ANS-C01 Question 258
Single answerAn e-commerce company has deployed its application on Amazon ECS with Fargate. The application uses a custom domain name, and the company has hosted its DNS zones in Amazon Route 53. Recently, customers have reported intermittent DNS resolution failures when accessing the application. Upon investigation, it was found that the DNS resolution failures occur during peak traffic hours. What can you do to ensure reliable DNS resolution for the application?
- A
Enable Route 53 latency-based routing to direct traffic to the nearest resource.
- B
Increase the TTL (Time-to-Live) value of the DNS records in Route 53 to reduce the frequency of lookups.
- C
Configure an Amazon VPC DNS resolver endpoint to handle DNS resolution within the VPC.
- D
Use Amazon CloudFront with an alternate domain name to cache DNS responses globally.
Show answer and explanation
Correct answer: B
Explanation
The root of the issue is the high frequency of DNS lookups during peak traffic hours, which can lead to DNS resolution failures. By increasing the TTL value in Route 53, clients can cache DNS responses for a longer period, reducing the load on the DNS servers and minimizing the likelihood of failures. While other options may improve performance or traffic distribution, they do not directly address the specific issue of intermittent DNS resolution failures caused by high lookup volumes.
- A. Incorrect.
Route 53 latency-based routing improves global traffic distribution, but it does not directly resolve DNS resolution failures caused by high lookup volume during peak traffic.
- B. Correct.
Increasing the TTL value reduces the frequency at which clients need to perform DNS lookups by allowing them to cache DNS responses for a longer time, which helps mitigate the impact of high lookup volumes.
- C. Incorrect.
Configuring an Amazon VPC DNS resolver endpoint is useful for private DNS resolution within a VPC but does not address public DNS resolution issues for external clients accessing the application.
- D. Incorrect.
Using Amazon CloudFront can improve performance and caching, but it does not directly address the DNS resolution failures that occur due to high lookup volumes.