Node.js #digpen presentation
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The document provides an overview of Node.js, a JavaScript runtime environment that allows JavaScript to be used for server-side scripting. Some key points: - Node.js uses Google's V8 JavaScript engine and allows JavaScript code to be run on the server side, providing a single language for both client-side and server-side development. - This avoids duplicating code across different programming languages and platforms and reduces maintenance. - Node.js is well-suited for real-time applications with many concurrent connections due to its asynchronous and event-driven model. - However, using JavaScript for all development has drawbacks like lack of specialization and debugging challenges. The future of Node.js depends on
![On the browser
/^[A-D][0-9]{4}$/i.test(v)
11](https://image.slidesharecdn.com/node-js-presentation-121001085500-phpapp01/85/Node-js-digpen-presentation-11-320.jpg)
![On the server
CF: ReFindNoCase("^[A-D][0-9]{4}$", v) GT 0
Java: Pattern.matches("(?i)^[A-D][0-9]{4}$", v)
.NET Regex.Match(v, "^[A-D][0-9]{4}$", RegexOptions.IgnoreCase)
12](https://image.slidesharecdn.com/node-js-presentation-121001085500-phpapp01/85/Node-js-digpen-presentation-12-320.jpg)
![The Implementation
Java Mozilla Rhino
Site
Browser
CF
Site
/^[A-D][0-9]{4}$/i.test(v) .NET
Site
MS Jscript
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![So we did it!
Forms generated using a simple template* containing JavaScript
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if ( Props["FIELDPROPERTIES"]["MAXLENGTH"] !== "") {
maxLength="maxlength='" + Props["FIELDPROPERTIES"]["MAXLENGTH"] + "'";
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<input type="text" name="<%=Props["FIELDID"]%>" id="<%=Props["FIELDID"]%>" <%=maxLength%>/>
18](https://image.slidesharecdn.com/node-js-presentation-121001085500-phpapp01/85/Node-js-digpen-presentation-18-320.jpg)
Node.js #digpen presentation
- 1. Node.js: JavaScript from Client to Server and Beyond! Robert McCarthy –CEO Gary Ratclliffe – Development Manager
- 2. Agenda 1. The best new technology in the world 2. The exciting future 3. The real world 4. If still alive Goto 1 2
- 3. Introduction to GOSS Robert McCarthy – GOSS CEO Gary Ratclliffe – Technical
- 4. Who we work with 4
- 6. How many of you use JavaScript? Put your hands UP if YES Is the majority of your JavaScript jQuery? Put your hands DOWN if YES Are you using any server-side JavaScript? Put yours hands DOWN if NO 6
- 7. Why? 7
- 9. The Problem? 9
- 10. Form validation for websites User needs simple validation 10
- 12. On the server CF: ReFindNoCase("^[A-D][0-9]{4}$", v) GT 0 Java: Pattern.matches("(?i)^[A-D][0-9]{4}$", v) .NET Regex.Match(v, "^[A-D][0-9]{4}$", RegexOptions.IgnoreCase) 12
- 13. 4 different implementations!! More work, more maintenance, more risk 13
- 14. The Solution? Server Side javascript = One language Less work, less maintenance, less risk 14
- 15. The Implementation Java Mozilla Rhino Site Browser CF Site /^[A-D][0-9]{4}$/i.test(v) .NET Site MS Jscript 15
- 16. What Next? Like the idea of common language on all platforms (But Clients still expect .NET sites to be .NET like & Java sites to be Java like) 16
- 17. Entire Forms engine? Complex Benefits from implementing once Needs to be extensible There is always a new requirements Clients could create their own extensions 17
- 18. So we did it! Forms generated using a simple template* containing JavaScript <% if ( Props["FIELDPROPERTIES"]["MAXLENGTH"] !== "") { maxLength="maxlength='" + Props["FIELDPROPERTIES"]["MAXLENGTH"] + "'"; } %> <label for='<%=Props["FIELDID"]%>'><%=Processor.htmlEsc(Props["FIELDPROPERTIES"]["LABEL"])%></label> <input type="text" name="<%=Props["FIELDID"]%>" id="<%=Props["FIELDID"]%>" <%=maxLength%>/> 18
- 19. Snag We really needed a good, fast JavaScript engine on all platforms. JScript was problem 19
- 20. V8 Arrives! Created by Google for Chrome Also designed to be used in other apps 20
- 21. V8 is FAST!! Clever optimisations and compiling to native code. Not quite as dramatic now as when it first appeared 21
- 22. V8 is Single Threaded!! Only one thread can execute JavaScript at a time V8 Locking can help synchronize multiple threads One of reasons it’s fast Multi-threading can get complex…and slow 22
