13 Running the system

You’ve spent a lot of time building a to-do system, and now it’s time to prepare it for production. There are various ways to start a system, but the basic idea is always the same. You have to compile your code as well as your dependencies. Then you start the BEAM instance and ensure that all compiled artifacts are in the load path. Finally, from within the BEAM instance, you need to start your OTP application together with its dependencies. Once the OTP application is started, you can consider your system to be running.

There are various approaches to achieving this, and in this chapter we’ll focus on two of them. First we’ll look at how you can use Elixir tools, most notably mix, to start the system. Then we’ll discuss OTP releases. Finally, I’ll end the chapter and the book by providing some pointers on how to interact with a running system, so you can detect and analyze faults and errors that inevitably happen at runtime.

13.1 Running a system with Elixir tools

Regardless of the method you use to start the system, some common principles always hold. Running the system amounts to doing the following:

13.1.1 Using the mix and elixir commands

13.1.2 Running scripts

13.1.3 Compiling for production

13.2 OTP releases

13.2.1 Building a release with distillery

13.2.2 Using a release

13.2.3 Release contents

13.3 Analyzing system behavior

13.3.1 Debugging

13.3.2 Logging

13.3.3 Interacting with the system

13.3.4 Tracing

Summary