UKBatch 0.2.2-alpha

Durable recovery for batch workflows: an in-flight run resumes after a restart, and a scheduled batch can catch up a fire it missed while down. Both build on the persistent run store and require the EF storage adapter.

Added

• Durable batch resume. A batch run interrupted by a host restart resumes from where it left off instead of being lost. The run records a step cursor (BatchRun.CurrentStepIndex); at startup the EF storage adapter re-launches each in-flight run under a resume policy — ResumeForward (skip already-completed steps, the default), RestartAll, or RestartFrom(n). A completed step is not re-run, and a pending approval gate is re-attached so a later decision still resolves it. An additive migration (AddBatchRunCursor) adds the cursor column; existing tables are unchanged.
• Per-batch missed-fire scheduler catch-up. A scheduled batch can opt in to replaying a fire it missed while the host was down, via BatchDefinition.ScheduleCatchUpWindow (set in code with .CatchUpMissedWithin(...), in the REST body as scheduleCatchUpWindow, or on the dashboard wizard's Schedule step). On restart the scheduler replays only the most recent occurrence missed within the window — exactly once (coalesced, never a burst) — and a persisted last-fire watermark guarantees the same occurrence never fires twice. Leaving the window unset keeps the previous skip-on-downtime behaviour. An additive migration (AddScheduleCatchUp) adds the ScheduleStates watermark table and the per-batch window column.

Changed

• A graceful host shutdown no longer cancels an in-flight batch run. The run is left in-flight and resumed on the next start (see durable resume above); an explicit administrative cancel still ends the run as Cancelled.

Known limitations

• Durable resume and scheduler catch-up require the EF storage adapter (PostgreSQL or SQLite). With the default in-memory storage they are inactive — there is no durable store to record the cursor or the last-fire watermark.
• Single-node: resume and catch-up act on the node that boots and do not coordinate across multiple instances sharing one database. Distributed/HA recovery is a later release.
• Scheduler catch-up replays at most one occurrence per batch per restart (the latest missed within the window); a gap older than the window is left for the operator to run manually.