Hi Julien, Thanks for your comments! You are right to say that if you use N to mean exact number of nodes in the network at any time, you will move replicas around a lot, and that would really suck! The idea is that N is an estimate of the number of nodes in the network, and there is no need for it to be exact. The value of N is used to guess at a distance between replica IDs such that those replica IDs are 'likely' to be owned by separate nodes. Being out by a few percent is perfectly acceptable. If your estimate of N is way off, you will get bad guesses at this distance, and poor performance.
Of course, there are situations where you get large fluctuations in membership, and you cannot pick a value of single value of N. In these situations, the symmetric placement function may well be a good choice. I have infact added symmetric replication to my analysis, and the results will be available in the journal version of the DAS-P2P paper you mentioned. I hope to make this available on my website real soon now. There will also be a much fuller discussion of these issues in my thesis, which is currently in the final draft stages. In comparison to other placement functions, I have found that the symmetric placement function will offer a reliability similar to successor placement, but with fetch times slightly slower than those offered by finger replication. I hope that answers some of your questions, I'd be glad to hear if you have any more. Matt -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Julien Lociuro Sent: 22 July 2006 11:16 To: theory and practice of decentralized computer networks Subject: RE: [Fwd: [p2p-hackers] Dynamic replication - successor placement] > There was a discussion about this scheme a while back. > There is another paper which described another scheme which was > similar called "Symmetric Replication", which was intended for Chord. > Maybe that paper answers your questions, it seemed kind of independent > of the system size. It can be found here: > > http://dks.sics.se/pub/replication.pdf > > Andersen Hello Andersen, Yes I know about the symmetric replication, wich seems good. But I would like to compare the different schemes. The paper I provided last time does a comparison between different schemes. But there is the question I asked I don't understand and is not referred in the paper. So if someone has an idea, or can resend the discussion about it, it would be great. I can't find it. Thank you very much. Julien. _______________________________________________ p2p-hackers mailing list [email protected] http://lists.zooko.com/mailman/listinfo/p2p-hackers _______________________________________________ p2p-hackers mailing list [email protected] http://lists.zooko.com/mailman/listinfo/p2p-hackers
