IT Services Circle

Sep 10, 2025 · Backend Development

Why Does Spring Cloud Gateway Return 404 After Nacos Config Changes?

After a year‑long mystery, we discovered that Spring Cloud Gateway 3.x caches stale weight data from Nacos, causing 404 errors when routes are removed, and we detail the debugging steps, root‑cause analysis, and a custom solution that synchronizes the weight cache on configuration changes.