In Node.js, both cluster.fork() and child_process.fork() are used to handle multiple processes, but they serve different purposes and operate in distinct ways.
child_process.fork()
child_process.fork() is a special case of child_process.spawn() used specifically to spawn new Node.js processes. Like spawn, the returned childProcess object will have built-in Inter-Process Communication (IPC) capabilities, allowing the parent and child processes to communicate via messages. This method is primarily used when you need to perform heavy computations or execute a separate Node.js module in parallel, without blocking the Node.js event loop. Each child process runs independently with its own V8 instance, allowing for the execution of heavy JavaScript tasks without affecting the main application's performance[1][7].
cluster.fork()
cluster.fork() is part of the cluster module, which allows you to easily create a network of processes that all share server ports. It is built on top of child_process.fork(), meaning it inherits the IPC functionality. The primary use of cluster.fork() is to enable the handling of network requests across multiple CPU cores, effectively distributing the load and improving the performance of Node.js applications that operate as TCP or HTTP servers. When cluster.fork() is called, it spawns worker processes that can all share the same TCP connection, making it ideal for scenarios where an application needs to handle a high number of concurrent connections efficiently[3][4].
Key Differences
Use Case:
child_process.fork() is used for creating separate processes for running heavy computations or isolated modules.
