Gain insights into building scalable backend applications with Elixir, OTP, and Phoenix. Learn about persistent connections via Phoenix Channels, and explore distinct, decoupled application layers.

Functional Web Development with  Elixir, OTP and Phoenix by The Pragmatic Programmer_ .png

elixir_islands_test.tar.gz

elixir-app

pheonix-app

elixir-app-guesses

island-interface

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phoenix-app-form

phoenix-app-new-module

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phoenix-app-final

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Elixir and OTP provide exceptional tools to build rock-solid backend applications that scale. In this course, you’ll build a web application in a radically different way, with a backend that holds application state. You’ll use persistent Phoenix Channel connections instead of HTTP’s request-response, and create the full application in distinct, decoupled layers.

In Part 1, you’ll start by building the business logic as a separate application, without Phoenix. You’ll model the application domain with Elixir functions and simple data structures.

In Part 2, you’ll add in the GenServer Behaviour to make managing in-memory state a breeze. 

In Part 3, you’ll build a web interface with Phoenix where you’ll use Phoenix Channels to establish persistent connections between the stateful server and a stateful front-end client.

Needless to say, you’re going to love this way of building web apps!

Functional Web Development with Elixir, OTP and Phoenix

## Looking into `GameSupervisor`

Supervisor processes can do their job only if they are running. We can’t know in advance when a player is going to start a new game, so we need to make sure that the `GameSupervisor` is running as soon as the application starts. That’s what we’ll focus on in this section.

We mentioned that since supervisors can supervise both workers and other supervisors, they can form trees of supervised processes. This implies that there is a single process at the root of the tree and that the root node begins the process of starting the whole tree.

# Looking into `GameSupervisor`

Supervisor processes can do their job only if they are running. We can’t know in advance when a player is going to start a new game, so we need to make sure that the `GameSupervisor` is running as soon as the application starts. That’s what we’ll focus on in this section.

We mentioned that since supervisors can supervise both workers and other supervisors, they can form trees of supervised processes. This implies that there is a single process at the root of the tree and that the root node begins the process of starting the whole tree.

Understand the details of the supervision tree.

Introduction

Mapping Our Route

Model Data and Behavior

Working of State Machines

Add OTP for Concurrency and Fault Tolerance

Process Supervision for Recovery

Generate a New Web Interface with Phoenix

Create Persistent Connections with Phoenix Channels

Appendix

Start the Supervision Tree

Looking into `GameSupervisor`