Why would control messages be exempt from backpressure logic? Control messages are not critically important, most of them are simple pings or pongs or close frames.

If you've reached the maxBackpressure, that's it. It will drop.

Why would control messages be exempt from backpressure logic? Control messages are not critically important, most of them are simple pings or pongs or close frames.

If you've reached the maxBackpressure, that's it. It will drop.

some ws client use ping pong to keep alive. client send ping, server return pong.
if client send ping, not receive pong, it will assume connection lost. when server handle lot of message in backpressure, connection is ok, but pong be dropped. client not not receive pong, client will assume connection be dead. connection will be close by client. this behavior is not right.