(As an aside, I’ve heard some anti-Hibernate bigots say that using Hibernate for anyting OVER 100 classes is silly, its amazing how much difference of opinion there is in the world)

As for point two, well, no, I’ve been working in the Rails app for around two months now. And I’m making an honest guess about how I think it would go. I suppose I could just sit back and say “Well, I have no firsthand knowledge, so even though I’ve been doing this for a long time, I can’t possibly make any educated guesses about whether or not this will succeed.” But, let’s ask it the other way:

“What is it about a guy who has never touched a technology that makes him able to say it can’t be done?”

You have your assumptions about what’s possible. I’m basing an educated guess on personal experience with a lot of major Java and .NET development under my belt.

I could be wrong. I might be right. But if I don’t make some guesses about what’s possible, I’ll never do anything, will I?

Back to the case at hand….a couple of comments:

1) From everything I’ve read about your experiment what it really came down to was a few cases. With caching disabled clearly you were mySql bound. With caching enabled in Rails you cached at the page level – and hence barely executed any code at all. A strong case can be made that you tested only the caching performance of a single user hitting Rails, but that you didn’t test any other aspect of Rails or Ruby.

Likewise, the Java no-cache vs. cache numbers clearly show that your Java caching code is horrible – I mean really horrible.

If you wished to show anything meaningful, turn on page-level caching for Java. You may also want to revisit the use of Hibernate for a project with <100 classes overall!

2) A single guy coding part time creates <2K lines of Ruby code in a few days. Based on this you feel qualified to say how this will scale to a team of several people going into at least the tens of thousands of lines? Again I must ask – what is it about a guy working alone pumping out a minor small app? How does that experience translate into, say, 5 people working on a 100,000 line app? Or 3 people working on a 50,000 line app? I would say it doesn’t, it doesn’t at all.

Where I *don’t* see it scaling is apps that have XA transactional requirements, and apps that need a lot of legacy connections (to mainframes, etc.) and apps that need corporate “no one ever got fired for choosing Java” support. But there are lots of projects out there that don’t have any of those requirements, and I can definitely see Rails reaching those projects.

Side note, kind of strange that I’ve seen your name in a lot of the circles I hang out in, but this is the first time we’ve directly interacted. And all on Dion’s blog comments, nonetheless.

We know you have an app that’s 3K lines in Java, ~1K in Ruby. Those 3K lines in Java were strung out over several months (5 if I recall correctly), the Ruby stuff was banged out in 3-4 days. This is the other end of the scale.

Unfortunately, you cannot extrapolate from one end to the other. So you saying that “Rails would work fine” in an app a half the size would appear, to me, to be guesswork. Based on translating a 3K line Java program into a 1KLine Ruby one, you’re now confident in saying you can take a 150K Line Java program and make it run equally well on Rails?

Come again? The tiny amount of time you spent writing that 1K Line Ruby program is sufficient for you to bet on a 150K line project?

But the bigger question is: where is the fuzzy line between a smallish web app and a biggish enterprise web app? Is 25K still trivial? 50K? What about 100K? From where I sit, working concurrently on a 3KLOC Ruby app and a, now, ~350KLOC Java app, I can *definitively* say that there are things in that Java app that I can’t do in Ruby. But most of them I wouldn’t even dream of wanting to do in a smaller app, and by smaller, I mean half the size and a quarter of the users. So Rails would work fine there.

Someday I’ll get the chance to find out, I hope. In the meantime, I only have what I have.

The plain fact is that an application with 3K lines of code is just not very intersting, and you just can’t draw that many conclusions from it. I don’t mean to be insulting Justin but a 3K app is trivial, plain and simple.