process.memoryUsage

const m = process.memoryUsage();
// { rss, heapTotal, heapUsed, external, arrayBuffers }

Periodic logging

setInterval(() => {
  const { rss, heapUsed, external } = process.memoryUsage();
  console.log(JSON.stringify({
    ts: new Date().toISOString(),
    rssMB: +(rss / 1024 / 1024).toFixed(1),
    heapUsedMB: +(heapUsed / 1024 / 1024).toFixed(1),
    externalMB: +(external / 1024 / 1024).toFixed(1),
  }));
}, 10_000);

Prometheus-style metric names

Metric	Source
`process_resident_memory_bytes`	`rss`
`nodejs_heap_size_used_bytes`	`heapUsed`
`nodejs_external_memory_bytes`	`external`

Soak test script

# Terminal 1
node examples/node/01-global-array-leak.js

# Terminal 2 — watch trend
while true; do date; ps -o rss= -p $(pgrep -f 01-global-array-leak) | awk '{print $1/1024 " MB rss"}'; sleep 5; done

All examples in examples/node/ log memory each tick — use them as templates.