Business considerations for node.js applications
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The document presents a comprehensive overview of Node.js, discussing its definitions, advantages, drawbacks, use cases, and challenges associated with its adoption. It highlights Node.js's event-driven architecture for managing concurrent operations and emphasizes the efficient resource usage leading to cost savings and potential revenue increases. The document also includes case studies from companies like LinkedIn and Yammer to illustrate successful implementations of Node.js.
Business considerations for node.js applications
- 1. 6000 Greenwood Plaza Blvd Suite 110 Greenwood Village, CO 80111 303.798.5458 www.aspenware.com Business Considerations for Node.js Applications Michael Filbin m.filbin@aspenware.com
- 2. Agenda… • Definitions • Introduction to Node.js • Problems it attempts to solve • Drawbacks and challenges to adoption • Use cases and case studies • Hello World example (if time) • Summary and conclusion Business Considerations for Node.js Applications
- 3. Who Am I? • Consultant at Aspenware Internet Solutions Inc. • Background in Open Source technologies • Currently JavaScript engineer at Pearson • Member of Linux and Free Software foundations • Co-founder of Gogy Inc. Business Considerations for Node.js Applications
- 4. Who Are You? Business Considerations for Node.js Applications
- 5. Acknowledgements Business Considerations for Node.js Applications
- 6. Key Terms… • API: A collection of publically exposed methods to facilitate use of a library • Asynchronous: The execution of a function and its result are not mutually exclusive. • JavaScript Runtime: Optimizes and executes JavaScript code • Language Binding: Uses of one programming language to ‘wrap’ a library in another • Callback: A reference to executable code that is passed as an argument to a function. • I/O Operations: Operations that involve reading/writing data through some time of interface. • Procedural Programming: Programs are expressed in terms of steps (procedures) to be carried out • Event-driven Programming: Execution of a program is carried out in response to events. • Blocking Process: A process that prevents the continuation of execution until it returns. Business Considerations Brief Introduction to Node for Node.js Applications
- 7. What Is Node? Business Considerations for Node.js Applications
- 8. What does Node do? • API for interacting with low-level system libraries asynchronously • Leverages features inherent in the JavaScript language • Intends to manage concurrency, latency, parallelism Business Considerations for Node.js Applications
- 9. Visualizing Latency 300000000 250000000 240000000 Processor Cycles 200000000 150000000 100000000 41000000 50000000 3 14 250 0 1 L1 Cache 3 L2 Cache 14 RAM 250 Hard Disk 41000000 Network 240000000 Business Considerations for Node.js Applications
- 10. Web Application Life Cycle? Route Request to Controller Action Respond to Request Make Database Query Write to log file Operate on results Business Considerations for Node.js Applications
- 11. Traditional Scaling Model… Route Request to Controller Action Route Request to Controller Action Route Request to Controller Action Route Request to Controller Action Route Request to Controller Action Respond to Request Respond to Request Respond to Request Respond to Request Respond to Request Make Database Query Make Database Query Make Database Query Make Database Query Make Database Query Operate on results Operate on results Operate on results Operate on results Operate on results Operate on results Operate on results Operate on results Operate on results Operate on results Route Request to Controller Action Route Request to Controller Action Route Request to Controller Action Route Request to Controller Action Route Request to Controller Action Respond to Request Respond to Request Respond to Request Respond to Request Respond to Request Make Database Query Make Database Query Make Database Query Make Database Query Make Database Query Operate on results Operate on results Operate on results Operate on results Operate on results Operate on results Operate on results Operate on results Operate on results Operate on results Route Request to Controller Action Route Request to Controller Action Route Request to Controller Action Route Request to Controller Action Route Request to Controller Action Respond to Request Respond to Request Respond to Request Respond to Request Respond to Request Make Database Query Make Database Query Make Database Query Make Database Query Make Database Query Operate on results Operate on results Operate on results Operate on results Operate on results Operate on results Operate on results Operate on results Operate on results Operate on results Business Considerations for Node.js Applications
- 12. Resource Limited Scaling Load Balancer Web App App Server Server Server Search Database Engine Business Considerations for Node.js Applications
- 13. Resource Limited Scaling Business Considerations for Node.js Applications
