Node.js

From Wikipedia, the free encyclopedia
  (Redirected from Nodejs)
Jump to: navigation, search
Node.js
Node.js logo.svg
Original author(s) Ryan Dahl
Developer(s) Node.js Developers, Joyent, GitHub Contributors
Initial release May 27, 2009 (2009-05-27)[1]
Stable release 0.12.7 / July 9, 2015 (2015-07-09)[2]
Development status Active
Written in C, C++, JavaScript
Operating system OS X, Linux, Solaris, FreeBSD, OpenBSD, Microsoft Windows (older versions require Cygwin), webOS, NonStop OS
Type Event-driven networking
License MIT
Website nodejs.org

Node.js is an open source, cross-platform runtime environment for server-side and networking applications. Node.js applications are written in JavaScript and can be run within the Node.js runtime on OS X, Microsoft Windows, Linux, FreeBSD, NonStop, IBM AIX, IBM System z and IBM i. Its work is hosted and supported by the Node.js Foundation,[3] a Collaborative Project at Linux Foundation.[4]

Node.js provides an event-driven architecture and a non-blocking I/O API that optimizes an application's throughput and scalability. These technologies are commonly used for real-time web applications.

Node.js uses the Google V8 JavaScript engine to execute code, and a large percentage of the basic modules are written in JavaScript. Node.js contains a built-in library to allow applications to act as a Web server without software such as Apache HTTP Server or IIS.

Node.js is gaining adoption as a server-side platform[5] and is used by IBM,[6] Microsoft,[7][8] Yahoo!,[9] Walmart,[10] Groupon,[11] SAP,[12] LinkedIn,[13][14] Rakuten, PayPal,[15][16] Voxer,[17] and GoDaddy.[18]

History[edit]

Ryan Dahl, creator of Node.js

Node.js was invented in 2009 by Ryan Dahl, and other developers working at Joyent.[19] Node.js was created and first published for Linux use in 2009. Its development and maintenance was spearheaded by Ryan Dahl and sponsored by Joyent, the firm where Dahl worked.[20]

Dahl was inspired to create Node.js after seeing a file upload progress bar on Flickr. The browser did not know how much of the file had been uploaded and had to query the Web server. Dahl desired an easier way.[21]

It garnered international attention after its debut at the inaugural European JSConf on November 8, 2009.[22][23][24] Dahl presented Node.js, which combined Google's V8 JavaScript engine, an event-loop, and a low-level I/O API.[19] The project received a standing ovation, and has since then experienced significant growth, popularity and adoption.[19]

In 2011, a package manager was introduced for Node.js library, called npm. The package manager allows publishing and sharing of open-source Node.js libraries by the community, and simplifies installation, updating and uninstallation of libraries.[19]

In June 2011, Microsoft partnered with Joyent to implement a native Windows version of Node.js.[25] The first Node.js build to support Windows was released in July.

In January 2012, Dahl stepped aside, promoting coworker and npm creator Isaac Schlueter to manage the project.[26]

In January 2014, Schlueter announced Timothy J. Fontaine would be Node.js's new project lead.[27]

In December 2014, Fedor Indutny started io.js, a fork of Node.js. Due to internal conflict over Joyent's governance, io.js was created as an open governance alternative with a separate technical committee.[28]

In February 2015, the intent to form a neutral Node.js Foundation was announced. By June 2015, the Node.js and io.js community voted to work together under the Node.js Foundation [29]

Overview[edit]

Node.js allows the creation of web servers and networking tools, using JavaScript and a collection of "modules" that handle various core functionality.[19][22][30][31][32] Modules handle file system I/O, networking (HTTP, TCP, UDP, DNS, or TLS/SSL), binary data (buffers), cryptography functions, data streams, and other core functions.[19][31][33] Node's modules have a simple and elegant API, reducing the complexity of writing server applications.[19][31]

Frameworks can be used to accelerate the development of applications, and common frameworks are Express.js, Socket.IO and Connect.[19][34] Node.js applications can run on Microsoft Windows, Unix and Mac OS X servers. Node.js applications can alternatively be written with CoffeeScript[35] (a more readable form of JavaScript), Dart or Microsoft TypeScript (strongly typed forms of JavaScript), or any language that can compile to JavaScript.[35]

