ApsaraDB for RDS offers four editions: Basic Edition, High-availability Edition, Cluster Edition, and Enterprise Edition. This topic describes the Enterprise Edition.

The Enterprise Edition supports the following database engine versions and instance families:
- Database engine versions: MySQL 5.7 and 8.0
- Instance families: dedicated instance family and dedicated host instance family
Limits
To ensure optimal performance, you must deploy the primary and secondary instances in the same region.
Benefits
- High reliability
- The Enterprise Edition provides enterprise-grade reliability with a Recovery Point Object (RPO) of 0.
- The primary and secondary instances can be deployed in three different data centers of the same city to support cross-zone disaster recovery.
- Comprehensive functionality
The High-availability Edition supports all of the features that are provided by ApsaraDB for RDS. These features include automatic scaling, backup and restoration, performance optimization, read/write splitting, and SQL Explorer. The SQL Explorer feature is used to log all of the SQL statements that are executed within the last 30 days. Therefore, you can trace database access and ensure the security of important data.
For more information, see Overview of ApsaraDB for RDS editions.
NoteIf you are using MySQL 5.7 or 8.0 with the Enterprise Edition, a trial edition of the SQL Explorer feature is provided free of charge.
- Strong consistency and high availability
The database engines of ApsaraDB for RDS have been improved to increase consistency and availability in the Enterprise Edition.
- A distributed consensus algorithm, Raft, is used to ensure the reliability and atomicity of switchovers between the primary and secondary instances.
- Two data replicas and three log replicas are supported. In addition, transaction logs are synchronized from the primary instance to the two secondary instances. A transaction is committed only after the related log is written into at least two of the three instances.
- In MySQL 5.7 and 8.0, the Raft algorithm is used to control the commitment, rollback, and crash recovery of transactions. This allows you to ensure the consistency of data for your database system.
- Non-primary instances only replay the transaction logs that have been written into most instances of your database system. In addition, parallel replication algorithms at different levels, such as database, table, logical clock, and WriteSet, are used to improve replay efficiency. Therefore, you can reduce Recovery Time Objective (RTO) and ensure instance availability.
Create an RDS instance
For more information about how to create an RDS instance that runs the Enterprise Edition, see Create an ApsaraDB RDS for MySQL instance.
FAQ
Does the Enterprise Edition of ApsaraDB for RDS support read-only instances?
No, the Enterprise Edition of ApsaraDB for RDS does not support read-only instances.