[zeromq-dev] Pub/Sub anchoring/keyframing and administrative layers in general

[Pieter Hintjens]

On Sun, Jul 25, 2010 at 10:21 AM, Oliver Smith <oliver at kfs.org> wrote:

> Before a given client can start applying changes, though, it needs the
> most recent snapshot of the overall picture.
>
> My first-hash implementation adds a thread listening on a second socket
> REQ/REP socket, which builds an image of the current snapshot and then
> itself joins the PUB/SUB socket.

You may still get race conditions unless you subscribe at the same
time as you request the snapshot, queue updates, and then apply them
to the snapshot.

Presumably the snapshot is very large compared to the updates?  What
is your strategy for recovering from loss of some updates?

-Pieter