Sandboxed Worker using a lot of ram when doing nothing

[arthurvanl]

The pid 107183 is the main process. But the whole night it has been like this and seems to me that it's not doing anything anymore because the jobs already finished a long time ago

I started a job last night (23:38) and it finished around 23:53
At the same time I started another job (but diff queue) and it finished (23:38)

But now it's not starting new jobs anymore??? even though I setup node-cron:

But now it still shows that it's using a lot of ram while actually not doing anything

[egeominotti]

Hey @arthurvanl!

Investigated this and confirmed the issue — SandboxedWorker child processes were never terminated when idle. With concurrency: 3 and maxMemory: 512, that's ~1.5 GB of RAM sitting idle doing nothing.

Root cause: The existing idleTimeout option (default: 0 = disabled) stops the entire pool, which also prevents new cron jobs from being processed. There was no mechanism to recycle individual worker processes.

Fixed in v2.6.12 — added per-worker idle recycling via new idleRecycleMs option:

• Default: 30 seconds — idle worker subprocesses are automatically terminated after 30s of inactivity
• At least 1 worker stays alive for fast response
• Workers are lazily respawned on demand when new jobs arrive
• The pool stays running (cron jobs continue to work)

// Default behavior (v2.6.12+): workers recycle after 30s idle
const worker = new SandboxedWorker("queue", {
  processor: "processor.ts",
  concurrency: 3,
  maxMemory: 512,
  // idleRecycleMs: 30000  <- default, workers auto-terminate when idle
});

// Customize the recycle timeout
const worker2 = new SandboxedWorker("queue", {
  processor: "processor.ts",
  concurrency: 3,
  idleRecycleMs: 60000, // recycle after 60s idle
});

// Disable recycling (old behavior)
const worker3 = new SandboxedWorker("queue", {
  processor: "processor.ts",
  concurrency: 3,
  idleRecycleMs: 0, // never recycle
});

You can also check recycled workers via getStats():

const stats = worker.getStats();
// { total: 3, busy: 0, idle: 1, recycled: 2, restarts: 0 }

This should significantly reduce your idle RAM usage. Let me know if you still see issues after upgrading!