Ruby 3x3 is coming in about a month. One of its new concurrency primitives is Ractors, which used to be called "Guilds." (The other new concurrency primitive is Autofibers.)
Ruby has a Global VM Lock (GVL), also called the Global Interpreter Lock (GIL), that prevents running Ruby code in more than one thread at once. So Ruby threads are great for I/O like waiting on files or databases. And they're great for cases where a C extension can keep calculating in a background thread while a foreground thread runs Ruby. But you can't do calculations in Ruby in more than one thread at once within the same process.
At least not until Ruby 3 and not without Ractors.
Great! Now how fast is the current implementation of Ractors?
Do you ever look at the list of Amazon EC2 instance types?. Those are sizes of virtual machine you can rent to run your code on. Well, okay, they're groups of sizes, since each one of those headings has a bunch of different sizes of VM...
So what type of EC2 instances should you run your Rails app on?
The answer is simpler than it looks.
Do you love numbers? I love numbers. Do you hate numbers? Skip to the bottom, there's a nice summary paragraph. Do you really really love numbers? There are raw data dumps including all my intermediate results.
The new Ruby 3.0 preview is out! Woo-hoo!
If you've heard of me, you know performance is kinda my thing, especially Rails performance on large apps. I do other stuff too, but I got paid to do that for years (thanks, AppFolio!), so I've written a lot about it.
How does the new preview's performance stack up on Rails? And how reliable are these numbers?