Techtalk#6: NodeJs: pitfalls (based on game project)

Techtalk#6: NodeJs: pitfalls (based on game project)

• 1.
  {Node.JS} Common pitfalls (The story of small Game Development Project )
• 2.
  Agenda • Event Loop,Non-Blocking I/O, Async Development • Debugging • Lessons learned, lessons forgotten • Born to Scale (Scalability in mind) • Hey going to production!! Oooops ….
• 3.
  Event Loop Single Thread– one global scope
• 4.
  Async Development –Burn in Hell
• 5.
  Async Development –Callback Hell Resolving Give the names to your callbacks
• 6.
  Async Development –Callback Hell Resolving Divide your structure to small functions
• 7.
  Async Development –Callback Hell Resolving Promises
• 8.
  Debugging WebStorm IDE Debugger ›Node-Inspectormodule
• 9.
  Lessons learned, lessonsforgotten (Development Phase) • Choose framework you know or used in previous projects • Don't forget to clear the timer once you set it – or the magic will happen in your app • Divide the code to modules and classes – from beginning • Bot is the same as the user – unification for clarity • Don't use multistep CSS3 animation – you will need to have “animation finished” event • Don't start full refactoring – you will loose a time and will through this idea soon • Use class constants instead of magic numbers 0,1,2 … • Put conditions into functions
• 10.
  Born to Scale(Scalability In mind) • One way – store application state in cache or db Then put the NodeJs behind the reverse proxy like Nginx • Another way – split socket.io connections across servers + use so called “sticky sessions”
• 11.
  Hey going toproduction!! Oooops …. • Logging – log more, log early • Forget about debugger • Who will up your server when it's down - “Forever” • Exceptions - don't throw them until you catch them • Load Balancing – Nginx as reverse Proxy • One thread – one CPU core – Use cluster module
• 12.
  Links http://strongloop.com/strongblog/node-js-callback-hell-promises-generators/ http://callbackhell.com/ https://github.com/nodejitsu/forever http://nodejs.org/docs/v0.6.0/api/cluster.html http://blog.keithcirkel.co.uk/load-balancing-node-js/