Separation of concerns vs Physical Segregation

aka Do I really need an App server If you've ever planned out an application I'm sure you've heard the term "n-tier".  The idea is to take the logical capabilities required in a system (i.e. presentation, business logic and data management) and distribute them physically across a number of servers.The classic Microsoft diagram looks like this:There are a couple of guidances from MS about how to deploy these logical tiers, but they fundamentally resolve into distributed and non-distributed models:Non-distributedDistributedThe argument put forward by the experts is:> Because all of your layers share resources, one layer can ... more ...

AJAX url parsing on nested controllers in rails

So I've spent the last little while getting aquainted with Ruby on Rails.  My assessment so far?  What a brilliant collection of conventions.  But the number of times I've been missing an 's' or had one to many is rediculous in the extreme.  But it occurred to me that as I was getting along so well, that what convention means is consistency.  In software, you can't go down to the local software store and pick up a CMS that will integrate with your current enterprise.  But a plumber can go down to the local hardware store and pick up a ... more ...