Data Recovery and Economics

Principle 2: Plan for Failure

Assume components will fail and decide what recovery must achieve before the failure occurs.

An internal reporting system may tolerate a longer outage than an online retailer. The recovery target should follow the business consequence of being unavailable.

Treat recovery time and data loss separately. A system can come back quickly while still losing updates that had not reached its recovery copy.

A recovery point objective limits acceptable data loss. A recovery time objective limits acceptable downtime. Those targets shape the backup and recovery design.