[Nel] Suggestion for the NeL network library / architecture

[Vincent Archer]

According to MIGUEL ANGEL BLANCH LARDIN:
> Just imagine that both copies of a object multicast different 
> positions, you have to choose what is the best one, and whatever your 
> choose is, it will be wrong, and servers can't be wrong.

Ahem, no. I might have used object and agent in various contexts, but
an agent is the only one which is authorised to change its state. The
other objects are "replica", or passive objects. Each agent may exist
only as a single copy over the set of processes, and he is the entity
responsible for updating the local states of the replica objects in
the other processes.

If you want "what is your XYZ", the local replica answers. However, if
you want "teleport to XYZ", the message is transmitted across the network
to the unique agent, which updates its internal state, and then retransmits
to all replicas "set internal state XYZ". And the latter is when multicast
helps when there are many replicas to update.

> Replycating work can be a real pain.

Hey, if I could buy a terahertz processor and have everything run on a
single process, I'd be happy too :)

-- 
Vincent Archer                                         Email: archer@nevrax.com

Nevrax France.                              Off on the yellow brick road we go!