git clone git://github.com/dcramer/django-idmapper.git



Every document (forum message) forms two overlaying networks of nodes
that has a copy of that document. The networks are connected graphs,
and one of them is a strict subnetwork of the other one. The smaller
one is the "subscribing" set. Nodes in the subscribing set gets copies
of all comments to the document. The protocol is push-based: When you
have a peer that is subscribed to a document you have, and you have a
comment to that document, you send that comment to the peer. The
protocol attempts to keep the network for a document a connected graph
by allways electing a "root node" among themselves, and keeping track
of their distances from that root node. This way, no closed,
disconnected circles can form (circles can still form, bur they'r
obvious). This means that a document is only present on the nodes
actually interested in that particular document. It is a bit like what
NNTP would be, where nodes subscribe to newsgroups, if every message
had its own newsgroup.

Node A only pushes comments to document x to B if A and B share
document x. Every node should probably have a max-peers-per-document
setting to keep the branching level reasonable. For two nodes to
initiate contact, they both need to know a third node, and share the
same document with that third node. For eaxmple a "root document"

Every "virtual forum" consist of a root document, and you have to have
its id, and the address of a peer that also has it, to initiate
contact / usage of that forum. Every document (forum message) linked
from teh root, or from documents linked from the root (and so on)
forms its own network, and the original peer with the root document
need not be part of every such network.

You install i2p and cliqueclique on your machine, then go to
localhost:whatever in your browser. You enter a peer address and forum
root document id You _can_ of course run a node publicly as a website
too

My current django code supports multiple nodes in one installation,
each node connected to a django user object It's a rather simple idea
really. Only drawback I can think of is overhead :S


Algorithms
===========

Metadata sync
--------------


Node1 (server)
---------------
Data:
 local: Its own data
 serial: Version of its data
 serialcopy: copy of the other nodes' copy of its own serial
 time=1

When local changes:
  serial += 1
  time = 1

While serial != serialcopy:
  Send (local, serial) to other node
  Wait time
  time *= 2

When receiving:
  if received.serial == serial:
    serialcopy = serial
     

Node2 (client)
---------------
Data
  peer: a copy of the other nodes' data
  peerserial: copy of the other nodes' serial

When receiving:
  Copy received.local to peer
  Send received.serial back to other node



Metadata deletion
------------------


Node1 (server)
---------------
Data:
 local: Its own data

While local exists:
 Send delete request to other node

When receiving:
 Delete local


Node2 (client)
---------------
Data
  peer: a copy of the other nodes' data

When receiving:
 Delete peer
 Send ACK to peer