- 14. Node’s Execution Model • Using an event loop • Event occurs (emitted) • Non-I/O operations return immediately • I/O operations defer to libeio or libuv • I/O interrupt received and callback is executed • Data returned to client Event 1 libeio FS … Network Crypto Event N libuv All on a single thread on a single processor RESTful Web Services with Node.js
- 15. Event Loop Analogy RESTful Web Services with Node.js
- 16. Node Architecture… Async DNS V8 RunLme OpenSSL libuv libeio Business Considerations for Node.js Applications
- 17. Scaling Node Applications: Load Balancer / Reverse Proxy App Content Server Delivery Network (CDN) Search Database Engine Business Considerations for Node.js Applications
- 18. Managing Node Dependencies • ‘Requiring’ external libraries is handled though the CommonJS module pattern. • 3rd party libraries distributed though NPM package management tool • Packages can be installed globally or locally • Application dependencies can be expressed in a manifest file (package.json) Business Considerations for Node.js Applications
- 19. Including Dependencies <script type="text/javascript" src="scripts/myscript.js"></script> Business Considerations for Node.js Applications
- 20. Including Dependencies // System-wide (global) libraries/modules // Stored in /usr/local/lib/node_modules var path = require('path'); var fileSystem = require('fileSystem') // Local (project) libraries // ./node_modules var restify = require('restify'); var nconf = require('nconf'); // Including scripts from somewhere in // the file system var MyModel = require("./lib/models/ MyModel"); Business Considerations for Node.js Applications
- 21. Use Cases for Node.js • Creating REST APIs (JSON APIs) • Creating chat servers or messaging clients • Single-page RIA • Data Streaming Business Considerations for Node.js Applications
- 22. Challenges to Adoption Business Considerations for Node.js Applications
- 23. Evolving API • (2012.01.06 – 24.10.2012): 46 Releases! • Minor, even release number is stable • Minor, odd release number is development Business Considerations for Node.js Applications
- 24. Windows Support • Was written originally for *NIX systems • Node core largely supports WIN, 3rd party libs… not so much • Build tools recently switched to better support WIN Business Considerations for Node.js Applications
- 25. Error Handling & Debugging • Asynchronous code breaks call stacks • For synchronous code, you must handle exceptions carefully (try/catch) • For asynchronous code, you must pass errors around to callbacks Business Considerations for Node.js Applications
- 26. Example: outerFunction(arg1, arg2, function (callback){ if(!arg1 || !arg2){ return callback(new Error("Are you forgetting something?")); } else { return innerFunction(ar1, arg2, function (error, data){ if(error){ callback(error); } else { try{ var json = JSON.parse(data) callback(null, json); } catch(error){ callback(error); } } }) } }); Business Considerations for Node.js Applications
- 27. Asynchronous Code is Complex • Deeply nested callbacks can become difficult to read & maintain Business Considerations for Node.js Applications
- 28. Single Threaded Business Considerations for Node.js Applications
- 29. Entire Stack Must Be Non-Blocking Business Considerations for Node.js Applications
- 30. Case Studies Business Considerations for Node.js Applications
- 31. Linkedin • Originally build on Rails Application Framework • Need to composite service calls for the client • Persistent socket connections • Much smaller code base (~50Kb when minified) • Reduce the amount of memory leak (from mongrel) • Benchmarked at 20X faster • Using 10% original resource (from 30 servers to just 3! & 300MB or RAM to just over 30MB) • More Stable Business Considerations for Node.js Applications
- 32. Linkedin Mobile Architecture iOS Android Mobile Client Web Libraries Node.js Mobile Server MongoDB Database ApplicaLon Bg. Data Data Other Tracking Queue Service Service Process Business Considerations Credit: Kirin Prasad, Linkedin Mobile Engineer for Node.js Applications
- 33. Yammer • Similar use case as LinkedIn (cross-domain proxy) • JSON Out/JSON In Business Considerations for Node.js Applications
- 34. Resources: • Concurrent Programming for Scalable Web Architectures, Benjamine Erb. http://berb.github.com/diploma-thesis/community/042_serverarch.html • Benchmark Comparisons: http://shootout.alioth.debian.org/u64/benchmark.php? test=all&lang=nodejs&lang2=fsharp Business Considerations for Node.js Applications
- 35. Conclusion Business Considerations for Node.js Applications
- 36. Summation • Node.js leverages an evented programming model to handle concurrency and availability • Because Node does not rely on threads/processes to scale, it can use considerably fewer resources • Fewer resources means lower cost • More concurrent users means greater revenue potential • Because node support the real-time web, you can improve your user’s experience Business Considerations for Node.js Applications
- 37. 6000 Greenwood Plaza Blvd Suite 110 Greenwood Village, CO 80111 303.798.5458 www.aspenware.com Michael Filbin Michael Filbin, Software Developer m.filbin@aspenware.com