Application Deployment - 01

AWS Components used in This Architecture

Route 53

CloudFront

Load Balancer ELB

EC2 Instance

Sample CloudFront dynamic web distribution Architecture

The most popular usage of Amazon CloudFront is to distribute static content such as images, videos or other objects existing in an Amazon S3 bucket. However, you can also use Amazon CloudFront to distribute your dynamic content such as a Ruby on Rails or PHP web application and benefit from the advantages of utilizing the globally distributed network infrastructure of AWS. In this blog post, I will talk about the advantages and the necessary configuration options for creating an Amazon CloudFront distribution for a dynamic web application.

Why to use CloudFront for dynamic content?

Well, at first, it might not seem feasible as your data will be dynamic. But, actually there are many benefits:

  • when we use cloud-front , your clients will connect to your applications through an AWS edge location closest to them. Then, this connection will utilize AWS network infrastructure which is expected to be more stable and provide faster access to your servers on an AWS region, even if the content was not cached before.

  • Although we will decrease the time to live (TTL) or cache expiration to 0 as I will describe below; this will not mean that CloudFront will not cache your content. Actually, it will. The only difference will be that it will send the last caching time of the content alongside with the request to your origin. This will allow your origin to respond faster if the content was not changed and edge location will serve the content from its cache. When you compare the small packet size in this process with retrieving the full content from your origin, this will decrease the load on your servers and delivery time of your content to your clients.

  • The most obvious benefit will be the decrease in SSL handshaking time and time to first byte metrics. SSL handshaking is done on edge locations and time to first byte improvement is a result of the enhanced network speed.

    To explain this benefit better, you can see a Route 53 health check - latency graph below which is for a dynamic web application placed behind Amazon CloudFront at December 7th. Amazon Route 53 makes these health checks geographically distributed allover the world and what you see on the graph is an aggregate. As can be seen, placing the load balancer behind a CloudFront distribution made a simultaneous improvement in both average SSL handshaking and time to first byte values. The good thing is it is an easy process once you understand the basics.

  • Amazon CloudFront only accepts well-formed connections and reduces the number of requests and TCP connections back to your web application. These will help you to prevent many of the common DDoS attacks such as SYN floods and UDP reflection attacks; because they will not reach to your origin. Also geographically distributed architecture will help you to isolate these attacks in a close location to them, allowing you to continue to serve your application without any impact on other locations.

Lets Build this Architecture -01

Sample CloudFront dynamic web distribution Architecture

Lets Build this Architecture -02