Node.js

Node.js is an open source, cross-platform runtime environment and library that is used for running web applications outside the client’s browser

It is used for server-side programming, and primarily deployed for non-blocking, event-driven servers, such as traditional web sites and back-end API services, but was originally designed with real-time, push-based architectures in mind. Every browser has its own version of a JS engine, and node.js is built on Google Chrome’s V8 JavaScript engine. Sounds a bit complicated, right?

In simple terms, what this means is that entire sites can be run using a unified ‘stack’, which makes development and maintenance quick and easy, allowing you to focus on meeting the business goals of the project.

The fact that Node.js is open source means that it is free to use and constantly being tweaked and improved by a global community of developers.

An important thing to understand about Node.js is that it is actually neither a framework or a library - as with traditional application software -, but a runtime environment.

A runtime environment (sometimes shortened to RTE) contains Web API’s that a developer can access to build a code, and a JavaScript engine that parses that code. This makes it lightweight, flexible and easy to deploy, all features that will help to optimize and speed up your application project.

The history of Node.js

Node.js was created in 2009 by Ryan Dahl. Previously, Dahl had criticized the limited possibilities offered by existing popular web servers and common coding methods.

At the time, servers struggled to handle high-volume concurrent connections, and codes either blocked the entire process or implied the need for multiple stacks. These were all issues that hampered the ability of businesses to build versatile products that engaged with and met high-volume user requirements.

In response, Dahl created Node.js to provide developers with the power to use JavaScript for server-side scripting and unifying web application development around a single programming language.

The initial release of Node.js only supported Linux and Mac OS X operating systems. Its development and maintenance was led by Dahl at first, and later sponsored by Joyent, a software and services company.

In January 2010, a package manager for Node.js was introduced to make it easier for programmers to publish and share source code of Node.js packages and simplify installation, uninstallation and updates.

In 2011, Microsoft and Joyent came together to develop a native Windows version of Node.js, expanding the number of operating systems it could support and giving developers more options than ever.

Since then, a neutral Node.js Foundation has been formed to bring developers together in one community. The Node.js foundation was merged with the JS Foundation in 2019, to form the OpenJS Foundation. The foundations help to govern the open-source, distributed development project of Node.js.

Interesting facts

Node.js is used by big business and small enterprises alike. While the likes of Amazon, Netflix, eBay, Reddit and Paypal all use it, over 43% of developers using Node.JS do so for enterprise applications.

Some of the most common words users associate with Node.js are: fast, simple, easy, powerful and flexible. Node.js is not perfect for every project, of course, but with all of this in mind it’s easy to see why it’s so popular with start-ups and globals alike.

Node.js architecture

The mechanics of Node.js are what contributes to its popularity with developers. Whereas most alternative runtime environments utilize multi-threaded processing models, Node.js does it all in a single thread.

In multi-threaded processing setups, each server has a limited thread pool it can access. So every time a server receives a request, it pulls a thread from the pool and assigns it to that request, to take care of processing it. In this case, the processing is synchronous and sequential, which means that one operation is performed at a time.

In multiple-thread processing, a thread is picked out every time a request is made until all of the limited threads are used up. When this happens, the server has to wait for a busy thread to become free again. This can make for slow and inefficient applications, which leads to knock-on effects on anything from customer experience to lead conversions. It can particularly become a problem if your application has to deal with a high number of concurrent client requests.

Node.js, however, uses single-threaded processing. The difference between the two is as you’d imagine: single-thread architectures process every request using a single main thread, utilizing event loops to run blocking Input/Output operations in a non-blocking way. Don’t worry if some of these terms seem unfamiliar. The ‘Terms To Know’ section, below, will explain it all in more detail.

A single-thread architecture can, in theory, perform and scale much more quickly and efficiently than multiple-thread setups. This is what Ryan Dahl had in mind when he first wrote Node.js and is a big part of why it is so popular among web application developers.

Node.js terms worth knowing

Below is a list of common terms you’ll see when reading about or discussing Node.js, and their definitions.

What is JavaScript?

JavaScript is the programming language that underpins Node.js. It is a high-level and multi-paradigm language characterized by ‘curly bracket’ syntax, dynamic typing, prototype-based object orientations and first class functions.

These features mean JavaScript can convert a static webpage to an interactive one, adding features such as search boxes, embedded videos or news feed refresh tools. These are features that aim to improve user experience by encouraging intuitive engagement.

