Pod scheduling and placement

Cases, by severity

1. IL-0100 PostHog's feature flags pods were packed onto Kubernetes nodes that were too small for their CPU requests, and CPU saturation above 90% caused three outages in ten days through Redis overload, connection pool exhaustion and slow queriesPostHog · 2025

   Root cause Capacity exhaustion

2. IL-0148 A kube-scheduler regression in Kubernetes v1.27.14, v1.28.10 and v1.29.5 made the scheduler panic on a pod whose node affinity named a nonexistent node, so no pods were scheduled on affected AKS clustersMicrosoft · 2024

   Root cause Software defect

3. IL-0182 Too few CoreDNS replicas on EKS were overloaded during traffic spikes, raising latency and cutting the network for task pods, and the over-provisioned, tightly spread CoreDNS pods added later blocked Karpenter consolidation이언철 · 2024

   Root cause Capacity exhaustion

4. IL-0064 CPU-heavy pods packed onto one Google Cloud node drove it to kernel panics, and the crash moved from node to node until the site was downMoonlight · 2019

   Root cause Capacity exhaustion

5. IL-0036 A reindex Job that kept failing exhausted one node after another until the whole cluster was downUniverse · 2017

   Root cause Capacity exhaustion