How to tell why Kubernetes liveness probe gets HTTP 503 while logs show 200 OK?

I’ve deployed a pod with Apache httpd (official image, tag 2.4.41), serving HTTP/2.0 plaintext on port 8082, and it’s working “fine”, but I see restarts every few hours (kubectl get pod/mypod, showing 60 restarts in 5 days). The logs always show “caught SIGWINCH, shutting down gracefully” (-p, for previous pod): $ kubectl logs -c httpdcontainer…