This topic describes how to convert the storage engine of DRDS from InnoDB to X-Engine.
Background information
Most users of existing ApsaraDB for RDS instances want to use X-Engine. These users have the following characteristics:
- Most RDS instances run MySQL 5.6 or MySQL 5.7. Few RDS instances run MySQL 8.0.
- A single instance has a large volume of data, which reaches the upper limit of disk space supported by the instance type. For example, an RDS instance with 4 CPU cores and 8 GB of memory supports up to 2 TB of local SSDs.
- The users also use DRDS. In addition, some users use an old version of DRDS and have customized functions, such as SQL passthrough.
To address the user requirements, Alibaba Cloud allows you to convert the storage engine of DRDS from InnoDB to X-Engine by following the procedure in this topic.
Conversion plan
RDS for MySQL 8.0 instances provide consistent API operations and user experience regardless of whether they use InnoDB or X-Engine. In this situation, after a DRDS upgrade, we recommend that you convert the storage engines for the RDS instances from InnoDB to X-Engine one by one. For example, if a DRDS instance has eight RDS instances, first convert the storage engine for one of the eight RDS instances. Monitor the instance running for a period of time. If you confirm that no compatibility or performance issues occur, convert the storage engines for the remaining seven RDS instances.
Compression ratio verification before conversion
Before conversion, we recommend that you purchase an RDS instance that is powered by X-Engine with the same specifications as the existing RDS instance that is powered by the InnoDB storage engine. Then, you can use Alibaba Cloud Data Transmission Service (DTS) to import data from the existing RDS instance to the purchased instance. This way, you can check the compression efficiency. The compression efficiency allows you to determine the following items:
- Instance storage capacity
Based on the compression efficiency, you can determine the instance specifications that you need to purchase after you convert a storage engine from InnoDB to X-Engine. For example, if the space required after compression is below 30% of the original space, you can purchase an RDS instance with 1 TB of disk space after you convert the storage engine of an RDS instance that originally requires 3 TB of disk space. Alternatively, you can purchase an RDS instance with the same specifications to reserve storage space for future business development.
- Number of database shards
After storage space is reduced, you can reduce the number of database shards. For example, you can merge databases that are distributed across instances to one instance. This reduces costs.