Millions (literally) of error messages like Notice: Undefined index: channels in /srv/mediawiki/php-master/includes/objectcache/ObjectCache.php on line 340 since about 2018-04-17/18 midnight UTC; which is apparently breaking T192471 and another global rename I was requested to perform today. Thanks.
https://logstash-beta.wmflabs.org/goto/d4ac7b432beed9503464aa12e97930e1