网络仿真软件

网络仿真工具，很多商业网络公司用来模拟网络情况改变后的网络情况，以预计网络的效率和性能。一些新的协议也可用通过这些工具来确定新的协议是否有效。

• opnet 这个可能是商业化程度最好的网络仿真软件了
  

• Omnet++ 学术研究和非盈利使用是可以Free享用的。如果用作商业用途，则需要购买License
  

• NS2 开源社区使用的最多的一个仿真器。这个列表收集了很多和NS2相关的资料
  

下面列出的是一些生成网络拓扑的工具

• inet 基于幂律的PLGR算法。大量利用了BGP的数据来产生相关参数，生成的拓扑图可信度很高。很多文章都使用这个工具来生成网络拓扑。
  

• Brite 可惜这个工具不再被开发者发展了。Brite能够实现Waxman、基于幂律的BA算法和基于层次模型的GT-ITM算法。代码是用java写的。
  

关于网络拓扑的一些文章

• A Basis for Systematic Analysis of Network Topologies. Priya Mahadevan, Dmitri Krioukov, Kevin Fall, Amin Vahdat. SIGCOMM 2006. 这篇文章还没有怎么看，而且文章也只能在预印版文库里面下载。

• Internet测量与分析综. 张宏莉, 方滨兴, 胡铭曾, 姜 誉, 詹春艳, 张树峰.软件学报 2003

• Internet拓扑建模综述.张宇, 张宏莉, 方滨兴. 计算机学报2004
  

CAIDA 这个是internet网络分析和研究的大本营了。上面的论文和数据都很多。

blogspot可以用了

忽然在论坛上面发现blogspot可以使用了。试了一下，果然可以，而且也不用在hosts文件里面加什么就可以用beta.blogger.com。不过论坛上面的人还说，还是不要声张的好，因为不知道什么时候就不可以用了。而且还有可能只是一个错误呢。这些时间，差点把我活活逼成一个愤青。

我想起我曾经认识的一个女孩，她看上次中国女排的奥运会决赛，觉得自己在电视机前的时候，女排老是失误，而只要自己稍微离开一会儿，女排姑娘们就得分了。后来情况危急的时候，她便决定自己躲进屋子里，不看了，在屋子里默默的听着，直到听到她爸爸的欢呼，她才出来。心里特别高兴。

人们的心情何其相似。

ps.这几天被Ubuntu Edgy 上教育网直通车的问题搞疯了，没有什么时间来blog，希望可以早点儿搞定。刚买不久的鼠标又坏了，郁闷。下次一定买个好点儿的，用个几年。

纳什在得奖时候的演讲词（电影：美丽心灵）

......I've always believed in numbers and the equations and logics that lead to reason.But after a life time of such pursuits,I ask,"What truly is logic? Who decides reason?" My quest has taken me through the physical, the metaphysical, the delusional -- and back.

And I have made the most important discovery of my career, the most important discovery of my life:It is only in the mysterious equations of love that any logic or reasons can be found. I'm only here tonight because of you.

You are the reason I am. You are all my reasons.

DHT Read List

希迁注：The original list copied from this page. I read some of the papers in this list and so want to give some notes on them. I also add some links and content to the list. It is really a good habit to collect literature in a list.

CAN (Content-Addressable Network)

• A Scalable Content-Addressable Network. Sylvia Ratnasamy (University of California at
  Berkeley and ACIRI), Paul Francis (Tahoe Networks), Mark Handley (ACIRI), Richard Karp (U.C. Berkeley and ACIRI), Scott Shenker (ACIRI) 这篇文章发表在sigcomm2001上，介绍了CAN的概念。CAN后继的文章不多，这一篇和后面Chord的一篇都是出现在sigcomm2001上。

Chord

• Analysis of the Evolution of Peer-to-Peer Systems. Liben-Nowell, D.; Balakrishnan, H. and Karger, D. In this paper, a theoretical analysis of peer-to-peer networks operating in the face of concurrent joins and unexpected departures is given.

