AWS US-East-1 Outage Analysis: Key Takeaways and Resilient AWS Best Practices
Tags: aws, reliabilityarchitectures, sre, devops
Published: 2023-06-18 17:12:00

Discover the impact and lessons learned from the AWS US-East-1 outage. Explore resilient cloud architecture best practices to safeguard your AWS infrastructure and ensure uninterrupted availability.

**Actual Issue:**

- AWS experienced an outage at its US-East-1 cloud region.
- Services impacted: AWS CloudFormation, Lambda, and Amazon Connect.
- Increased error rates, latencies, and degraded performance reported.

**Service Impact:**

- AWS Management Console home page was unavailable.
- Companies and organizations, including Webflow, Chatbase, Cloudsmith, The Associated Press, PlutoTV, Hinge, Delta, Webflow, Simplecast, Shutterfly, Crunchyroll, Barclays, Goodreads, Story Origin, Option Research, DCU Center, Decent.xyz, Simplecast, and Mobile Assistant reported degraded performance or outages.
- Major websites, such as the Boston Globe and New York City's Metropolitan Transit Authority, experienced digital publishing and service disruptions.

**Root Cause:**

- The root cause was identified as an issue with AWS Lambda.
- Subsystem responsible for capacity management for AWS Lambda at a Virginia data center experienced problems.

**High-Level Timeline of Events:**

- 2:49 PM PDT: AWS reports increased error rates and latencies for multiple services, identifies AWS Lambda as the root cause.
- 3:42 PM PDT: AWS states active resolution efforts and ongoing work to resolve the issue.
- 5:00 PM PDT: Many AWS services are fully recovered, but manual relaunch of services may be required for some customers.
- 6:42 PM PDT: AWS confirms the issue as resolved, and all services are operating normally.
- Incident duration: Approximately four hours from the initial report to resolution.

**PoR for Customers - Best Practices:**

- Avoid dependency on a single region: Design your system to be hosted across multiple regions to mitigate the impact of region-specific issues. Distributing your workload across regions can enhance availability and reduce the risk of a single point of failure.
- Implement multi-region architecture: Utilize AWS services and features, such as Amazon Route 53 and AWS Global Accelerator, to distribute traffic across multiple regions and ensure high availability.
- Leverage AWS Load Balancers: Use Elastic Load Balancers (ELB) or Application Load Balancers (ALB) to distribute traffic to instances or containers hosted in multiple regions. This helps distribute the workload and improves fault tolerance.
- Implement automated backup and disaster recovery: Regularly back up your data and design automated disaster recovery mechanisms using AWS services like Amazon S3, AWS Backup, and AWS Disaster Recovery services. This ensures that your critical data is protected and recoverable in the event of an outage.
- Utilize AWS Multi-AZ and Auto Scaling: Configure your infrastructure using AWS Multi-AZ (Availability Zones) and Auto Scaling groups to automatically launch and terminate instances based on demand. This enhances availability, fault tolerance, and scalability.
- Monitor and alert on service health: Utilize AWS CloudWatch to monitor the health and performance of your AWS resources. Set up appropriate alarms and notifications to proactively detect and respond to any service disruptions.
- Regularly review and test your architecture: Conduct regular architecture reviews and simulations to identify potential single points of failure and ensure the effectiveness of your multi-region setup. Test failover mechanisms to validate the resiliency of your system.


Note: The information presented in this article is based on publicly available sources and does not guarantee its completeness or correctness.