You can call the CalculateDBInstanceWeight operation to query the read weights of a primary ApsaraDB RDS instance and its read-only instances.
When the read/write splitting feature is enabled, this operation is used to calculate system-specified read weights. For more information, see Read/write splitting overview. For more information about custom read weights, see DescribeDBInstanceNetInfo.
Before you call this operation, make sure that the following requirements are met:
- The shared proxy feature must be enabled for the primary instance.
- The primary instance must run one of the following database engine versions and RDS
editions:
- MySQL 5.7 on RDS High-availability Edition (with local SSDs)
- MySQL 5.6
- SQL Server 2017 on RDS Cluster Edition
Debugging
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 of DBInstanceWeight |
An array that consists of the system-specified read weights. |
|
DBInstanceWeight | |||
DBInstanceId | String | rm-uf6wjk5xxxxxxx |
The ID of the instance. |
DBInstanceType | String | Master |
The role of the instance. Valid values:
|
Weight | String | 100 |
The read weight that ApsaraDB RDS calculates in real time for the instance. |
ReadonlyInstanceSQLDelayedTime | String | 30 |
The threshold for the latency of data replication from the primary instance to the read-only instances. The read-only instances start to synchronize data from the primary instance after the time specified by the ReadonlyInstanceSQLDelayedTime parameter elapses. Unit: seconds. |
RequestId | String | C816A4BF-A6EC-4722-95F9-2055859CCFD2 |
The ID of the request. |
Examples
Sample requests
http(s)://rds.aliyuncs.com/? Action=CalculateDBInstanceWeight
&DBInstanceId=rm-uf6wjk5xxxxxxx
&<Common request parameters>
Sample success responses
XML
format
<CalculateDBInstanceWeightResponse>
<items>
<DBInstanceId>rm-uf6wjk5xxxxxxx</DBInstanceId>
<DBInstanceType>Master</DBInstanceType>
<Weight></Weight>
<Availability></Availability>
</items>
<requestId>C816A4BF-A6EC-4722-95F9-2055859CCFD2</requestId>
</CalculateDBInstanceWeightResponse>
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.