AWS Certified Developer Associate (#177)

A Developer is asked to implement a caching layer in front of Amazon RDS. Cached content is expensive to regenerate in case of service failure. Which implementation below would work while maintaining maximum uptime?

Implement Amazon ElastiCache Redis in Cluster Mode
Install Redis on an Amazon EC2 instance.
Implement Amazon ElastiCache Memcached.
Migrate the database to Amazon Redshift.