Amazon Route 53 Overview

Amazon Route 53 is a DNS web service that effectively connects user requests to infrastructure running in AWS such as EC2 instances, ELB load balancers, or S3 buckets. It can also be used to route users to infrastructure outside of AWS. 

Route 53 is designed to be extremely reliable, highly available, scalable and cost effective. Amazon Route 53 is fully compliant with IPv6 as well.

Routing Polices

Route 53 Have 5 Routing Polices:

1. Simple

   1. All requests for your domain that come to Route 53 will be forwarded to one region.

   2. Default routing policy when you create a new record set.

   3. Commonly used when you have a single resource (e.g. one web server) that performs a given function for your domain (http://buddytutor.com). 

2. Weighted

   1. Requests for your domain that come to Route 53 will be forwarded to different regions or even different ELBs based on weight specified. E.g. 20% to one region, 80 % to another or 20% to one ELB, 80 % to another.

3. Latency

   1. Allows you to route based on lowest latency for end user (e.g. which region will give fastest response time).

   2. Need to create a latency record set for the EC2 or ELB resource in each region that hosts your website. AWS will select a record for each request based on least latency and use it for responding back.

4. Failover

   1. When you want an active/passive setup.

   2. Route 53 will monitor the health of your endpoints and when primary is down, it connects to the secondary one.

5. Geolocation

   1. Lets you chose where traffic will be sent based on geographical location of users. E.g. European customers can be send to European servers and US customers to US servers.

Important Notes (Exam Tips)

1. Route 53 is a global service (not region specific).

2. DNS port is 53 and hence Route 53 got its name.

3. With Route 53, there is a default limit of 50 domain names. However, this limit can be increased by contacting AWS support.