The heartbeat task of client not support keepalive function well，is it a bug?
The heartbeat request of sshClient is a SSH_MSG_GLOBAL_REQUEST, but the
default buffer of heartbeat set false (see ClientConnectService#sendHeartbeat)
buf.putBoolean(false);
The sshServer reponse the heartbeat by the KeepAliveHandler, then
AbstractConnectionService #sendGlobalResponse.
boolean wantReply = buffer.getBoolean();
as the buffer of heartbeat set false, then the sendGlobalResponse will
not reponse sshClient because of the wantReply is false .(see
[AbstractConnectionService #globalRequest)
1 、Is it a Bug(set the heartbeat buffer false default)? how the sshClient
know the server is available when the server don't response.
I have test it whth create a client with params (
HEARTBEAT_INTERAL = 60
IDLE_TIMEOUT = 300
NIO_READ_TIMEOUT = 315)and a server, and the client will close
seesion after the NIO_READ_TIMEOUT.
2、If the client reach the NIO_READ_TIMEOUT, then thows a
InterruptedByTimeoutException,and close the session.But the task of heratbeat
not stoped, it will continue to run even though it will not send
packet.See the ClientConnectionService #startHeartBeat
service.scheduleAtFixedRate(this::sendHeartBeat, interval, interval,
TimeUnit.MILLISECONDS);
if the sshClient reopen a new session and close it many times,the
number of invalid scheduling heartbeat task will become very large, it's not
equitable.
