Daniel Stutzbach wrote: > I think the key difference is how the search/lookup is conducted, and > not the structure of the graph. If you use flooding over a DHT, the > DHT will be just as resilient. The resiliency difficulties of DHTs > are result of wanting the additional constraint that you need the > DHT-style lookup to go to one particular node. There really isn't any > risk of the graph fragmenting into tiny pieces.
The point with the type of networks discussed earlier in this thread (which do not fall into the category of structured DHT nor flooding an unstructured network) is that they offer a middle-ground. Look-ups are routed queries, but they need not necessarily go to one particular node (there only needs to be a high probability that two queries for the same thing will intersect), and nodes do not have any "canonical neighbors" (*) in the graph. Also, because the network is formed dynamically from the normal procedure of routing, no special join or leave procedures are necessary. Structured DHT networks are brittle. If a Chord node, for instance, for some reason thinks that a node on the other side of the ring is actually its closest neighbor, bad things will happen, and in theory it could cause the whole network to degenerate. Similar scenarios are possible for other structured DHTs. The randomly-structured (in lack of a better word) small-world networks OTOH can live through a complete netsplit and just keep ticking, without any special adjustment needing to made. // oskar (*) By canonical neighbor I mean a neighbor that the node must know based on their respective IDs. _______________________________________________ p2p-hackers mailing list p2p-hackers@zgp.org http://zgp.org/mailman/listinfo/p2p-hackers _______________________________________________ Here is a web page listing P2P Conferences: http://www.neurogrid.net/twiki/bin/view/Main/PeerToPeerConferences
