OceanBase Cloud achieves high availability through a cross-cloud active-active architecture, ensuring continuous and stable services even in the face of failures.
Overview
OceanBase Cloud supports deploying identical data and services across different cloud providers. Each cloud environment remains active, handling business requests while maintaining data consistency using real-time synchronization.
In the event of a failure in one cloud environment, the other seamlessly takes over all traffic, ensuring uninterrupted services. This architecture not only enhances fault tolerance but also reduces reliance on a single cloud provider, improving overall system reliability and stability.
The cross-cloud active-active replication capability consists of two major components: cross-cloud deployment and active-active synchronization links.
Implementation
Cross-cloud deployment
Cross-cloud deployment requires connecting different clouds using specialized network solutions (e.g., dedicated lines, public networks, or cloud enterprise networks). This introduces challenges such as network complexity, the impact of bandwidth and latency on performance, and data transmission security. OceanBase Cloud addresses these challenges through the following optimizations:
Cloud gateway service automation
OceanBase Cloud automates cross-cloud networking using a built-in gateway service. You only need to specify the source and target cloud providers and regions. The system automatically determines the necessary network services based on the cloud properties and handles network construction, monitoring, and maintenance behind the scenes, ensuring a seamless experience without impacting your business network.
Localized transmission components
Cross-cloud network traffic and latency directly affect data transmission performance. To address this, OceanBase Cloud deploys log parsing components on the source cloud and data writing components on the target cloud. This architecture filters unnecessary data at the source while minimizing latency issues during data writing on the target, thereby enhancing transmission performance.
Encrypted data transmission
OceanBase Cloud ensures transmission security using AES-128-GCM encryption, a widely adopted standard used by major cloud providers like Google Cloud and AWS. Session keys between gateways are transmitted via secure private network tunnels and are periodically rotated to maintain data security during cross-cloud transfers.
Active-active synchronization links
For disaster recovery scenarios, active-active solutions are increasingly favored over traditional backup-restore or primary-secondary clusters. In an active-active setup, both data centers handle read and write requests simultaneously. To ensure data consistency across both sides, real-time bidirectional synchronization is required.
OceanBase Cloud supports bidirectional synchronization between heterogeneous databases, including MySQL, Oracle, and OceanBase Database, ensuring stability and consistency through mechanisms like loopback prevention and conflict detection.
Loopback prevention
When data is written to one side, database logs are recorded and parsed for synchronization to the other side. This process may inadvertently create infinite loops as synchronized data is logged and re-synchronized back.
To prevent this, OceanBase Cloud implements database-specific loopback prevention:
- MySQL and Oracle: Transaction tables record synchronized data during incremental writes. Before log parsing, the system checks if the data exists in the transaction table. If yes, it discards the data; otherwise, it proceeds with synchronization.
- OceanBase: Synchronization components assign unique thread IDs to data writes. During log parsing, the system automatically discards data marked with these thread IDs, preventing loopback issues.
Conflict detection
Active-active setups require businesses to avoid simultaneous writes or updates to the same record (unique key) in both data centers. Such scenarios can lead to data conflicts, where updates from both sides overwrite each other.
OceanBase Cloud’s active-active replication links provide real-time conflict detection. Based on your configuration, the system can:
- Overwrite the target data,
- Ignore the conflict and retain the target data,
- Preserve the conflict data for analysis.
Additionally, OceanBase Cloud records all conflicting data, allowing you to download and analyze it for identifying root causes and improving business logic to minimize future conflicts.