A retail company wants to improve the response time of its product catalog website, which is backed by an Amazon RDS for PostgreSQL database. The catalog data is read-heavy and does not change frequently, but the caching layer must be highly available, support data replication across multiple Availability Zones, and allow for automatic failover.
Which two actions should a solutions architect recommend to implement this caching layer? (Select TWO.)
- Deploy Amazon ElastiCache for Redis in a Multi-AZ replication group.Answer
- Modify the application code to read from the cache first, and query the RDS database only if there is a cache miss.Answer
- CDeploy Amazon ElastiCache for Memcached with multi-node replication enabled.
- DCreate an Amazon RDS PostgreSQL Read Replica and configure it in Multi-AZ mode to serve as the caching layer.
- EDeploy Amazon ElastiCache for Memcached and enable Multi-AZ with automatic failover.
Answer
Deploying Amazon ElastiCache for Redis in a Multi-AZ replication group and modifying the application code to query the cache first before the database.
Deploying Amazon ElastiCache for Redis in a Multi-AZ replication group provides the required high availability, automatic failover, and data replication across Availability Zones. Modifying the application to check the cache first before querying the RDS database implements the cache-aside pattern, which effectively offloads read-heavy query traffic and reduces response times.
Step-by-Step Solution
Key Concept
Improving database efficiency by introducing a highly available, memory-based caching layer with ElastiCache for Redis using a cache-aside pattern.