class Fluent::Plugin::ForwardOutput::FailureDetector

def initialize(heartbeat_interval, hard_timeout, init_last)
  @heartbeat_interval = heartbeat_interval
  @last = init_last
  @hard_timeout = hard_timeout
  # microsec
  @init_gap = (heartbeat_interval * 1e6).to_i
  @window = [@init_gap]
end