The Little Elixir & OTP Guidebook

Excellent book! Elixir is a great language, and the author creates a very digestible approach to the language and framework. You can go into it knowing only the very basics of Ruby and functional programming, come out of it capable of building applications in Elixir with OTP, and never be overwhelmed or bewildered.

I have several books on Elixir and this is by far the best, most succinct one.

Well-written, the coverage of OTP comes earlier and with more focus than most of the other Elixir books.

Clear, concise and to the point. Not unnecessarily complicated. Great book.

Lots of good, very hands on content. Helps you learn both Elixir, and offers great insights into OTP, and also building distributed applications. I would love to give this 5 stars, however there are a number of errors - in particular in a number of code listings which can result in spending quite a bit of time debugging. Certain areas felt glossed over, while others were explained in too much detail. In addition the Elixir version is outdated, so some code is slightly out of date (but nothing too serious). All in all, I would say that the book is worth getting, but it could really benefit from a revision.

A solid introduction to OTP.

It probably was a good book when it was written, but in 2018 there have been so many changes with Elixir that code just doesn't work. I got to chapter 3 for the metex program and spent considerable time just getting "mix deps.get" to work and was elated that finally succeeded. Next was the worker.ex program and it just won't compile. Even the github code for that chapter and exercise, from 2016, is different from the code in the book. But neither work. Unfortunately I'm past my return date so wasted about $35.

This is the best Elixir OTP book I've read so far. The example project in the book, building a resource pooler, is substantial enough to dive into some of the more interesting architectural questions around supervision. While other books I've read or talks I've viewed, enumerate through the nebulous idea of supervision strategies, I still wasn't sure if I was doing it right. I was left with many questions: How do I add another supervised child dynamically? Does it need to be of the same module type? What if I need to store some state about the supervision, does that go in the supervisor too or should that go in a separate GenServer? Can I control the start order of these processes? All these questions and more were answered as I read chapters 6-8 with great interest. It validated some theories of my own and showed that it's quite common to use a GenServer within a Supervision Tree to act as the "brains" while Supervisors themselves should concentrate on doing only one thing, supervising. The brains can then add more children to this Supervision Tree or start another Supervision Tree for something else, it's incredibly flexible and powerful.While the book does cover the classic basics of Elixir and processes a little bit, at no point does it feel boring. The writing style is clear, fun and easy to understand.There were a few minor typos, but you can get the source code and errata in the manning forum. I wish there was an additional few chapters on other OTP patterns, particularly GenEvent (now GenStage if that is replacing it) as I think this could be useful for reactive programming/event sourcing.

What an excellent book!! And excellent technology! I love it. I read it all, and then re-read several of the chapters. I worked through many of the examples on my computer, as well.Most Elixir books focus on Elixir, but this one stands out for focusing on OTP. The author's style is fun, and enjoyable to read. I am pleased to see Benjamin Tan Wei Hao is publishing another book now (on Ruby closures), and I hope he continues to author more. He has a gift for writing.A mild complaint was that when he presents Supervisors (he implements a worker-pool application, where there are a finite number of workers available as resources), almost all the processes are named the same. For example, there is a "Pooly.Supervisor" and a "Pooly.PoolsSupervisor" and a "Pooly.PoolSupervisor", and a "Pooly.WorkerSupervisor", and a "Pooly.PoolServer". A little more thought into unique names would have made that example easier to follow, in my opinion. But, it's fine. I was able to follow along anyway.An extra bonus are the last 2 chapters. In chapter 10 he dives into Dialyzer and type specifications. And in chapter 11 he examines non-conventional testing tools for Elixir -- in particular, he works through some examples of property-based testing with QuickCheck, and concurrency testing with Concuerror. Those chapters are gems to read through, as such documentation is hard to find elsewhere at the moment, and those tools are powerful.I suggest reading this as a 2nd book on Elixir. He does fly through Elixir really quickly (in 2 chapters), but you'll probably want to read an introductory book on Elixir first (I enjoyed "Programming Elixir 1.3").

Intermediate to advanced book on Elixir with main focus on fault tolerance through supervisors and on concurrency. Example are worked through in great detail. Friendly informal writing style that sometimes annoys me personally ("Sweet!") losing one star but not a deal breaker as ultimately the material is covered well. Get Dave Thomas' book also if you need an intro with this one to go deep into OTP.Edit: while the style did annoy me in places - I decided that removing a star was harsh so I'm giving it back - especially because I just read the last chapter on Property Based Testing which is new to me and very interesting so that's worth the star back.

I like this book a lot because it doesn't mess around trying to soft-step for the Ruby and Python people. It's quite full on, but the great thing is it dives right in to processes by Chapter 3, where other books take an eternity to go through all the possible permutations of the single-process use cases before getting to the very purpose of why you were attracted to BEAM in the first place. I have all the Elixir books and along with Sasa Juric's book this is my favourite.

Great book, on time all good.