way to inform rev apps to get something from web server

[Alex Tweedly]

Andre Garzia wrote:
> Sims,
>
> I think the trick is not on the client side but on the server side.
> Instead of pointing your Rev client to a fixed server, use a balancing
> solution, there are load balancers that are able to distribute the
> request among multiple servers so that you can scale (add more
> servers) as needed without the need to rewrite things.
>
> This way you script your app normally, but on the server you put
> enough logic so that you can add more servers to a pool if you see
> that it is getting hard to cope with the demand.
>
> One good balancer is 'Pound': http://www.apsis.ch/pound/
>
> With a solution like that you'll be able to plan your scaling needs.
>   
Sorry, andre, but I have to disagree.  Most load-balancers, including 
Pound, allow you to scale your servers - but they do nothing to save on 
bandwidth. Each request comes to the same loadbalancer, which 
distributes them between back-end serves. So one of the the original 
concerns, web traffic, is undiminished - the same level of traffic 
passes over the network-facing interface in either case.

In general, load-balancing is most effective when the processing 
required is considerable, and that can be shared beteen servers; or when 
the quantity of data output is significant (and you use the request 
redirector feature). But in this case, the typical request is small, and 
results in a small amount of output data (i.e. a one line file).

So although I'm all in favour of these schemes (I helped develop what I 
think was the first commercially successful  load distributor, Cisco's 
Distributed Director :-), I don't think it does much in this case.

Also, in this case, we hve control over the requesting app, and so have 
capabilities not available to the average Web developer.  (see also 
further reply to sims email ...)

-- Alex.