Publications
Disclaimer :
These papers are made available as a means to ensure timely dissemination of scholarly and technical work
on a non-commercial basis. Copyright and all rights therein are maintained by the authors or by other copyright holders,
notwithstanding that they have offered their works here electronically. It is understood that all persons copying
this information will adhere to the terms and constraints invoked by each author's copyright. These works may not
be reposted without the explicit permission of the copyright holder.
2012
NCShield: Securing Decentralized, Matrix Factorization-Based Network Coordinate Systems ,
Shining Wu , Yang Chen , Xiaoming Fu , Jun Li, IEEE/ACM International Workshop on Quality of Service (IWQoS 2012), Coimbra, Portugal,
IEEE, June 2012.
CloudGPS: A Scalable and ISP-Friendly Server Selection Scheme in Cloud Computing Environments ,
Cong Ding , Yang Chen , Tianyin Xu , Xiaoming Fu , IEEE/ACM International Workshop on Quality of Service (IWQoS 2012), Coimbra, Portugal,
IEEE, June 2012.
Measurement-based Optimization of P2P Networking and Applications ,
Xiaoming Fu , Yang Chen , Guy Leduc, Laurent Mathy, Computer Networks, special issue on easurement-based Optimization of P2P Networking and Applications (editorial), 56(3): 1077-1079,
Elsevier, February 2012.
2011
Phoenix: A Weight-based Network Coordinate System Using Matrix Factorization ,
Yang Chen , Xiao Wang, Cong Shi, Eng Keong Lua, Xiaoming Fu , Beixing Deng, Xing Li, IEEE Transactions on Network and Service Management, Vol 8, Issue 4,
IEEE, December 2011.
Read abstract
Network coordinate (NC) systems provide a lightweight and scalable way for predicting the distances, i.e., round-trip latencies among Internet hosts. Most existing NC systems embed hosts into a low dimensional Euclidean space. Unfortunately, the persistent occurrence of Triangle Inequality Violation (TIV) on the Internet largely limits the distance prediction accuracy of those NC systems. Some alternative systems aim at handling the persistent TIV, however, they only achieve comparable prediction accuracy with Euclidean distance based NC systems. In this paper, we propose an NC system, so-called Phoenix, which is based on the matrix factorization model. Phoenix introduces a weight to each reference NC and trusts the NCs with higher weight values more than the others. The weight-based mechanism can substantially reduce the impact of the error propagation. Using the representative aggregate data sets and the newly measured dynamic data set collected from the Internet, our simulations show that Phoenix achieves significantly higher prediction accuracy than other NC systems. We also show that Phoenix quickly converges to steady state, performs well under host churn, handles the drift of the NCs successfully by using regularization, and is robust against measurement anomalies. Phoenix achieves a scalable yet accurate end-to-end distances monitoring. In addition, we study how well an NC system can characterize the TIV property on the Internet by introducing two new quantitative metrics, so-called RERPL and AERPL. We show that Phoenix is able to characterize TIV better than other existing NC systems.
Phoenix_TNSM.pdf [433.5 kB]
Tarantula: Towards an Accurate Network Coordinate System by Handling Major Portion of TIVs ,
Zhuo Chen, Yang Chen , Yibo Zhu, Cong Ding , Beixing Deng, Xing Li, IEEE GLOBECOM 2011 - Next Generation Networking Symposium, Houston, TX, USA,,
IEEE, December 2011.
Read abstract
Network Coordinate (NC) systems provide an efficient and scalable mechanism to estimate latencies among hosts. However, many popular algorithms like Vivaldi suffer greatly from the existence of Triangle Inequality Violations (TIVs). Two-layer systems like Pharos and hierarchical Vivaldi have been proposed to remedy the impact of TIVs. They divide the whole space into several location-based clusters and run NC systems on both global layer and local layer. However, the two-layer model is only able to optimize the intra-cluster links relating to a limited portion of TIV triangles. In this paper, we propose a new NC system, Tarantula, which divides the space in a novel way. By categorizing the TIVs into three classes, we show that Tarantula handles a much larger portion of existing TIVs than two-layer systems. Moreover, we present two techniques to further strengthen the Tarantula system: 1) relate the updating step size in the Vivaldi algorithm used in Tarantula to ground-truth latency so as to improve the prediction for short links; 2) propose Dynamic Cluster Optimization to dynamically adjust clustering of hosts. Our experimental results show that Tarantula outperforms Pharos and Vivaldi significantly in terms of estimation accuracy. When implementing different NC systems in the application of server selection and detour finding, Tarantula again performs the best.
