On Tue, Sep 27, 2005 at 09:37:46PM +0100, Matthew Toseland wrote: > One more detail: > > HTL should be reset, or decremented, when we receive the message, NOT > when we send the request to another node. > > It might be argued that RNF should contain a nearestLoc as well as an > HTL. I don't think this is profitable, on the grounds that if it does > find a closer node, it is probably a false minima - a node which is not > in the right place and randomly ended up with a location close to this > request's target. Loop protection means that not including a nearest > location on RNFs does not necessarily cause lots of extra hops.
Actually, I'm not convinced of that.. False minima can occur anywhere, and will often cause the request to fail. So maybe RNF should have a location? It would be most consistent that way, and would avoid excess extra hops... > > If we get a loop, we decrement the HTL. If we get an RNF, the HTL will > be min(HTL-1, RNF.HTL). > > On Fri, Sep 23, 2005 at 02:58:51PM +0100, Matthew Toseland wrote: > > Ian and I have agreed to a further change to the HTL mechanism in 0.7, > > to solve a few problems: > > > > HTL starts off at the maximum value. > > A request carries the value of the closest location so far seen to the key. > > When we find a node which is closer than this, we update the location on > > the request, *and we reset the HTL to the maximum value*. > > If we go through a node which is not closer than the closest-so-far, we > > decrement the HTL. > > If the HTL reaches 0, we send back a DataNotFound. > > If we cannot find any more nodes, we send back a RouteNotFound. > > > > Max HTL can then be as low as 5. > > > > There remain probabilistic decrement at maximum and minimum values of > > HTL. > > > > For a subscription request, if we get a DNF and we have reset the > > closest location, we know we are the closest location to the key, within > > max HTL hops, therefore we are the root. > > -- > > Matthew J Toseland - toad at amphibian.dyndns.org > > Freenet Project Official Codemonkey - http://freenetproject.org/ > > ICTHUS - Nothing is impossible. Our Boss says so. > > > > > _______________________________________________ > > Tech mailing list > > Tech at freenetproject.org > > http://dodo.freenetproject.org/cgi-bin/mailman/listinfo/tech > > -- > Matthew J Toseland - toad at amphibian.dyndns.org > Freenet Project Official Codemonkey - http://freenetproject.org/ > ICTHUS - Nothing is impossible. Our Boss says so. > _______________________________________________ > Tech mailing list > Tech at freenetproject.org > http://dodo.freenetproject.org/cgi-bin/mailman/listinfo/tech -- Matthew J Toseland - toad at amphibian.dyndns.org Freenet Project Official Codemonkey - http://freenetproject.org/ ICTHUS - Nothing is impossible. Our Boss says so. -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 189 bytes Desc: Digital signature URL: <https://emu.freenetproject.org/pipermail/tech/attachments/20050927/025445c5/attachment.pgp>
