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Introduction to Node.js
Node.js is a JavaScript runtime built on Chrome's V8 JavaScript engine. It allows JavaScript to be run on the server-side and is well-suited for real-time, event-driven applications due to its asynchronous and non-blocking I/O model. It was created in 2009 by Ryan Dahl who was frustrated by the limitations of JavaScript in the server-side. Node.js uses an event loop that handles asynchronous callbacks and a single thread model to achieve scalable performance. Many large companies like Uber, LinkedIn, and Netflix use Node.js for applications that require real-time features or high throughput.
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Introduction to Node.js
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- 2. –The Smiths “When yousay it's gonna happen "now" Well when exactly do you mean? See I've already waited too long And all my hope is gone.” 2
- 3. 3 “I hate almostall software…The only thing that matters in software is the experience of the user. ” -Ryan Dahl , Inventor of Node.js http://tinyclouds.org/rant.html
- 4. 1. What isNode.js? 2. How does it work? 3. What can I do with it? 4. Who is using it? 5. “Hello World!” 6. Resources Aaron Rosenberg Mark Keith 4 Agenda
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- 6. What is Node.js®? •Server-side JavaScript platform • Built on Google's V8 high performance Javascript runtime. The same one Chrome uses. • NOT JavaScript, but rather a set of fast backend tools written in C/C++. • Designed with an asynchronous architecture that works pretty much like your browser. • An event-driven, non-blocking I/O model perfect for data-intensive, real-time applications • A way to run javascript outside of your browser. • The only way (I know of) to build web sites end-to-end using only one language. • Used in production by top products and companies • A growing community and platform 6
- 7. Web servers areold. • 20 years of Web servers had one general design: Receive a connection. Accept a client request. Return a response. Shut down the connection. • By the early-mid 2000s, web applications were significantly more interactive, complex and real-time. • Completely avoiding the old “stateless” request-response paradigm was hard. REQUEST RESPONSE 7
- 8. This guy gotfed up. In 2006, a web developer named Ryan Dahl got hired to build a snowboarding website. And he “got into this feature where users could upload images.” FEATURE: “How do you give people feedback on how much of the file has been uploaded?” Meant doing two things at the same time, but the server side of things was messy. Why was it so hard to check what was happening in another connection? So in 2009, he created Node.js. NOTE: There were and still are a lot of solutions to deal with real-time applications, I/O and user concurrency. (Scala/ Java, Python/Twisted, Ruby EventMachine, PHP React & Go). But doing those things wasn’t particularly easy then (and still isn’t). 8
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- 10. What if everythingwas non-blocking? How do we make concurrent requests and responses easier? What if you never waited for any IO to happen? 10
- 11. How does itwork? 11
- 12. Node works likeyour browser. • Node.js is built on top of Google’s V8 JavaScript runtime. • V8 takes code you write in JavaScript, compiles it into machine code, and executes it. • Similar to browser, Node has a bunch of helpers that can do other stuff in parallel. 12 Application APIs Low Level I/O Stuff Javascript Google JavaScript Engine DOM AJAX Network Filesystem DISCLAIMER: GROSS OVER-SIMPLIFICATION!
- 13. The power ofthe asynchronous callback. • I/O can still be a huge bottleneck for servers. • Special sauce of Node is ability for code to go off to execute somewhere else to do it’s thing, while the rest of your code continues. • Code is called an “asynchronous callback.” • HIGH LEVEL Asynchronous callbacks are functions that can go off on their own, do some stuff and come back when they are done. (It’s those parallel helpers that make it happen.) • Event Loop running all the time picks up executed code and sends it back to you. 13
- 14. How your codeworks in the browser. call stackcode BrowserAPIs task queue DOM (document) ajax (XMLHTTPRequest) SetTimeout checkEmailAddress() { containsATsymbol(); endsWithTLDomain(); }; checkEmailAddress(); checkEmailAddress() containsATsymbol() endsWithTLDomain() 14 onClick() onMouseover() onFocus() event loop Architecture diagram and stack animation credited to Philip Roberts.
