Backup & Restore (Low-cost, High-RPO Approach) | Deep Dive.

A deep dive into Backup & Restore (DR) Strategy - the Low-cost, High-RPO Approach.

Scope:

•        Architecture notes,
•        Concrete implementation recommendations,
•        Sample automation snippets,
•        Sample restore runbook,
•        Testing checklist,
•        Cost/security considerations.

Breakdown:

•        Overview,
•        Architecture,
•        RPO / RTO expectations & how to achieve them,
•        Implementation best practices,
•        Sample automation snippets,
•        Restore runbook (step-by-step — simplified),
•        Testing & validation (must-do),
•        Monitoring & alerting,
•        Cost & governance considerations,
•        Security & compliance,
•        Common pitfalls & how to avoid them,
•        Quick checklist to implement now.

1) Overview

• Backup & Restore suits workloads that can tolerate larger data loss (RPO: hours to days) and longer recovery times (RTO: hours → days) in exchange for much lower ongoing cost.

Typical uses:

•         Non-critical internal apps, analytics, batch jobs, dev/test environments
•         Long-term retention for compliance or audits
•         Systems where the business can accept data loss window

2) Architecture (concept)

•         Primary Region: Production systems run as normal (EC2/ECS/EKS, RDS, EBS, S3, etc.).
•         Backups: Periodic snapshots/backups are taken and stored in durable object storage (S3) or Backup vaults.
•         Secondary Region (or Account): Backups are copied or replicated (cross-region replication or transfer) to a secondary region or account for geographic separation.
•         Recovery: In a disaster, provision compute and restore data from backups to new resources in the recovery region.

Key components (typical):

•         Amazon S3 for durable backup storage (CRR for cross-region copies)
•         AWS Backup for central scheduling and retention
•         RDS automated snapshots / manual snapshot exports
•         EBS snapshots and AMIs for EC2
•         Glacier/Infrequent Access for long retention/cost savings

3) RPO / RTO expectations & how to achieve them

•         RPO (hours–days): Achieved by backup frequency. Sample: daily DB snapshot → RPO = up to 24 hours.
•         RTO (hours–days): Depends on restore time — snapshot restore + reprovisioning. Test measured restore times and tune (prebuilt AMIs, scripts).
•         To improve RTO without moving to warm standby, pre-build automation (Infrastructure-as-Code) to spin up resources quickly on restore.

4) Implementation best practices (actionable)

Backup frequency & scope

•         Databases: schedule regular snapshots (daily/weekly). For critical tables consider more frequent exports or logical dumps.
•         Block storage (EBS): automated snapshot schedule (e.g., daily) + periodic longer retention snapshots.
•         Object storage (S3): use versioning + lifecycle; enable Cross-Region Replication (CRR) for critical buckets.
•         Config/state: export configuration (IAM, Route53 configs, Parameter Store/Secrets Manager exports) regularly.
•         Infrastructure definitions: keep CloudFormation/Terraform templates in git (immutable, versioned).

Retention & lifecycle

•         Use tiered retention: short-term daily snapshots (7–30 days), weekly/monthly long retention (90–365+ days) moved to S3-IA/Glacier.
•         Implement lifecycle rules on S3/backup vaults to move older backups to cheaper storage.

Encryption & security

•         Encrypt backups at rest (KMS keys). Use separate KMS keys per account/region for defense in depth.
•         Protect backup access with strict IAM policies; require MFA for deletion of backups (when possible, via governance).
•         Harden the recovery account/role with limited admins and strong logging.

Cross-region/cross-account

•         Prefer cross-region replication for higher resilience; cross-account replication adds isolation for accidental deletion/corruption.
•         Use replication roles with least privilege and monitor replication success.

Automation & IaC

•         Automate snapshot creation, copy, and lifecycle using:
•    AWS Backup plans & vaults (centralized)
•    Lambda or SSM Automation for custom workflows
•    CloudWatch Events (EventBridge) to orchestrate
•         Keep automated restore playbooks (SSM Documents, Step Functions) to run restores with minimal human error.

5) Sample automation snippets

a) S3 Cross-Region Replication (CloudFormation fragment)

# json

Resources:

  BackupBucket:

    Type: AWS::S3::Bucket

    Properties:

      BucketName: twtechapp-backups-prod

      VersioningConfiguration:

        Status: Enabled

  BackupBucketReplicationRole:

    Type: AWS::IAM::Role

    Properties:

      AssumeRolePolicyDocument:

        Statement:

          - Effect: Allow

            Principal: { Service: "s3.amazonaws.com" }

            Action: "sts:AssumeRole"

      Policies:

        - PolicyName: S3ReplicationPolicy

          PolicyDocument:

            Statement:

              - Effect: Allow

                Action:

                  - "s3:GetObjectVersion"

