Faultline

What happens when DNS goes down?

When DNS resolution fails, services can't find each other — APIs can't resolve endpoints, databases can't connect, and users see "site not found" errors. In a simulated DNS + AWS infrastructure failure across 18 interconnected services, 11 services failed completely and 3 degraded, with an estimated revenue impact of $950,000+ over 3 hours. This is the most devastating cascade scenario: nearly everything goes dark.

DNS is the internet's phone book. When it fails alongside cloud infrastructure, the blast radius is massive. Use the interactive simulator below to trigger it and watch the full cascade in real time.

[Interactive simulator loads here — requires JavaScript]

Expected Impact Summary

When this scenario is triggered, the cascade engine traces every dependency path and calculates the full blast radius. Here's what happens to the 18-service infrastructure over 3 hours:

Cascade order: AWS us-east-1 → Auth0 → AWS RDS Primary → AWS S3 Storage → Redis Cache → Message Queue → Core API Gateway → Transaction Ledger → Payment Processing → Fraud Detection → User Account Service → Notification Service → Admin Dashboard → Compliance Engine

This simulation is powered by Faultline's dependency mapping and cascade analysis engine — the same engine you can use on your own infrastructure. Get early access to map your services, run your own simulations, and identify single points of failure before they cause real outages.

Frequently Asked Questions

What happens during a DNS outage?

DNS is the internet's phone book. When it fails, services can't find each other. APIs can't resolve endpoints, databases can't connect, and users see "site not found" errors. It's one of the most devastating infrastructure failures.

How do I protect against DNS failures?

Use multiple DNS providers, implement DNS caching at the application level, configure lower TTLs for critical records, and have IP-based fallback routes for your most critical service-to-service communication.

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