Incident Library

API · MCP 한국어

API and MCP kubegap Corrections and proposals

Incident Library

API · MCP 한국어

Contributing factor

No caching

캐시 부재 · no-caching

4 cases · 2019 to 2025

Root cause Capacity exhaustion3 DNS or network fault1

Component CoreDNS3 Client-side DNS resolver and cache2 Container memory limit2 conntrack table1 kube-dns1

Symptom DNS resolution failures4 High error rate2 OOMKilled2 Service outage2

Organisation Backpackr1 Mercari1 Preply1 Zalando1

Cases

IL-0080 kube-dns on Mercari's GKE clusters could not keep up with peak-hour DNS query rates, and a Sev1 production outage followed when several services failed DNS resolutionMercari · 2025 · sev1
Root cause Capacity exhaustion
IL-0027 All CoreDNS pods landed on one node, the node ran out of memory, and DNS for the whole service went downBackpackr · 2025
Root cause Capacity exhaustion
IL-0049 Partial DNS outage after CoreDNS scaled down and kube-proxy failed to delete stale conntrack entries

View on the graph

Intermittent connection failures1

Intermittent timeouts1

Monitoring outage1

Stale endpoint routing1

Preply · 2020

Root cause DNS or network fault

IL-0001 Cluster-wide DNS outage after CoreDNS pods were OOM-killed again and again under a burst of DNS queriesZalando · 2019

Root cause Capacity exhaustion