I find it very surreal that the first performance degradation on the matrix.org homeserver in about 6 months warrants its own HN thread - I guess it's a testimony to how reliable people have grown to expect the server to be these days! Fwiw, this was very much a partial degradation over about 3 hours caused by a pathological database query, and most people didn't notice it. The biggest issue was that to-device messages were delayed, impacting new E2EE sessions.

Eitherway, apologies for the degradation. Obviously anyone on their own server won't have been affected anyway.