Which solution will meet these requirements?
Create an Amazon ElastiCache for Redis instance. Enable encryption of data in transit and at rest. Store frequently accessed data in the cache.
Create an Amazon ElastiCache for Memcached instance. Enable encryption of data in transit and at rest. Store frequently accessed data in the cache.
Create an Amazon RDS for MySQL read replica. Connect to the read replica by using SSL. Configure the read replica to store frequently accessed data.
Create an Amazon DynamoDB table and a DynamoDB Accelerator (DAX) cluster for the table. Store frequently accessed data in the DynamoDB table.
Explanations:
Amazon ElastiCache for Redis supports encryption of data in transit and at rest. Redis provides the ability to store frequently accessed data and supports sorting/ranking of datasets using its sorted sets.
Amazon ElastiCache for Memcached supports encryption of data in transit and at rest, but Memcached does not support sorting or ranking of cached data, which is a requirement in this case.
Amazon RDS for MySQL read replicas cannot efficiently cache data. While a read replica can handle read queries, it doesn’t offer the ability to store frequently accessed data in a cache with sorting or ranking capabilities.
DynamoDB and DAX are not suitable for caching frequently accessed data with encryption requirements for PHI. DynamoDB does not offer the ability to store and rank datasets in the way the application requires.
I infer that the answer is:
Create an Amazon ElastiCache for Redis instance. Enable encryption of data in transit and at rest. Store frequently accessed data in the cache.