• Serving DNS using a Peer-to-Peer Lookup Service. Cox, R.; Muthitacharoen, A. and Morris, R.T. The DNS security extensions (DNSSEC) allow verification of records obtained by alternate means, opening exploration of alternative storage systems for DNS records. We explore one alternative using DHash, a peer-to-peer distributed hash table built on top of Chord.

• Observations on the Dynamic Evolution of Peer-to-Peer Networks. Liben-Nowell, D.; Balakrishnan, H. and Karger, D. A fundamental challenge in peer-to-peer systems is proving statements about the evolution of the system while nodes are continuously joining and leaving.

• Security Considerations for Peer-to-Peer Distributed Hash Tables. Sit, E. and Morris, R.T. This paper looks at what sorts of security problems are inherent in large peer-to-peer systems based on distributed hash lookup systems.

• Wide-area cooperative storage with CFS. Dabek, F.; Kaashoek M.F.; Karger, D.; et al. The Cooperative File System (CFS) is a new peer-to-peer read-only storage system that provides provable guarantees for the efficiency, robustness, and load-balance of file storage and retrieval.

• Chord: A Scalable Peer-to-peer Lookup Service for Internet Applications. Stoica, I.; Morris, R.; Karger, D.; et al. A fundamental problem that confronts peer-to-peer applications is to efficiently locate the node that stores a particular data item. This paper presents Chord, a distributed lookup protocol that addresses this problem.

• Building Peer-to-Peer Systems with Chord, a Distributed Lookup Service. Dabek, F.; Brunskill, E.; Kaashoek, M.F.; et al. The core problem facing peer-to-peer systems is locating documents in a decentralized network and propose Chord, a distributed lookup primitive. Chord provides an efficient method of locating documents while placing few constraints on the applications that use it.

• The Circle

  The Circle: one ring, no rulers. The Circle is an open source scalable decentralized peer-to-peer application. The Circle is written in Python and it runs on Linux and Windows. At the core of the Circle is a decentralized hash table, or "Chord". Very interesting PDF slides available here.

Pastry, Scribe, PAST, ...
Pastry

• Security for structured peer-to-peer overlay networks. Castro, M.; Druschel, P.; Ganesh, A.; et al. Current overlays are not secure; even a small fraction of malicious nodes can prevent correct message delivery throughout the overlay. This paper studies attacks aimed to preventing correct message delivery in structured peer-to-peer overlays and presents defenses to these attacks.
  

• One ring to rule them all: Service discovery and binding in structured peer-to-peer overlay networks. Castro, M.; Druschel, P.; Kermarrec, A.M.; et al. One major problem with existent DHT systems is how to bootstrap them. In this position paper, the design of an infrastructure that uses a universal overlay to provide scalable infrastructure to bootstrap multiple service overlays is sketched.

• Pastry: Scalable, distributed object location and routing for large-scale peer-to-peer systems. Rowstron, A. and Druschel, P. This paper presents the design and evaluation of Pastry, a scalable, distributed object location and routing substrate for wide-area peer-to-peer applications.

• Scalable Application-level Anycast for Highly Dynamic Groups. Castro, M.; Druschel, P.; Kermarrec, A.M.; et al. An application-level implementation of anycast for highly dynamic groups is presented.

Scribe

• An Evaluation of Scalable Application-level Multicast Built Using Peer-to-peer overlays. Castro, M; Jones, M.B.; Kermarrec, A.M.; et al. This paper reports the first head-to-head comparison of CAN-style versus Pastry-style overlay networks, using multicast communication workloads running on an identical simulation infrastructure.
  

• Scribe: A large-scale and decentralised application-level multicast infrastructure. Castro, M.; Druschel, P.; Kermarrec, A.M. This paper presents Scribe, a scalable application-level multicast infrastructure. Scribe supports large numbers of groups, with potentially large numbers of members per group.

