Stop 11 · Cloud Architecture PatternsTopics · 3/9

Disaster Recovery Strategies

In short

High availability handles a broken server. Disaster recovery handles the bad day: a whole region down, or someone deleting the production database. You choose how fast and how much data you can afford to lose.

Planning for recovery from a major failure — from simple backup-and-restore to fully mirrored multi-region setups — the right strategy depends on how much downtime and data loss the business can tolerate.

The blob character sits outside a locked door as a neighbour hands over a spare key.

Think of it like this

The spare house key

Locked out? If the spare is with a relative across town, you wait an hour. With the neighbour, five minutes. A second key in your bag, instantly. Each option costs a bit more effort, and buys a faster way back in.

Watch it happen

Four strategies, cheapest to fastest

Backup & restore

Pilot light

Warm standby

Active-active

1/5Two numbers drive the choice. RTO: how long you can be down. RPO: how much recent data you can lose.

The big ideas

What you need to know

RTO

Recovery time objective: the longest outage the business can accept, like 4 hours.

RPO

Recovery point objective: how much data loss is acceptable, like the last 15 minutes of orders.

Another region

Keep backups in a different region and ideally a different account, so one mistake can't delete both.

Test restores

A backup you've never restored is a hope, not a plan. Practise recovery on a schedule.

See it in code

Walk through the code

bash

1aws rds copy-db-snapshot \2  --source-db-snapshot-identifier arn:aws:rds:ap-south-1:123456789012:snapshot:notes-2026-10-27 \3  --target-db-snapshot-identifier notes-2026-10-27-dr \4  --source-region ap-south-1 --region ap-southeast-1 \5  --kms-key-id alias/dr-key

1/3The full ARN of the source snapshot in Mumbai.

Copies a Mumbai snapshot to Singapore. The KMS key must exist in the destination region. AWS Backup can schedule copies like this for you.

Save yourself the pain

Common mistakes

Oops

Keeping backups in the same account and region as production.

Do this instead

A region outage or a compromised admin can wipe both. Copy to another region and account.

Oops

Choosing active-active for an internal tool that can be down for a day.

Do this instead

Start from the business RTO and RPO. Often backup and restore is perfectly fine.

Your mission

Time a real restore

~45 min

Quick check

The business says: "We can lose at most 5 minutes of data." Which number is that?

Go deeper

1Learn the difference between RTO (how fast you recover) and RPO (how much data you can afford to lose).
2Compare 3 disaster recovery strategies (backup/restore, pilot light, warm standby, multi-site) by cost and recovery speed.
3Draft a simple disaster recovery plan for a hypothetical critical service.