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@???
Freenet Project Official Codemonkey - http://freenetproject.org/
ICTHUS - Nothing is impossible. Our Boss says so.
