Safe Scheduled Runtime Upgrade

Core outcomes

• Exact target and clean-source verification with recovery ownership
• Runtime, trigger, service-dependency and queued-job inventory
• Bounded draining with preservation of original scheduling states
• Fresh state-bound review and a single guarded release application
• Recovery decisions for stale reviews, cancellation and ambiguous switches
• Process-reported runtime readiness separated from pending asynchronous work
• Configuration restart planning with full stop scope and durable handoff

Requirements

Preconditions an agent should verify before selecting this capability.

• A runtime driven by systemd timers or a scheduler with equivalent inspection and pause controls
• An exact target revision or artifact digest and reviewable source
• Access to service, process, queued-job and release-state observations
• A release mechanism that rejects stale state or equivalent concurrent drift
• Authority for the affected operational changes and a named recovery owner
• Durable recovery evidence and a readiness check identifying the running instance

Boundaries

Published limitations that constrain safe use.

• A source checkout or successful apply response does not establish running-process readiness
• Paused timers and empty PID fields do not establish that queued or in-flight work has drained
• Worker termination, lock deletion and receipt rewriting are not shortcuts to quiescence
• An ambiguous switch must be reconciled before repetition or rollback
• Resuming schedules may start consequential catch-up work and requires the agreed recovery rule
• Asynchronous start acceptance and slow diagnostic snapshots do not prove operational completion
• Host and virtual-machine restarts require authority covering their full stop scope
• The workflow provides no universal safety guarantee or claim of live acceptance