As we conclude my series on deploying and managing microservices on Amazon EKS, we turn our focus to the crucial aspects of disaster recovery (DR) and high availability (HA). Ensuring that your application can withstand and quickly recover from failures—not just at the application level, but also at the infrastructure level—is essential for maintaining user trust and business continuity. This article explores implementing DR and HA strategies in EKS using Velero for backups and leveraging AWS’s multi-zone deployment capabilities.

High Availability in Amazon EKS

High availability is about designing your system in such a way that it can tolerate and quickly recover from failures, with minimal impact on users.

Multi-AZ Deployments

AWS EKS supports multi-AZ deployments, which allow you to distribute your workloads across multiple Availability Zones (AZs) within a region. This setup provides the foundation for building highly available applications by ensuring that your application can continue running even if one AZ goes down.

  1. Create a Multi-AZ EKS Cluster: When setting up your EKS cluster, ensure that your node groups span multiple AZs. This can be specified during the cluster creation process in the AWS Management Console or via the AWS CLI.

  2. Deploy Services with Multi-AZ Awareness: Design your services to be stateless where possible, and use AWS services (like RDS, S3) that inherently support multi-AZ configurations for stateful components.

Disaster Recovery with Velero

Disaster recovery involves preparing for and recovering from a disaster that causes significant application downtime or data loss. Velero is an open-source tool that helps you back up and restore your Kubernetes cluster resources and persistent volumes.

Installing Velero

  1. Set Up an S3 Bucket: Velero requires an S3 bucket to store backups. Create a bucket in your AWS account.

  2. Install Velero: Download and install the Velero CLI tool from the Velero GitHub releases page. Then, install Velero in your cluster, configuring it to use your S3 bucket:

velero install \
    --provider aws \
    --plugins velero/velero-plugin-for-aws:v1.0.0 \
    --bucket <VELERO_BUCKET_NAME> \
    --backup-location-config region=<AWS_REGION> \
    --snapshot-location-config region=<AWS_REGION> \
    --secret-file ./credentials-velero

Replace <VELERO_BUCKET_NAME> and <AWS_REGION> with your S3 bucket name and AWS region, respectively. The credentials-velero file should contain your AWS credentials.

Creating and Restoring Backups

  • Create a Backup: To back up your entire cluster:
velero backup create <BACKUP_NAME>
  • Restore from a Backup: To restore your cluster from a backup:
velero restore create --from-backup <BACKUP_NAME>

Conclusion

Implementing disaster recovery and high availability strategies in Amazon EKS is essential for any production-grade application. By leveraging AWS’s multi-zone capabilities and tools like Velero for backups and restores, you can ensure that your application remains resilient in the face of infrastructure failures. These strategies not only help in maintaining service continuity but also in preserving data integrity, ultimately ensuring a seamless experience for your users.

Gotchas and Tips

  • Regularly Test DR Procedures: Regular testing of your disaster recovery procedures is crucial to ensure they work as expected during an actual disaster.
  • Monitor Backup and Restore Processes: Keep an eye on the success and failure of backup and restore jobs, and set up alerts to notify you of any issues.
  • Consider RTO and RPO: When designing your DR strategy, consider your Recovery Time Objective (RTO) and Recovery Point Objective (RPO) to align your backup frequency and restoration capabilities with business requirements.

Adopting these DR and HA strategies ensures that your applications hosted on

Amazon EKS are robust, resilient, and capable of providing continuous service to your users, regardless of the challenges that may arise. By preparing for the worst-case scenarios with comprehensive backup and failover strategies, you can safeguard your applications against significant downtime and data loss, maintaining the trust and reliability that your users expect.