Cloudflare confirmed a global outage on Tuesday after a change in ClickHouse query behavior caused the Bot Management configuration file to be generated with duplicated lines. The duplicate entries eventually *exceeded memory limits* and crashed the proxy core that processes customer traffic.
Key facts
- Root cause: Change in ClickHouse query behavior created duplicated Bot Management rules.
- Technical impact: Configuration file grew beyond memory limits and crashed Cloudflare’s proxy core.
- Customer impact: Sites relying on Cloudflare bot rules began *blocking legitimate traffic*.
- Response: Cloudflare says it will adopt measures to prevent similar incidents.
Why it matters
- The incident shows how a database query change can cascade into a global service disruption when configuration generation and memory limits interact.
- Services that depend on centralized bot rules risk widespread traffic interruption if configuration integrity is compromised.
Source
- The Verge reported the details; Cloudflare provided the explanation and committed to fixes.
