Quick Weather Display & Flight Booking for Travellers

Answer: D.

On reading the scenario carefully, we can see here that the website's performance is of prime importance to its users.

It gives them a lot of business value, enabling them to choose their flight paths and make flight bookings on time.

So, “Latency based routing” is the best answer to this scenario.

Option A is incorrect because GeoLocation routing is often used to localize content and present the website in the language of its users.

Geolocation routing lets you choose the resources that serve your traffic based on your users' geographic location, meaning the location that DNS queries originate from.

For example, you might want all queries from Europe to be routed to an ELB load balancer in the Frankfurt region irrespective of latency in that region.

Option B is incorrect because Failover routing is usually used in Disaster Recovery scenarios where an Active-Passive Disaster recovery configuration is present & the Passive resource that was originally the Backup resource has now become the Active resource due to the original Active resource being unhealthy.

Option C is incorrect sinceMultivalve answer routing provides the ability to return multiple health-checkable IP addresses which is a way to use DNS to improve availability and load balancing.

Option D is CORRECT since Latency based routing always routes DNS queries to the best performing website (region) irrespective of what happens in the Amazon infrastructure, Internet.

Going back to our scenario, if we have ELB load balancers in the US West (Oregon) region and the Asia Pacific(Mumbai) region for the Weather tracking & Airline Ticketing website and if a user from London enters the name of your domain in a browser, the following things will happen:

DNS routes the query to a Route 53 name server.

Route 53 refers to its data on latency between London and the Mumbai region and between London and the Oregon region.

If latency is lower between the London and Oregon regions, Route 53 responds to the query with the Oregon load balancer's IP address.

If latency is lower between London and the Mumbai region, Route 53 responds with the Mumbai load balancer's IP address.

References:

https://docs.aws.amazon.com/Route53/latest/DeveloperGuide/routing-policy.html#routing-policy-latency https://youtu.be/BtiS0QyiTK8

Based on the requirements stated in the question, the routing policy that would be most appropriate for the weather tracking system is the Latency-Based Routing Policy.

The Latency-Based Routing Policy directs traffic to the Amazon EC2 instances that provide the lowest latency for the end user. In other words, it routes traffic to the instance that can serve the user the fastest. This makes it ideal for services that require quick response times.

In the case of the weather tracking system, travellers expect quick turnaround time in which the weather display and flight booking will happen. This means that response time is critical to the success of the business. By using the Latency-Based Routing Policy, traffic can be routed to the instance that can provide the fastest response time to the end user.

Route 53's Latency-Based Routing Policy works by measuring the latency between the end user and the AWS resources, such as EC2 instances, that are serving the website. The policy automatically directs traffic to the resource with the lowest latency.

In addition to the Latency-Based Routing Policy, other routing policies that can be used with Route 53 include the GeoLocation Routing Policy, which routes traffic based on the geographic location of the user, the Failover Routing Policy, which is used for high availability and failover scenarios, and the Multivalue Answer Routing Policy, which returns multiple values in response to DNS queries.

However, for the weather tracking system, the Latency-Based Routing Policy is the most appropriate routing policy to use because it ensures that users receive the fastest response time possible, which is critical for the success of the business.