Autoscaling Controller · View 17 of 37 · 3 · Data
Decisions
- No cross-region read on the control path, without exception. A region's control loop functions with every other region unreachable.
- The only shared state is declared intent in Git, and it reaches a region by deployment rather than by query.
- Fleet-wide cost and SLO views are asynchronous exports and are never a dependency of a decision.
What this costs
- A genuinely global capacity ceiling cannot be enforced exactly, only per region. The fleet ceiling is therefore expressed as a sum of regional ceilings.
- That is the honest form of the constraint anyway: a global ceiling enforced by a cross-region read would make every decision depend on a network no one controls.
Scale
- 500 targets/region at launch, 2,000 at design ceiling.
- 50,000 managed instances/region at launch, 200,000 at design ceiling.
- Adding a region is a deployment of an identical control plane.
