BackupsDisaster RecoverySecurity

Disaster Recovery Test Plan: What to Validate After a Cloud Provider Outage

UUnknown

2026-02-14

10 min read

Run a practical DR test that proves RTO/RPO, DNS cutover, SSL re-issuance, and traffic routing after a cloud outage—step-by-step with KPIs.

When a major cloud provider fails, your website—your revenue—can disappear in minutes. Here’s exactly what to run and measure to prove your Disaster Recovery (DR) works.

Cloud outages in early 2026 (widely reported on January 16 after a chain of provider incidents) reminded organizations that even dominant infrastructures can fail. If your team struggles with long DNS propagation windows, manual certificate re-issuance, or complex traffic-steering during failover, this DR test plan is for marketing teams, SEOs, and website owners who must validate recovery targets with measurable KPIs.

What this test validates (executive summary)

RTO / RPO — Are your recovery time and data loss targets achievable under a provider-wide outage?
DNS cutover — Can you redirect traffic quickly from a failed provider to an alternate origin/CDN?
SSL / certificate re-issuance — Can TLS be re-established automatically or manually within SLA?
Traffic routing & health checks — Does traffic actually reach the backup environment and meet performance targets?

Assumptions and prerequisites

Before you start the test: confirm the following. Tests fail because assumptions aren’t validated.

Multi-provider architecture: at least one alternate cloud/CDN and DNS provider configured but not actively serving production traffic.
Automated infrastructure as code (IaC) runbooks: Terraform/CloudFormation/Arm/Ansible playbooks versioned in Git.
Certificate management integrated with an ACME-capable CA (e.g., Let's Encrypt, or your private CA) or a documented manual re-issue runbook.
Short DNS TTLs in place for critical records (e.g., 60–300 seconds) for test windows.
Global synthetic test endpoints (ThousandEyes, RIPE Atlas, or custom curl probes) and observability dashboards ready (Prometheus + Grafana, Datadog, New Relic).
Backups and replication tested: database replication, object storage snapshots, and transaction log retention align to RPO targets.

High-level DR test flow

Pre-test validation and stakeholder notification
Controlled outage simulation (provider-isolation)
Automated failover trigger
DNS cutover and validation
SSL/TLS re-issuance or validation
Traffic routing + performance checks
Data integrity and application functional checks
Failback and cleanup
Post-test KPIs, lessons learned, and remediation

Step 0 — Pre-test checklist (runbook)

Designated DR lead and communications owner (phone + backup contact).
Business-hour window and rollback window scheduled; legal & PR notified if public impact is possible.
Create a read-only snapshot of production data and a list of services that may be impacted by the test.
Confirm alternate DNS provider zone is configured and ready to accept updates via API/console.
Ensure monitoring dashboards and synthetic probes and comm test kits run at 30s–60s frequency for the test window.

Step 1 — Simulate provider outage safely

Do not intentionally break a provider in production. Instead, simulate the outage from your control plane:

Isolate traffic by updating traffic policies to remove the primary origin from load balancers (or add a deny ACL) to mimic unreachability.
Use a network-level block from your edge/CDN to upstream origin to replicate routing loss.
Document the exact command or API call used to simulate the outage for postmortem reproducibility.

Example: remove primary origin from load balancer

aws elb deregister-instances-from-load-balancer --load-balancer-name prod-lb --instances i-0123456789abcdef0

Step 2 — Measure RTO (Recovery Time Objective)

RTO measurement starts when the outage is recognized and ends when end-to-end service functionality and performance targets are met on the DR environment.

Start time: outage detection timestamp (automated alert or runbook start).
Stop time: first timestamp when synthetic global probes return expected HTTP status codes and latency targets are met for N consecutive probes.

RTO KPI examples

Target RTO: 15 minutes (medium-critical site); Measured RTO: 12:37 minutes
Alerting requirement: RTO breaches generate an incident page and SMS alert.
Validation method: global synthetic tests (US/EU/APAC) must see 200 OK for 3 consecutive checks.

Step 3 — Measure RPO (Recovery Point Objective)

RPO defines acceptable data loss. For transactional systems this is often minutes or seconds. Validate the backup/replication pipeline.

Identify the time of last successful backup or replication commit visible to the DR site.
Create a test transaction after that point in the original system and confirm whether it exists in DR.
RPO KPI: target 5 minutes; measured RPO: timestamp difference between last replicated commit and outage time.

Example checks

# On primary before outage
INSERT INTO orders (id, created_at) VALUES (99999, NOW());
# On DR read replica
SELECT created_at FROM orders WHERE id = 99999;

Step 4 — DNS cutover test and validation

DNS is the most common bottleneck in provider failover. Test both automation and global propagation.

Reduce TTLs on critical records to 60–300s at least 24–48 hours pre-test for accurate measurement.
Use DNS provider APIs to patch the relevant A/AAAA/CNAME/ALIAS records to point to the backup IPs or CDN endpoints.
Validate via multiple global resolvers: Google (8.8.8.8), Cloudflare (1.1.1.1), OpenDNS, and RIPE Atlas probes.

Commands to validate DNS propagation

# Query specific resolver
dig +short @1.1.1.1 www.example.com A
# Trace authoritative chain
dig +trace www.example.com

DNS KPIs

DNS cutover completion: percentage of global resolvers returning DR endpoint within target window (e.g., 90% within 5 minutes).
TTL-awareness: ensure at least 95% of resolvers respect configured TTLs during the test window.
DNS failure rate: < 0.5% NXDOMAIN or SERVFAIL for critical records post-cutover.

Step 5 — SSL/TLS re-issuance and validation

TLS is commonly overlooked. If certs were managed by the failed provider (managed SSL), you must validate re-issuance on the alternate provider or via your ACME flow.

