Welcome to the first chapter of the “Elixir, 7 Steps to Start Your Journey” series. In my previous post, I discussed my journey with the programming language.

In this chapter, we will discuss the Erlang Virtual Machine, the BEAM.

To understand why the Elixir programming language is so powerful and reliable, we must understand its foundations, which means talking about Erlang.

Elixir runs on the Erlang Virtual Machine and inherits many of its virtues. In this post, you will learn a little about the history of Erlang, the objective with which it was initially created, and why it is fundamental for Elixir.

What is Erlang?

Erlang as a programming language

Erlang is a programming language created in the mid-1980s by Joe Armstrong, Robert Virding, and Mike Williams at the Ericsson Computer Science Laboratory. Initially designed for telecommunications, it is now a general-purpose language. It was influenced by other programming languages, such as ML and Prolog, and was released as open-source in 1998.

Erlang was designed with distributed, fault-tolerant, massively concurrent, and soft real-time systems in mind, making it an excellent choice for today’s systems. Most are looking for these features, in addition to having confidence in Erlang’s history in productive systems.

Some of the characteristics of this programming language are:

It is a declarative language, which means it is based on the principle of describing what should be calculated instead of how.
Pattern matching is possible at a high level and also on bit sequences.
Functions in Erlang are first-class data.

Erlang as the development ecosystem

Up to this point, we have referred to Erlang as the programming language; however, it should be noted that Erlang can also refer to an entire development ecosystem that is made up of:

The Erlang programming language
The framework OTP
A series of tools and
The virtual machine, BEAM

Erlang, as an ecosystem, was explicitly created to support highly available systems, which provide service even when errors or unexpected circumstances occur, and this is due to many of the characteristics of its virtual machine (VM).

So, although Erlang as a programming language is pretty cool on its own, the real magic happens when all the ecosystem elements are combined: the programming language, libraries, OTP, and the virtual machine.

If you want to know more about the history of Erlang, the list of resources below will be very helpful.

Resources

Erlang Virtual Machine, BEAM

The Erlang Virtual Machine, known as the BEAM, runs as an operating system process and is responsible for executing the Erlang code. It is also responsible for creating, scheduling, and managing Erlang processes, which are the fundamental basis of concurrency.

Thanks to the BEAM schedulers, these processes can be executed in the most efficient way possible, allowing the system to be highly scalable. The processes do not share memory; they communicate through asynchronous message passing. This mechanism is the foundation for a system’s fault tolerance. As they are entirely isolated, the other system processes will not be affected if an error occurs in one of them.

The BEAM is also responsible for parallelizing your concurrent Erlang programs, making the most of a machine’s resources. Initially, the virtual machine model was a single-run queue. However, it evolved into a run queue for each available processor, ensuring no bottlenecks and that Erlang programs work correctly on any system, regardless of the number of machine cores.

Another characteristic is that storage management is automated. Garbage collection is implemented per process, which allows a system’s response time to always remain in the order of milliseconds without performance degradation.

And lastly, one of my favourite features is error detection. The virtual machine provides all the elements necessary for efficient error detection and handling, thus promoting an always-available system regardless of failures.

In summary, the BEAM is responsible for the scalability, distribution, and responsiveness of a system:

Manages the concurrency of it.
It has a mechanism for error detection and handling.
Make the most of the computer’s resources.

If you’d like to learn more about the duo that is Erlang and Elixir, check out the “What is Elixir” post.

Elixir in the BEAM

Like Erlang, Elixir was also influenced by other programming languages, including Erlang itself. Its code runs on the Erlang Virtual Machine, which means it takes advantage of all its features and can use all the Erlang libraries and the OTP framework.

Different programming languages besides Elixir and Erlang run in the BEAM, but Elixir has ensured that the approach between BEAM and programmers is fluid and quickly understandable.

Elixir code is compiled into bytecode that runs in the BEAM and is more compact than Erlang code. Its syntax is similar to how we communicate daily, allowing for early familiarization with the language, even if it is the first time you program with it. It also reduces the boilerplate and has amazing documentation.

So, when writing code with Elixir, we have the best of both: a solid and battle-tested foundation that allows us to create fail-safe systems and, on the other hand, nice syntax, well-defined patterns, and code simplification, among other things. Thanks to this, Elixir has been so well accepted and has rapidly gained popularity.

Elixir is a cool programming language that allows you to write code that is easy to understand and maintain and takes advantage of the Erlang concurrency model, which we will discuss in the next chapter.

> iex


iex(1)> list = [4,5,21,1,38]


iex(2)> erlang_example = :lists.sort(list);
[1, 4, 5, 21, 38]


iex(3)> elixir_example = Enum.sort(list)
[1, 4, 5, 21, 38]

Example of how you can run Erlang and Elixir code in an interactive Elixir shell

Next chapter

In the next post, “Understanding Processes and Concurrency,” we will discuss how Erlang processes work and their importance in developing robust and scalable systems. We will also see how concurrency works in Erlang and how this relates to Elixir. Do not miss it! You can drop the team a message if you’d like to discuss Elixir in more detail.

Lorena Mireles

Lorena is a Mexican backend developer who loves working with Elixir and drinking coffee. She is a co-founder of the Temachtiani community in CDMX and an active promoter of women's participation in technology.