Hot-Hot vs Hot-Warm vs Hot-Cold in OCI

These are disaster-recovery models defining how prepared the secondary OCI region is when the primary region fails.

1. Hot-Hot: Active–Active

Both OCI regions are fully operational and serve users simultaneously.

Flow: Users → Global Traffic Management → Region A + Region B

• Continuous data replication
• Immediate traffic redirection
• Highest availability
• Highest infrastructure cost

2. Hot-Warm: Active–Standby

The primary region serves users. The secondary region is running with minimum capacity and continuously receives replicated data.

Flow: Region A Active → Data Replication → Region B Standby → Scale Up During Failure

• Faster recovery
• Some failover or scaling is required
• Balanced cost and availability

3. Hot-Cold: Active–Backup

Only the primary region is operational. The secondary region contains backups or infrastructure templates.

Flow: Region A Active → Backup/Replication → Object Storage → Build Region B After Failure

• Infrastructure may be created using Terraform
• Data must be restored from backup
• Longest recovery time
• Lowest operating cost

Simple Memory Trick

- Hot-Hot: Both are working.

- Hot-Warm: Backup is running but waiting.

- Hot-Cold: Backup must be built or started.