PAST

• PAST: A large-scale, persistent peer-to-peer storage utility. Druschel, P. and Rowstron, A. This paper sketches the design of PAST, a large-scale, Internet-based, global storage utility that provides scalability, high availability, persistence and security.

SplitStream

• SplitStream: High-bandwidth multicast in a cooperative environment. Castro, M.; Druschel, P; Kermarrec, A.M.; et al. In tree-based multicast systems, a relatively small number of interior nodes carry the load of forwarding multicast messages. This works well when the interior nodes are highlyavailable, dedicated infrastructure routers but it poses a problem for application-level multicast in peer-to-peer systems. SplitStream addresses this problem by striping the content across a forest of interior-node-disjoint multicast trees that distributes the forwarding load among all participating peers.

Tapestry, Bayeux, OceanStore, ...
Tapestry

• Optimizations for Locality-Aware Structured Peer-to-Peer Overlays. Stribling, J.; Hildrum, K. and Kubiatowicz, J. Several optimizations aimed at improving the object location performance of locality-aware structured peer-to-peer overlays are presented.

• Exploiting Routing Redundancy via Structured Peer-to-Peer Overlays. Zhao, B.Y.; Huang, L.; Stribling, J.; et al. In this paper, we present two adaptive mechanisms for structured overlays and illustrate their operation in the context of Tapestry, a fault-resilient overlay from Berkeley. We also describe a transparent, protocol-independent traffic redirection mechanism that tunnels legacy application traffic through overlays.

• Tapestry: A Resilient Global-scale Overlay for Service Deployment. Zhao, B.Y.; Huang, L; Stribling, J.; et al. We present Tapestry, a peer-to-peer overlay routing infrastructure offering efficient, scalable, location-independent routing of messages directly to nearby copies of an object or service using only localized resources.

• Distributed Object Location in a Dynamic Network. Hildrum, K.; Kubiatowicz, J.D.; Rao, S.; et al. A new distributed algorithm that can solve the nearest-neighbor problem for certain network topologies is presented.

• Tapestry: An Infrastructure for Fault-tolerant Wide-area Location and Routing. Zhao, B.Y.; Kubiatowicz, J. and Joseph, A. Tapestry is an overlay location and routing infrastructure that provides location-independent routing of messages directly to the closest copy of an object or service using only point-to-point links and without centralized resources.

Bayeux

• Bayeux: An Architecture for Scalable and Fault-tolerant Wide-Area Data Dissemination. Zhuang, S.Q.; Zhao, B.Y.; Joseph, A.D.; et al. In this paper, we propose Bayeux, an efficient application-level multicast system that scales to arbitrarily large receiver groups while tolerating failures in routers and network links.

Brocade

• Brocade: landmark routing on overlay networks. Zhao, B.Y.; Duan, Y.; Huang, L.; et al. In this paper, we propose a systemic design for a secondary overlay of super-nodes which can be used to deliver messages directly to the destination's local network, thus improving route efficiency.

OceanStore

• OceanStore: An Architecture for Global-scale Persistent Storage. Kubiatowicz, J.; Bindel, D.; Chen, Y.; et al. OceanStore is a utility infrastructure designed to span the globe and provide continuous access to persistent information. Since this infrastructure is comprised of untrusted servers, data is protected through redundancy and cryptographic techniques. To improve performance, data is allowed to be cached anywhere, anytime.

Storm

• How to use the Tapestry overlay to implement Storm ?. A Tapestry and SEDA overview, including its APIs.

Viceroy

• Viceroy: A Scalable and Dynamic Emulation of the Butterfly. Malkhi, D.; Naor, M. and Ratajczak, D. We propose a family of constant-degree routing networks of logarithmic diameter, with the additional property that the addition or removal of a node to the network requires no global coordination, and only a constant number of linkage changes in expectation, and a logarithmic number with high probability.

Churn

• Handling Churn in a DHT. Sean Rhea, Dennis Geels, Timothy Roscoe, and John Kubiatowicz. Proceedings of the USENIX Annual Technical Conference, June 2004.

