Disaster recovery planning

Can you describe the key components of a Disaster Recovery (DR) plan on AWS?

The key components of a DR plan on AWS include the Recovery Time Objective (RTO), Recovery Point Objective (RPO), resources allocation, backup strategy, replication across regions, failover and failback procedures, data lifecycle management, testing and simulation of DR scenarios, and an up-to-date and detailed documentation of DR procedures.

What is the difference between RTO and RPO in the context of disaster recovery, and how do they influence the design of a DR plan on AWS?

RTO, or Recovery Time Objective, is the maximum acceptable length of time a service can be offline after a disaster. RPO, or Recovery Point Objective, represents the maximum acceptable amount of data loss measured in time. They influence DR design by determining the backup frequency, the selection of synchronous or asynchronous replication, and the choice of AWS services to meet these objectives.

How would you use AWS services to achieve a multi-tier backup strategy for disaster recovery?

A multi-tier backup strategy on AWS could involve using Amazon S3 for frequently accessed data, Amazon Glacier for archival, and AWS Storage Gateway for on-premises to cloud data backup. Regularly scheduled snapshots of EBS volumes and AMIs for EC2 instances can also be part of this strategy, with the data being replicated across multiple AWS regions or availability zones.

Can you explain the concept of a pilot light environment in AWS disaster recovery?

A pilot light scenario involves the setup of a minimal version of an environment always running in the cloud. Critical core elements such as database servers are kept up-to-date so that if a disaster occurs, the system can quickly scale up to a full-scale production environment by provisioning additional resources like web and application servers.

How would you configure cross-region replication for Amazon RDS as part of your DR planning?

Amazon RDS supports cross-region replication by allowing the creation of read replicas in a different region than the source DB instance. In a DR scenario, the read replica can be promoted to be the new primary DB instance if the source region fails, to ensure database availability.

Discuss the use of Amazon Route 53 in disaster recovery planning for maintaining high availability.

Amazon Route 53 can be used in DR planning by directing user traffic to healthy endpoints through health checks and DNS failover. It can route traffic to different AWS regions or data centers, enabling a multi-region approach to DR that automatically redirects users to a failover site if the primary site becomes unavailable.

Describe the role of AWS CloudFormation in disaster recovery planning.

AWS CloudFormation plays a critical role in DR planning by allowing the creation of infrastructure as code, which ensures quick and consistent deployment of AWS resources. In a DR event, entire stacks can be launched in a different region or zone, using saved templates that replicate the original environment’s architecture.

How do AWS Elastic Disaster Recovery (AWS DRS) and AWS Backup services facilitate disaster recovery efforts?

AWS Elastic Disaster Recovery (AWS DRS) helps in automating and orchestrating the recovery of EC2 instances, and facilitates the replication of on-premises workloads to AWS. AWS Backup provides centralized backup across AWS services, allowing scheduled backups, retention management, and restoring data across regions which is essential for a comprehensive DR plan.

How would you ensure data durability and prevent accidental deletions or malicious actions as part of your DR strategy in AWS?

Data durability can be ensured by using versioning and cross-region replication features in Amazon S3, enabling MFA Delete on S3 buckets, and using S3 object lock for immutability. Additionally, IAM policies and permissions should be used to restrict access, alongside using AWS Key Management Service (KMS) for encryption to secure data against unauthorized access.

How frequently should a disaster recovery plan be tested, and what does this process normally include on AWS?

A disaster recovery plan should be tested at least annually, but the frequency can increase depending on the criticality of the application. The testing process involves simulating disaster scenarios to verify the effectiveness of backup and restore procedures, the failover and failback operations, the accuracy of the DR documentation, and the time needed to recover operations to a predetermined RTO and RPO.

What are the considerations when choosing between AWS regions for disaster recovery purposes?

Considerations include geographic diversity to avoid regional outages, compliance with data sovereignty laws, latency to end-users, service availability across different regions, and cost differences. The chosen regions should provide enough isolation to survive regional failures but also be accessible and efficient in terms of performance and data transfer costs.

How can AWS Organizations be leveraged for effective disaster recovery planning and management?

AWS Organizations can help manage and govern the environment across multiple AWS accounts. It allows for the setup of consolidated billing, Service Control Policies (SCPs) for compliance and security, and streamline the sharing of resources like AMIs and snapshots, which are important for DR planning across different accounts and regions within an organization’s AWS environment.