Real-Time Disaster Recovery

Precautions

The performance indicators provided in this section are for reference only. The actual environment is affected by factors such as the performance of the source or destination database, network bandwidth, data model, and service model.

Specification Description

Based on the maximum performance of data flows, there are four types of specifications: micro, small, medium, and large. Table 1 lists the maximum performance of each specification.

**Table 1** Maximum performance
Specifications	Reference Value of Maximum Performance (Rows/Second)
Micro	300
Small	3,000
Medium	7,500
Large	10,000

The performance of each specification is affected by factors such as the networks, service and DR database performance, and latency. The values in the table are for reference only.
DRS provides specifications of different performance which is measured by DR initialization (no flow control) and DR performance.
The maximum performance (rows/second) is measured by the number of DR rows per second, including all data changes caused by DML statements (INSERT, DELETE, and UPDATE). You can view the destination database write frequency (apply_rows_rate) monitoring metric on Cloud Eye.
DRS allows you to upgrade specifications only for DR tasks from MySQL to MySQL, MySQL to TaurusDB, and TaurusDB to TaurusDB. Task specifications cannot be downgraded. For details, see Changing Specifications.
If you want to compare values for a DRS task, select large specifications when creating the DRS task.

Multiple Specifications

DRS real-time DR allows you to select specifications for some specified data flow tasks.

**Table 2** Data types that support multiple specifications
DR Direction	Data Flow	Multiple Specifications	Specification Upgrade
Current cloud as standby	MySQL -> MySQL	Supported	Yes
Current cloud as active	MySQL -> MySQL	Supported	Yes
Current cloud as standby	MySQL -> TaurusDB	Supported	Yes
Current cloud as standby	DDM -> DDM	Unsupported	No
Current cloud as active	DDM -> DDM	Unsupported	No
Current cloud as standby	TaurusDB -> TaurusDB	Supported	Yes
Current cloud as active	TaurusDB -> TaurusDB	Supported	Yes
Dual-active DR	MySQL -> MySQL	Supported	Yes
Dual-active DR	TaurusDB -> TaurusDB	Supported	No