PID1101352.pdf [366.9 kB]
Scaling Microblogging Services with Divergent Traffic Demands ,
Tianyin Xu , Yang Chen , Lei Jiao , Ben Y. Zhao, Pan Hui, Xiaoming Fu , ACM/IFIP/USENIX 12th International Middleware Conference (Middleware 2011), Lisboa, Portugal, Lecture Notes in Computer Science 7049, pages 20-40,
Springer Verlag, December 2011.
Read abstract
Today’s microblogging services such as Twitter have long outgrown their initial designs as SMS-based social networks. Instead, a massive and steadily-growing user population of more than 100 million is using Twitter for everything from capturing the mood of the country to detecting earthquakes and Internet service failures. It is unsurprising that the traditional centralized client-server architecture has not scaled with user demand, leading to server overload and significant loss of availability.
In this paper, we argue that the divergence in usage models of microblogging services can best be addressed using complementary mechanisms, one that provides reliable messages between friends, and another that delivers events from popular celebrities and media outlets to their millions of followers. We present Cuckoo, a new microblogging system that offloads processing and bandwidth costs away from a small centralized server base while ensuring reliable message delivery. We use a 20-day Twitter availability measurement to guide our design, and trace-driven emulation of 30,000 Twitter users to evaluate our Cuckoo prototype. Compared to a centralized approach, Cuckoo achieves 30-50% server bandwidth savings and 50-60% CPU load reduction, all while guaranteeing reliable message delivery.
cuckoo.pdf [2593.3 kB]
Pomelo: Accurate and Decentralized Shortest-path Distance Prediction in Social Graphs ,
Zhuo Chen, Yang Chen , Cong Ding , Beixing Deng, Xing Li, ACM SIGCOMM Computer Communication Review, Volume 41, Issue 4, Pages 406-407,
ACM, October 2011.
Read abstract
Computing the shortest-path distances between nodes is a key problem in analyzing social graphs. Traditional methods like breadth-first search (BFS) do not scale well with graph size. Recently, a Graph Coordinate System, called Orion, has been proposed to estimate shortest-path distances in a scalable way. Orion uses a landmark-based approach, which does not take account of the shortest-path distances between non-landmark nodes in coordinate calculation. Such biased input for the coordinate system cannot characterize the graph structure well. In this paper, we propose Pomelo, which calculates the graph coordinates in a decentralized manner. Every node in Pomelo computes its shortest-path distances to both nearby neighbors and some random distant neighbors. By introducing the novel partial BFS, the computational overhead of Pomelo is tunable. Our experimental results from different representative social graphs show that Pomelo greatly outperforms Orion in estimation accuracy while maintaining the same computational overhead.
p406-chen.pdf [488.2 kB]
Understanding Graph Sampling Algorithms for Social Network Analysis ,
Tianyi Wang, Yang Chen , Zengbin Zhang, Tianyin Xu , Long Jin, Pan Hui, Beixing Deng, Xing Li, The 3rd ICDCS Workshop on Simplifying Complex Networks for Practitioners (SIMPLEX'11),
Minneapolis, MN, USA, June 2011.
Read abstract
Being able to keep the graph scale small while capturing the properties of the original social graph, graph sampling provides an efficient, yet inexpensive solution for social network analysis. The challenge is how to create a small, but representative sample out of the massive social graph with millions or even billions of nodes. Several sampling algorithms have been proposed in previous studies, but there lacks fair evaluation and comparison among them. In this paper, we analyze the state-ofart graph sampling algorithms and evaluate their performance on some widely recognized graph properties on directed graphs using large-scale social network datasets. We evaluate not only the commonly used node degree distribution, but also clustering coefficient, which quantifies how well connected are the neighbors of a node in a graph. Through the comparison we have found that none of the algorithms is able to obtain satisfied sampling results in both of these properties, and the performance of each algorithm differs much in different kinds of datasets.
simplex11.pdf [167.5 kB]
Albatross Sampling: Robust and Effective Hybrid Vertex Sampling for Social Graphs ,
Long Jin, Yang Chen , Pan Hui, Cong Ding , Tianyi Wang, Athanasios Vasilakos, Beixing Deng, Xing Li, The 3rd ACM Workshop on Hot Topics in Planet-scale Measurement (HotPlanet'11), Co-located with ACM MobiSys 2011,
June 2011.
