Worker pool pattern in Node.js - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the Worker Pool Pattern in Node.js?

It is a way to run multiple tasks in parallel by using a fixed number of worker threads. This helps to manage heavy or blocking tasks without freezing the main program.

beginner

Why use a Worker Pool instead of creating a new worker for each task?

Creating a new worker for every task is slow and uses more memory. A worker pool reuses a set number of workers, making the program faster and more efficient.

intermediate

How does the Worker Pool Pattern improve Node.js performance?

It offloads CPU-heavy tasks to worker threads, so the main thread stays free to handle other tasks like user requests, keeping the app responsive.

beginner

What Node.js module is commonly used to implement the Worker Pool Pattern?

The 'worker_threads' module is used to create and manage worker threads in Node.js for the worker pool pattern.

intermediate

Describe a simple flow of how tasks are handled in a Worker Pool.

Tasks are added to a queue. Available workers pick tasks from the queue, process them, then become free to pick new tasks. This cycle repeats to handle many tasks efficiently.

What is the main benefit of using a worker pool in Node.js?

A Run multiple tasks in parallel without blocking the main thread

B Make the code shorter

C Avoid using any threads

D Automatically fix bugs

Worker pools allow parallel task execution, keeping the main thread free and responsive.

Which Node.js module helps create worker threads for a worker pool?

A http

B worker_threads

C fs

D events

The 'worker_threads' module is designed for creating and managing worker threads.

What happens when all workers in a pool are busy and a new task arrives?

A The task waits in a queue until a worker is free

B A new worker is created automatically

C The task is ignored

D The main thread processes the task

Tasks wait in a queue until a worker becomes available to keep resource use controlled.

Why is creating a new worker for each task inefficient?

A Workers use no memory

B It is the recommended way

C It makes the program faster

D It slows down the program and uses more memory

Creating many workers wastes resources and slows down the system.

Which of these is NOT a part of the worker pool pattern?

A Task queue

B Fixed number of workers

C Main thread blocking on tasks

D Workers processing tasks

The main thread should stay free and not block on tasks in the worker pool pattern.

Explain how the worker pool pattern helps keep a Node.js application responsive.

Think about how tasks move from the main thread to workers.

Describe the steps to implement a simple worker pool using Node.js worker_threads.

Focus on worker creation, task management, and communication.