AWS Disaster Recovery Options

A useful comparison chart of DR options from a CloudAcademy AWS Architect (Associate) Certification course:

click on image for enlarged view

Options	Backup & Restore	Pilot Light	Warm Standby	Multi Site
Description	Like using AWS as a Virtual Tape Library	Minimal version of environment running on AWS	Scaled down version of fully functional environment always running	Fully operational version of fully functional environment always running off site or in another region
Services Used	AWS Storage Gateway, Import/Export, Glacier, S3	AMIs, ELBs, CloudFormation, RDS replication	AMIs, ELBs, CloudFormation, RDS replication	All
RTO	High  (8-24 hours)	Moderate  (4-8 hours)	Minimal  < 4 hours	Lowest < 60 minutes
RPO	Since the last backup; up to 24 hours	Since the last snapshot. While core pieces of system are in place, some installation and preparation may be required.	Since the last data write if a master / slave multi-AZ DB. May be asynchronous only which would increase the RPO	Choice of data replication influences RPO
Cost considerations	Low Recovery time may involve getting tapes/media delivered to site Disk/tape management	Low Keeping all services/ libraries / patches up to date adds an administrative overhead	Medium Environment can be used for dev/test off setting cost	High The ongoing cost of maintenance / operation needs to be factored in.

Traditional DR vs DR on Public Cloud

High level steps to be performed during DR -

1. Update Status Page
2. Restore Datastore(s) in prodY from latest prodX
3. DB
4. Authentication
5. Authorization
6. Cache
7. Blob Storage
8. Restore backend microservices
9. Bootstrap services with particular focus on upstream and downstream dependencies
10. Swap CloudFront distribution(s)
11. Swap API endpoint(s) via DNS
12. Update DNS records to point to prodY API endpoints
13. Verify recovery is complete
14. Redeploy stack from user account to verify service level
15. Update Status Page