Concepts
AWS outlines several disaster recovery strategies with varying levels of complexity and cost:
- Backup and Restore: The simplest strategy, it involves regularly taking backups and storing them in AWS (e.g., Amazon S3). In the event of a disaster, these backups can be used to restore the system. This method typically has the longest recovery time but is also the most cost-effective.
- Pilot Light: A scaled-down version of your environment is always running in the cloud. Core services are set up and data is replicated. In case of a disaster, you can quickly scale your resources to handle the production load.
- Warm Standby: A minimal but full version of your environment is always running in the cloud. The system runs at a reduced capacity, which can be quickly scaled up in the event of a disaster.
- Multi-Site: A full-scale version of your environment runs in more than one location, and the workload is balanced between them. This allows for seamless failover in the event of a catastrophe.
Recovery Point Objective (RPO) and Recovery Time Objective (RTO)
Before implementing a DR solution, you should define your Recovery Point Objective (RPO) and Recovery Time Objective (RTO). RPO indicates the acceptable amount of data loss measured in time, while RTO refers to the acceptable amount of time that a service can be offline after a disaster.
| Strategy | RPO | RTO |
|---|---|---|
| Backup/Restore | Hours to Days | Hours to Days |
| Pilot Light | Minutes to Hours | Seconds to Minutes |
| Warm Standby | Seconds to Minutes | Seconds to Minutes |
| Multi-Site | Near-Zero | Near-Zero |
Implementing DR Procedures with AWS Services
1. Backup and Restore with Amazon S3
Regularly backing up data to S3 can be facilitated using AWS Backup or custom scripts. For databases, you might use Amazon RDS backups or snapshots. To restore, you would provision new EC2 instances and restore the data from S3 backups. For example, the AWS CLI command to copy a backup file to S3 would look something like:
aws s3 cp /path/to/backupfile s3://my-backup-bucket/backupfile
2. Pilot Light with Amazon RDS and EC2
For a Pilot Light approach, you may use Amazon RDS with its Multi-AZ feature for data replication and EC2 instances for your application, which will remain in a stopped state until needed:
aws ec2 start-instances –instance-ids i-1234567890abcdef0
You might also have AMIs (Amazon Machine Images) prepared to launch new instances quickly if the current ones are compromised.
3. Warm Standby with Auto Scaling and Load Balancing
Your Warm Standby environment would typically be a mirrored version of your production, running on a smaller scale. Services like Elastic Load Balancing (ELB) and Auto Scaling ensure your environment can handle a production load within minutes:
aws autoscaling update-auto-scaling-group \
–auto-scaling-group-name my-asg \
–desired-capacity 8 \
–min-size 8 \
–max-size 10
4. Multi-Site Setup with Route 53 and CloudFront
In a Multi-Site scenario, you can use Route 53 for DNS routing and failover between regions, and CloudFront to serve your content from edge locations. For real-time data replication across regions, services like Amazon DynamoDB Global Tables can be used.
Implementing automated failover can involve configuring Route 53 health checks and using failover routing policies:
aws route53 change-resource-record-sets –hosted-zone-id Z3M3LMPEXAMPLE \
–change-batch file://failover-config.json
Testing Disaster Recovery
An often-overlooked part of disaster recovery is regularly testing your DR plan to ensure it’s both functional and meets RPO and RTO requirements. AWS provides the ability to simulate many disaster scenarios and validates the effectiveness of your DR strategy through services like AWS Fault Injection Simulator.
As an AWS Certified SysOps Administrator, you must be comfortable planning, implementing, and testing these DR strategies within AWS. With the proper use of AWS services and a well-defined RPO/RTO strategy, you can ensure that your system is resilient and capable of weathering any disaster.
Answer the Questions in Comment Section
T/F: AWS CloudFormation can be used to automate disaster recovery procedures.
- Answer: True
Explanation: AWS CloudFormation allows you to create and manage a collection of related AWS resources, automating and simplifying the deployment and management of resources, which can be utilized for disaster recovery procedures.
T/F: EBS volumes can be copied across AWS regions for disaster recovery purposes.
- Answer: True
Explanation: Amazon EBS volumes can be copied via snapshots to other regions to ensure that if one region is affected by a disaster, you can recover your data in another region.
