K8s QoS Classes Explained ⚖️💀

OOM Killer order:

BestEffort (no requests/limits) → First sacrifice
Burstable (requests < limits) → Second
Guaranteed (requests = limits) → Last

Root cause: No requests = scheduler overcommits = node runs out of RAM

Fix:

Set requests = limits

Use LimitRange

Reserve memory for OS (--system-reserved)

medium post :- https://medium.com/@saadcnx/the-silent-app-killer-how-kubernetes-qos-classes-can-secretly-wipe-out-your-nodes-919edae91712

#Kubernetes #DevOps #SRE