Title

AWS re:Invent 2023 - Best practices for creating multi-Region architectures on AWS (ARC308)

Summary

• Multi-region AWS architectures are complex and driven by needs such as performance improvement, availability, and compliance with data residency laws.
• AWS regions are designed for resilience, with multiple Availability Zones (AZs) providing fault tolerance.
• It's crucial to understand current architecture and requirements before extending to multi-region.
• Real-world scenarios were discussed to extract best practices for multi-region architectures.
• The session covered two fictitious customer scenarios based on real-world use cases: a fintech retail bank and an authentication service provider.
• The fintech bank focused on disaster recovery (DR) and operational continuity, using AWS services like Aurora Global Databases and Route 53 Application Recovery Controller (ARC).
• The authentication service provider aimed to improve uptime SLAs and global application performance, using services like Route 53 latency-based routing, DynamoDB Global Tables, and AWS CloudFormation.
• Best practices include using infrastructure as code, ensuring regional independence, and understanding the CAP theorem for data replication.
• Observability is foundational for both single-region and multi-region applications.
• Additional costs and operational overhead must be considered when planning for multi-region deployment.
• AWS provides resources like white papers on multi-region fundamentals and the Resilience Lifecycle Framework, as well as services like AWS Fault Injection Service and AWS Resilience Hub to aid in building resilient architectures.

Insights

• Resilience by Design: AWS regions are inherently resilient, and not all applications require multi-region deployment. Decisions to go multi-region should be business-driven.
• Understanding Requirements: A deep understanding of the current architecture and new requirements is essential before embarking on a multi-region journey.
• Data Replication and Consistency: The choice between synchronous and asynchronous replication is critical and should align with the application's consistency requirements.
• Observability and Monitoring: Implementing comprehensive observability and monitoring strategies is crucial for detecting and responding to issues across regions.
• Operational Complexity and Cost: Multi-region architectures introduce additional complexity and costs, which must be factored into the decision-making process.
• Infrastructure as Code: Using infrastructure as code tools like AWS CloudFormation ensures consistent deployments across regions and helps manage complexity.
• Regional Independence: Architecting for regional independence by enforcing strict fault isolation boundaries improves application resilience.
• Service Quotas and Limits: Awareness of service quotas and limits is important, especially when they are set at the regional level and need to be managed across multiple regions.
• Differential Observability: Employing multiple viewpoints for application health checks, such as server logs, synthetic checks, and real user monitoring, provides a more accurate picture of the application's health.
• Continuous Improvement: Resilience is an ongoing journey, and architectures should continuously evolve to meet changing business needs and leverage new AWS features and services.