Disaster Recovery & Business Continuity

RTO · RPO · Multi-Region · Backup Strategy · DR Runbooks

4hr

RTO Target

Revenue-critical services

15min

RPO Target

Maximum data loss window

Geographic Regions

Primary + DR site

24hr

DR Test Frequency

Chaos engineering cadence

Service Tier	Examples	RTO	RPO	DR Strategy	Backup Freq
Tier 0 — Critical Revenue	Billing, Rating, Payment	15 min	0 min (sync)	Active-Active multi-region; real-time sync replication	Continuous (WAL shipping)
Tier 1 — Customer-Facing	Party Mgmt, CRM, Orders	1 hr	5 min	Active-Passive warm standby; async replication <5 min lag	Every 5 min (incremental)
Tier 2 — Important	Catalog, Notification, IAM	4 hr	15 min	Active-Passive cold standby; restore from snapshot	Hourly snapshots
Tier 3 — Non-Critical	Reporting, DMS, Monitoring	24 hr	1 hr	Backup and restore; rebuild from event replay if needed	Daily backup

Backup Strategy

3-2-1 Rule · Immutable Backups · Tested Restores

3-2-1 Rule3 copies of data. 2 different storage media. 1 offsite (different region). Applied to all Tier 0 and Tier 1 databases.

Immutable BackupsBackups written to Immutable (Write-Once Read-Many) storage. Cannot be deleted or modified for the retention period. Ransomware protection. Retention: 90 days operational, 7 years financial.

Restore TestingAutomated restore test on a daily cadence for Tier 0. Every 72 h for Tier 1. A backup that has not been successfully restored is not a backup — untested restores are not accepted.

Event Replay DREvent streaming acts as a secondary DR mechanism. Any service can be rebuilt by replaying its domain events from the topic. Event retention: configurable hot and cold retention periods.

Chaos Engineering & DR Testing

Failure Injection · GameDay · DR Runbooks

Chaos EngineeringScheduled failure injection in pre-production: pod kill, network partition, disk full, CPU spike, dependency latency injection. Tools: Chaos Engineering Framework / Chaos Engineering Framework.

GameDay ExercisesQuarterly full-team DR simulation: trigger a region-level failure scenario in pre-production. Measure actual RTO vs target. Document gaps and remediation actions.

DR RunbooksAutomated runbooks for every DR scenario. Runbooks version-controlled in Git. Executed in minimal steps to minimise operator error under stress. Tested in GameDays.

Region FailoverAutomated DNS failover triggers within seconds (configurable) of primary region health check failure (GSLB). Traffic routed to DR region. Manual runbook confirms data consistency before declaring DR active.

Non-Functional Requirements — Summary Reference

NFR Category	Requirement	Target / Standard	Status
Availability	Platform availability SLO	99.99% (≈ minutes per year)	Mandatory
Latency	API P99 latency (tier-1 services)	< Sub-second P99	Mandatory
Throughput	CDR processing rate	Very High — stream processing sustained	Mandatory
RTO	Revenue-critical service recovery	<Minutes (Tier 0 — near-zero)	Mandatory
RPO	Maximum data loss window	Near-zero (Tier 0 — synchronous replication)	Mandatory
Security	Encryption in transit	TLS 1.3+ on external traffic, mTLS on all inter-service communication	Mandatory
Security	Encryption at rest	AES-256-GCM all data stores	Mandatory
Identity	Authentication protocol	OAuth 2.0 / OIDC + Workload Identity Standard workload identity	Mandatory
PII Compliance	GDPR — Right to Erasure SLA	Confirmed deletion within the regulatory SLA window	Mandatory
Resilience	Circuit breaker on all external calls	Error rate >50% in 10 s window triggers open	Mandatory
Idempotency	All financial mutation endpoints	Idempotency key + 24 h dedup store	Mandatory
Scalability	HPA on all stateless services	CPU target 60%, scale within a short cool-down window	Mandatory
Anti-Affinity	Pod distribution	Required: no two replicas on same node; Preferred: spread across AZs	Mandatory
Technical Debt	Sprint debt remediation allocation	Minimum 20% per sprint	Recommended
Observability	Distributed tracing coverage	100% of requests carry traceId; 10% sampled	Mandatory
CI/CD Security	SAST + SCA in every pipeline	Critical/High CVEs block merge	Mandatory

Disaster Recovery & Continuity

Telecom

Apps

Company