Read abstract
Nowadays, Online Social Networks (OSNs) have become dramatically popular and the study of social graphs attracts the interests of a large number of researchers. One critical challenge is the huge size of the social graph, which makes the graph analyzing or even the data crawling incredibly time consuming, and sometimes impossible to be completed. Thus, graph sampling algorithms have been introduced to obtain a smaller subgraph which reflects the properties of the original graph well. Breadth-First Sampling (BFS) is widely used in graph sampling, but it is biased towards high-degree vertices during the process of sampling. Besides, Metropolis-Hasting Random Walk (MHRW), which is proposed to get unbiased samples of the social graph, requires the graph to be well connected. In this paper, we propose a vertex sampling algorithm, so-called Albatross Sampling (AS), which introduces random jump strategy into MHRW during the sampling process. The embedded random jump makes the sampling procedure more flexible and avoids being trapped in some locally well connected part. According to our evaluation, we find that no matter using tightly or loosely connected graphs, AS performs significantly better than MHRW and BFS. On the one hand, AS estimates the degree distribution with much lower Normalized Mean Square Error (NMSE) by consuming the same resource budget. On the other hand, to get an acceptable estimation of the degree distribution, AS requires much less resource budget.
AS_HotPlanet11.pdf [381.0 kB]
Exploring User Social Behaviors in Mobile Social Applications ,
Konglin Zhu , Pan Hui, Yang Chen , Xiaoming Fu , Wenzhong Li , 4th ACM Workshop on Social Network Systems (SNS 2011), in conjunction with ACM EuroSys 2011, Salzburg, Austria,
April 2011.
Read abstract
Mobile social applications are popular as the proliferating of mobile devices. Understanding user social behaviors is important to improve mobile social applications and enhance its quality of service. However, there is still lack of data for real deployment mobile social application on data analysis of human interaction and social behaviors in mobile social networks.
In this paper, we introduce the experiment methodology of deploying the Goose software in two campuses located in Germany and China respectively. Goose is a mobile social network application allows microblogging, message sending. With the help of volunteers, we collect user interaction data in the duration of 15 days. Based on the collected data, our observation reveals the following aspects of user interactions and their influences. First, user overall activities approximately match user daily life work pattern
with a slightly longer time duration and periodically appearance. Second, user encounters in mobile social network follow the heavy tail distribution in small social communities, and user interactions follow the Pareto principle, where about 20% of users make close connections to the other users. Third, communication path between a pair of mobile nodes is mostly within 6 hops, and information diffusion using an epidemic strategy demonstrates that the informed population reaches to 50% in a short term and approaches to 80% in a long term.
PDF [185.3 kB]
Cuckoo: Scaling Microblogging Services with Divergent Traffic Demands ,
Tianyin Xu , Yang Chen , Lei Jiao , Ben Y. Zhao, Pan Hui, Xiaoming Fu , Technical Report No. IFI-TB-2011-01, Institute of Computer Science, University of Goettingen, Goettingen, Germany, ISSN 1611-1044,
January 2011.
Read abstract
Today's microblogging services such as Twitter have long outgrown their initial designs as SMS-based social networks. Instead, a massive and steadily-growing user population of more than 100 million is using Twitter for everything from capturing the mood of the country to detecting earthquakes and Internet service failures. It is unsurprising then, that the traditional centralized client-server architecture has not scaled with user demand, leading to server overload and significant loss of availability.
In this paper, we argue that the divergence in usage models of microblogging services can best be addressed using complementary mechanisms, one that provides reliable messages between friends, and another that delivers events from popular celebrities and media outlets to their millions of followers. We present Cuckoo, a new microblogging system that offloads processing and bandwidth costs away from a small centralized server base while ensuring reliable message delivery. We use a 20-day Twitter availability measurement to guide our design, and trace-driven emulation of 30,000 Twitter users to evaluate our Cuckoo prototype. Compared to a centralized approach, Cuckoo achieves 30-50% server bandwidth savings and 50-60% CPU load reduction, all while guaranteeing reliable message delivery.
Technical Report.pdf [4259.3 kB]
2010
Taming the Triangle Inequality Violations with Network Coordinate System on Real Internet ,
Yibo Zhu, Yang Chen , Zengbin Zhang, Xiaoming Fu , Dan Li, Beixing Deng, Xing Li, ACM Workshop on Re-Architecting the Internet (ReArch 2010), co-located with ACM CoNEXT 2010, Philadelphia, USA,
ACM, December 2010.
