Re: Mesh linking - technical (Was: Re: [Unreal-users] Planned features for 3.3?)

[Saturn, t. b. of o. a. <sa...@su...>]

On Sun, 2005-06-19 at 17:01 -0400, tabris wrote:
> On Sunday 19 June 2005 11:02 am, Bram Matthys (Syzop) wrote:
> > Basically the problem is sequencing and difference in lag.
> > Example:
> > - a mesh network ABC where all nodes are connected to each other.
> > - A<->B has 0.1s of lag
> > - A<->C has 0.5s of lag.
> > - B<->C has 0.1s of lag (irrelevant in this example)
> >
> > [SERVER A] User a connects to this server and joins #chan
> > [SERVER B] Got this message from server A, a user on this server
> > sends a 'MODE #chan +v a' (say, an autovoice bot).
> > [SERVER C] Server C still hasn't received the message from A yet, but
> > does get the 'MODE #chan +v a', however 'a' does not exist, hence
> > this mode is ignored.=20
> > [SERVER C] Server C gets the connect+join message from server A.

There are a couple ways to deal with this, one off the top of my head
is: each server has its own sequence number that gets incremented every
time it sends a line. Then when something that depends on previous state
happens it refers to this number. So you get something like:

Server A user connects then joins the channel on line number 500
Server B sends the mode command with its own line number but also refers
  back to line number 500 from server A
Server C stores the mode command until it receives line number 500
  from server A, then processes it.

Please CC me as I'm not subscribed to the list.