ADR-0004: Day-part and boost scale batch size

Status

Accepted

Context

Batch mode fires on a cadence of N per hour, day, week, or month, and emits records per batch per action. The day-part weight and the boost factor have to apply somewhere: to the size of each batch, or to how often batches fire.

Decision

The day-part weight and boost factor scale the size of each batch at its fire time. The cadence stays fixed at the configured frequency.

Consequences

• A nightly load stays recognizably nightly; the boost makes the batch fatter or thinner.
• The cadence is simple to reason about and does not drift with the schedule.
• Real-time mode is unaffected; it accrues against the per-hour rate.

Alternatives considered

• Scale the cadence and keep batch size fixed. Rejected because a varying cadence is harder to reason about and blurs the meaning of "four per day".