Read abstract
Network Coordinate (NC) systems are efficient in scalable Internet latency estimation. While most of the focus has been put on how to distort Triangle Inequality Violation (TIV) in metric spaces to relieve the inaccuracy caused by it, TIV is a persistently and widely existing phenomenon on the Internet and thus should be embraced by future NC systems rather than being eliminated. Besides high accuracy, such an NC system can also provide the benefit of reducing the data transmission time by use of proper relay routes. With that in mind, we design an NC system with a hierarchical architecture, which is motivated by the natural idea of partitioning the three TIV links into different autonomous NC systems, in order to make as many as TIVs inherently embeddable in metric space. We implement and deploy our work, named Toread, on real Internet. Evaluation results show that Toread 's metric space can well characterize more than 60% TIVs, thus Toread is highly accurate (0.54 in Toread versus 1.06 in Pyxida at 90th percentile Relative Error) and effective in searching detour paths (succeeds in 58.2% cases).
Toread_ReArch10.pdf [372.8 kB]
Unbiased Sampling in Directed Social Graph ,
Tianyi Wang, Yang Chen , Zengbin Zhang, Peng Sun, Beixing Deng, Xing Li, ACM SIGCOMM Computer Communication Review, Volume 40, Issue 4, Pages 401-402,
ACM, October 2010.
Read abstract
Microblogging services, such as Twitter, are among the most important online social networks(OSNs). Different from OSNs such as Facebook, the topology of microblogging service is
a directed graph instead of an undirected graph. Recently, due to the explosive increase of population size, graph sampling has started to play a critical role in measurement and characterization studies of such OSNs. However, previous studies have only focused on the unbiased sampling of undirected social graphs. In this paper, we study the unbiased sampling algorithm for directed social graphs. Based on the traditional Metropolis-Hasting Random Walk (MHRW) algorithm, we propose an unbiased sampling method for directed social graphs(USDSG). Using this method, we get the first, to the best of our knowledge, unbiased sample of directed social graphs. Through extensive experiments comparing with the ‘ground truth’ (UNI, obtained through uniform sampling of directed graph nodes), we show that our method can achieve excellent performance in directed graph sampling and the error to UNI is less than 10%.
SocialGraph_sigcomm10.pdf [58.3 kB]
Twittering by Cuckoo -- Decentralized and Socio-Aware Online Microblogging Services ,
Tianyin Xu , Yang Chen , Xiaoming Fu , Pan Hui, ACM SIGCOMM Computer Communication Review, Volume 40, Issue 4, Pages 473-474,
ACM, October 2010.
Read abstract
Online microblogging services, as exemplified by Twitter, have become immensely popular during the latest years. However, current microblogging systems severely suffer from performance bottlenecks and malicious attacks due to the centralized architecture. Thus, centralized microblogging systems may threaten the scalability, reliability as well as availability of the offered services, not to mention
the high operational and maintenance cost.
This demo presents a decentralized, socio-aware microblogging system named Cuckoo. The key aspects of Cuckoo’s design is to take advantage of the inherent social relations while leveraging peer-to-peer (P2P) techniques in order to provide scalable, reliable microblogging services. The demo will show these aspects of Cuckoo and provide insights on the performance gain that decentralization and socioawareness can bring for microblogging systems.
Cuckoo_sigcomm10.pdf [257.5 kB]
Improving Prediction Accuracy of Matrix Factorization Based Network Coordinate Systems ,
Yang Chen , Peng Sun, Xiaoming Fu , and Tianyin Xu , IEEE ICCCN 2010 Track on Multimedia and Peer-to-Peer Networking (MP2P),
IEEE, August 2010.
Read abstract
Network Coordinate (NC) systems provide a lightweight and useful way for scalable Internet distance prediction while serving as an important component in many Peer-to-Peer applications. Most of the existing NC systems utilize the Euclidean distance model, which is largely impaired by the persistent occurrence of Triangle Inequality Violation (TIV) in the Internet. Recently, matrix factorization (MF) based NC systems, which can completely remove the TIV constraint, provide an alternative approach towards better prediction accuracy. Phoenix, an NC system based on the MF model, well explores the advantage of the MF model and becomes the most accurate NC system so far. However, through experimental study, we find that the prediction accuracy of Phoenix for short links is significantly worse compared with the overall prediction accuracy. Based on the observation, we propose a new NC system, named Pancake, aiming at reducing the high prediction error for short links. By introducing a two-level architecture, Pancake achieves much higher prediction accuracy than other selected existing NC systems. Through extensive experiments, we demonstrate that Pancake reduces the 90th percentile relative error by up to 25.37% from Phoenix. Moreover, Pancake converges very fast and is robust to different dimension values. For further insights, we study the performance of Pancake using a dynamic data set in addition to the widely used aggregate data sets. With varying RTTs over time, Pancake outperforms other NC systems consistently.
