On Nov 17, 2009, at 8:12 AM, Richard Kelsey wrote:
From: Roger Alexander <roger.alexander at ekasystems.com>
Date: Mon, 16 Nov 2009 15:33:33 -0800
Not clear why there is a need to know who records DAOs. In
response to
a new child a parent that does maintain state will add itself to the
path information from the child and pass that information to it's
parent. That information will pass inward towards the root until a
node is encountered that can store the path information and
previously
supported connectivity to the node at the same cost.
[nice example of what DAOs need to be sent]
In the first case a single DAO needs to be sent. In the
second case D has to send two DAOs and the nodes in its
subdag, just E here, each need to send one. If only the
root caches DAOs then the first case always applies. If
other nodes may cache DAOs, then we have to assume that we
are in the second case after every move.
I was in the process of creating a similar example. All I'll add is
that, intuitively, the more places state gets "replicated" within
the network, the more costly it is to maintain that state and the
more you have to deal with inconsistencies between replicated
instances. Of course, the hope in replicating this routing state is
that it creates shorter paths and ultimately offsets the cost of
maintaining that state.
I'll have to admit that I'm not yet convinced of the benefits in
storing DAO state as it currently exists in the draft. It seems
like a mediocre attempt to optimize point-to-point routing and
something that folks wanting P2P support aren't satisfied with. If
that is the end-goal, then we should be developing better
mechanisms. For now, we are focusing on one-to-many and many-to-
one. And, I see more benefits to simply maintaining state at the
root.
