Stripe Investigates Unexpected DNS Error Spike: A Tale of Complex Network Troubleshooting
2024-12-12
Stripe recently experienced an unexpected spike in DNS errors. This post details how they used tools like Unbound, tcpdump, and iptables to track down the root cause. The investigation revealed that a Hadoop job analyzing network logs was performing numerous reverse DNS lookups (PTR records), leading to traffic amplification due to retries exceeding the AWS VPC resolver's limits. Stripe resolved the issue by adjusting Unbound forwarding configurations to distribute the load across individual Hadoop hosts. The case highlights the importance of robust monitoring, multi-faceted troubleshooting, and strategies for handling traffic surges in high-availability systems.