Pancake_ICCCN10.pdf [269.1 kB]
Towards Decentralized, Socio-Aware Online Microblogging Services and Data Measurement ,
Tianyin Xu , Yang Chen , Jin Zhao , and Xiaoming Fu , In Proc. ACM MobiSys 2010 HotPlanet Workshop,
ACM, June 2010.
Read abstract
Online microblogging services, as exemplified by Twitter and Yammer, have become immensely popular during the latest three years. Twitter, the most successful microblogging service, has attracted more than 41.7 million users as of July 2009 and is still growing fast. However,
current microblogging systems severely suffer from performance bottlenecks and central points of failure due to their centralized architecture. Thus, centralized microblogging systems may threaten the scalability, reliability, as well as availability of the offered services, not to mention the extremely high operational and maintenance cost.
However, it is not trivial to decentralize microblogging services in a peer-to-peer fashion. The challenges first derive from the heterogeneity of the inherent online social network (OSN) features. The non-reciprocation feature of microblogging services also increases the heterogeneity. Moreover, different from traditional approaches used in centralized server based systems, an efficient, robust and scalable approach for data collection and dissemination in such distributed heterogeneous environments is desirable.
In this paper, we present a decentralized, socio-aware microblogging system named Cuckoo. The design takes advantages of the inherent social relationships while leverages P2P techniques towards scalable, reliable microblogging services. Besides, Cuckoo provides a flexible interface for data collection while circumventing unnecessary traffic on the server. We discuss the benefits that our system may bring for both service providers and end users. We also discuss the technical aspects to be considered and report our work in progress.
Cuckoo_Hotplanet10.pdf [223.9 kB]
Rigel: A Scalable and Lightweight replica selection Service for Replicated Distributed File System ,
Yuan Lin, Yang Chen , Guodong Wang, Beixing Deng, Proc. of the 10th IEEE/ACM International Symposium on Cluster, Cloud and Grid Computing (CCGrid'10),
May 2010.
Network congestion estimation using packet time series analysis ,
Lin Cong, Guohan Lu, Yang Chen , Beixing Deng, Xing Li, IET Communications, 4(8):980-989,
May 2010.
NC-APT: An Efficient and Scalable Download Mirror Selecting System ,
Yibo Zhu, Yang Chen , Guodong Wang, Beixing Deng, Xing Li., Proc. of the 29th IEEE Conference on Computer Communications (INFOCOM'10) Student Workshop,
March 2010.
Read abstract
When large files are offered by many mirrors for clients to download, selecting the proper download mirrors is necessary in speeding up the clients’ download. The existing method, which measures all the Round Trip Time (RTT) between clients and all mirrors, costs much time and Internet traffic. In this paper, we propose NC-APT, an efficient and scalable download mirror selecting system, which is capable to provide clients an efficient method to select quick download mirror. NC-APT is scalable because it only requires the mirrors to response to ICMP ping instead of keeping running an NC software program. Our experimental results show that NC-APT significantly improves the clients’ download rates with slight cost of time and Internet traffic.
NCAPT_INFOCOM10SW.pdf [123.2 kB]
Dimension Reduction of Network Bottleneck Bandwidth Data Space ,
Peng Sun, Yang Chen , Yibo Zhu, Xiaoming Fu , Beixing Deng, Xing Li, Proc. of the 29th IEEE Conference on Computer Communications (INFOCOM'10) Student Workshop,
March 2010.
Read abstract
The network proximity metrics, such as bottleneck
bandwidth and round-trip time, are very useful in different
network applications. The round-trip-time prediction has been studied extensively. However, the prediction of bottleneck bandwidth has received much less attention. Therefore, we attempt to design a new bottleneck bandwidth prediction system by matrix factorization. As a first step, we focus on the dimension reduction of network bottleneck bandwidth data space in this paper. Evaluation is carried out based on real-world bottleneck bandwidth datasets, which are collected in the past three months. The results show that a 250D data space can be compressed to 10D and the average median-relative-error is only 8.65%. Although preliminary, our work provides some insights into the
design direction towards matrix factorization based distributed system to predict the bottleneck bandwidth.
