...
Interval is the size, in seconds, of a sliding window of time in which a Worker must have contacted contact the Supervisor . Window begins interval seconds from the current time.after failing to respond within the supervisor_heartbeat_interval window. If there is no response, the Worker will be marked as "down" and a second request sent. If that second request gets no response within this timeout limit, then any instances currently running on that Worker are migrated off. This value should be at least as large as the value for supervisor_heartbeat_interval.
Example
supervisor_heartbeat_timeout = 1200
Defaults
720