After node2 OOM incident, right-size memory across the cluster by setting
requests=limits based on max_over_time(container_memory_working_set_bytes[7d])
with 1.3x headroom. Eliminates ~37Gi overcommit gap.
Categories:
- Safe equalization (50 containers): set req=lim where max7d well within target
- Limit increases (8 containers): raise limits for services spiking above current
- No Prometheus data (12 containers): conservatively set lim=req
- Exception: nextcloud keeps req=256Mi/lim=8Gi due to Apache memory spikes
Also increased dbaas namespace quota from 12Gi to 16Gi to accommodate mysql
4Gi limits across 3 replicas.
CPU limits cause CFS throttling even when nodes have idle capacity.
Move to a request-only CPU model: keep CPU requests for scheduling
fairness but remove all CPU limits. Memory limits stay (incompressible).
Changes across 108 files:
- Kyverno LimitRange policy: remove cpu from default/max in all 6 tiers
- Kyverno ResourceQuota policy: remove limits.cpu from all 5 tiers
- Custom ResourceQuotas: remove limits.cpu from 8 namespace quotas
- Custom LimitRanges: remove cpu from default/max (nextcloud, onlyoffice)
- RBAC module: remove cpu_limits variable and quota reference
- Freedify factory: remove cpu_limit variable and limits reference
- 86 deployment files: remove cpu from all limits blocks
- 6 Helm values files: remove cpu under limits sections
Secondary instance on a separate node replicates all zones from primary via
zone transfer. LoadBalancer routes DNS queries to both pods. PDB ensures at
least 1 DNS pod survives voluntary disruptions. Setup job automates zone
transfer enablement and secondary zone creation via Technitium REST API.