BW_INFOCOM10SW.pdf [77.7 kB]
2009
What Level of Estimating Accuracy Does TCP Need and Can TCP Achieve ,
Lin Cong, Guohan Lu, Yang Chen , Beixing Deng, Xing Li, Poster session of the 5th ACM International Conference on emerging Networking EXperiments and Technologies (CoNEXT 2009), Rome, Italy,
December 2009.
Neighbor Selection Based on TIV Severity Sort Model in Vivaldi Network Coordinate System ,
Peng Sun, Yang Chen , Beixing Deng, Xing Li, 17th IEEE International Conference on Network Protocols (ICNP 2009) Poster Session,
Princeton, New Jersey, USA, October 2009.
Read abstract
Network Coordinate (NC) system is an efficient and
scalable mechanism to estimate the distance between Internet
hosts. However, the existence of Triangle Inequality Violation
(TIV) decreases the accuracy of NC system. With focus on
most widely used NC system, Vivaldi, we propose an effective
mechanism of neighbor selection based on TIV Severity Sort to
improve Vivaldi performance. By sorting existing hosts based on
corresponding edges’ TIV severity, the 90th percentile relative
error(NPRE) of Vivaldi is decreased by 13.9%. The convergence
rate is improved, and the final median prediction error is 7.9%
smaller.
ICNP_SunPeng.pdf [171.3 kB]
Understand the Unfairness of BitTorrent ,
Zengbin Zhang, Yao Li, Yang Chen , Pei Cao, Beixing Deng, Xing Li, In the Poster session of ACM SIGCOMM 2009 (SIGCOMM'09),
August 2009.
Read abstract
BitTorrent (BT) is the most popular P2P file-sharing application. Its tit-for-tat mechanism aims to guarantee the efficiency and fairness of sharing. However, while BT’s download efficiency has been proven, we find that the current protocol suffers seriously from unfairness, in the sense that
certain peers will always serve as Super Peers. In this paper, we report on experiments conducted to pinpoint the cause of unfairness. The results indicate that the occurrence of Super Peer has a strong correlation with the bandwidth between
the initial seed and the peer, and a weak correlation with the start time of the peer.
BT_SIGCOMM09.pdf [68.7 kB]
Phoenix: Towards an Accurate, Practical and Decentralized Network Coordinate System ,
Yang Chen , Xiao Wang, Xiaoxiao Song, Eng Keong Lua, Cong Shi, Beixing Deng, Xing Li, In Proc. of 8th International IFIP-TC6 Networking Conference (Networking 2009),
May 2009.
Read abstract
Network coordinate (NC) system allows efficient Internet distance prediction with scalable measurements. Most of the NC systems are based on embedding hosts into a low dimensional Euclidean space. Unfortunately, the accuracy of predicted distances is largely hurt by the persistent occurrence of Triangle Inequality Violation (TIV) in measured Internet distances. IDES is a dot product based NC system which can tolerate the constraints of TIVs. However, it cannot guarantee the predicted
distance non-negative and its prediction accuracy is close to the Euclidean distance based NC systems. In this paper, we propose Phoenix, an accurate, practical and decentralized NC system. It adopts a weighted model adjustment to achieve better prediction accuracy while it ensures the predicted distances to be positive and usable. Our extensive Internet trace based simulation shows that Phoenix can achieve higher prediction accuracy than other representative NC systems. Furthermore, Phoenix
has fast convergence and robustness over measurement anomalies.
Networking09_Phoenix.pdf [2929.9 kB]
Pharos: Accurate and Decentralised Network Coordinate System ,
Yang Chen , Yongqiang Xiong, Xiaohui Shi, Jiwen Zhu, Beixing Deng, Xing Li, IET Communications, 539-548,
April 2009.
Read abstract
Network coordinates (NC) system is an efficient mechanism for Internet distance prediction with scalable measurements. The intrinsical cause for the unsatisfactory accuracy of the simulation-based NC algorithms has been identified. Then Pharos, a fully decentralised and hierarchical scheme, is proposed to solve this problem. Pharos leverages multiple coordinate sets at different distance scales, with the right scale
being chosen for prediction each time. We evaluate the performance of Pharos system with the King data set and latency data from PlanetLab, and compare it with the representative NC system, Vivaldi. The experimental results show that Pharos greatly outperforms Vivaldi in Internet distance prediction without adding any significant overhead. Our extensive evaluation results also demonstrate that Pharos can significantly improve
the performance in distributed Internet applications, such as overlay multicast and server selection.
IET_Pharos.pdf [546.4 kB]