Node.js is primarily used to build network programs such as web servers, making it similar to PHP and Python.[30] The biggest difference between PHP and Node.js is that PHP is a blocking language (commands execute only after the previous command has completed), while Node.js is a non-blocking language (commands execute in parallel, and use callbacks to signal completion).[30]

Node.js brings event-driven programming to web servers, enabling development of fast web servers in JavaScript.[19] Developers can create highly scalable servers without using threading, by using a simplified model of event-driven programming that uses callbacks to signal the completion of a task.[19] Node.js was created because concurrency is difficult in many server-side programming languages, and often leads to poor performance.[22] Node.js connects the ease of a scripting language (JavaScript) with the power of Unix network programming.[19]

Node.js is built on the Google V8 JavaScript engine, because:[22]

  • V8 is open-source under the BSD license
  • V8 is extremely fast
  • V8 is focused on the web, so is proficient with internet fundamentals like HTTP, DNS, TCP

Thousands of open-source libraries have been built for Node.js, and can be downloaded for free from the npm website. Node.js has a developer community centered around two mailing lists and the IRC channel #node.js on freenode. The community gathers at NodeConf, an annual developer conference focused on Node.js.[36]

Technical[edit]

Threading[edit]

Node.js operates on a single thread, using non-blocking I/O calls, allowing it to support tens of thousands of concurrent connections without incurring the cost of thread context-switching. The design of sharing a single thread between all the requests means it can be used to build highly concurrent applications. The design goal of a Node.js application is that any function performing I/O must use a callback.

A downside of this approach is that Node.js doesn't allow scaling with the number of CPU cores of the machine it is running on without using an additional module such as cluster, StrongLoop Process Manager, or pm2.

V8[edit]

V8 is the JavaScript execution engine built for Google Chrome, open-sourced by Google in 2008. Written in C++, V8 compiles JavaScript source code to native machine code instead of interpreting it in real time.

Node.js contains libuv to handle asynchronous events. V8 provides the run-time for JavaScript. Libuv is an abstraction layer for network and file system functionality on both Windows and POSIX-based systems like Linux, Mac OS X and Unix.

The core functionality of Node.js resides in a JavaScript library. The Node.js bindings, written in C++, connect these technologies to each other and to the operating system.

Package management[edit]

npm is the pre-installed package manager for the Node.js server platform. It is used to install Node.js programs from the npm registry. By organizing the installation and management of third-party Node.js programs, it helps developers build faster. npm is not to be confused with the CommonJS require() statement. It is not used to load code: instead, it is used to install code and manage code dependencies from the command line. The packages found in the npm registry can range from simple helper libraries like Underscore.js to task runners like Grunt.

Unified API[edit]

Node.js combined with a browser, a document DB (such as MongoDB or CouchDB) and JSON offers a unified JavaScript development stack. With the increased attention to client-side frameworks and the adaptation of what were essentially server-side development patterns like MVC, MVP, MVVM, etc., Node.js allows the reuse of the same model and service interface between client-side and server-side.

Event loop[edit]

Node.js registers itself with the operating system so that it is notified when a connection is made. When a connection is made, the operating system will issue a callback. Within the Node.js runtime, each connection is a small heap allocation. Traditionally, relatively heavyweight OS processes or threads handled each connection. Node.js, however, uses an event loop, instead of processes or threads, to scale to millions of connections happening at the same time.[37] In contrast to other event-driven servers, Node.js's event loop does not need to be called explicitly. Instead callbacks are defined, and the server automatically enters the event loop at the end of the callback definition. Node.js exits the event loop when there are no further callbacks to be performed.

Tools[edit]

Desktop IDEs
Online code editors
Runtimes and debuggers
Application performance management
Frameworks
Social network
  • Node.js World is a social networking website where Node.js developers can interact, chat, follow each other, desktop notification, share tutorials, etc.

