On Wed, Jun 21, 2006 at 05:17:45PM +0100, Michael Rogers wrote: > Thought experiment: we have three peers: one fast, one medium, one slow. > We answer roughly 1/4 of incoming requests locally, and forward roughly > 1/4 to each peer. How many requests should we accept?
IMHO we should slow down to the speed of the *median* peer - the medium one. An ubernode *must not* cause us to accept too many requests which are then all misrouted to it. However if we have a single peer on a dial-up then it's not unreasonable to route most of the traffic we would have sent to that peer to the next-best peer. > > If we slow down to the speed of the slowest peer and our neighbours do > likewise, the slowest node will determine the speed of the whole > network. Indeed, this is bad. > If we exclude nodes below a certain speed, we waste their > resources and don't offer them anonymity. This is also bad. We don't want to have to require top end broadband for freedom of digital speech! > If we misroute whenever a peer > is busy and run at the speed of the fastest peer, one ubernode can > attract a large share of the network's traffic. Right. > > We need a compromise - a limited degree of misrouting. > > Let's define the imbalance factor i = r_max / r_natural, where r_max is > the maximum rate at which a peer is allowed to accept requests, and > r_natural is the arrival rate of requests that would ideally be routed > to that peer. The value of i determines how much misrouting we will allow. > > Let's say i = 2. In the example above, r_natural is 1/4 for all peers, > so r_max is 1/2, meaning that no peer should be given more than 1/2 of > the requests on average, no matter how many it's willing to accept. This > allows us to run somewhat faster than the slow peer, and our neighbours > can run somewhat faster than us, etc - a few slow peers don't drag down > the whole network. I do think that we should take into account the median ... fewer arbitrary parameters is generally better. i = 2 essentially means we can send up to twice the number of requests to a peer as we ought to, correct? I think this is a bad way of looking at it ... > > Any thoughts? > > Cheers, > Michael -- 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/20060621/54af0192/attachment.pgp>
