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Comment by speedgoose | Hacker News Reader

I think Ruby on Rails should be more asynchronous. Doing a http request or a sql query blocks everything until it finishes. The solution is to spawn many instances, but it uses a lot of memory and a slow http service may block all rails instances very quickly.

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This is not correct. When Ruby is doing I/O such as this is the only time it’s not blocking. This is due to Ruby, not specific to Rails.

Here are a few references: https://github.com/puma/puma/issues/1003 https://thoughtbot.com/blog/untangling-ruby-threads

I have to admit that I have not used puma for development.

Edit: your links show that indeed its blocking and you need to spawn many threads/instances, which use memory.

Extra processes (workers) consume extra memory, threads do not.

So, threads and instances are two very different things. They both use memory, though threads use far, far less memory - just like in other languages where you would use threads for concurrency. When Ruby's GIL is waiting on I/O, it allows other threads to do their work. Per the first link, from the author of Puma:

"The reason for that is waiting on IO (talking to a DB, etc) will allow another thread to run"

The threads don't run in parallel, but they do run concurrently. While this isn't the panacea of performance, it does work well with many web apps which tend to be I/O bound (waiting for a database or remote service). So to your original of "Doing a http request or a sql query blocks everything until it finishes. The solution is to spawn many instances" - an HTTP request or SQL query will, in fact, allow other threads to execute while waiting for a response meaning you can rely on threads, rather than instances, and maintain a very low memory footprint.

If you like Ruby but want true multi-threading and parallelism, I'd highly recommend taking a look at JRuby (https://www.jruby.org). Those guys have done an incredible job with it.

Yes, it's called Elixir with Phoenix :)

I thought all DB access was pooled in rails, and the server most everyone uses (Puma) multi threaded?

How would a SQL query block other threads? Sincere question

Elixir is the solution to this with similar ergonomics.

I've been experimenting with it, and it definitely has the feeling of working in rails / ruby. My only gripe is that the tooling is not as mature as rails.

I use rubymine and the debugger has truly spoiled me.

I tried to get the debugger going with a third party plugin for Intelli-j but it would crash when inspecting variables.

Any tips?

I think most elixir dev's have a CLI based workflow where IEx.pry works very well.

There is not much I can comment on editor support as I’ve had the experience of both successfully and unsuccessfully using various debuggers in editors. If you jump into IEX and use the built in introspection it’s some of the most advanced tooling I’ve ever seen in any language. Especially when doing OTP-level topology.

The company I work for (mostly standard Web Dev) uses almost exclusively Elixir for any backend work. Only the fanboys of Elixir and functional everything are happy with it, just to be different to everyone else.

The experience is terrible: Tooling (editor plugins, tests runners, IDEs (oh, there are no IDEs...), debugging) is like going back 20 years.

There are no libraries for the most basic stuff you get almost by default on the Ruby, Python, Node or Java ecosystems. So we end up reinventing half assed solutions to anything we need to do.

Some days I think we would be sooo much better by just using Rails or Django.

Of course, concurrency and the Erlang VM are awesome and the perfect fit for the web... if your problem is performance, it will solve that problem for you of course... other than that, is all wasted time in my opinion from my experience after years of using it.

Really? I've been able to find everything I need in the Elixir ecosystem from auth to background jobs and one of if not the best GraphQL server implementations out there. Do you mind sharing which libraries you found missing or incomplete?

Yes, in fact we have ourselves published a few open source packages out of the need we had to build them.

The latest incarnation of this problem, was when we had to validate RUT codes (a tax code with a checksum we use here in Chile). Options for Python [1], options for Node [2], options for elixir [3] (don't mind to click, it's a list with nothing to do with RUTs or modulo11 validations). So we had to implement it ourselves. Looking for information we found example implementations [4], where as you can see you have example implementations even for Asterisk Dialplans (!!) but no mention of Elixir.

[1] https://pypi.org/search/?q=rut [2] https://www.npmjs.com/search?q=rut [3] https://hex.pm/packages?search=rut&sort=recent_downloads [4] https://es.wikipedia.org/wiki/Anexo:Implementaciones_para_al...

There are many more examples. Of course you get libraries for the "standard" stuff, it is when you get into the detailes, and that happens when you are already too deep into your project, that you realise all the missing pieces.

Also, what code editor do you use? we've tried everything, and seems the best option is you grow a beard and go emacs/vim. The VSCode plugins hog your laptop and are really inconsistent, incomplete and sluggish [1] [2].

[1] https://github.com/JakeBecker/elixir-ls/issues/54 [2] https://github.com/elixir-lsp/elixir-ls/issues/96

Of course there is no IDE similar to intellij, rubymine or pycharm.

Fair enough, thank you for sharing.

I've had good luck with VSCode but I've never really been an IDE user (even with Ruby) so I can't comment much on that.

That's not the experience I had with the environment. The tooling is amazing and the libraries are plenty for pretty much anything.

I’ve found the ecosystem to be quite high quality but the editor tooling does fall short sometimes. Particularly the transition from Alchemist to an editor powered by the new language server protocol.

I can’t say it’s anything other than the fault of not enough spare time. The community is a bit smaller so there are not as many volunteers to build out the latest and greatest tooling for editor support.

Despite this, I’ve had a wonderful experience working within the elixir ecosystem and using it as a gateway to erlang. One of the things I had to acknowledge was my bias towards recent updates as a measure of quality. The ecosystem is so good that you’ll find packages years old and never updated. It simply does that it does and does it well.

I found overall great support in VS Code at the end of the day for Elixir. I wanted it to work well with emacs but it wasn’t consistently enjoyable.

VS Code works well enough for now between the satisfaction of shipping code and the satisfaction of a flick of the wrist for editor commands.

I don't think that's true - the Ruby VM switches threads when blocked on IO like http or db. This happens regardless of what Rails is doing. Maybe you're talking about suboptimal usage of cores...afaik it's indeed being worked on in the Ruby community and it's not something Rails can solve.

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