Scale compute to zero

A scale-to-zero workload snapshots and stops when it goes idle, then restores on the next request. You pay no CPU or memory for an idle service, and a cold request pays a restore instead of a full boot. It applies to microVM workloads, whose device-model state (including in-flight queue cursors) can be snapshotted and resumed.

Enable it per workload with --scale-to-zero:

boatramp compute build web \
  --image nginx:1.27 --kernel <vmlinux-blob-hash> \
  --port 80 --scale-to-zero

workload web set: 1 replica, port 80, scale-to-zero on

The workload runs normally under load. When it is idle, its state is snapshotted and the microVM stops; the next request restores it from the snapshot. A restore is faster than a boot because the guest resumes where it left off rather than re-initializing.

Note: the snapshot/restore mechanism is validated live (a serve → snapshot → restore → serve round-trip). The automatic idle→snapshot and request→restore reconcile is being finished; treat scale-to-zero as production-ready for the mechanism and pre-1.0 for the fully automatic idle detection. See Maturity, validation & support.

For the mechanism itself and when to choose scale-to-zero over always-on, see Compute: handlers vs containers vs microVMs.