# File lib/ec2/ec2.rb, line 449
    def describe_instances(list=[])
      link = generate_request("DescribeInstances", hash_params('InstanceId', list.to_a))
      request_cache_or_info(:describe_instances, link, QEc2DescribeInstancesParser, @@bench, list.blank?) do |parser|
        get_desc_instances(parser.result)
      end
    rescue Exception
      on_exception
    end