediawiki/php-1.34.0-wmf.11/extensions/WikibaseQualityConstraints/src/Job/CheckConstraintsJob.php(90): WikibaseQuality\ConstraintReport\Api\CachingResultsSource->getResults(array, array, NULL, array)
#27 /srv/mediawiki/php-1.34.0-wmf.11/extensions/WikibaseQualityConstraints/src/Job/CheckConstraintsJob.php(79): WikibaseQuality\ConstraintReport\Job\CheckConstraintsJob->checkConstraints(Wikibase\DataModel\Entity\ItemId)
#28 /srv/mediawiki/php-1.34.0-wmf.11/extensions/EventBus/includes/JobExecutor.php(64): WikibaseQuality\ConstraintReport\Job\CheckConstraintsJob->run()
#29 /srv/mediawiki/rpc/RunSingleJob.php(76): JobExecutor->execute(array)
#30 {main}
```
=== Impact ===
* 768 occurrences in the last 7 days for this error at this line of code
* total occurrences of this error seems to be about double that number: https://logstash.wikimedia.org/app/kibana#/dashboard/AWra4yyim2VjIW0682f0?_g=h@8b5b71a&_a=h@0936916
=== Notes ===
* first occurrence seems to be `XRspOwpAMEQAAKZsFwkAAABJ` at 2019-07-02 09:52:34
* this doesn't seem to be restricted to `data-model/src/Entity/ItemId.php`, even so it happens there most often by far
** see for example also `[XSMCUQpAMD4AAF27XEcAAABY] /rpc/RunSingleJob.php PHP Fatal Error from line 290 of /srv/mediawiki/php-1.34.0-wmf.11/vendor/wikibase/data-model/src/Snak/SnakList.php: request has exceeded memory limit`