> I've been down the road of traditional clustering with appservers
> sending messages to each other furiously duplicating state, and also
> with session affinity to avoid some of the duplication, but presently I
> feel the "shared nothing" architecture is best for me. It has some
> successful precedences with high-volume sites, and you basically get it
> for free with Ruby/Rails/Apache/Mongrel.

I would agree in general, but as you mentioned earlier eventually
something is going to become a bottleneck if user growth is enourmous.
I expressely wish to explore the clustered appserver side of things
since it does ultimately scale endlessly. This particular app is
simple enough for me to consider trying my had at it.

So it is interesting to read your comments about "furious duplication"
and session affinity. Were there other notable features to such a
system, and to the developemnt of it?

Greg