## Summary
Each scheduled-task tick previously issued **3 Prisma `UPDATE`s**
against
`TaskSchedule.lastRunTriggeredAt`,
`TaskScheduleInstance.lastScheduledTimestamp`,
and `TaskScheduleInstance.nextScheduledTimestamp`. All three were pure
denormalization — every value can be derived without persisting.
After this PR `TaskSchedule` and `TaskScheduleInstance` become **near
read-only**:
writes happen only on schedule create / update / delete (rare admin
actions),
so the per-tick autovacuum churn on these hot tables disappears.
## Design
The previous fire time travels forward through the **schedule worker
payload**,
not through the database. Concretely:
- The `schedule.triggerScheduledTask` worker payload gains an optional
`lastScheduleTime: z.coerce.date().optional()` field.
- When the engine fires a schedule, it re-enqueues the next tick with
`lastScheduleTime = scheduleTimestamp` (the just-fired time).
- When the next tick dequeues, `payload.lastTimestamp` is sourced from
`params.lastScheduleTime` directly. No DB round-trip, no cron-derivation
drift across DST boundaries, no caveats around recently-edited cron
expressions.
`payload.lastTimestamp` keeps its `Date | undefined` SDK shape.
First-ever
fires still report `undefined`, so customer `if
(!payload.lastTimestamp)`
first-run patterns keep working.
For Redis jobs that were enqueued **before** this change (which lack
`lastScheduleTime` in their payload), the engine falls back to
`instance.lastScheduledTimestamp` once. Once those drain, the column is
never read again. Revert is code-only; the columns stay in place and can
be dropped in a follow-up once the rollout is stable.
## Files
- `internal-packages/schedule-engine/*` — engine refactor,
`workerCatalog`
schema field, `TriggerScheduleParams` extension, tests updated to assert
on the worker-payload flow rather than DB readbacks.
- `internal-packages/database/prisma/schema.prisma` — `/// @deprecated`
triple-slash docstrings on the three columns. No migration.
- `apps/webapp/app/presenters/v3/ScheduleListPresenter.server.ts` —
drops
the `lastRunTriggeredAt` Prisma select; "Last run" cell is approximated
from the cron expression's previous slot, gated on `schedule.createdAt`
so brand-new schedules show "–". UI is best-effort; the runs page is the
source of truth.
- `apps/webapp/app/v3/utils/calculateNextSchedule.server.ts` — adds a
`previousScheduledTimestamp` helper for the UI cell above. Public API
responses (`api.v1.schedules.*`) already compute `nextRun` from cron and
don't expose `lastTimestamp` — no public API change.
- `references/scheduled-tasks/` — new reference project with declarative
schedules at multiple cadences and three throw-on-fail validators
(`first-fire-detector`, `interval-validator`, `upcoming-validator`) for
E2E-verifying the worker-payload flow.
Refs TRI-8891
## Test plan
- [x] `pnpm run typecheck --filter @internal/schedule-engine --filter
webapp`
- [x] `pnpm run build --filter @trigger.dev/core`
- [x] `pnpm run test --filter @internal/schedule-engine` — integration
test
asserts first-fire `lastTimestamp === undefined`, second fire carries
the previous fire's timestamp exactly.
- [x] E2E against local webapp via `references/scheduled-tasks`:
- Fresh schedules attached → all three deprecated columns stay `NULL`
after
multiple fires.
- Redis payload at second fire contains
`"lastScheduleTime":"<previous fire timestamp>"`.
- `TaskRun.payload` and the every-minute task's returned output both
confirm
`lastTimestamp = null` on first fire and `lastTimestamp = <prev fire>`
on
second fire, exactly 60s apart.
- All three throw-on-FAIL validators completed successfully on every
non-first fire.
- [x] Schedules REST API end-to-end (`POST` / `GET` / `PUT` / `activate`
/
`deactivate` / `DELETE`) — `nextRun` recomputed live from cron + tz on
every response, no reads of deprecated columns.
Eric Allam
ac7177d61f