You can call the DescribeReadDBInstanceDelay operation to query the latency of data replication between a primary ApsaraDB RDS instance and its read-only instance.

Before you call this operation, make sure that the following requirements are met:

  • The primary instance must run the MySQL or PostgreSQL database engine.
  • The primary instance must be attached with a read-only instance.

Debugging

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 DescribeReadDBInstanceDelay

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

DBInstanceId String Yes rm-bpxxxxxxx

The ID of the primary instance.
ReadInstanceId String Yes rr-bpxxxxxxx

The ID of the read-only instance.

Response parameters

Parameter Type Example Description
DBInstanceId String rm-bpxxxxxxx

The ID of the primary instance.
DelayTime Integer 0

The latency of data replication between the primary instance and the read-only instance.
Items Array of Items

An array that consists of latency information.
Items
DBInstanceId String rm-bpxxxxxxx

The ID of the primary instance.
ReadDBInstanceNames List "ReadDBInstanceName": ["rr-bpxxxxx"]

An array that consists of information about the read-only instance.

Note This parameter is returned only when the primary instance runs the MySQL database engine.
ReadDelayTimes List "ReadDelayTime": ["0"]

An array that consists of latencies.

Note This parameter is returned only when the primary instance runs the MySQL database engine.
ReadonlyInstanceDelay Array of ReadonlyInstanceDelay

An array that consists of information about the write-ahead log (WAL) latency.

Note This parameter is returned only when the primary instance runs the PostgreSQL database engine.
ReadonlyInstanceDelay
FlushLag String 0

The duration that is allowed for the latency in the persistence of WAL data. Unit: seconds.

FlushLatency String 0

The data size that is allowed for the latency in the persistence of WAL data. Unit: MB.

ReadDBInstanceName String rr-bpxxxxxxx

The ID of the read-only instance.
ReplayLag String 0

The duration that is allowed for the latency in the playback of WAL data. Unit: seconds.
ReplayLatency String 0

The data size that is allowed for the latency in the playback of WAL data. Unit: MB.
SendLatency String 0

The data size that is allowed for the latency in the sending of WAL data. Unit: MB.
WriteLag String 0

The duration that is allowed for the latency in the write-back of WAL data. Unit: seconds.

WriteLatency String 0

The data size that is allowed for the latency in the write-back of WAL data. Unit: MB.

ReadDBInstanceId String rr-bpxxxxxxx

The ID of the read-only instance.
RequestId String F1BDDEA8-452D-450B-AB10-CD5C5BAFC5DF

The ID of the request.

Examples

Sample requests

http(s)://rds.aliyuncs.com/? Action=DescribeReadDBInstanceDelay
&RegionId=cn-hangzhou
&DBInstanceId=rm-bpxxxxxxx
&ReadInstanceId=rr-bpxxxxxxx
&<Common request parameters>

Sample success responses

XML format 

<DescribeReadDBInstanceDelayResponse>
  <RequestId>11152741-D854-4E18-920E-64E75D484D57</RequestId>
  <DBInstanceId>rm-bpxxxxx</DBInstanceId>
  <Items>
        <Items>
              <ReadDBInstanceNames>
                    <ReadDBInstanceName>rr-bpxxxxx</ReadDBInstanceName>
              </ReadDBInstanceNames>
              <ReadDelayTimes>
                    <ReadDelayTime>0</ReadDelayTime>
              </ReadDelayTimes>
              <DBInstanceId>rm-bpxxxxx</DBInstanceId>
              <ReadonlyInstanceDelay>
        </ReadonlyInstanceDelay>
        </Items>
  </Items>
  <DelayTime>0</DelayTime>
</DescribeReadDBInstanceDelayResponse>

JSON format 

{
    "RequestId": "11152741-D854-4E18-920E-64E75D484D57",
    "DBInstanceId": "rm-bpxxxxx",
    "Items": {
        "Items": [
            {
                "ReadDBInstanceNames": {
                    "ReadDBInstanceName": [
                        "rr-bpxxxxx"
                    ]
                },
                "ReadDelayTimes": {
                    "ReadDelayTime": [
                        "0"
                    ]
                },
                "DBInstanceId": "rm-bpxxxxx",
                "ReadonlyInstanceDelay": {
                    "ReadonlyInstanceDelay": []
                }
            }
        ]
    },
    "DelayTime": "0"
}

Error codes

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