Queries read weights of an ApsaraDB for RDS instance.

When read/write splitting is enabled, this operation is used to calculate the read weights specified by the system. For custom read weights, see DescribeDBInstanceNetInfo.

Before you call this operation, make sure that the instance runs one of the following database engine versions and RDS editions:

  • MySQL 5.7 in the High-availability Edition (with local SSDs)
  • MySQL 5.6
  • SQL Server 2017 EE


OpenAPI Explorer automatically calculates the signature value. For your convenience, we recommend that you call this operation in OpenAPI Explorer. OpenAPI Explorer dynamically generates the sample code of the operation for different SDKs.

Request parameters

Parameter Type Required Example Description
Action String Yes CalculateDBInstanceWeight

The operation that you want to perform. Set the value to CalculateDBInstanceWeight.

DBInstanceId String Yes rm-uf6wjk5xxxxxxx

The ID of the primary instance.

Response parameters

Parameter Type Example Description
Items Array

The list of weights specified by the system.

DBInstanceId String rm-uf6wjk5xxxxxxx

The ID of the instance.

DBInstanceType String Master

The type of the instance. Valid values:

  • Master: The instance is primary.
  • Readonly: The instance is read-only.
Weight String 100

The read weight that is calculated by the system in real time.

ReadonlyInstanceSQLDelayedTime String 30

The replication latency between the read-only instance and the primary instance. The read-only instance replicates data from the primary instance based on the latency specified by the ReadonlyInstanceSQLDelayedTime parameter. Unit: seconds.

RequestId String C816A4BF-A6EC-4722-95F9-2055859CCFD2

The ID of the request.


Sample requests

http(s)://rds.aliyuncs.com/? Action=CalculateDBInstanceWeight
&<Common request parameters>

Sample success responses

XML format


JSON format

    "items": [
            "DBInstanceId": "rm-uf6wjk5xxxxxxx",
            "DBInstanceType": "Master",
            "Weight": "",
            "Availability": ""
    "requestId": "C816A4BF-A6EC-4722-95F9-2055859CCFD2"

Error codes

For a list of error codes, visit the API Error Center.