On Mar 2, 2:35 am, Michael K <[email protected]> wrote: > On Feb 28, 3:54 am, Daniel Paull <[email protected]> wrote: > > Please excuse my ignorance, but why can't the client treat those "3rd > party" deltas, after transforming them locally, the same way as it > treats its own? If the server and client can agree on an earlier state > S(0), the client has all the information needed to move from S(0) to > the current state S(t). I don't see why this information cannot be > resubmitted to the server. > > Can you give an example where this will not work?
The problem will be shown up when work is done before all clients have reconnected to the server. For example: 1) The server goes down at version 20 and comes back up at version 10. 2) Some clients reconnect to the server and the server gets some operations back from the clients - let's say it is now at version 15. 3) Work is then done and the wave is now at, say, version 30. 4) A client connects and is at version 17 - what does it do with the two operations it has that the server is missing? Let's say that it sends them to the server as if it was work that it did, so the server accepts the operations, transforms them and broadcast them to other clients. These ops are now 31st and 32nd in the servers list of operations. 5) Another client connects and is at version 18. What is the server going to do here? It has to be careful not to send the 31st and send operations to this client, but it must send operations 17 through 30. The client has to send the missing operation (op 18) to the server. If the server and client did (5), then Wave's rules for the ordering of operations has been broken. I expect that there is a scenario out there that would result in divergence amongst the clients. Such a case would emulate a TP2 puzzle and show that one client ends up with the wrong state. Cheers, Dan -- You received this message because you are subscribed to the Google Groups "Wave Protocol" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/wave-protocol?hl=en.