- 23. V8.net wrapper Replaced JScript with JavaScript .NET from Noesis Proved reliable in production deployment Real JavaScript Much faster than Jscript!! 23
- 24. V8 is Single Threaded!! A problem for traditional server-side scalability How do you handle multiple concurrent requests? 24
- 25. V8.net wrapper Limited by single threading Resorted to a global lock around execution But an evolutionary dead-end while V8 is single threaded 25
- 26. Along came Node.JS 26
- 27. Along came Node.JS 27
- 28. Non blocking vs Threads Threads use a lot of memory and are limited Use asynchronous IO and an event loop like NGINX 28
- 29. Weakness now a strength Ryan Dahl, creator of Node.JS used these concepts in Node.JS The single threaded nature of V8 was no longer a problem 29
- 30. You’ve gotta love it 30
- 31. Node.JS
- 32. What can Node.js do? Simple http hello world 32
- 33. Simple web server Continuations break processing into steps Function called on each request Function called when file contents available 33
- 34. Node.JS Lots of additional modules Really learn JavaScript the language not just jQuery Google ‘Douglas Crockford’ Look at source code of real projects Combine it with MongoDB for end-to-end JSON 34
- 35. Node.JS Think carefully if your application needs it Highly interactive? Loads of AJAX? Very high number of requests? Not just because you can! 35
- 36. 1000’s of concurrent requests All server-side JavaScript
- 37. Writing continuations for everything is hard Sooner or later something has to do something
- 38. Writing continuations for everything is hard 38
- 39. Real world code is hard How many developers really understand it? Many can tweak, but starting from scratch… Debugging can be difficult Node-inspector worth a look 39
- 40. Our Solution Lets call it pragmatic 40
- 41. IcedCoffeeScript? Not a drink but derived from coffeesript CoffeeScript = Cool, elegant syntax, JavaScript without the Bad Bits 41
- 42. IcedCoffeeScript? What happen to the 1 language It makes you think different. 42
- 43. await and defer used to express callbacks Cleaner code layout but you do have to learn CoffeeScript Extra build step to generate JavaScript 43
- 44. And that other issue? 44
- 45. Sooner or later something has to do something For many things this is not a problem eg Database modules written to be asynchronous 45
- 46. Non blocking? This example is computationally intensive. It results in high CPU use on any system. On Node.JS it would only process one request at a time. n=40 takes about 5s 3 concurrent requests: 1 client will wait 15s 46
- 47. V8 is single threaded! A badly written extension and Bye Bye server… 47
- 48. Use Node.JS for it’s strengths 48
- 49. Multiple workers processes JavaScript Worker JavaScript Worker JavaScript Worker TeaJS TeaJS TeaJS Worker Manager Node.JS Java Worker Requests Java Worker Java Worker Java VM Java VM Management Java VM Security Node.JS Worker Node.JS Worker Node.JS Worker Node.JS Node.JS Node.JS 49
- 50. Best of all worlds Requests delegated to a suitable worker or queued if worker busy A CGI style wrapper round the V8 engine allowing use of traditional linear JavaScript. It’s a good match for our approach to forms rendering 50
- 51. Where Next? Does the industry need Node.JS? Other web servers can/will achieve similar performance So its really all about the language? 51
- 52. Is 1 Language an ideal? Same developers for UI and Backend? Common in start-ups Less so in the ‘enterprise’ Jack of all trades master of none? 52
- 53. So will it survive? 53
- 54. Today most sites.. 54
- 55. Multiple Dev Languages 55
- 56. Client is a dumb browser 56
- 57. Clients are isolated from one another 57
- 58. Anything more interactive tends to be bespoke 58
- 60. Imagine 60
- 62. Imagine One Language 62
- 63. Imagine One Data Format: JSON? 63
- 64. Imagine Transfer Data not UI 64
- 66. 66
- 67. So is it just a dream? 67
- 68. 68
- 69. But that’s for the next talk? 69
- 70. Final Thoughts…. The web is changing at pace. There will be lots of shiny toys They might not lead to nirvana but they will often give you a glimpse of a very exciting future!! Stay Excited… 70
- 71. Any questions? Thank you!! PS. We are hiring!