App Engine Flexible creates an nginx.health_check log. It logs all health check requests, not just failed health checks. If your health check interval is under 10 seconds the log can grow to multiple gigs in just a few days. Is there any way to configure it to only record failed checks, or disable the log altogether?
The only way to disable this right now is to completely disable health checking (which I wouldn't recommend). We're looking at ways to fix this - apologies!