Cloudflare Worker Cron Watchdog: SPOF Fix and Automatic DNS Failover for the Vercel Proxy Architecture
The third-party CNAME node pool in the optimized proxy setup is a hidden single point of failure (SPOF). This guide implements a zero-cost watchdog using Cloudflare Worker Cron Triggers: Google DoH serves as an external probe to monitor upstream health, with automatic DNS failover and recovery between the optimized CNAME and CF official IPs.
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