#Preface
This article will introduce the boot of Eggjs that is a Node.js web framework.
It is based on Koa and can satisfy your requirement through a large of plugins and middleware, even a your own framework. It is very important to create a cluster, an agent process and some worker processes when it is running. The cluster makes it stronger. Next, we can understand it by reading the source code.
Eggjs has a few major libs, egg-core、egg、egg-cluster、egg-bin、egg-scripts and so on.
egg-core: it extends Koa and is as a parent object of every agent and worker.
egg: it defines some actions for agent and worker, you can almost use these actions to create an app of a single process.
egg-cluster: it creates a cluster and manages them.
egg-scripts and Egg-bin: their job is run the whole app in a different environment.
Tips: We will discuss Eggjs with basing 2.x.x version.