🔄 Backup & Disaster Recovery

Master cross-region backup, disaster recovery strategies, and RPO/RTO planning.

Module: AWS Data Engineering • Topic 34 of 65 • Premium Content

DR Strategies

Architecture Diagram

┌─────────────────────────────────────────────────────────────────────────────┐
│                    DR STRATEGIES (RPO/RTO)                                   │
│                                                                             │
│  ┌─────────────────────────────────────────────────────────────────────┐    │
│  │  1. BACKUP & RESTORE                                                │    │
│  │     RPO: Hours  |  RTO: Hours  |  Cost: $                           │    │
│  │     S3 versioning, snapshots, cross-region replication              │    │
│  └─────────────────────────────────────────────────────────────────────┘    │
│                                                                             │
│  ┌─────────────────────────────────────────────────────────────────────┐    │
│  │  2. PILOT LIGHT                                                     │    │
│  │     RPO: Minutes |  RTO: 10-30 min |  Cost: $$                      │    │
│  │     Minimal infrastructure running, scale up on failover            │    │
│  └─────────────────────────────────────────────────────────────────────┘    │
│                                                                             │
│  ┌─────────────────────────────────────────────────────────────────────┐    │
│  │  3. WARM STANDBY                                                    │    │
│  │     RPO: Seconds |  RTO: <5 min  |  Cost: $$$                       │    │
│  │     Scaled-down replica, ready to scale                             │    │
│  └─────────────────────────────────────────────────────────────────────┘    │
│                                                                             │
│  ┌─────────────────────────────────────────────────────────────────────┐    │
│  │  4. MULTI-SITE ACTIVE-ACTIVE                                        │    │
│  │     RPO: Zero   |  RTO: Zero   |  Cost: $$$$                       │    │
│  │     Full infrastructure in multiple regions                         │    │
│  └─────────────────────────────────────────────────────────────────────┘    │
└─────────────────────────────────────────────────────────────────────────────┘

Cross-Region S3 Replication

import boto3

s3 = boto3.client('s3')

# Enable versioning
s3.put_bucket_versioning(
    Bucket='data-lake-primary',
    VersioningConfiguration={'Status': 'Enabled'}
)

# Configure cross-region replication
s3.put_bucket_replication(
    Bucket='data-lake-primary',
    ReplicationConfiguration={
        'Role': 'arn:aws:iam::123456789012:role/S3ReplicationRole',
        'Rules': [
            {
                'Status': 'Enabled',
                'Priority': 1,
                'Filter': {'Prefix': ''},
                'Destination': {
                    'Bucket': 'arn:aws:s3:::data-lake-dr',
                    'StorageClass': 'STANDARD_IA',
                    'ReplicationTime': {
                        'Status': 'Enabled',
                        'Time': {'Minutes': 15}
                    }
                }
            }
        ]
    }
)

Interview Q&A

Q1: What is RPO and RTO?

Answer: RPO (Recovery Point Objective) is maximum acceptable data loss. RTO (Recovery Time Objective) is maximum acceptable downtime.

Q2: When should you use Pilot Light vs. Warm Standby?

Answer: Pilot Light for cost-sensitive workloads with higher RTO tolerance. Warm Standby for critical systems requiring fast failover.

Q3: How does S3 cross-region replication work?

Answer: S3 CRR asynchronously replicates new objects to a destination bucket in another region. Supports RTC for 15-minute SLA.

Summary

RPO/RTO: Define acceptable data loss and downtime
Strategies: Backup/Restore → Pilot Light → Warm Standby → Multi-Site
S3 Replication: Cross-region for DR, RTC for 15-min SLA
Redshift: Cross-region snapshot copy
Testing: Regular DR drills are essential

Backup & Disaster Recovery on AWS