Removed the layouts plugin and the location plugin and the problem resolved itself for now. Because its really late my time I haven’t had a chance to isolate whether one or both or none are causing the issue, but @angus@merefield giving you a heads up.
I didn’t have a chance to check the errors before I took down the plugins. And then today I rebuilt Discourse to 2.6.0.beta6 ( e7bad9f05d ). Problem went away.
Eine grundlegende Frage: Woran erkennt man, welches Plugin wie viel CPU und Speicher verbraucht? htop zeigt nur die Unicorn-Worker an, aber nicht, wie viele Ressourcen jedes Plugin nutzt.