  This paper describes the hotel price aggregation system - PriceAggregator,
deployed at Agoda, a global online travel agency for hotels, vacation rentals,
flights and airport transfer. Agoda aggregates non-direct suppliers' hotel
rooms to ensure that Agoda's customers always have the widest selection of
hotels, room types and packages. As of today, Agoda aggregates millions of
hotels. The major challenge is that each supplier only allows Agoda to fetch
for the hotel price with a limited amount of Queries Per Second (QPS). Due to
the sheer volume of Agoda's user search traffic, this limited amount of QPS is
never enough to cover all user searches. Inevitably, many user searches have to
be ignored. Hence, booking lost. To overcome the challenge, we built
PriceAggregator. PriceAggregator intelligently determines when, how and what to
send to the suppliers to fetch for price. In this paper, we not only prove
PriceAggregator is optimal theoretically but also demonstrate that
PriceAggregator performs well in practice. PriceAggregator has been deployed in
Agoda. Extensive online A/B experimentation have shown that PriceAggregator
increases Agoda's bookings significantly.
