Code RoomPod memory climbs then OOMKilled
HardPrep Room Coding #2743

Pod memory climbs then OOMKilled

On-callReliability & on-callMid–Senior~30 min

A read-heavy catalog service on Kubernetes (limit 2Gi) starts getting OOMKilled (exit 137) a few times a day, always 6–10 hours after a pod starts, never right away. The memory graph climbs a slow staircase and never plateaus, but request rate and latency are normal. Heap/RSS grows roughly in proportion to the number of *distinct* product IDs seen since boot, not to current QPS. A release last week added an in-process `map[string]Product` cache 'to cut DB load' — it had a great hit rate in the demo. There is no eviction configured. Triage and mitigate.

What a strong answer looks like

Stop the bleeding first (mitigate), then form hypotheses from real signals. Separate root cause from symptom, communicate status as you go, and close with what prevents a repeat.

0:00 of about 30 min
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