Keepalive option indicates whether
SO_KEEPALIVE on the socket should be enabled.
keepalive attribute configures keepalive. The following fields are supported:
7200) The number of seconds a connection needs to be idle before keep-alive probes start being sent.
75) The number of seconds between keep-alive probes.
9) is the maximum number of keepalive probes to send without response before deciding the connection is dead.
Keepalive probes defined on a single mapping:
A global keepalive configuration: