Book Image

JavaScript Concurrency

By : Adam Boduch
Book Image

JavaScript Concurrency

By: Adam Boduch

Overview of this book

Concurrent programming may sound abstract and complex, but it helps to deliver a better user experience. With single threaded JavaScript, applications lack dynamism. This means that when JavaScript code is running, nothing else can happen. The DOM can’t update, which means the UI freezes. In a world where users expect speed and responsiveness – in all senses of the word – this is something no developer can afford. Fortunately, JavaScript has evolved to adopt concurrent capabilities – one of the reasons why it is still at the forefront of modern web development. This book helps you dive into concurrent JavaScript, and demonstrates how to apply its core principles and key techniques and tools to a range of complex development challenges. Built around the three core principles of concurrency – parallelism, synchronization, and conservation – you’ll learn everything you need to unlock a more efficient and dynamic JavaScript, to lay the foundations of even better user experiences. Throughout the book you’ll learn how to put these principles into action by using a range of development approaches. Covering everything from JavaScript promises, web workers, generators and functional programming techniques, everything you learn will have a real impact on the performance of your applications. You’ll also learn how to move between client and server, for a more frictionless and fully realized approach to development. With further guidance on concurrent programming with Node.js, JavaScript Concurrency is committed to making you a better web developer. The best developers know that great design is about more than the UI – with concurrency, you can be confident every your project will be expertly designed to guarantee its dynamism and power.
Table of Contents (17 chapters)
JavaScript Concurrency
About the Author
About the Reviewer

Process Clusters

In the preceding section, we introduced child process creation in NodeJS. This is a necessary measure for web applications when request handlers start consuming more and more CPU, because of the way that this can block every other handler in the system. In this section, we'll build on this idea, but instead of forking a single general-purpose worker process, we'll maintain a pool of general-purpose processes, which is capable of handling any request.

We'll start by reiterating the challenges posed by manually managing these processes that help us with concurrency scenarios in Node. Then, we'll look at the built-in process clustering capabilities of Node.

Challenges with process management

The obvious problem with manually orchestrating processes within our application is that the concurrent code is right there, out in the open, intermingling with the rest of our application code. We actually experienced the exact same problem earlier in this book when implementing web workers...