    # File lib/active_support/vendor/memcache-client-1.6.5/memcache.rb, line 350
      def flush_all
        raise MemCacheError, 'No active servers' unless active?
        raise MemCacheError, "Update of readonly cache" if @readonly

        begin
          @servers.each do |server|
            with_socket_management(server) do |socket|
              socket.write "flush_all\r\n"
              result = socket.gets
              raise_on_error_response! result
              result
            end
          end
        rescue IndexError => err
          handle_error nil, err
        end
      end