As we discussed in Chapter 1, Appreciating Node, libuv is used within the Node environment to manage multiple I/O threads. The OS itself also schedules threads, distributing the work required by various processes. Node provides a way for a developer to take advantage of this OS-level scheduling by spawning and forking many processes. In this section, we will learn how to distribute your program's tasks across independent processes generally and how to distribute a Node server's load across multiple cooperating server processes.

Modern software development is no longer the realm of monolithic programs. Modern applications are distributed and decoupled. We now build applications that connect users with resources distributed across the Internet. Many users are accessing shared resources simultaneously. A complex system is easier to understand if the whole is understood as a collection of interfaces to programs that solve one or a few clearly defined,...