Test ACME issuance to the DR endpoint using automated scripts. Measure issuance time and handshake success rate.
If using CDN-managed certificates, ensure a documented manual key/cert import path is available — see our certificate recovery plan primer for runbook templates.
Check OCSP and CRL responses; ensure certificate transparency logs are updated (if relevant).

Sample ACME test (Certbot / demo script)

# Request cert for staging (do not hit production CA during tests)
certbot certonly --test-cert --noninteractive --agree-tos -d www.example.com --manual --preferred-challenges http
# After issuance, test TLS handshake
openssl s_client -connect www.example.com:443 -servername www.example.com

SSL KPIs

Certificate issuance time: target < 10 minutes for ACME; measured issuance time recorded.
TLS handshake success rate: > 99.9% across global probes.
Certificate chain health: zero validation errors in browsers and API clients.

Step 6 — Traffic routing and performance validation

Confirm that the DR environment serves content correctly and within performance budgets.

Run synthetic load tests from multiple geographies to validate latency and error budget (p95 latency, p99 latency).
Measure HTTP error rates (5xx and 4xx) and compare against SLOs.
Validate session persistence, cookies, and SEO-sensitive headers (e.g., canonical tags, hreflang, robots) — preserving search signals is critical; see best practices on Edge SEO.

Recommended traffic KPIs

p95 page load time: < 1.5x production baseline.
HTTP 2xx success rate: > 99% within RTO window.
Error budget burn: measure and log to ensure you stay inside agreed SLA.

Step 7 — Application and data integrity checks

Functional tests ensure the site not only responds but behaves correctly.

Run smoke tests: homepage, login, key API endpoints, checkout flow (if applicable).
Verify analytics tracking (UTM preservation) and SEO-critical elements are intact (noindex misconfiguration).
Database consistency: run checksums or row counts on critical tables.

Sample health-check script outline

# Pseudo-steps
1. GET / -> expect 200 and correct canonical header
2. POST /api/login -> expect 200 and session cookie
3. GET /cart -> expect last item present (if testing session persistence)
4. Validate analytics beacon fired (mock endpoint or server-side logs)

Step 8 — Failback and cleanup

The test isn’t complete until you can return to normal safely.

Run controlled failback once DR KPI thresholds are met for a stabilisation period.
Reverse DNS records to production and verify DNS propagation with the same metrics as cutover.
Revoke or retire temporary certificates issued for DR if they should not remain live.
Restore original routing and confirm all monitoring shows green.

Step 9 — Post-test reporting and continuous improvement

Every test must conclude with a postmortem and an updated runbook.

Collect all KPI timestamps and compare against targets. Log discrepancies with root causes.
Update runbooks for any manual steps that failed automated paths (e.g., manual SSL import required).
Schedule remediation work: shorten TTLs, automate ACME flows, add cross-provider VPNs, or improve replication cadence.

“Outages like the January 2026 provider incidents show that no single vendor is infallible — validation beats hope.”

KPIs and sample reporting dashboard

Your post-test dashboard should summarize the core KPIs so executives can see behavioral outcomes at a glance.

RTO: target vs measured (minutes)
RPO: target vs measured (minutes of data loss)
DNS cutover: % resolvers on DR endpoint at T+5 minutes
Cert issuance: time to valid TLS across probes
Traffic health: p95 latency and 2xx rate during failover
Application checks: % automated smoke tests passed

Advanced strategies and 2026 trends to adopt

Use the latest tooling and architecture patterns to reduce future DR friction.

Edge-first, multi-CDN: combine Anycast-based CDNs and regional origin failover to reduce dependence on a single cloud control plane — see our edge migrations playbook for low-latency region design.
Automated ACME and private PKI: by 2026, many orgs run hybrid ACME flows that issue short-lived certs automatically to multiple endpoints.
DNS over HTTPS (DoH) and DNSSEC awareness: monitor for resolver behavior differences that can impact propagation during cutover.
Observability as a service: integrate global synthetic tests and SLO reporting into incident ops (Prometheus/Grafana, Datadog, ThousandEyes).
Zero Trust and least-privilege automation: use ephemeral credentials and just-in-time access for DR operations to reduce human error risk.

Common failure modes and quick fixes

DNS TTLs too high — reduce TTLs and plan a pre-test window of 48 hours for caching to expire.
Certificates bound to a provider-managed CA — automate ACME or maintain a secondary certificate store; reference our certificate recovery plan examples.
Data lag in replication — increase commit frequency or use change-data-capture (CDC) tools to lower RPO.
Traffic still routed to failed provider — verify global route maps and Anycast mappings; use global probe diagnostics to identify rogue resolvers.

Checklist: Quick-run validation (10-minute readout)

Confirm start time and outage simulation executed.
DNS API call executed; record API response and timestamp.
First 3 synthetic probes (US/EU/APAC) return 2xx — timestamp.
ACME cert issuance successful and TLS handshake validated — timestamp.
Core smoke tests passed (login, key API, checkout) — pass/fail summary.
RTO and RPO measured and logged.

Final takeaways (actionable)

Run this full DR test quarterly for high-risk sites and semi-annually for lower-risk properties.
Automate as many steps as possible: DNS via API, cert issuance via ACME, infra via IaC.
Keep TTLs conservative only during tests — overly low TTLs in production can increase DNS query costs; balance cost vs agility.
Integrate synthetic global monitoring into your SLOs so outages are measured rather than inferred.

Call to action

If you want a tailored DR test runbook (including ready-to-run scripts and a KPI dashboard template) we’ll build a custom plan aligned to your RTO/RPO targets and SEO preservation needs. Schedule a DR review with our team at webs.direct or download our DR test checklist to run your first controlled failover this week.

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