def error_add(error)
      message = error
      message = "#{error.class.name}: #{error.message}" if error.is_a?(Exception)
      @state[@server] = { :count => error_count+1, :time => Time.now, :message => message }
    end
def error_add(error)
      message = error
      message = "#{error.class.name}: #{error.message}" if error.is_a?(Exception)
      @state[@server] = { :count => error_count+1, :time => Time.now, :message => message }
    end
add an error for a server