Which solution meets these requirements?
Use a database in Amazon RDS with Multi-AZ and at least one read replica.
Use a database in Amazon RDS with Multi-AZ and at least one standby replica.
Use databases that are hosted on multiple Amazon EC2 instances in different AWS Regions.
Use databases that are hosted on Amazon EC2 instances behind an Application Load Balancer in different Availability Zones.
Explanations:
Amazon RDS with Multi-AZ provides high availability and failover support. Adding a read replica allows for read traffic distribution, minimizing the impact on the current traffic flow. This option is easy to manage and involves minimal effort for migration.
While Multi-AZ with a standby replica provides high availability, it does not support read scaling. This option does not address the need for high-read traffic, which requires read replicas for load distribution.
Hosting databases on multiple EC2 instances in different AWS Regions involves significant complexity and management effort. This option does not guarantee high availability or effective load balancing for read traffic, and it could lead to increased latency.
While hosting databases on EC2 instances behind an Application Load Balancer can support high availability, it requires more effort to set up and manage compared to Amazon RDS. Additionally, this option does not explicitly mention the support for read replicas, which is essential for handling high-read traffic effectively.