Codefol.io

If you’re new to Ruby on Rails, you may be new to the old debates (pro and con) about how “Rails doesn’t scale.” You might wonder why people say that, or where it came from.

Let’s talk about that.

As far as “Rails Doesn’t Scale”, the main arguments go something like:

1) Ruby is slow, often up to 50x slower than C, so the server will eventually collapse.

This isn’t actually a scaling argument. But it’s true that Ruby is slow. Not 50x any more, closer to 5x (up to maybe 20x), but still, that’s not terribly speedy.

Rails doesn’t help Ruby here. A lot of the metaprogramming techniques it uses are among the slowest things Ruby does. I wrote a book about how Rails uses those techniques called Rebuilding Rails. They’re awesome, but they’re not speedy.

In practice, Ruby and Rails apps often “farm out” the slow stuff. The database is the traditional place to put the heavy lifting, but you’ll see Redis and Cassandra used in similar ways. Want Ruby to be fast? Call to something that isn’t Ruby, and is designed for speed :-)

Pure Ruby is quite slow, but just as scalable as any other language or library. It doesn’t get somehow slower as you add more.

2) Ruby/Rails leaks resources, so large or long-running projects don’t work

There was once more truth to this. Ruby had a few leaks and Rails exercised Ruby like nothing else. Also, ActiveRecord encourages large amounts of garbage per request, which was easy to mistake for leaks.

rails business favourite

You’ve made it mostway through your free Ruby on Rails Internals class. Today we’ll be poking around the Rails source code. If you have money but not time, Rebuilding Rails lets you find a lot quickly… But in case you have more time, we’ll see where in the Rails source you can learn the same things...

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A fellow asked me how he could store information per-user in Rack. This was my (brief) response:

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Evan Light recently used the wonderful phrase ”Use Rails Until It Hurts”. He meant that Rails has built-in mechanisms for organizing your code and objects, and they usually result in simpler, cleaner code that mixing Rails with non-Rails.

I say your startup should use Rails until it hurts. And it...

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Rack comes with a fair bit of built-in middleware that you can use to put together a simple app frame. Unfortunately, Rack authentication’s documentation is pretty bad, so let’s see some simple, self-explanatory examples, shall we?

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If you do Ruby web programming, you’ll often hear about “Rack.” You might hear about it from a Ruby dev you respect, and that you won’t get better at Ruby web stuff until you know what’s underneath.

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Rails parameter parsing can be hard to understand, but it goes beyond that.

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rails rebuildingrails