As I discovered in T389863#10671903, cirrusSearchElasticaWrite jobs are consistently failing in quibble-apitests, and get re-enqueued over and over again, until they're dropped. This is especially problematic because the api-testing framework, for unrelated reasons, will under certain conditions wait for the job queue to be empty. When there are many of these jobs enqueued (and Flow will enqueue some: T389894), the test becomes prone to timing out. Here are the relevant excerpts from the MW log:
2025-03-24 20:52:16 cirrusSearchElasticaWrite Special: method=sendData arguments=["general",[{"data":{"version":9,"wiki":"wikidb","page_id":9,"namespace":10,"namespace_text":"Template","title":"Archive for converted wikitext talk page","timestamp":"2025-03-24T20:51:56Z","create_timestamp":"2025-03-24T20:51:56Z","redirect":[]},"params":{"_id":"9","_index":"","_cirrus_hints":{"BuildDocument_flags":0,"noop":{"version":"documentVersion"}}},"upsert":true}]] cluster=default jobqueue_partition=default-0 update_group=page update_kind=page_refresh root_event_time=1742849517 createdAt=1742849536 errorCount=0 retryCount=0 requestId=f83047a9bb4bcb171e3bb648 namespace=-1 title= (id=23,timestamp=20250324205216) STARTING
2025-03-24 20:52:16 cirrusSearchElasticaWrite Special: method=sendData arguments=["general",[{"data":{"version":9,"wiki":"wikidb","page_id":9,"namespace":10,"namespace_text":"Template","title":"Archive for converted wikitext talk page","timestamp":"2025-03-24T20:51:56Z","create_timestamp":"2025-03-24T20:51:56Z","redirect":[]},"params":{"_id":"9","_index":"","_cirrus_hints":{"BuildDocument_flags":0,"noop":{"version":"documentVersion"}}},"upsert":true}]] cluster=default jobqueue_partition=default-0 update_group=page update_kind=page_refresh root_event_time=1742849517 createdAt=1742849536 errorCount=0 retryCount=0 requestId=f83047a9bb4bcb171e3bb648 namespace=-1 title= (id=23,timestamp=20250324205216) t=62 error=ElasticaWrite job failed: Requeued2025-03-24 20:52:16 sending 1 documents to the wikidb_general index(s) against wikidb_general took 1 millis. Requested via web for 2c33c9c64851a02e2ba8143c6550a3b8 by executor 840951780
2025-03-24 20:52:16 Search backend error during sending 1 documents to the wikidb_general index(s) after 1: http_exception: Couldn't connect to host, Elasticsearch down?
2025-03-24 20:52:16 Failed to update documents 9
#0 /workspace/src/vendor/ruflin/elastica/src/Request.php(183): Elastica\Transport\Http->exec(Elastica\Request, array)
#1 /workspace/src/vendor/ruflin/elastica/src/Client.php(545): Elastica\Request->send()
#2 /workspace/src/vendor/ruflin/elastica/src/Bulk.php(298): Elastica\Client->request(string, string, string, array, string)
#3 /workspace/src/extensions/CirrusSearch/includes/DataSender.php(270): Elastica\Bulk->send()
#4 /workspace/src/extensions/CirrusSearch/includes/Job/ElasticaWrite.php(178): CirrusSearch\DataSender->sendData(string, array)
#5 /workspace/src/extensions/CirrusSearch/includes/Job/JobTraits.php(139): CirrusSearch\Job\ElasticaWrite->doJob()
#6 /workspace/src/includes/jobqueue/JobRunner.php(375): CirrusSearch\Job\CirrusGenericJob->run()
#7 /workspace/src/includes/jobqueue/JobRunner.php(337): MediaWiki\JobQueue\JobRunner->doExecuteJob(CirrusSearch\Job\ElasticaWrite)
#8 /workspace/src/includes/jobqueue/JobRunner.php(232): MediaWiki\JobQueue\JobRunner->executeJob(CirrusSearch\Job\ElasticaWrite)
#9 /workspace/src/includes/specials/SpecialRunJobs.php(132): MediaWiki\JobQueue\JobRunner->run(array)
#10 /workspace/src/includes/specials/SpecialRunJobs.php(117): MediaWiki\Specials\SpecialRunJobs->doRun(array)
#11 /workspace/src/includes/specialpage/SpecialPage.php(729): MediaWiki\Specials\SpecialRunJobs->execute(null)
#12 /workspace/src/includes/specialpage/SpecialPageFactory.php(1737): MediaWiki\SpecialPage\SpecialPage->run(null)
#13 /workspace/src/includes/actions/ActionEntryPoint.php(499): MediaWiki\SpecialPage\SpecialPageFactory->executePath(string, MediaWiki\Context\RequestContext)
#14 /workspace/src/includes/actions/ActionEntryPoint.php(143): MediaWiki\Actions\ActionEntryPoint->performRequest()
#15 /workspace/src/includes/MediaWikiEntryPoint.php(202): MediaWiki\Actions\ActionEntryPoint->execute()
#16 /workspace/src/index.php(58): MediaWiki\MediaWikiEntryPoint->run()
#17 {main}Full output, LocalSettings and everything else can be found in https://integration.wikimedia.org/ci/job/mediawiki-quibble-apitests-vendor-php74/40825/ (kept forever). I'm assuming it might be a simple misconfiguration, but I don't know how to fix it.