This document discusses using Node to build scalable server components. It introduces Node and Express JS, explaining that Node allows running JavaScript on the server and is lightweight and fast. It describes Node's single-threaded architecture but how it handles concurrency using an event loop. It discusses scaling Node through clustering, load balancing, and offloading tasks. The document provides an example Express app and recommends Node may not be best for CPU-intensive tasks or if relying heavily on relational databases. Source code is available on GitHub for further reference.

1. Using Node to build scalable
server component

2. Who are we?
Andhy Koesnandar
MBA – UW Foster, MS CS – Nebraska
7+ years software development @Bing,
Azure and Microsoft Dynamics
Oby Sumampouw
MS CS – Stanford
6+ years distributed computing and
engagement hacker @LinkedIn and @oracle

3. About Cermati
• Financial product comparison site
• location based credit card promotions

4. What is this talk about
Node JS
• Run JS on Server
• Single threaded
Express JS
• MVC Web Library for Node.Js

5. Why should you care
• Its Javascript and this is JakartaJS
• Javascript is fun
• Uses unified language across the stack
• Its lightweight and its super fast
“Ruby is like a minivan, with all the features and Node is like a Ferrari –
crazy efficient and fast”
Sri Viswanath, SVP Engineering Groupon

6. Node Architecture

7. Its Single Thread app…
• Enter mighty Event Loop (libuv)
Client
Event loop
(main thread)
C++
Threadpool
(worker
threads)
Clients send HTTP requests
to Node.js server
An Event-loop is woken up by OS,
passes request and response objects
to the thread-pool
Long-running jobs run
on worker threads

8. I/O latency Pyramid
• L1: 3 cycles
• L2: 14 cycles
• RAM: 250 cycles
• DISK: 41,000,000 cycles
• NETWORK: 240,000,000 cycles

9. Apache vs nginx request / sec

10. Memory consumption in Apache vs nginx

13. What it means in code
• Traditional I/O
var result = db.query(“select x from table_Y”);
doSomethingWith(result); //wait for result!
doSomethingWithOutResult(); //execution is blocked!
• Non-traditional, Non-blocking I/O
db.query(“select x from table_Y”,function (result){
doSomethingWith(result); //wait for result!
});
doSomethingWithOutResult(); //executes without any delay!

14. Express JS
• The de-facto standard for the majority of Node.js web application
• Example:

15. Scaling Node
• Offload to Http proxy server
• Http caching Static Files
• Gzip compression
• SSL
• Application Scaling
• Worker Roles
• Node clustering
• Cluster Round Robin Load Balancing

16. Background Tasks
• Spawn child process that can run on the background

17. Node Clustering
• Can take advantage of multi core machines
• Load balance across multiple processes
• Increase throughput

20. No Clustering With Clustering

22. Node Clustering Round Robin
• Algorithm to choose in 0.10 is doesn’t let everyone to party
• Choose the process in round robin fashion
• New in 0.12
• That way everyone gets to party

23. When not to use Node?
• CPU Hungry applications. Not much I/O
• Video transcoding
• Encryption software
• AI and Machine learning
• You use relational DB
• There is no mature ORM yet for Node
• Current popular packages:
• Sequelize
• Node ORM2

24. Who uses Node

25. Source Code Available on GitHub
• https://github.com/akoesnan/express-cluster-tutorial

26. Nerds, questions?