Alternatives[edit]

io.js[edit]

io.js
io.js logo
Original author(s) Fedor Indutny
Developer(s) io.js Developers, GitHub Contributors
Initial release January 14, 2015 (2015-01-14)[43]
Stable release 2.0.1 / May 7, 2015 (2015-05-07)[44]
Preview release 2.0.2-nightly20150512c58264e58b / May 12, 2015 (2015-05-12)[45]
Development status Active
Written in C, C++, JavaScript
Operating system OS X, Linux, Microsoft Windows
Type Event-driven networking
License MIT
Website iojs.org

io.js is a fork of Node.js, started in December 2014,[28] by a contributor to the Node.js project.[46] It is expected to be marked stable in March 2015.[47] The reason for forking away from Node.js, was that the authors wanted a project outside corporate governance, and have therefore created an "open governance" system consisting of a technical committee which the authors are part of.[46]

Like Node.js, it is an open source, cross-platform runtime environment for server-side and networking applications. io.js applications are written in JavaScript, and can be run within the io.js runtime on OS X, Microsoft Windows, and Linux. io.js provides an event-driven architecture and a non-blocking I/O API that optimizes an application's throughput and scalability.

io.js uses the Google V8 JavaScript engine to execute code, but unlike Node.js[48] plans are to keep it up-to-date with latest releases of this engine.[47]

As of the week of May 15, 2015, the io.js organization has voted and officially agreed to merge back with the Node.js project under the rubric of a new foundation, the Node Foundation.[49] The combined organization will be named 'nodejs'.

JXcore[edit]

JXcore is a fork of Node.js targeting mobile devices and IoTs. Its first beta was released in January 2014. It was open sourced[50] on February 13, 2015 and made available through a GitHub repository. JXcore can use both Google V8 and Mozilla SpiderMonkey as its JavaScript engine. As a result, JXcore can run Node applications on iOS devices using Mozilla SpiderMonkey.

Other languages[edit]

Similar environments available for other programming languages include:

See also[edit]

References[edit]

