While scalability means many things to many people, it is often the label attached to the belief that something needs to be “bigger,” or perhaps just “faster.” Ruby, as demonstrated by many applications, contains the bits and pieces needed to solve 90% of problems. Perhaps Java can be used to solve an additional 2-3%, but at what cost?

People often misconstrue complexity for “scalability,” and the inverse is actually true. Complexity is the hubris of most architectures and is where they fail miserably. This is an unfortunate situation when many EAs are paid for their complexity. True insight, however, is in the reduction, not addition, of complexity.

If Mr. McGovern were truly trying to improve anything, other than his own visibility and traffic, he might consider spending a modicum of time understanding the technology he spouts off about. When you make wild statements like “Ruby needs a version of JUnit,” which are demonstrably false by anyone with 12 neurons and access to Google, it’s really difficult to proffer more than ridicule as a response.

I don’t really know if I agree because I don’t know very much about the Java world, but I find it very interesting.

Just one comment: when you’re talking about scalability and you say “I’ve not seen any extensive benchmarking, but I find it difficult to imagine that JRuby is any faster than the CRuby1 interpreter. Certainly Jython was never any faster than the regular Python.”, I think you’re missing the point. Scalability is not about performance. JRuby could be twice as slower than CRuby and still win in scalability (or viceversa).

Scalability is about the ability of a system to grow up, and is independent of performance. It is about, for example, the difficult to make a system run in a fairly large number of boxes. Ruby (I mean Rails in my case) manages this well, but I don’t know about Java.

Ruby’s (I mean CRuby’s; I did’n try JRuby) performance is horrible. But that doesn’t matter as long as:

1) It’s scalable. It’s easy to, say, double the number of servers running yout app.

2) Increases developer’s performance.

A new server is cheaper than a new developer. Double servers + Half developers + Half time = Nice project!

Finally, I find that when someone in the “enterprise” complains about performance, it’s even more laughable than when most “dot-commers” complain. With the exception of perhaps 10-20 companies, no internal-facing application will ever be even half as slammed as a moderately successful Internet organization. Performance just isn’t the primary concern for most people, it’s just the red herring everyone loves.