The refreshLinkRecommendation job is failing for hyw.wikipedia for quite some time, because the models for that wiki are not available (cf. T370558):
[urbanecm@mwmaint1002 /var/log/mediawiki/mediawiki_job_growthexperiments-refreshLinkRecommendations-s3]$ grep -h -F hywwiki syslog.log* | head Jul 11 07:24:29 mwmaint1002 mediawiki_job_growthexperiments-refreshLinkRecommendations-s3[8417]: hywwiki Jul 11 07:24:30 mwmaint1002 mediawiki_job_growthexperiments-refreshLinkRecommendations-s3[8417]: hywwiki: Refreshing link recommendations... Jul 11 07:24:30 mwmaint1002 mediawiki_job_growthexperiments-refreshLinkRecommendations-s3[8417]: hywwiki: processing topic biography... Jul 11 07:24:30 mwmaint1002 mediawiki_job_growthexperiments-refreshLinkRecommendations-s3[8417]: hywwiki: 500 new tasks needed Jul 11 07:24:30 mwmaint1002 mediawiki_job_growthexperiments-refreshLinkRecommendations-s3[8417]: hywwiki: fetching 500 tasks... Jul 11 07:24:30 mwmaint1002 mediawiki_job_growthexperiments-refreshLinkRecommendations-s3[8417]: hywwiki: checking candidate Սարգիս_Արարատեան... There was a problem during the HTTP request: 400 Bad Request Jul 11 07:24:30 mwmaint1002 mediawiki_job_growthexperiments-refreshLinkRecommendations-s3[8417]: hywwiki: checking candidate Էրեբունի_թանգարան_եւ_երեգան_թանգարան... There was a problem during the HTTP request: 400 Bad Request Jul 11 07:24:30 mwmaint1002 mediawiki_job_growthexperiments-refreshLinkRecommendations-s3[8417]: hywwiki: checking candidate Աղաւնոյ_Գիւղ... There was a problem during the HTTP request: 400 Bad Request Jul 11 07:24:30 mwmaint1002 mediawiki_job_growthexperiments-refreshLinkRecommendations-s3[8417]: hywwiki: checking candidate 1676_թուական... There was a problem during the HTTP request: 400 Bad Request Jul 11 07:24:30 mwmaint1002 mediawiki_job_growthexperiments-refreshLinkRecommendations-s3[8417]: hywwiki: checking candidate Սամուէլ_Ակոբ_Ուլուչեան... There was a problem during the HTTP request: 400 Bad Request [urbanecm@mwmaint1002 /var/log/mediawiki/mediawiki_job_growthexperiments-refreshLinkRecommendations-s3]$
This was apparently not noticed during the team's chores, because those only involves reviewing logs in Logstash, not checking logs from maintenance jobs (those are checked only when needed for a technical investigation).
Within this task, we should ensure those failures are visible in Logstash as well, so that we can discover inconsistencies like the hywwiki one promptly.