  1. ^ https://github.com/joyent/node/tags?after=v0.0.4. Retrieved 2 August 2014.  Missing or empty |title= (help)
  2. ^ "Release v0.12.7: 2015.07.09, Version 0.12.7 (Stable)". Retrieved 17 July 2015. 
  3. ^ "Node.js Foundation - Node.js". Retrieved 4 July 2015. 
  4. ^ "Linux Foundation Collaborative Projects". Retrieved 4 July 2015. 
  5. ^ Industry Usage, Node.js Website
  6. ^ "IBM Bluemix". Retrieved 4 July 2015. 
  7. ^ "Here's why you should be happy that Microsoft is embracing Node.js". The Guardian. November 9, 2011. Retrieved May 10, 2012. 
  8. ^ "WebMatrix - Front End Web Developers take note (ASP.NET, PHP, node.js and more)". Retrieved 2 August 2014. 
  9. ^ "Yahoo! Announces Cocktails – Shaken, Not Stirred". Retrieved 7 April 2015. 
  10. ^ "Why Walmart is using Node.js". VentureBeat. January 24, 2012. Retrieved May 10, 2012. 
  11. ^ Geitgey, Adam (30 October 2013). "I-Tier: Dismantling the Monoliths". Groupon. Retrieved 30 April 2014. 
  12. ^ "SAP AppBuilder". SAP. March 10, 2014. Retrieved March 10, 2014. 
  13. ^ "You'll never believe how LinkedIn built its new iPad app". VentureBeat. May 2, 2012. Retrieved May 10, 2012. 
  14. ^ "Blazing fast node.js: 10 performance tips from LinkedIn Mobile". Retrieved 7 April 2015. 
  15. ^ "Clash of the Titans: Releasing the Kraken, NodeJS @paypal". fluentconf.com. May 28, 2013. Retrieved September 11, 2013. 
  16. ^ "All such companies and their products in which Node.js is used". Retrieved 2 August 2014. 
  17. ^ The Node Ahead: JavaScript leaps from browser into future, The Register, March 1, 2011
  18. ^ Why GoDaddy’s Nodejitsu deal is great for Node.js, VentureBeat, February 10, 2015
  19. ^ a b c d e f g h i j k Professional Node.js: Building Javascript Based Scalable Software, John Wiley & Sons, 01-Oct-2012
  20. ^ Alex Handy (2011-06-24). "Node.js pushes JavaScript to the server-side". SDTimes. Retrieved 2011-09-04. 
  21. ^ Harris, Amber (April 1, 2012). "The Birth of Node: Where Did it Come From? Creator Ryan Dahl Shares the History". Devops Angle. Retrieved 26 October 2013. 
  22. ^ a b c d Sams Teach Yourself Node.js in 24 Hours, Sams Publishing, 05-Sep-2012
  23. ^ "Ryan Dahl at JSConf EU 2009". 
  24. ^ "Ryan Dahl at JSConf EU 2009 Video". 
  25. ^ "Porting Node to Windows". Retrieved 2 August 2014. 
  26. ^ Dahl, Ryan. "New gatekeeper". Retrieved 26 October 2013. 
  27. ^ Schlueter, Isaac (January 15, 2014). "The Next Phase of Node.js". Retrieved 21 January 2014. 
  28. ^ a b Krill, Paul (Dec 4, 2014). "Why io.js Decided to Fork Node.js". JavaWorld. Retrieved Dec 15, 2014. 
  29. ^ "Node.js Foundation Advances Community Collaboration, Announces New Members and Ratified Technical Governance". Retrieved 4 July 2015. 
  30. ^ a b c Node.js for PHP Developers, O'Reilly Media, Inc., 2013
  31. ^ a b c Node.js Essentials, Packt Publishing, 09-Sep-2014
  32. ^ Smashing Node.js: JavaScript Everywhere, John Wiley & Sons, 14-Aug-2012
  33. ^ Modules, Nodejs Website
  34. ^ Express.js Guide: The Comprehensive Book on Express.js, Azat Mardan, 28-May-2014
  35. ^ a b "CoffeeScript on Node.js". O'Reilly Media, Inc. April 15, 2013. Retrieved May 17, 2015. 
  36. ^ Finley, Klint (April 7, 2011). "NodeConf Schedule Announced". ReadWriteHack. Retrieved 2 August 2014. 
  37. ^ About Node.js, Node.js Website
  38. ^ "Node.js Tools for Visual Studio". Codeplex. Retrieved 2 August 2014. 
  39. ^ "Bergius: Flowhub and the GNOME Developer Experience". LWN.net. 2014-05-02. Retrieved 2014-05-24. 
  40. ^ Mike Kopp (2014-11-27). "There’s a new kid in town: node.js monitoring". blog.ruxit.com. Retrieved 2014-11-28. 
  41. ^ Node.js Framework Comparison: Express vs. Koa vs. Hapi, AirPair
  42. ^ Peter Wayner (21 May 2014). "13 fabulous frameworks for Node.js". InfoWorld. Retrieved 4 July 2015. 
  43. ^ "Release v1.0.0-release". Retrieved 2 February 2015. 
  44. ^ "Release v2.0.1". Retrieved 13 May 2015. 
  45. ^ "Index of /download/nightly/v2.0.2-nightly20150512c58264e58b/". Retrieved 13 May 2015. 
  46. ^ a b Q&A: Why io.js decided to fork Node.js, Infoworld Tech Watch
  47. ^ a b Mikeal, Rogers (January 28, 2015). "State of io.js". Retrieved 2 February 2015. 
  48. ^ Ben Noordhuis (Nov 12, 2014). "Issue 3692: function suddenly becomes undefined". V8 JavaScript Engine Issues. Retrieved 2 February 2015. 
  49. ^ "io.js and Node.js merge". Retrieved 27 June 2015. 
  50. ^ Serdar Yegulalp (20 February 2015). "Node.js fork JXcore goes open source, aims for mobile developers". InfoWorld. Retrieved 4 July 2015. 
  51. ^ "Limitations". node-julia. 

Further reading[edit]

External links[edit]