Miscellaneous

• Towards a Common API for Structured Peer-to-Peer Overlays. Dabek, F.; Zhao, B.Y.; Druschel, P.; et al. In this paper, we describe an ongoing effort to define common APIs for structured peer-to-peer overlays and the key abstractions that can be built on them. In doing so, we hope to facilitate independent innovation in overlay protocols, services, and applications, to allow direct experimental comparisons, and to encourage application development by third parties.

• Sloppy hashing and self-organizing clusters. Freedman, M.J. and Mazières, D. We are building Coral, a peer-to-peer content distribution system. Coral creates self-organizing clusters of nodes that fetch information from each other to avoid communicating with more distant or heavily-loaded servers.

• Koorde: A simple degree-optimal distributed hash table. Kaashoek, M.F. and Karger, D.R. Koorde1 is a new distributed hash table (DHT) based on Chord and the de Bruijn graphs. While inheriting the simplicity of Chord, Koorde meets various lower bounds, such as O(log n) hops per lookup request with only 2 neighbors per node (where n is the number of nodes in the DHT), and O(log n/ log log n) hops per lookup request with O(log n) neighbors per node

• On Death, Taxes, and the Convergence of Peer-to-Peer and Grid Computing. Foster, I. and Iamnitchi, A.

• Scooped, Again. Ledlie, J.; Shneidman, J.; Seltzer, M; et al. Very interesting paper focusing on the Grid an p2p features.

• SOMO: Self-Organized Metadata Overlay for Resource Management in P2P DHT. Zhang, Z.; Shi, S.M. and Zhu, J. In this paper, we first describe the concept of data overlay, which is a mechanism to implement arbitrary data structure on top of any structured P2P DHT. With this abstraction, we developed a highly scalable, efficient and robust infrastructure, called SOMO, to perform resource management for P2P DHT.

• On the Feasibility of Peer-to-Peer Web Indexing and Search. Li, J.; Loo, B.T.; Hellerstein, J.; et al. This paper discusses the feasibility of peer-to-peer full-text keyword search of the Web.
  

• The Swan Project. Bonsma, E.; Hoile, C. SWAN (Small World Adaptive Networks) is a fully decentralised look-up system for Peer-to-Peer applications. In SWAN, information self-organises into a Small World Network, exploiting the principle of "six degrees of separation" to efficiently find resources without resorting to centralised look-up. The basic technology has been tested and is currently being built into serveral prototype applications, including iAnnotate and iLiftShare.
  

• Efficient Broadcast in Structured P2P Networks. El-Ansary, S.; Alima, L.O.; Brand, P.; et al. In this position paper, we present an efficient algorithm for performing a broadcast operation with minimal cost in structured DHT-based P2P networks.
  

• INS/Twine: A Scalable Peer-to-Peer Architecture for Intentional Resource Discovery. Balazinska, M.; Balakrishnan, H. and Karger, D. This paper describes the design, implementation, and evaluation of INS/Twine, an approach to scalable intentional resource discovery, where resolvers collaborate as peers to distribute resource information and to resolve queries.

• Routing Algorithms for DHTs: Some Open Questions. Ratnasamy, S.; Shenker, S. and Stoica, I.

• Locating Data in (Small-World?) Peer-to-Peer Scientific Collaborations. Iamnitchi, A; Ripeanu, M. and Foster, I.

• Complex Queries in DHT-based Peer-to-Peer Networks. Harren, M.; Hellerstein, J.M.; Huebsch, R; et al. This paper outlines a research agenda for building complex query facilities on top of these DHT-based P2P systems. We describe the issues involved and outline our research plan and current status.
  

• Efficient Peer-to-Peer Lookup Based on a Distributed Trie. Freedman, M.J. and Vingralek, R. Two main approaches have been taken for distributed key/value lookup operations in peer-to-peer systems: broadcast searches and location-deterministic algorithms. We describe a third alternative based on a distributed trie. This algorithm functions well in a very dynamic, hostile environment, offering security benefits over prior proposals.
  

