TencentDB for MySQL supports three types of architectures: single-node, two-node, and three-node. This document describes the three-node architecture.
- Three-node instances are built on a one-source-two-replica architecture that supports strong sync replication. They deliver finance-grade reliability and high availability by ensuring strong data consistency with real-time hot backup.
- Three-node instances support two resource isolation policies: general and dedicated. For more information, see Resource Isolation Policy.
They are widely used in a variety of industries, including gaming, the internet, IoT, retail, e-commerce, logistics, insurance, and securities.
- The three-node architecture supports such source/replica replication modes as async (default), strong sync, and semi-sync.
- The three-node architecture supports a complete set of features including read-only instances, disaster recovery instance, security groups, data migration, and multi-AZ deployment. For more information, see Strengths.
- The three-node architecture achieves a high availability of up to 99.99%. For more information, see TencentDB Service Level Agreement (New Version).
- The three-node instance provides multiple replicas to guarantee data persistence. The source node data can be synced to the replica nodes; the source instance data can be synced to the read-only instances (if any). This architecture ensures data security and achieves a data persistence of up to 99.99999%.
- The three-node architecture deploys data nodes on powerful hardware devices and uses local NVMe SSD disks as underlying storage with an IOPS of up to 240,000 (this value is the test result with MySQL's default page size of 16 KB and for your reference only. The actual value is subject to the specific configuration, page size, and business load).
- You can deploy the two replica nodes of a three-node instance in the same availability zone (e.g., Beijing Zone 5), but the TencentDB’s default node distribution strategy ensures that they are deployed on different physical servers. You can also deploy the two replica nodes in different availability zones (e.g., one replica node in Beijing Zone 5 and the other in Beijing Zone 7).