                  - "s3:GetObjectVersionAcl"

                Resource: !Sub "arn:aws:s3:::twtechapp-backups-prod/*"

              - Effect: Allow

                Action:

                  - "s3:ReplicateObject"

                Resource: !Sub "arn:aws:s3:::twtechapp-backups-dr/*"

  BackupBucketReplication:

    Type: AWS::S3::Bucket

    Properties:

      BucketName: tetechapp-backups-dr

      VersioningConfiguration:

        Status: Enabled

(This is a sample; production CRR requires a full replication configuration and role trust.)

b) AWS Backup plan (CLI Sample)

# bash

aws backup create-backup-plan --backup-plan '{

  "BackupPlanName": "twtech-prod-backup-plan",

  "Rules": [

    {

      "RuleName": "daily",

      "TargetBackupVaultName": "twtech-prod-vault",

      "ScheduleExpression": "cron(0 2 * * ? *)",

      "Lifecycle": {"MoveToColdStorageAfterDays":30,"DeleteAfterDays":365}

    }

  ]

}'

c) Restore automation tips

•         Have CloudFormation/Terraform templates parameterized to accept snapshot IDs.
•         Use SSM Automation documents to orchestrate: stop services → detach volumes → create volumes from snapshots → attach → start services.

6) Restore runbook (step-by-step — simplified)

Preconditions: DR team and runbook accessible; IAM role for DR with required privileges.

1.      Confirm scope: Identify which systems are impacted and prioritize by tier.
2.      Verify backup availability: Check latest snapshot marker and cross-region copy exists.

•    aws ec2 describe-snapshots --filters ...

3.     Provision compute/network: Use IaC to create VPC, subnets, security groups, and EC2/EKS/ECS cluster skeleton in recovery region.

•    Use parameterized templates to fill snapshot IDs.

4.     Restore storage/data: Create volumes from snapshots (EBS) and restore DB from latest snapshot or exported snapshot for RDS.

5.     Attach volumes and start services: Attach EBS volumes or mount restored file systems, start application stacks.

6.     DNS switch: Update Route 53 failover records or change ALB/ELB DNS to point to recovery endpoints.

7.     Validation: Run smoke tests — health checks, application-level transactions, database integrity checks.

8.     Bring users online: Gradually route traffic and monitor logs/metrics.

9.     Post-mortem & retention: After recovery, capture timeline, root cause, and update runbook.

7) Testing & validation (must-do)

•         Backup Integrity Test: Periodically restore a random snapshot to a test environment to verify integrity and restore scripts.
•         Full DR Drill: At least annually (more often for critical systems): simulate full restore to DR region including DNS cutover.
•         Partial Recovery Test: Restore a single node, restore DB, validate schemas, test data consistency.
•         Automated smoke tests after each restore run.
•         Track metrics: backup success rate, last successful backup timestamp, snapshot age, restore duration.

8) Monitoring & alerting

•         CloudWatch alarms for backup failures.
•         EventBridge rules for snapshot events (success/failure).
•         Daily/weekly automated reports summarizing backup health.
•         Pager or Slack alerts for failures.

9) Cost & governance considerations

•         Cost drivers: snapshot storage (EBS snapshots), S3 storage class & cross-region copies, AWS Backup vault costs, data transfer for replication.
•         Optimize: use lifecycle rules to move older backups to cheaper classes (S3-IA, Glacier).
•         Governance: enforce retention policies and deletion protections; log and audit all backup/restore operations.

10) Security & compliance

•         Backup data must maintain the same compliance requirements as production.
•         Use KMS key rotation policies, access logging, and role separation for backup admins vs restore operators.
•         Consider immutable backups / write-once policies for regulatory requirements.

11) Common pitfalls & how to avoid them

•         Not testing restores: backups are useless until tested. Run scheduled restores.
•         Single point of failure in backup account/region: replicate to a second region/account.
•         Misconfigured IAM on replication roles: replication fails silently — monitor and alert.
•         Configuration drift: keep IaC in source control and periodically reapply to ensure templates still work.
•         Overlooking secrets/config: backup secrets/parameters (Secrets Manager/SSM) or have documented regeneration methods.

12) Quick checklist to implement now

1.      Inventory all resources and map to backup requirements (RPO/RTO).
2.      Create AWS Backup plans for supported resources.
3.      Turn on S3 versioning + CRR for critical buckets.
4.      Implement automated EBS & RDS snapshot schedules and cross-region copies.
5.      Store IaC templates in git and test parameterized restores monthly.
6.      Implement lifecycle rules to move older backups to Glacier/IA.
7.      Establish monitoring & alerting for backup failures.
8.      Run a restore validation quarterly and a full DR drill annually (or as required by Service Level Agreement …SLA). SLA is a formal, often legally binding, contract between a service provider and a customer that defines the standard of service expected.