Will it blend?

David Heinemeier Hansson is again arguing that Rails is, after all, scalable:

Jason Hoffman from Joyent had a great tutorial at RailsConf Europe on Scaling a Rails Application from the Bottom Up. It defines the key terms and measurements of scaling and explains why scaling in essence have nothing to do with Rails. It’s a great story to have in hand when the inevitable fudzy "But does it scale?" nonsense is thrown at you.

The thing is, it seems that David is working with a very particular definition of "scaling" that seeks to sidestep the key issues at the heart of Rail’s scaling problems (and there are problems). "Scaling in essence has nothing to do with Rails". Really? Nothing at all? Nothing at all in essence? There are more than a couple words in there that are setting off the sophistry alarm bells…

My personal opinion is that Rails is a pretty nice framework but that it is undeniably slow, resource hungry, and only "scales" when you throw bucket-loads of money at it. And of course it "scales" if you do that… But that doesn’t make the performance problem vanish into thin air; it’s still there and it’s not "fudzy nonsense" but a legitimate concern. Compare with the alternatives and note that they all pretty much scale better than Rails (application performance, that is; not even touching the subject of programmer productivity which is another thing entirely).

It doesn’t mean that Rails programmers should all just throw in the towel: but it does mean that there is still much work to be done on improving performance, both in Rails and in Ruby itself.