ApsaraDB MyBase for MySQL Master-replica Edition instances are no longer available for purchase. If you already have one, you can continue to use it.
Master-replica Edition uses a primary plus read-only instance topology. Add up to five read-only instances to scale reads, distribute query load, or serve as failover targets when the primary instance fails.
How it works
Each read-only instance is a single-node instance with no replicas of its own. When the primary instance fails, the system automatically promotes a read-only instance — one with low workloads or matching specifications — to become the new primary.
Configure the topology based on your requirements:
Single-node: One primary instance with no read-only instances.
Multi-node: One primary instance with one to five read-only instances.
A single read-only instance does not provide high availability. Add at least two read-only instances to enable failover.
Use cases
Read scaling: Route read-heavy queries to read-only instances to offload the primary instance. Provision read-only instances with higher specifications than the primary to handle peak read loads.
Cost reduction: Read-only instances are single-node and always accessible, eliminating costs from idle standby resources.
Disaster recovery: When the primary instance fails, the system automatically promotes a read-only instance to primary. At least two read-only instances are required to ensure the high availability of your service.
Limitations
| Constraint | Detail |
|---|---|
| Maximum read-only instances | 5 |
| Minimum for high availability | 2 read-only instances |
| Read-only instance replicas | None — read-only instances are single-node |
| Specifications | Read-only instance specifications can differ from the primary; higher specifications are supported |
Supported MySQL versions
MySQL 8.0
MySQL 5.7