- 15. How your codeexecutes on a Node.js server. call stackcode NodeAPIs task queue File System Network Process formatEmailAddress() 15 saveEmailToDB() sendWelcomeEmail() checkLocalUbers() …and much more! event loop CB saveEmailToDB(); CB sendWelcomeEmail(); formatEmailAddress();
- 16. The fast foodanalogy. 1. Order is given to a cashier taking one order at a time. (call stack!) 2. After ordering, you step aside. 3. Helpers in the back then work on part of your order (callbacks!) 4. And drop it in the pick up area when it’s done. (task queue!) 5. Food is picked up by the cashier as it is ready. (event loop!) 16
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- 18. What are somegreat uses for Node? 18
- 19. Where Node.js shines. Whenreal-time, two-way interactivity with lots of concurrent users is a requirement, consider Node.js. • Chat • Data Streaming • Monitoring Dashboards • Team-based GPS Applications • Integrations (JSON) • Internet of Things - health monitors, sensors, thermostats, cars and “smart” devices that need to talk to disparate data sources and services both in real- time and offline. 19
- 20. But Node.js isn’tperfect. REASON #1 When you need something more powerful than JS. REASON #2 When I/O is not your problem. Applications that need heavy server-side computational processing or simple content delivery won’t take advantage of the platform. 20
- 21. Popular packages availablevia Node.js (NPM) • Express • Async.js • Request • Browserify • Grunt • PM2 • Socket.IO • Commander.js • Mocha • Bower 21 • Underscore • UglifyJS2 • Cheerio • Passport • Nodemailer • Hapi • React • Karma • Pug • Node MySQL • MongoDB • JSHint • Morgan • LESS • WebPack • Angular • Restify • Marked • GraphicsMagick • JSDom *Top 30 NPM Packages for Node.js Developers 2016 https://colorlib.com/wp/npm-packages-node-js/
- 22. Popular text editorsand IDEs (for Node) • Cloud 9 https://c9.io/ • Intellij IDEA https://www.jetbrains.com/idea/ • WebStorm https://www.jetbrains.com/webstorm/ • Komodo IDE www.activestate.com/komodo-ide • Koding https://koding.com/ 22 • Eclipse https://eclipse.org/ • WebMatrix https://www.microsoft.com/web/webmatrix/ • Sublime Text https://www.sublimetext.com/ • Atom https://atom.io/ • Visual Studio Code https://code.visualstudio.com/
- 23. Who is usingit? 23
- 24. Small and relativelynew, the community continues to grow. 24
- 25. Enterprise corporations usingNode.js 25
- 26. Case Studies UBER https://eng.uber.com/tech-stack-part-two/ •Uber’s core trip execution engine originally written in Node.js • Mobile client router API written in Node.js • Systems that handle pings from riders and drivers in real-time and then match them written in Node.js and Go. • Core of our web tech stack is built on top of Node.js EBAY & PAYPAL • Moved production from Java to Node.js • 2x as fast with fewer people • 33% fewer lines of code • 40% fewer files LINKEDIN • 20x faster • Frontend and backend mobile teams combined into single unit • Servers cut from 30 to 3. Enough headroom to handle 10x current capacity. NETFLIX • Shifted UI to Node.js GODADDY • Started prototyping in 2013. • Revamped entire backend to Node.js. • Increased hosting capabilities • Handled same load with 10% of the hardware. ATOM —> VS CODE • Written with Node.js! 26
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- 29. Learning More AboutNode.js Online Training • Node Hero - Getting Started With Node.js Tutorial https://blog.risingstack.com/node-hero-tutorial-getting-started-with-node-js/ • You Don't Know Node.js https://github.com/azat-co/you-dont-know-node Books • Node.js Design Patterns Blog Posts • Understanding Stateful Web Connections Using JavaScript https://www.meteor.com/articles/stateful-web-connections-with-meteor • Why The Hell Would I Use Node.js? A Case-by-Case Tutorial https://www.toptal.com/nodejs/why-the-hell-would-i-use-node-js • Architecture of Node.js’ Internal Codebase https://arenli.com/architecture-of-node-js-internal-codebase-57cd8376b71f Videos • What the Heck is an Event Loop Anyway by Philip Roberts @ JSConf EU 2014 https://www.youtube.com/watch?v=8aGhZQkoFbQ • Ryan Dahl Interview, Node Summit 2012 https://www.youtube.com/watch?v=Fc26auhSLqM 29
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