Hotel ARI Sync: Restrictions, Stop-Sell, CTA/CTD and Reconciliation

ARI synchronization is more than sending room counts and prices. Availability, rates, inventory and restrictions must remain consistent on the same product identity. Google and Booking.com documentation show that ARI carries sellability and restriction state at room/rate/date level.

State model

A minimum key is commonly property + room + rate plan + date. Inventory and availability are different: physical rooms can exist while restrictions make the product unsellable.

Restrictions

Stop-sell, minimum/maximum length of stay, closed-to-arrival (CTA) and closed-to-departure (CTD) are distinct business rules and should not be flattened into one availability boolean.

Delivery

Change detection and delta updates reduce bandwidth and conflict risk. Track source timestamp/version for every mutation and process updates idempotently.

Reservation delivery and overbooking

A downstream reservation changes inventory state. If ARI delivery succeeds but reservation notification is lost, overbooking risk increases. These flows require separate health metrics.

Reconciliation

Periodically compare source and destination state. Measure drift, rejected updates, queue lag and stale state separately.

Failure modes

• stale availability causing oversell,
• restriction ordering/version errors,
• losing inventory updates while rates are applied,
• delayed reservation delivery,
• duplicate reservations/events after provider retry,
• incorrect open/close state around timezone/date boundaries.

Observability

Track ARI update success, propagation latency, stale-inventory age, restriction mismatch, reservation-delivery lag, overbooking incidents and reconciliation repairs.

Production checklist

• ARI version/timestamp model,
• idempotent updates,
• ordering/sequence guards,
• timezone normalization,
• reservation-delivery acknowledgement,
• stale-state reconciliation,
• overbooking alerts,
• provider/channel-level metrics.