Automation & Orchestration of DR
A plan that executes itself — mostly
DR as code: infra-as-code turn-up, runbook automation (promote, DNS flip, smoke), policy-driven backups, self-healing playbooks, and deterministic approvals. The gold: DR that runs mostly itself and always reports its state.
What you will learn
- Encode the DR turn-up as infrastructure-as-code
- Automate promote/DNS/smoke steps safely
- Gate destructive actions with approvals + audit
DR automation: IaC applies the standby in region-B; stacks for promote (DB promote, DNS flip), smoke, and failback; policy engines enforce backups; playbooks at an ops-runner with approval gates. Humans decide when; machines execute deterministically; state reports.
What is this?
Tools: Terraform/CDK for DR stacks + drift detection; GitHub Actions / pipelines triggered by ops-runner (Hashicorp, AWS OpsAutomation, Azure Automation runbooks) for runbook steps; Route53/Traffic Manager DNS automation; DB promote via SDK/CLI (rds promote-read-replica / aurora failover); monitoring hooks (healthcheck-driven or manual 'declare DR' button). Self-healing: health-check auto-recovery within region (ASG) vs DR escalation script that pages owner on sustained regional impact. Policy/backup automation: AWS Backup plans + Org policies, Azure backup policies, GCP backup configs; enforcement + coverage reports. Safety: approval gates for promote/DNS flip (2-person or approval queue), dry-run mode, journal of every action, rollback steps, versioned playbooks in git, RBAC-scoped creds. Metrics: every DR action emits logs/metrics for the scorecard.
Why do you need it?
- Human recall under pressure causes the mistakes the drill keeps finding — automation removes the recall.
- IaC makes 'region-B exists' deterministic and reviewable (drift is a code review away).
- Policy-driven backups fix coverage gaps silently (new services auto-covered).
- Automated reporting turns 'did we do the backup' to 'every backup, every region, proven'.
Mental model
A pilot's auto-takeoff with a trained pilot in the loop: automation flies the numbers, a human makes the call
DR automation
You'd never automate the whole landing without a human at the controls; the same for promote/DNS-flip. Automate the steps, gate the decision, journal every move.
How it works
- IaC describes DR stack in region-B; CI keeps it drift-free and fresh.
- Runbook steps encoded: promote DB, flip DNS, smoke → executed by the ops-runner.
- Approval gate on the destructive steps; dry-run first; journaled actions.
- Monitoring + policy reports run continuously (backup coverage, replication lag, standby health).
- On declare-DR: exec playbook, stream stage-by-stage status to a dashboard, produce the scorecard.
DR orchestration stack.
Examples
DR playbook step (pseudo — HashiCorp/ops-runner)
steps: - name: "promote_db" when: "declared == true and approved == true" run: "aws rds promote-read-replica --db-instance-identifier dr-standby" ok_on: "exit 0" journal: "promote_db:started" - name: "flip_dns" run: "aws route53 change-resource-record-sets --change-batch <batch>" ok_on: "changed == true" rolls_back: "// restore primary batch" - name: "smoke" run: "curl -f --max-time 10 https://app.dr.example.com/healthz", - name: "report" run: "scorecard → metrics + slack"Deterministic steps, approvals, journaling, and a smoke + report — the whole cutover is a one-trigger pipeline.
In production
- Terraform modules for DR stack; nightly drift check reports to the dashboard.
- Ops-runner playbook 'DR: promote' gated on 2-person approval, journaled.
- AWS Backup org policy covering every account/region; coverage dashboard + alerts on gaps.
Best practices
- Run DR as code: IAM, LB, DNS, certs all declarative in the standby region.
- Automate the boring steps; keep a human approval on destructive acts (promote, DNS flip, migrations).
- Journal everything; every playbook action feeds metrics for the drill scorecard.
- Versioned playbooks in git, PR-reviewed like code; drill each release.
- Idempotency + dry-run + rollback steps on every playbook (re-run safe after partial failure).
Common mistakes
- Fully automatic DR button with zero approval: one false trigger = self-inflicted switchover.
- IaC drift left unchecked — region-B stack has rotted between drills.
- Playbooks opaquely 'magic'; on-call can't explain or trust; scorecard untrusted.
- Automated backups that silently stopped covering a new workload (coverage report missing).
Debugging tips
- A DR playbook fails at step 3 → steps should be idempotent; add skip-if-already checks and retries.
- Drift report red but stack looks fine → compare against deployed resources by arn/id, not just state file.
- Approval gate freezes mid-process → journaling should let you resume from the failed step without re-running earlier actions.
- Backup coverage gap last month → policy engine missed the account/region; add org-level enforcement + alerts.
Interview checkpoint
Quick quiz
The step that should usually stay human-approved in DR automation is:
Why keep DR steps idempotent?