  Multinational enterprises conduct global business that has a demand for
geo-distributed transactional databases. Existing state-of-the-art databases
adopt a sharded master-follower replication architecture. However, the
single-master serving mode incurs massive cross-region writes from clients, and
the sharded architecture requires multiple round-trip acknowledgments (e.g.,
2PC) to ensure atomicity for cross-shard transactions. These limitations drive
us to seek yet another design choice. In this paper, we propose a strongly
consistent OLTP database GeoGauss with full replica multi-master architecture.
To efficiently merge the updates from different master nodes, we propose a
multi-master OCC that unifies data replication and concurrent transaction
processing. By leveraging an epoch-based delta state merge rule and the
optimistic asynchronous execution, GeoGauss ensures strong consistency with
light-coordinated protocol and allows more concurrency with weak isolation,
which are sufficient to meet our needs. Our geo-distributed experimental
results show that GeoGauss achieves 7.06X higher throughput and 17.41X lower
latency than the state-of-the-art geo-distributed database CockroachDB on the
TPC-C benchmark.