Node.js modules

Node.js features multiple ‘modules’ that are kept within individual contexts so they do not interfere with other modules or pollute the global scope of node.js. This is crucial for open source softwares.

A module in Node.js is a functionality - either simple or complex - which is organized into JavaScript files and reusable throughout the Node.js application. There are three types of module within Node.js: Core Modules, Local Modules and Third Party Modules.

Core Modules include the basic, bare-bones functionalities of Node.js. They load automatically when a node process starts and are part of Node.js’s binary distribution.

Local Modules are modules that are created within the Node.js application. They include different and additional functionalities in separate files and folders to the core functionality package. Local modules can also be packaged and distributed for use by the wider Node.js community.

A third party module is an existing code written by a third party, and can be imported into your Node.js application to expand or add different features and functions.

Microservices

A microservice is an individual, self-contained unit that works alongside others to make up a large application. Splitting an app up into multiple small parts makes it easy to maintain, independently deployable and scalable. They can be written by different teams and tested individually.

Microservices can be beneficial for developers because they allow components to be compartmentalized and managed individually, offering greater control and flexibility. Microservices allow components to be modified or updated without impacting the overall application or interrupting performance.

Microservices are not always the best option for every project. A common issue with microservices is ‘orchestration’, the challenge of integrating the services with a drive that guides the process. ‘Discovery’ can also be a problem, where microservices struggle to locate and relate to each other on a server. These issues can be solved with a more ‘monolithic’ structure, which is a single, autonomous unit.

Both approaches have their advantages and choosing which to use depends upon the scope and requirement of the individual project.

What is event-driven programming?

Event-driven programming is a feature of applications designed to respond to various forms of user engagement. It is known as a ‘programming paradigm’, whereby the flow of the program’s execution is determined by events.

In this context, events are any action made by a user, such as clicks or key presses. They can also mean messages from other threads or programs.

Event-driven programming is designed to detect actions as they occur, and processes them using establishing event-handling procedures. This provides for a more reactive and intuitive user experience and adds flexibility to applications handling concurrent requests.

Node package manager

Node package manager (or ‘npm’ for short) does a few things; firstly, it acts as an online repository for publishing open-source Node.js projects. Secondly, it is used as a command-line facility for interacting with that repository, assisting with package installation, version management and dependency management.

It is used most commonly to publish, discover, install and develop Node programs. Essentially, it helps developers to make best use of Node.js tools and packages with a useful interface.

Node.js worker threads

Worker threads is a feature within Node.js that is useful for performing heavy JavaScript tasks. The worker_threads module enables execution of JavaScript codes in parallel, making the entire process quicker and more efficient. It does this by using an existing pool of ‘workers’ to handle new and incoming tasks.

Worker threads help with CPU-intensive tasks without disturbing the main Node.js thread, offering flexibility and compartmentalization.

Event loop

The event loop is what allows Node. js to perform non-blocking I/O operations — despite the fact that JavaScript is single-threaded — by offloading operations to the system kernel whenever possible. Since most modern kernels are multi-threaded, they can handle multiple operations executing in the background.

Generally speaking, the event loop is a mechanism that waits for and dispatches events or messages in a program. In Node.js, event loops are the central control flow constructs. For example, every time a request is about to be handled, it’s put on the event loop and processed as soon as it’s ready to be processed.

Node, instead of doing it on its own, delegates the responsibility of handling the system. Because of such behaviour, Node is not actively waiting for this task to finish and can handle other requests in the meantime. The event loop makes Node.js faster and more efficient than other technologies

The Pros and Cons of Node.js

The Popularity of Node.js

JavaScript, which underpins Node.js, has been one of the most popular programming languages available for some time. While it has more commonly been used for front-end web development, it has also gained ground in different areas of application and on distinct platforms, such as Node.js.

Even though Node.js was originally written in 2009, it wasn’t widely adopted until recently. Currently, numerous successful brands have leveraged Node.js to develop both front and back-end applications, including Walmart, Netflix, Medium, LinkedIn or Groupon.

Node.js is rising in popularity for a number of reasons, which we will go through shortly. It’s also important to know that, as with every technology, there are some drawbacks which mean Node.js isn’t perfect for every project.

What can Node.js do and what kind of products can be built with Node.js?

Node.js is a versatile JavaScript runtime environment built upon event-driven programming that enables non-blocking I/O (Input/Output) capable of serving multiple concurrent events in a single thread. This makes Node.js fast, lightweight, scalable, and efficient in handling data-heavy and I/O-heavy workloads characteristic of several types of web applications.