• A survey of implemented DHT overlays as of July 2003. Created by Hermanni Hyytiälä. Very interesting survey of many existent DHT overlays.

这世界真是疯狂

我一个朋友，在一个大学里面教书，计算机系的。这学期没有排到课，因为大学里面上课是有课酬的，很多老师会有些竞争。不过后来我这个朋友居然阴差阳错又排上课程了。原因是，一个上计算机网络的老师被学生赶下讲台了，因为听不懂。再后来才知道，这个上课的老师原来是哲学系的。后来我朋友笑，说文科的人想象力就是丰富。

这个世界够疯狂吧，这个学校可是一类的大学，按理不该有这样的事情。不过有什么办法，它就在红旗下发生了。天日昭昭，天日昭昭！

以前的一个记录

忽然翻到以前的一个笔记本，那个时候我每天写点我做了什么和打算做什么。摘两条回忆一下：

2004年3月12日 阴

1. 给F写了一封信;
2. 收到W的打印文档;
3. 搞定了开题报告;
4. 收到张的打印文档。

2004年3月16日 晴

上午
Prepare for the MPI PPT（讲计算机体系结构，MPI的通信方式，MPI的数据模式）；

下午
3：30以前准备了实验室机器上网问题。
1. 有几台机器改动IP后无法上网,没有搞定;
2.借投影,开始听组员汇报:
a. T没有到;
b. X和S的PPT表现力不强,细节问题没有讲清楚;
c. J的多数PPT业做的很少,数据库要求自己使用;
d. L的PPT过于复杂,细节要加强;
e. C没有PPT,要求其与J多联系。

6：10-7:40
调试IBM大机器，放上给张的安装文件。

这拳打不下去了

形意拳里面有些劲做不好。心里觉得很矛盾，不知道该如何了。

李文彬和尚芝蓉合著的《形意抉微》里说道“龙身”时这样写：

龙身就是学龙有三折之势。因别的动物在角斗中，如有折身情况，就会因而受伤失力，唯龙身则不然，反因转折腾挪而使身力得展。我们就是要学它这一点。站三体势时，前膝要求向前微挺，后膝要求里扣而使上身也随之转向前方，这样就无法求得裹胯之劲，影响腰部发劲，也使上下肢“三催”之劲不能顺达。因此学习“龙折身”至关重要。当后膝里扣，上身能以反拧而顺胯，形成腰腿的抻拔，使上体成为似正非正，似斜非斜，腰顺劲催，这就是“龙折身”。只因这一折产生裹胯之劲，腰劲得发，腰催胯，使下肢“三催劲”得逞，腰催肩，使上肢的“三催”劲得发。丹田发劲则更可无不如意。

我对裹胯劲始终搞不清楚，以自己的想法，裹胯的劲和意都应该在胯，即大腿和髋骨结合的地方着意，往里收。如果他们说的“后膝里扣”是朝后面用力就可以理解，如果理解为朝另一只腿的方向用力，就很别扭。上个学期就是在这个地方老是搞不对，弄得都不想打了。

郝月如《武式太极拳》中对于裹裆有这样的句子：

何谓裹裆？两膝着力，有内向之意，两腿如一条腿，能分虚实，谓之裹裆。

何解？

现在写blog也变难了

今天起来发现 beta.blogger.com也无法访问了。这样，即使通过inblogs来看我的blog都会显示有些不正常，因为有一些Javascript和图片是在beta.blogger.com上的。我写Blog也变得麻烦得多了，要通过privoxy和Tor（vidalia）绕过国内的防火墙。这样速度很慢，到上传图片的时候就很麻烦。不过这段时间只好如此。默默的等到解封的那一天吧。

这段时间要写论文和看书。不过其实期间有很多东西要记录在Blog上面，好像每天写写已经是一个习惯了。