class Fluent::Plugin::ForwardOutput::Node

def tick
  now = Time.now.to_f
  if !@available
    if @failure.hard_timeout?(now)
      @failure.clear
    end
    return nil
  end
  if @failure.hard_timeout?(now)
    @log.warn "detached forwarding server '#{@name}'", host: @host, port: @port, hard_timeout: true
    @available = false
    @resolved_host = nil  # expire cached host
    @failure.clear
    return true
  end
  if @sender.phi_failure_detector
    phi = @failure.phi(now)
    if phi > @sender.phi_threshold
      @log.warn "detached forwarding server '#{@name}'", host: @host, port: @port, phi: phi, phi_threshold: @sender.phi_threshold
      @available = false
      @resolved_host = nil  # expire cached host
      @failure.clear
      return true
    end
  end
  false
end