Learn from Cloudflare

When a Single Regex
Took Down the Internet (Almost)

In 2019, a poorly written regular expression in a Cloudflare WAF rule triggered a global outage. Incident Drill helps your team prepare for and prevent similar catastrophic events through realistic incident simulations.

Cloudflare | 2019 | Outage (Software Bug)

Practice This Scenario →

The High Cost of Unforeseen Errors

Incidents like the Cloudflare Regex WAF outage highlight the critical need for robust testing and incident response plans. Even seemingly minor code changes can have catastrophic consequences, leading to downtime, financial losses, and reputational damage. Teams need to be prepared to quickly identify, diagnose, and resolve these issues.

PREPARE YOUR TEAM

How Incident Drill Helps

Incident Drill provides a platform for teams to practice handling real-world scenarios like the Cloudflare outage. Our simulations allow engineers to experience the pressure of a live incident in a safe environment, improving their skills and building confidence in their ability to respond effectively. Learn to debug regex performance issues before they impact your users.

🚨

Realistic Simulations

Experience incidents based on real-world events like the Cloudflare Regex WAF outage.

🔎

Root Cause Analysis

Practice identifying the root cause of complex issues under pressure.

🧑‍💻

Collaborative Response

Work together as a team to troubleshoot and resolve incidents.

📈

Performance Metrics

Track your team's performance and identify areas for improvement.

📚

Post-Incident Reviews

Conduct thorough post-incident reviews to learn from mistakes and prevent future incidents.

⚙️

Customizable Scenarios

Tailor simulations to your specific infrastructure and codebase.

WHY TEAMS PRACTICE THIS

Master Incident Response Skills

✓ Reduce downtime and improve reliability
✓ Enhance team collaboration and communication
✓ Improve incident response time and accuracy
✓ Develop a culture of continuous improvement
✓ Identify and mitigate potential risks
✓ Build confidence in your team's ability to handle any incident

Incident Timeline

10:00 AM

New WAF rule deployed

10:05 AM

CPU usage spikes on edge servers ERROR

10:10 AM

85% of network at 100% CPU ERROR

10:20 AM

WAF rule disabled RESOLVED

How It Works

Step 1: Identify the Spike

Recognize the initial signs of a CPU spike across the Cloudflare network.

Step 2: Isolate the Cause

Quickly determine that the new WAF rule is the source of the problem.

Step 3: Mitigate the Impact

Disable the problematic WAF rule to restore network stability.

Step 4: Analyze and Prevent

Conduct a post-incident review to identify the root cause and prevent future occurrences.

EXPLORE MORE

Related Incidents

Ready to Level Up Your Incident Response?

Join the Incident Drill waitlist and be among the first to experience realistic incident simulations. Prepare your team for anything.

Get Early Access →

✓ Founding client discounts ✓ Shape the roadmap ✓ Direct founder support

When a Single Regex Took Down the Internet (Almost)