OT: why are LAMP sites slow?

[Paul Rubin]

Jeremy Bowers <jerf at jerf.org> writes:
> > Hmm, I'm not familiar with Nevow.  Twisted is pretty neat, though
> > confusing.  I don't see how to scale it to multiple servers though.
> 
> Same way you'd scale any webserver, load balancing in hardware, store all
> user state in a database, and tell the load balancer to try to "persist"
> a user's connection to a machine, so Twisted doesn't even have to go back
> to the server then?

I understood the Twisted suggestion as meaning avoiding database
traffic by keeping both user and server state resident in the
application.  Yes, if you use a database for that, you get multiple
app servers instead of a heavily loaded centralized one.  But you now
have a heavily loaded centralized database server instead.  You
haven't really solved your scaling problem, you've just moved it back
a layer.