Worker Threads vs Child Processes

Parallel Processing: Workers vs. Processes

Because the main Node.js event loop is single-threaded, computationally intensive algorithms (image processing, big data mathematical manipulation) will block the thread, denying service to all other users. Node.js provides two mechanisms for parallel execution.

Child Processes

Utilizing child_process.fork() spawns an entirely new, isolated V8 instance and OS process. It possesses its own isolated memory footprint (around 30MB base). Inter-process communication (IPC) is achieved by passing serialized JSON messages back and forth. They are heavy but strictly isolated.

Worker Threads

Introduced in Node v10, Worker Threads operate within the exact same OS process. They share the same memory boundaries by utilizing SharedArrayBuffer instances. Because they don't necessitate booting new V8 engines from scratch, they are extraordinarily lightweight to spin up, making them the definitive choice for parallelizing heavy JavaScript computations.