SAA-C03 Question 489
Single answerAn e-commerce company is experiencing increased latency on their product catalog API due to high traffic. The API retrieves product details from a relational database. To improve performance and reduce database load, the company wants to implement a caching strategy. Which solution would provide the best performance improvement while ensuring cache freshness when product details are updated?
- A
Use Amazon ElastiCache with a time-to-live (TTL) expiration policy and set a short TTL value.
- B
Deploy AWS Lambda to query the database and cache results locally in memory.
- C
Use Amazon ElastiCache with a write-through caching strategy and update the cache whenever the database is updated.
- D
Enable Amazon RDS read replicas and use them to serve the API requests instead of implementing a cache.
Show answer and explanation
Correct answer: C
Explanation
In this scenario, the company needs a solution that improves performance and ensures cache freshness when product details are updated. A write-through caching strategy with Amazon ElastiCache is the best approach because it updates the cache immediately whenever the database is updated, ensuring data consistency and reducing latency for API requests. Other options either do not ensure cache freshness or do not provide the same level of performance improvement.
- A. Incorrect.
Using Amazon ElastiCache with a short TTL expiration policy can reduce database load and improve performance temporarily. However, this does not ensure cache freshness for updated product details as the cache could serve stale data until the TTL expires.
- B. Incorrect.
Querying the database with AWS Lambda and caching results locally in memory is not scalable for high-traffic APIs. Additionally, it does not provide a centralized or persistent cache that can be shared across multiple API instances.
- C. Correct.
Using Amazon ElastiCache with a write-through strategy ensures that the cache is updated whenever the database is updated, providing both performance improvement and cache consistency. This is the most suitable solution for the scenario.
- D. Incorrect.
Using Amazon RDS read replicas can offload read traffic from the primary database but does not provide the same level of performance improvement as a caching solution. Additionally, it does not solve the issue of reducing latency by caching frequently accessed data.