DNS Performance Research Articles

The Analysis of Saccharide in Black Garlic and its Antioxidant Activity

Black garlic was created by keeping whole ordinary garlic in a humidity controlled room at 70-80°C for 10-15 days without any artificial treatments and additives. The black garlic was extracted with 80% ethanol and concentrated to obtain black garlic ethanol extracts. The saccharides of the extracts were analyzed according to the method of Phenol Sulphate colorimetry, DNS and High Performance Liquid Chromatography (HPLC). The antioxidant capacity in vitro of the extracts was assessed by measuring the scavenging activities on 1, 1-Diphenyl-2- Picrylhydrazyl (DPPH). Drosophila melanogaster were employed to explore the effect of black garlic extract on lifespan and antioxidant index in vivo. The results showed that the total sugar content in the black garlic extracts was 55.5% including monosaccharide, disaccharide and polysaccharide, the content of reducing sugar was 25.22%. The results from this study demonstrated black garlic extracts possessed strong antioxidant capacity in vitro in a dose- dependent manner, the longevity of Drosophila melanogaster treated with black garlic extract was prolonged evidently and the content of MDA was decreased by improving SOD (including CuZn-SOD and Mn-SOD) and CAT activities.

A Comparative Analysis on Existing DNS Performance Measurement Mechanisms

A Comparative Analysis on Existing DNS Performance Measurement Mechanisms

EasyMANET: an extensible and configurable platform for service provisioning in MANET environments

Mobile ad hoc networks are highly dynamic networks that offer multihop communications in the presence of changing topologies without the need for any fixed infrastructure support. These networks can be useful in a wide variety of scenarios, but setting them up and deploying services on them is a difficult task, even for experienced users. In this article we present EasyMANET - an extensible platform the main objective of which is to encourage the widespread adoption and use of MANETs by non-expert users. To achieve this objective, EasyMANET provides two essential elements: an address autoconfiguration system and a name resolution service known as Visual DNS. The autoconfiguration system allows users to join an 802.11-based MANET by establishing the parameters of their terminal interfaces quickly and transparently. Thereafter, Visual DNS offers a graphical view of MANET participants and gives users the possibility to access the services made available by other users. Examples are communication services (text-based chat, VoIP, videoconference), file sharing, and localization services. We performed several laboratory experiments, and evaluated the performance of EasyMANET based on address autoconfiguration time and Visual DNS performance. Results show that EasyMANET can be established within seconds, and EasyMANET applications are easy to use. In fact, over 360 students have tried using Easy- MANET without problems.

Research of method for DNS performance measurement and evaluation based on benchmark DNS servers

DNS is the baseline for the Internet. However, no method has yet been established for measurement of the service situation of DNS. In the present research, a method is established for measurement and evaluation of the performance of DNS as the name resolving system of the Internet. The method proposed in this paper can easily be adopted at any location in the world and can be applied to any DNS server or DNS server set. In this method, measurement is easily performed with a tool called dnsprobe and dialup. By using the reference DNS server, the measured results can be corrected. In this way, measured results obtained throughout the world can be uniformly compared. Using this method, the reachability of a root DNS was measured from 27 locations. The results make it possible to understand the reachability of present root DNS servers from various locations in the world and to reveal its tendencies. This research methodology allows judgment of the fairness of DNS service and provides assistance in choosing installation locations when new DNS servers are installed. © 2006 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 89(10): 66–75, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20211

Piggybacking related domain names to improve DNS performance

In this paper, we present a novel approach to exploit the relationships among domain names to improve the cache hit rate for a local DNS server. Using these relationships, an authoritative DNS server (ADNS) can piggyback resolutions for future queries as part of the response message for an initial query. The approach improves the cache hit rate as well as reducing the total queries and responses. The approach is particularly attractive because it can be implemented with no changes to the existing DNS protocol. Trace-based simulations show more than 50% of cache misses can be reduced in the best case while straightforward policies, using frequency and relevancy data for an ADNS, reduce cache misses by 25–40% and DNS traffic by 20–35%. These percentages improve if we focus the policies on resource records with smaller authoritative TTLs. We also show improved performance for hybrid approaches that combine the approach with renewal-based approaches. In conjunction with this work we also did a study on current DNS performance for 20 locations in the United States. The outcome of this study is that the current average DNS latency is generally in the range of 200–300 ms, but range from 500 ms to multiple seconds if we look at the 95% response time. Approaches, such as what we propose, that reduce the amount of DNS traffic will improve the overall response time for applications.

An analysis of wide-area name server traffic

Over a million computers implement the Internet's Domain Name System of DNS, making it the world's most distributed database and the Internet's most significant source of wide-area RPC-like traffic. Last year, over eight percent of the packets and four percent of the bytes that traversed the NSFnet were due to DNS. We estimate that a third of this wide-area DNS traffic was destined to seven root name servers. This paper explores the performance of DNS based on two 24-hour traces of traffic destined to one of these root name servers. It considers the effectiveness of name caching and retransmission timeout calculation, shows how algorithms to increase DNS's resiliency lead to disastrous behavior when servers fail or when certain implementation faults are triggered, explains the paradoxically high fraction of wide-area DNS packets, and evaluates the impact of flaws in various implementations of DNS. It shows that negative caching would improve DNS performance only marginally in an internet of correctly implemented name servers. It concludes by calling for a fundamental change in the way we specify and implement future name servers and distributed applications.