The Phoenix framework tests in October got up to 2m concurrent active (well, mostly just awake) connections, without timeouts.<p><a href="http:&#x2F;&#x2F;www.phoenixframework.org&#x2F;blog&#x2F;the-road-to-2-million-websocket-connections" rel="nofollow">http:&#x2F;&#x2F;www.phoenixframework.org&#x2F;blog&#x2F;the-road-to-2-million-w...</a>