ra VS livebook

Erlang/OTP doesn't handle leader election, and by itself is bad at handling netsplits.

There is https://github.com/rabbitmq/ra which is a Raft implementation in Erlang that is Jepsen-tested. You could use it to build "etcd in Erlang", or https://github.com/rabbitmq/khepri which is built on top of Ra.

Just to add to this, there are some implementations of things like consensus algorithms in Erlang such as Ra: https://github.com/rabbitmq/ra

You may find these interesting...

- "The Onion Layer Theory" https://learnyousomeerlang.com/building-applications-with-ot...

- "On Erlang, State and Crashes" http://jlouisramblings.blogspot.com/2010/11/on-erlang-state-...

- "Why Restarting Works" https://ferd.ca/the-zen-of-erlang.html (search for "Heisenbug")

> you should store the state in the external system

Disk works too, but if you're multi-node this means you now have a distributed database embedded in your system, which may or may not be your goal :)

RabbitMQ does this, they developed a library for "persistent, fault-tolerant and replicated state machines" based on Raft: https://github.com/rabbitmq/ra.

Here is link number 1 - Previous text "Ra"

To get started you need a running instance of Livebook

LiveBook site

I prefer functional programming with Livebook[1] for this type of thing. Once you run a cell, it can be published right into a web component as well.

[1] - https://livebook.dev

If you're a coder, Livebook might be worth a look too. I certainly have my eyes on it.

Would highly recommend looking at Jose's use of livebook to answer these. It makes testing easier. It's old but still relevant. Video link inside

That's hard to say. Racket is a rather complete language, as is F# and Elixir. And F# and Racket are extremely capable multi-paradigm languages, supporting basically any paradigm. Elixir is a bit more restricted in terms of its paradigms, but that's a feature oftentimes, and it also makes up for it with its process framework and deep VM support from the BEAM.

I would say that the key difference is that F# and Elixir are backed by industry whereas Racket is primarily backed via academia. Thus, the incentives and goals are more aligned for F# and Elixir to be used in industrial settings.

Also, both F# and Elixir gain a lot from their host VMs in the CLR and BEAM. Overall, F# is the cleanest language of the three, as it is easy to write concise imperative, functional, or OOP code and has easy asynchronous facilities. Elixir supports macros, and although Racket's macro system is far more advanced, I don't think it really provides any measurable utility over Elixir's. I would also say that F# and Elixir's documentation is better than Racket's. Racket has a lot of documentation, but it can be a little terse at times. And Elixir definitely has the most active, vibrant, and complete ecosystem of all three languages, as well as job market.

The last thing is that F# and Elixir have extremely good notebook implementations in Polyglot Notebooks (https://marketplace.visualstudio.com/items?itemName=ms-dotne...) and Livebook (https://livebook.dev/), respectively. I would say both of these exceed the standard Python Jupyter notebook, and Racket doesn't have anything like Polyglot Notebooks or Livebook. (As an aside, it's possible for someone to implement a Racket kernel for Polyglot Notebooks, so maybe that's a good side project for me.)

So for me, over time, it has slowly whittled down to F# and Elixir being my two languages that I reach for to handle effectively any project. Racket just doesn't pull me in that direction, and I would say that Racket is a bit too locked to DrRacket. I tried doing some GUI stuff in Racket, and despite it having an already built framework, I have actually found it easier to write my own due to bugs found and the poor performance of Racket Draw.

This looks very similar to LiveBook¹. It is purely Elixir/BEAM based, but is quite polished and seems like a perfect workflow tool that is also able to expose these workflows (simply called livebooks) as web apps that some functional, non-technical person can execute on his/her own.

1: https://livebook.dev/