Hi Wang, If you want to use a faster algorithm than a DHT, you can use a membership protocol to have a single search hop. But in an high churn environment, the overhead can be high.
You could have a look to Census for a very scalable membership protocol: http://www.pmg.csail.mit.edu/pubs/census-usenix09-abstract.html Florent Weber 2009/6/9 Wang Danqi <beyond...@gmail.com>: > Hi Kazuyuki, > > Thank you for your reply. I'd agree with you after I investigated a couple > of papers. Your paper is very interesting and helpful. As presented in your > paper, Chord, Pastry and Kademlia can be enhance to be very good in dealing > peer churn. I also learned that the search hops could be well bounded, from > both my simulation an other papers. > > I am doing same work to provide good content discovery service for P2P VoD > systems. It seems that the industry, for example, PPLive in China, prefer to > use centralized server-assisted approach to accomplish this task. I think > the reason they don't use DHT is not because DHT is poor, but because DHT is > complicated to implement and debug in real world, especially in such kind of > latency intensive systems for comecial use. > > Now I doubt whether it is possible to come up with a content discovery > algorithm that is faster and more robust than DHT, as the search hops of DHT > is so well bounded, less than 4 with 10000 nodes in my simulation. Do you > have any comments on this? > > I appreciate all your help. > > On Tue, Jun 9, 2009 at 12:18 AM, Kazuyuki Shudo <2...@shudo.net> wrote: >> >> Hi Wang, >> >> My results with Chord, Pastry and Kademlia are shown in this paper >> (draft): >> >> "Churn Tolerance Improvement Techniques in an Algorithm-neutral DHT" >> >> http://www.shudo.net/publications/AIMS-2009-churn-resilience/shudo-AIMS-2009-churn-resilience.pdf >> >> The results are heavily dependent on the parameters of each routing >> algorithms as you pointed out. It is difficult to derive general rules >> but my feeling is that Chord with proper parameters is not so weak in >> churn compared with Kademlia. It's just feeling. >> >> Kazuyuki Shudo 2...@shudo.net http://www.shudo.net/ >> >> >> > Message-ID: >> > <60b162860906072311l7942bc80qf8540f8751acb...@mail.gmail.com> >> > From: Wang Danqi <beyond...@gmail.com> >> > Date: Mon, 8 Jun 2009 14:11:08 +0800 >> >> > Hi all, >> > >> > I have implemented both Chord and Kademlia in my simulator according to >> > the >> > Chord paper in Sigcomm'01 and Kademlia paper in IPTPS'02 respectively. I >> > ran >> > a simulation with 1000 nodes and 1000 keys. The user arrival pattern >> > follows >> > a Poisson distribution and the lifespan is exponentially distributed. >> > 1000 >> > queries are generated for each key after every node gets online. >> > However, I >> > found the results from the two designs are significantly different. >> > Chord >> > performs much worse than Kademlia in terms of the fraction of successful >> > queries, and it highly relies on the routing table refresh interval. Do >> > you >> > have any experience like this? I doubt whether Chord is so poor or I >> > made >> > some mistake in implementation. >> > >> > Thank you so much for your help. >> > >> > >> > -- >> > Best wishes, >> > >> > Wang Danqi >> _______________________________________________ >> p2p-hackers mailing list >> p2p-hackers@lists.zooko.com >> http://lists.zooko.com/mailman/listinfo/p2p-hackers > > > > -- > Best wishes, > > Wang Danqi > > _______________________________________________ > p2p-hackers mailing list > p2p-hackers@lists.zooko.com > http://lists.zooko.com/mailman/listinfo/p2p-hackers > > _______________________________________________ p2p-hackers mailing list p2p-hackers@lists.zooko.com http://lists.zooko.com/mailman/listinfo/p2p-hackers
