rustfs/docs/architecture/runtime-lifecycle.md

# Runtime And Lifecycle Contracts

Runtime and lifecycle work must preserve startup ordering, readiness behavior, and
shutdown semantics.

## Startup And Readiness

- HTTP can listen early, but normal requests must remain behind readiness gates.
- `FullReady = storage_ready && iam_ready && lock_quorum_ready`.
- Boot phases must keep the old fatal and non-fatal boundaries.
- AppContext migration keeps context-first lookup with global fallback until the
  global path is proven unused.
- Notify and audit lifecycle behavior must not drift during lifecycle movement.
- IAM and KMS startup, deferred recovery, and fatal boundary behavior must not be
  changed by pure movement PRs.

## Service Registry Scope

`ServiceRegistry` is only for lifecycle and shutdown ordering. It must not become a
general dependency injection container.

Allowed responsibilities:

- Register start and stop order.
- Expose read-only status snapshots.
- Coordinate graceful shutdown.

Disallowed responsibilities:

- Construct arbitrary dependencies for business logic.
- Hide globals behind a service-locator API.
- Change startup side effects while moving code.

## AppContext Foundation

Early AppContext work should split resolver files and add compatibility tests before
boot extraction or consumer migration. This keeps the migration context-first while
preserving the old global fallback path during transition.