FatalIfUnexpected calls Log.Fatal(err) unless err is nil, cmux.ErrListenerClosed, or the net package's errClosed.

IsClosedConnection returns true if err is cmux.ErrListenerClosed, grpc.ErrServerStopped, io.EOF, or the net package's errClosed.

ListenAndServeGRPC creates a listener and serves the specified grpc Server on it, closing the listener when signaled by the stopper.

MakeServer constructs a Server that tracks active connections, closing them when signaled by stopper.

NewInitialHeartBeatFailedError creates a new InitialHeartbeatFailedError.

InitialHeartbeatFailedError indicates that while attempting a GRPC connection to a node, we aren't successful and have never seen a heartbeat over that connection before.

Server is a thin wrapper around http.Server.