Concurrent Ruby VS Ruby on Rails

After this, I took a look at the semaphore class in the popular library, concurrent-ruby to see how they implement it, and I learnt about something new: condition variables. And Ruby comes with this included!

https://github.com/ruby-concurrency/concurrent-ruby has great docs if someone is looking for alternatives.

I wonder how this would compare to using concurrent-ruby under ruby 2.7, especially in a real-world setting (where the calls are actually to external services that return and buffer data, instead of just sleep). The author says that he's felt that ruby threads "feel easy to mess up," but I've found that concurrent-ruby makes it pretty simple, and performant enough even with the GIL.

As I could not find a clear example about how to rescue exceptions from Concurrent::Promises (part of the Concurrent Ruby gem ) I read through the documentation and here are two examples: one that documents success case and one that shows what is happening when there is an error.

In a sense the GIL (or actually GVL as it's called in current ruby versions) has already been removed for ruby.

It's only the original MRI Ruby that still has it several over Ruby implementations already removed it. e.g. JRuby.

Concurrent-Ruby[1] is probably a good place to start if you want to work with GVL free ruby on JRuby. It's quite well supported and is currently used by Rails.

If you just want async or non-blocking IO I'd take a look at the Async Gem[2]. It looks pretty solid in Ruby > 3.0 and it's been invited by Matz to be part of the stdlib, which I think is a pretty good endorsement.

For MRI itself I don't think it's likely they'll ever remove the GVL. Ractors are probably a better solution for CPU concurrency in the long run, although I think they're pretty experimental currently.

1. https://github.com/ruby-concurrency/concurrent-ruby

I like how the article exposes you to tools to prove/disprove the problem. I would have hoped it introduced to tools like concurrent ruby and the use of atomics like u/Freeky already mentioned though.

Using conccurrent-ruby, how can I execute a set of promises and then get the results?

I’d highly recommend the concurrent-ruby gem that has implementations of various metaphors of concurrency, from async to promises, as well as edge features such as actors.

You may want to consider using something like concurrent-ruby that provides nice abstractions over multithreading.

[0] is a my favorite demonstration of it.

[0]: https://github.com/rails/rails/commit/b83965785db1eec019edf1...

Here's a real life example: Imagine a Ruby on Rails app on which a team of developers are working. The code is hosted on GitLab and all the work is coordinated using GitLab issues. In other words: For every commit, there's an associated issue and the issue number acts as a sort of primary key for documentation, time reporting and so forth. This convention has a few advantages, most notably the ability to easily learn more about how, when and by whom features were implemented as well as how this implementation came to be.

Ruby on Rails is regarded as one of the best ruby frameworks. It was the primary language in developing big projects such as Twitter and helped the language boost the community. Often referred to as “Rails,” Ruby on Rails is a web development framework with an MVC control structure and currently running its 6.1 version. The 16-year-old language has dramatically influenced the web development structures and managing databases, web pages, and other components on a web application.

In Rails 7.1, a new option _instance_methods is introduced, allowing developers to opt-out of the automatic generation of instance methods for enums. When enum is defined with _instance_methods: false, Rails will no longer generate methods like pending?, processed?, etc.

Rails isn't super opinionated about database writes, its mostly left up to developers to discover that for relational DBs you do not want to be doing a bunch of small writes all at once.

That said it specifically has tools to address this that started appearing a few years ago https://github.com/rails/rails/pull/35077

The way my team handles it is to stick Kafka in between whats generating the records (for us, a bunch of web scraping workers) and and a consumer that pulls off the Kafka queue and runs an insert when its internal buffer reaches around 50k rows.

Rails is also looking to add some more direct background type work with https://github.com/basecamp/solid_queue but this is still very new - most larger Rails shops are going to be running a second system and a gem called Sidekiq that pulls jobs out of Redis.

I'm looking forward to see what extractions from this will land on rails. For example: https://github.com/rails/rails/issues/50454

Here is what strict_loading does (source):

Kamal is a wonderfully simple way to deploy your applications anywhere. It will also be included by default in Rails 8. Kamal is trivial, but I don’t recommend using it on your development machine.

Here's the GitHub milestone I've based this article on — https://github.com/rails/rails/milestone/87