KBY Engineering Utilities

Kubernetes Resource & Runtime Profiler

Generate conservative Node.js, Go, or Java runtime starting policies for a supplied Kubernetes CPU and memory limit, with explicit caveats.

Accuracy contract: The flags follow documented runtime controls, but the headroom percentages are explicit starting heuristics that require workload measurement.

Inputs

Defined calculation contract

Application runtimeThe primary language runtime for the container.CPU Limit (Cores)The strict CPU limit for the container (e.g. 2 for 2000m).Memory Limit (MiB)The container memory limit in mebibytes (MiB).

Exact output

Calculation result

2 cores

Container CPU Limit

2048 MiB

Container Memory Limit

Node.js (V8)

Runtime

Planning thread ceiling

1433 MiB

Runtime memory ceiling

615 MiB

Process headroom

Starting configuration

These conservative runtime policies leave headroom inside the container limit; they do not guarantee that the whole process will remain below the cgroup limit.

NODE_OPTIONS="--max-old-space-size=1433"No universal CPU flag — tune worker pools from measurements

Memory policy: 70% V8 old-space ceiling / 30% process headroom
CPU policy: 2 CPU is a cgroup time quota; 2 is only the nearest whole-thread planning ceiling.

max-old-space-size limits V8 old space, not total Node.js process memory.
UV_THREADPOOL_SIZE depends on blocking I/O and native work, not CPU limit alone.

Versioned sources

Kubernetes Resource Management Go GC Guide: Memory Limit Node.js CLI: max-old-space-size

Deterministic v2026.08.1 — Principal · 4 min