An OceanBase Database cluster spans one or more regions. A Region consists of one or more zones, and one or more servers are deployed in each zone. A region refers to a city or a geographic region. If an OceanBase Database cluster spans two or more regions, the data and services of the OceanBase Database cluster have the geo-disaster recovery capability. If a cluster has only one region, the data and services of OceanBase Database will be affected when a city-wide failure occurs. A zone refers to an IDC with an independent network and power supply. The OceanBase Database cluster that spans two or more zones in the same region has the disaster recovery capability when servers in one zone fail. Generally, each zone of an OceanBase Database cluster retains only one data replica. If the cluster has only one zone, this cluster has no disaster recovery capability. If your cluster has several servers deployed in only one IDC, you can create virtual zones and distribute your servers among them to have disaster recovery capability.
OceanBase Database provides innovative disaster recovery capabilities in several deployment modes. For example, you can deploy your cluster in five IDCs across three regions to implement zero-loss disaster recovery for city-wide disasters or in three IDCs of the same city to implement zero-loss disaster recovery for IDC failures. OceanBase Database retains data replicas in multiple regions or zones and uses the Paxos consensus protocol to ensure strong consistency among replicas. When city-wide disasters or IDC failures occur, OceanBase Database ensures and balances the data reliability and the database service availability.
Multi-region cluster:
Multi-zone cluster:
The zero-loss disaster recovery capability of OceanBase Database also facilitates operations on the cluster. When you replace or repair an IDC or server, you can delete the corresponding IDC or server, replace or repair it, and then add a new one. OceanBase Database automatically replicates and balances data to avoid impact on the database service.
OceanBase Database runs the OBServer process on each server of the cluster. The OBServer process manages various features of the database service, including resource management, tenant creation, data distribution management, Paxos protocol for data replicas, and standalone or distributed data query and modification.