Internet of Things

IoT (Internet of Things) is a network of devices such as sensors, beacons, actuators, and any other items embedded with electronics that enables them to send and exchange data. IoT may consist of thousands of such devices, which makes it challenging to manage requests and data streams from and between the devices.

Since 2012, Node.js has become one of the preferred solutions for enterprises and organizations seeking to develop IoT systems because it can process multiple concurrent requests and events emitted by thousands or even millions of devices on the network without seeing a decrease in speed or performance.

The avalanche of requests and data coming from IoT devices does not block Node.js servers thanks to their event-driven architecture and asynchronous processing suitable for I/O-heavy operations on the IoT network. This makes Node.js fast as an application layer between these devices and the databases that store data from them.

Real-time chats

Real-time chat is any online communication tool that enables the live transmission of text, video, or audio messages from a sender to a receiver. They are used widely across social media apps and commercial sites and, as a result, are an important part of many industries.

Node.js provides all basic functionalities for building real-time chats of any complexity. In particular, Node has a powerful Event API that facilitates the creation of “emitters”, which periodically emit named events “listened” to by event handlers. This functionality makes it easy to implement server-side events and the push notifications widely used in instant messaging and other real-time applications.

Complex single-page applications

Single-Page Applications (SPAs) are a popular approach to web development in which an entire application fits on a single page with the goal of providing a comprehensive user experience, similar to a desktop app.

These days, SPAs are widely used to create social networking apps, online drawing and text tools, and many more. The classic example of an SPA is Gmail, with its cohesive presentation and seamless updates of new incoming messages.

Node.js is a great fit for SPAs thanks to its ability to handle the asynchronous calls and data-heavy workloads characteristic of these applications. Node.js’s event loop can “delay” multiple concurrent requests from a client, which ensures smooth transitions between views and seamless data updates.

Finally, Node.js is good for SPAs because it is written in the same language (JavaScript) as many popular JavaScript frameworks (Ember, Meteor, React, Angular) used in building SPAs.

Since both Node.js and browsers use JavaScript, there is less context switching between them, and developers can use the same data and language structures and modular approaches both on the server and the client side. This results in faster development and better maintainability of your SPAs.

For this reason, Node.js is popular with several social sites, like LinkedIn and Medium.

Real-time collaboration tools

Real-time collaboration applications offer a variety of software solutions for co-browsing, project management, video and audio conferencing, application sharing, collaborative editing of documents, and more. Popular and successful examples include Slack, Trello and Google Docs.

As in the case of the real-time chats, Node’s asynchronous and event-based architecture is a great fit for collaboration apps. In these applications, many events and requests occur concurrently. For example, several users can edit the same paragraph, comment, post messages, and attach media from different devices. Changes to one piece of content might be applied only after a cascade of events, where each step depends on the previous one.

By emitting push notifications to the client, Node.js will also instantly update the collaboration environment so that all users have a single and coherent representation of the application. This is precisely the reason why the team of the project management application Trello uses the Node.js stack. The engineering team of Trello decided that Node.js would be great to instantly propagate multiple updates and hold a lot of open connections, thanks to its event-driven and non-blocking architecture.

Streaming apps

Application streaming allows parts of the application to be downloadable on demand without overloading the server and the local computer. Initially, only certain parts of the application needed for bootstrap are downloaded. The remainder can be downloaded in the background if necessary. When the application is completely downloaded, it can function without any network connection at all.

Node.js is excellent for the development of streaming applications thanks to its native Stream API. It has an interface of readable and writable streams that can be processed and monitored very efficiently. Stream instances are basically Unix pipes that allow parts of the app’s executable code to be transmitted to the local machine, keeping a connection open for new components to download on demand.

As a bonus, streams do not require caching and temporary data – just an open connection to stream application data from one place to another.

Microservices architecture

In recent years, microservices architecture has become extremely popular with many major applications such as Netflix, Facebook, Amazon, and eBay, which have evolved from monolithic applications to a suite of microservices.

Node.js is an excellent solution for developing microservices and creating easy-to-use APIs to connect them. In particular, the Node.js repository features Express and Koa frameworks, which make it easy to mount several server instances for each microservice and design routing addresses for them.

These benefits have been successfully leveraged by PayPal, which has used Node.js to power its microservices architecture since 2013..