Heroku is a mature PaaS cloud-hosting solution that supports the development of Node applications. To get started, visit http://www.heroku.com and submit an e-mail address. Heroku is free to start with. After you've confirmed your account, you can start deploying apps right away.

Scaling Heroku applications involves increasing the number of dynos that you are paying for. Each dyno is an isolated container running your application and you are able to increase or decrease the number of dynos your application uses with ease. In this way, there aren't any hosting packages to buy—you simply scale as needed by asking for more, or fewer, dynos.

Heroku allows you to deploy applications on many platforms and languages—it is not Node-centric. This is something to keep in mind should you anticipate the need to add services to your application not written in Node.

To control Heroku remote instances, you will use a local utility belt application...

Red Hat, the enterprise Linux company, operates OpenShift, a cloud-hosting solution. OpenShift offers several options for how you want to deploy your apps—via a web-based interface, via the command line, or through an online IDE. As we've worked on the command line for our other deployment examples, we'll do the same with OpenShift.

Once you've joined and confirmed your account, you will need to install the OpenShift client tools—rhc. For the purposes of this section, I'll use the Mac OS X client. Regardless of which package you happen to choose, the command set remains the same:

sudo gem install rhc
gem update rhc

This will install the client and update it to the latest version.

Once installed, you will need to set up your SSH keys and authenticate with the system by running an rhc setup. Just enter your authentication information, confirm the installation of keys, and confirm the upload of credentials.

You will then be...

This image from the Docker website (http://www.docker.com/) gives information on how and why the Docker team feels their technology fits into the future of application development:

The preceding image, concisely describing the generational shift in application architecture we are now experiencing, can just as easily be used to describe the how and why of Node's design.

Docker, according to the website, …is an open source engine that automates the deployment of any application as a lightweight, portable, self-sufficient container that will run virtually anywhere. Once you have created a Docker image of your application, a running instance of that image can be spun in milliseconds. Yes, that's right: a few milliseconds. Docker lets you create even hundreds of deployments of your application in a few seconds.

The Docker ecosystem has three main components. Here's some information about the components from the documentation...

In this chapter, you learned how to create Node servers and applications, both locally and in the cloud. Having deployed a simple document-editing application using Node and MongoDB across three different PaaS providers, you have an early sense of what is available to the Node developer who is looking to scale their application. You were introduced to Docker, which offers a powerful new containerization technology, allowing us to make many cheap clones of our applications; wherever there is Linux, there exists a deploy target for Docker.

In the next chapter, we will take these simple ideas about scaling farther and deeper by exploring in more detail how Node can be scaled both vertically and horizontally—across cores and across many machines.