Handling boot and plugin errors

This section will analyze some of the most common Fastify boot errors and how we can deal with them. But what are boot errors anyway? All errors thrown during the initial load of our application, before the ready event is dispatched and the server listens for incoming connections, are called boot errors.

These errors are usually thrown when something unexpected happens during the registration of a plugin. If there are any unhandled errors during a plugin registration, Fastify, with the help of Avvio, will notify us and stop the boot process.

We can distinguish between two error types:

• Errors that we can recover from
• Errors that are not recoverable by any means

First, we will look at the most common non-recoverable error, ERR_AVVIO_PLUGIN_TIMEOUT, which usually means we forgot to tell Fastify to continue with the boot process.

Then, we will learn about the tools Fastify gives us to recover from other kinds of errors. It is...