Question

Over ~6 hours after a deploy, your service slowly degrades: new client connections start getting refused, logs show `Too many open files` and `accept: too many open files`, and the process's open file-descriptor count (from `/proc/<pid>/fd`) has climbed steadily to its 65536 `ulimit -n` ceiling and plateaued. Request rate is flat and normal — this isn't a traffic event. Restarting an instance fixes it for a few hours, then it recurs. The deploy added a new outbound integration that makes HTTP calls. How do you triage and find the leak?