Getting Started with Node.js in the Cloud

Node.js

• Evented
• Non-blocking
• Asynchronous
• Lightweight
• Scalable
• Fast

The "Cloud"

• Scalable
• Elastic
• Flexible
• "Building blocks" - vast array of services and products

Node.js in the Cloud

We can build scalable, efficient, and fast web applications and services.

At the micro-level, Node.js applications can support large numbers of connections and glue together many different services.

At the macro-level, the cloud allows us to scale out servers, and provide various backing components.

Use Cases

• Real-time web applications.
• Mobile application backends. (LinkedIn Mobile)
• API endpoints. (eBay + ql.io)

Anti-Use Cases

Some situations where Node.js may not be the best choice.

• CPU-bound applications.
• Simple CRUD applications.
• Need a library in a specific language.

PAAS Providers

Node.js Platform-as-a-Service offerings:

• Heroku
• Joyent
• Cloud Foundry
• Nodester
• NodeJitsu
• Microsoft Azure

IAAS Providers

Infrastructure-as-a-Service providers. Host it yourself!

• Amazon Web Services
• Rackspace Cloud
• ... and many others ...

Heroku

• Deploy Node.js (and other) apps straight from git.
• Pay-per-use model.
• Scalable web and worker servers.
• Numerous add-ons (database, mail, logging, etc. services).
• Integrated in the Amazon Web Services cloud.

Hooking up Heroku

Heroku provides an excellent Node.js guide that can get you up and running. (devcenter.heroku.com/articles/nodejs)

• Sign up: api.heroku.com/signup
• Log in: api.heroku.com/login
• Install Heroku: (See Node guide)
• Install NVM: github.com/creationix/nvm (Highly recommended for development)

Hello World!

Here is everyone's first Node.js application:

Let's try it in development...

And, let's see a slightly more enhanced version...

Package the App

We have to package things up appropriately.

• Create a Git repository. (github.com/ryan-roemer/novanode-cloud-talk)
• Add a "package.json" file.
• Add a Heroku "Procfile" file.

web: node server-hello.js

This tells Heroku to run "server-hello.js" as a Node.js web application.

Deployment

Now that we've developed our app, we're ready for prime time!

$ heroku create --stack cedar

$ heroku rename novanode

$ git push heroku master

We're Live!

Get ready for "hello world" goodness at: novanode.herokuapp.com

$ heroku ps

$ heroku logs

$ heroku run bash

Let's Scale!

Scaling with Heroku is incredibly easy and fast.

$ heroku ps:scale web=11

$ heroku ps

$ heroku ps:scale web=1

Chat Server

"Hello world" is scalable, but not useful. Let's try something that leverages Node.js's strengths: chat!

• nodejs-pub-sub-chat-demo
• Simple HTML/JS client and Node.js server.
• Uses Redis' Pub/Sub feature to allow clients to subscribe to channels and publish messages.
• Lots of connections that we'll leave open. Clients will use websockets, AJAX long-polling, etc. with Socket.IO.

Let's try it out in development...

Prepare our Chat App

$ heroku addons:add redistogo:nano

web: node chat/app_redis.js

$ git push heroku master

Heroku Chat

And we're up at novanode.herokuapp.com.

However, we're now using AJAX long-polling, which leads us into...

Heroku / PAAS Gotcha's

Sometimes you have to go with an IAAS or self-managed system.

• Lack of websockets support.
• Expense of scaling the core service and add-on's.
• Outlier request latencies.
• Integrating Node.js with add-on's / services. (Memcached).
• Limited monitoring, system insight.

Heroku / PAAS Benefits

But you can get a lot done in the Node.js PAAS ecosphere.

• Automatic application restarts on crashes.
• Intelligent routing during application upgrades.
• Rollback.
• Integration with AWS. Runs in AWS, and can directly hook to RDS.
• Takes care of virtually all operations issues.
• First web server on each application is free!

Wrapping up the Cloud

• For prototyping and lightning speed development, Node.js PAAS services are often the winning ticket.
• For production, you'll often need look to IAAS providers. We run in the Amazon cloud, and our Node.js apps run with low system resource usage and minimal latency. We have full control over our systems.
• But like Node.js itself, offerings in the cloud are evolving at a rapid pace, so be sure to check your options when you decide where and how to roll out your Node.js applications.

Reflections of a Node Developer

• JavaScript has its warts, but you can learn to love it.
• Asynchronous programming ain't that bad. (Especially compared to threads and locks).
• Watch out for blocking code and missed callbacks.
• The library ecosystem resembles the Wild West.
• The community is responsive, growing, and eager to help.
• Give it a try!

Thanks!