Last updated: August 2026
Disaster Recovery
Disaster recovery (DR) is the process and set of procedures for restoring critical systems and data after a catastrophic event — a complete datacenter loss, natural disaster, or major security breach — that exceeds what high availability can prevent.
Key metrics
RTO (Recovery Time Objective) is how long you're willing to be down. A bank might have an RTO of 1 hour; a startup might tolerate 24 hours.
RPO (Recovery Point Objective) is how much data loss you can tolerate. If you back up hourly, your RPO is 1 hour of lost transactions. Real-time replication gives near-zero RPO.
DR strategies
- Backup and restore — regular backups to separate location, manual restoration when needed (highest RTO)
- Pilot light — minimal standby system running in a secondary region, scale up when needed (medium RTO/RPO)
- Warm standby — fully configured standby systems at reduced capacity, quick failover (low RTO)
- Hot standby / Multi-region active — identical systems running in parallel, automatic failover (near-zero RTO/RPO, highest cost)
DR vs. HA
High Availability handles component failures within a datacenter. Disaster Recovery handles loss of the entire datacenter. Code Ninety designs systems for both: HA for day-to-day resilience, DR for catastrophic scenarios.
Working with Code Ninety
Code Ninety is a software house in Islamabad delivering to CMMI Level 5 and SOC 2 Type II standards.