T/F: Amazon RDS does not support automated backups which can be used for disaster recovery.
- Answer: False
Explanation: Amazon RDS supports automated backups and DB snapshots that you can use to restore a database to a specific point in time, which is crucial for disaster recovery.
Which of the following AWS services can be used to orchestrate and automate disaster recovery plans? (Select TWO)
- A) AWS Lambda
- B) Amazon CloudFront
- C) AWS Step Functions
- D) Amazon Route 53
Answer: A) AWS Lambda, C) AWS Step Functions
Explanation: AWS Lambda can run custom scripts or functions in response to events, and AWS Step Functions can coordinate multiple AWS services into serverless workflows, both of which can be used for automating disaster recovery plans.
T/F: When restoring an Amazon EC2 instance from a snapshot, the restored instance will have the same IP address as the original.
- Answer: False
Explanation: When restoring an EC2 instance from a snapshot, a new instance is created with a new IP address, unless you specifically reassign an Elastic IP from the original instance to the restored instance.
Which of the following AWS services provides a fully managed disaster recovery service that can be used to quickly recover your virtual machines, server, and apps?
- A) AWS Backup
- B) AWS Elastic Beanstalk
- C) AWS Disaster Recovery
- D) AWS Elastic Disaster Recovery
Answer: D) AWS Elastic Disaster Recovery
Explanation: AWS Elastic Disaster Recovery (formerly known as AWS CloudEndure Disaster Recovery) is a service that helps quickly recover your systems and ensure business continuity in the event of a disaster.
T/F: Amazon S3 supports cross-region replication which is beneficial for disaster recovery.
- Answer: True
Explanation: Amazon S3 supports cross-region replication (CRR), which automatically replicates data to a different AWS region, providing geographical diversity for disaster recovery.
Which AWS feature can be used to geographically route traffic to different AWS regions for high availability and disaster recovery?
- A) AWS Auto Scaling
- B) Amazon CloudWatch
- C) Amazon Route 53
- D) Amazon Inspector
Answer: C) Amazon Route 53
Explanation: Amazon Route 53 is a scalable DNS web service that routes user traffic to the right endpoint and can be used for routing traffic to different regions for high availability and disaster recovery.
T/F: AWS CloudTrail is integral to disaster recovery because it helps in auditing changes to your AWS resources.
- Answer: True
Explanation: AWS CloudTrail records user activity and API usage, allowing for auditing and tracking changes to AWS resources. This information can be critical in understanding the events leading up to a disaster and planning recovery measures.
Which AWS service can be used in conjunction with Amazon EC2 to automate the geographic distribution of applications?
- A) AWS Global Accelerator
- B) Amazon VPC
- C) AWS Direct Connect
- D) Amazon Lightsail
Answer: A) AWS Global Accelerator
Explanation: AWS Global Accelerator improves the availability and performance of applications by directing traffic to optimal regional endpoints. This aids in geographic distribution which is beneficial for disaster recovery efforts.
T/F: You only need to back up EC2 instances for a robust disaster recovery plan on AWS.
- Answer: False
Explanation: A robust disaster recovery plan should include not only EC2 instances but also other components like EBS volumes, RDS databases, S3 buckets, and any other services in use. This ensures that all parts of the application can be recovered in case of a disaster.
Which AWS service can centrally manage backups across AWS services and supports data lifecycle management, ensuring compliance with retention policies?
- A) AWS Storage Gateway
- B) AWS Backup
- C) Amazon EFS
- D) Amazon Glacier
Answer: B) AWS Backup
Explanation: AWS Backup enables you to centralize and automate data protection across AWS services and is equipped with features to manage backup policies and data lifecycle management, helping to adhere to regulatory backup requirements and retention policies.
This blog post on performing disaster recovery procedures is fantastic! Thanks for sharing.
Very helpful information on the AWS SysOps exam. Appreciate the detailed steps.
Can anyone clarify the best practices for RPO and RTO in AWS disaster recovery?
Great article! Does anyone have tips on how CloudFormation can be used for disaster recovery procedures?
I found the section on cross-region replication particularly useful. Thanks!
Is it overkill to use both AWS Backup and AMIs for disaster recovery?
Thanks for breaking down the DR procedures! Really well-written.
Anyone using AWS Elastic Disaster Recovery? How reliable is it?