Building High-Availability Systems on AWS (2 of 2)

AWS Services for High Availability

1. Amazon EC2 with Auto Scaling

• Description: Use EC2 instances in multiple Availability Zones (AZs) to ensure redundancy. Auto Scaling can automatically adjust the number of instances based on traffic.
• Best Practice: Configure health checks to replace unhealthy instances automatically.

2. Amazon RDS (Relational Database Service)

• Description: RDS provides Multi-AZ deployments for high availability. It automatically creates a primary DB instance and synchronously replicates the data to a standby instance in a different AZ.
• Best Practice: Enable automated backups and snapshots for data recovery.

3. Amazon S3 (Simple Storage Service)

• Description: S3 is designed for 99.999999999% (11 nines) durability, making it an excellent choice for storing critical data.
• Best Practice: Use versioning and cross-region replication to enhance data availability and durability.

4. Elastic Load Balancing (ELB)

• Description: ELB automatically distributes incoming application traffic across multiple targets, such as EC2 instances, containers, and IP addresses.
• Best Practice: Use health checks to ensure traffic is only sent to healthy instances.

5. AWS Route 53

• Description: Route 53 is a scalable Domain Name System (DNS) web service that can route end-users to the best endpoint based on latency, health, or geolocation.
• Best Practice: Implement health checks and DNS failover to redirect traffic in case of an outage.

Best Practices for Building HA Systems on AWS

• Design for Failure: Assume that components will fail and plan for failover.
• Automate Recovery: Use tools like AWS CloudFormation and AWS Elastic Beanstalk to automate the deployment and recovery of your infrastructure.
• Regularly Test Your Failover Procedures: Simulate outages to ensure your failover mechanisms work as expected.
• Monitor and Optimize: Utilize AWS CloudWatch to monitor system performance and set alarms for potential issues.