AWS Certified Solutions Architect - Professional (#540)

Your company is getting ready to do a major public announcement of a social media site on AWS. The website is running on EC2 instances deployed across multiple Availability Zones with a Multi-AZ RDS MySQL Extra Large DB Instance. The site performs a high number of small reads and writes per second and relies on an eventual consistency model. After comprehensive tests you discover that there is read contention on RDS MySQL. Which are the best approaches to meet these requirements? (Choose 2 answers)

Deploy ElastiCache in-memory cache running in each availability zone
Implement sharding to distribute load to multiple RDS MySQL instances
Increase the RDS MySQL Instance size and Implement provisioned IOPS
Add an RDS MySQL read replica in each availability zone