The strict Property#
strict controls what happens when scheduled runs are missed (e.g. the server was offline):
| Value | Default? | Behavior |
|---|---|---|
strict: true |
Yes | Skip missed runs — only run on the future schedule |
strict: false |
No | Catch up — execute once on next startup if any runs were missed |
// Default — skip missed runs (suitable for cleanup jobs)
CronJob(name: 'cleanup', schedule: Schedule.parse('0 3 * * *'))
// Explicit skip
CronJob(name: 'cleanup', schedule: Schedule.parse('0 3 * * *'), strict: true)
// Catch up missed runs (suitable for billing jobs)
CronJob(name: 'billing', schedule: Schedule.parse('0 0 1 * *'), strict: false)
How Catch-Up Works#
On startup, Zonai checks _cron_jobs for the last successful run of each strict: false
job. If any scheduled runs were missed since then, it executes the job once before resuming the normal schedule — regardless of how many runs were missed.
When to Use Each#
strict: true (skip) is appropriate for:
- Periodic cleanups where missing one run causes no harm
- Metrics aggregation that is idempotent from the start of the next window
- Any job where the work is naturally re-done at the next scheduled time
strict: false (catch up) is appropriate for:
- Billing cycles — must process every interval
- Report generation where each run produces a distinct artifact
- Any job where skipping a run has business consequences
Cautions#
Even if the server was down for days, a strict: false job only runs once on catch-up.
runOnStartup vs. strict: false#
Both can trigger a run at startup but for different reasons:
-
runOnStartup: true— always runs once on startup, regardless of whether any runs were missed strict: false— only runs on startup if scheduled runs were actually missed
They can be combined: strict: false, runOnStartup: true — catches up missed runs AND runs once unconditionally at startup.