This post is on how to build beautiful APIs in Node.js. Great, and what is an API? The definition says Application Programming Interface, but what does it mean? It could mean on of the few things depending on the context:
Endpoints of a service service-oriented architecture (SOA)
Class attribute and methods
The main idea is that an API is a form of a contract between two or more entities (objects, classes, concerns, etc.). Your main goal as a Node engineer is to build beautiful API so that developers who consume your module/class/service won’t be cursing and sending you hate IM and mail. The rest of your code can be ugly but the parts which are public (mean for usage by other programs, and developers) need to be conventional, extendable, simple to use and understand, and consistent.
Let’s see how to build beautiful APIs for which you can make sure other developer
Container technology is one of the best options for software development and deployment. It allows you to share some of the OS resources while encapsulating the code and other concerns. You can think of containers as virtual machines but with less footprint.
Containers are great for micro services where you replace monoliths with many services. Each of them works in isolation and communicates with other services via a well defined interface (typically REST).
Docker is one of the most popular implementations of containers. Docker’s What is Docker? page has a a neat comparison of containers with VMs. In a nutshell, VMs use hypervisor and each VM has it’s own OS while containers share OS and only separate libraries, bin, executables, etc.
In the previous post, we learned how to perform HTTP/2 server push in a Node server. We also covered the benefits of server push there so to avoid duplication we won’t list them here. We used spdy for server push and H2. But most of the times Node developers don’t work with core HTTP server, they use a framework like Express. So let’s see how we can implement server push in Express.
HTTP/2 is the new standard of the web. It has many great features which will make the web faster and simplify the development. For example, no need to concatenate files thanks to multiplexing, or a server push which can send files before a browser knows it need them.
This post won’t cover all advantages of HTTP/2. You can read about them online. No need to go into all the details and duplicate text here. Instead, we’ll focus on server push and implement it in Node.js using Express and the spdy library.
Last week was very fruitful on conferences. Luckily, there were all in the Bay Area so I didn’t have to travel. I spoke at NodeSummit and ForwardJS, and attended npmCamp. At all of them, I met old friends and made new ones. All of them were great but in different way.
NodeSummit started on Tuesday with Executive Roundtable which consisted of tech leads from major companies most of you’re familiar with like Netflix, Disney, Dictionary.com, New York Times, me representing Capital One and others totally 12 or so. It’s the first time Joyent put together this round table. It was interesting to hear how other people use Node.js, their pains and wins. Sorry, but I can’t tell you anything more because we all swore to secrecy and weren’t allowed to record anything.
HTTP2 is the first major upgrade to the good old HTTP protocol in over 15 years (first HTTP is circa 1991)! It is optimized for modern websites. The performance is better without complicated hacks like domain sharding (having multiple domains) or file concatenation (having one large file instead of many small ones).
There’s a better alternative to the ubiquitous JSON as the communication protocol of the web. It’s Protocol Buffers (protobuf). In a nutshell, protobuf offers a more dense format (faster processing) and provides data schemas (enforcement of structure and better compatibility with old code).
The purpose of this article is not to highlight why protobufs are better or sell you on the concept. There are many article online that’ll do it for you. The purpose of this article is to show you how you can get started with this format in the Node.js environment.
This is a kitchen sink of subjectively the most interesting core features. The key takeaways of this essay are:
Event loop: Brush-up on the core concept which enables non-blocking I/O
Global and process: How to access more info
Event emitters: Crash course in the event-based pattern
Streams and buffers: Effective way to work with data
Clusters: Fork processes like a pro
Handling async errors: AsyncWrap, Domain and uncaughtException
C++ addons: Contributing to the core and writing your own C++ addons
We can start with event loop which is at the core of Node.
Node.js Non-Blocking I/O
It allows processing of other tasks while IO calls are in the process. Think Nginx vs. Apache. It allows Node to be very fast and efficient because blocking I/O is expensive!
Take look at this basic example of a delayed println function in Java:
Before we can get started with Node patterns, let’s touch on some of the main advantages and features of using Node. They’ll help us later to understand why we need to deal with certain problems.
Node Advantages and Features
Here are some of the main reasons people use Node:
Asynchronous + Event Driven: Node executes tasks concurrently with the use of asynchronous code and patterns, thanks to event loop.
Non-Blocking I/O: Node is extremely fast due to its non-blocking input/output architecture and Google Chrome V8 engine.
That’s all neat but async code is hard. Human brains just didn’t evolve to process things in an asynchronous manner where event loop schedules different pieces of logic in the future. Their order often is not the same order in which they were implemented.