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Public parameters

Last Updated: Mar 28, 2018

Public request parameters

Public request parameters refer to the request parameters that every interface must use.

Description of relevant parameters

Name Type Required? Description
Format String No Type of the returned value. Values: JSON and XML. Default value: XML.
Version String Yes API version number: Format: YYYY-MM-DD (date). The current version number is 2016-11-01.
AccessKeyId String Yes Key ID that Alibaba Cloud issues to a user for service access.
Signature String Yes Signature result string. For more information about the signature calculation method, see Signature mechanism.
SignatureMethod string Yes Signature method. Currently, HMAC-SHA1 is supported.
Timestamp String Yes Timestamp of a request. The date format follows the ISO8601 standard and uses UTC time. Format: YYYY-MM-DDThh:mm:ssZ, for example, 2013-08-15T12:00:00Z (20:00:00, August 15, 2013, Beijing time)..
SignatureVersion String Yes Signature algorithm version. The current version is 1.0
SignatureNonce String Yes Unique random number, used to prevent replay attacks. The user must use different random numbers for different requests.


  1. https://rds.aliyuncs.com/
  2. ?Format=xml
  3. &Version=2014-08-15
  4. &Signature=Pc5WB8gokVn0xfeu%2FZV%2BiNM1dgI%3D
  5. &SignatureMethod=HMAC-SHA1
  6. &SignatureNonce=15215528852396
  7. &SignatureVersion=1.0
  8. &AccessKeyId=key-test
  9. &OwnerId=12345678
  10. &Timestamp=2014-10-10T12:00:00Z

Public return parameters

Each time the user sends a call request to an interface, the system returns a unique identification code (RequestId) to the user, whether the request is successful or not.


  1. <?xml version="1.0" encoding="utf-8"?>
  2. <!—Result Root Node-->
  3. <Interface Name+Response>
  4. <!—Return Request Tag-->
  5. <RequestId>4C467B38-3910-447D-87BC-AC049166F216</RequestId>
  6. <!—Return Result Data-->
  7. </Interface Name+Response>

Returned results

After the API service is called, data is returned in a unified format. The returned HTTP status code 2xx indicates that the call is successful. The returned HTTP status code 4xx or 5xx indicates that the call fails. For successful calls, the primary formats of returned data are XML and JSON. When a request is sent, an external system can input a parameter to define the format of returned data, which is XML by default. In this document, examples of returned results are formatted in a way that is easier for users to view. The actual returned results do not contain line breaks, indentation, and so on.

Successful results

Returned XML results include the request processing result (successful or failed) and the specific service data. Example:

  1. <?xml version="1.0" encoding="utf-8"?>
  2. <!—Result Root Node-->
  3. <Interface Name+Response>
  4. <!—Return Request Tag-->
  5. <RequestId>4C467B38-3910-447D-87BC-AC049166F216</RequestId>
  6. <!—Returned Result Data-->
  7. </Interface Name+Response>

JSON example:

  1. {
  2. "RequestId": "4C467B38-3910-447D-87BC-AC049166F216",
  3. /* Returned Result Data*/
  4. }

Error results

When an error occurs in an interface call, no results are returned. The caller can refer to the Client error code table in the Appendix to identify the cause of the error.When an error occurs in a call, the HTTP status code 4xx or 5xx is returned for the HTTP request. The returned message body contains the specific error code and error message. The message body also contains the globally unique RequestId and the requested HostId. If the caller cannot identify the cause of the error, the caller can contact Alibaba Cloud Customer Service and provide the HostId and RequestId to help us solve the problem as quickly as possible.

  1. <?xml version="1.0" encoding="UTF-8"?>
  2. <Error>
  3. <RequestId>8906582E-6722-409A-A6C4-0E7863B733A5</RequestId>
  4. <HostId>rds.aliyuncs.com</HostId>
  5. <Code>UnsupportedOperation</Code>
  6. <Message>The specified action is not supported.</Message>
  7. </Error>

JSON example:

  1. {
  2. "RequestId": "7463B73D-35CC-4D19-A010-6B8D65D242EF",
  3. "HostId": "rds.aliyuncs.com",
  4. "Code": "UnsupportedOperation",
  5. "Message": "The specified action is not supported."
  6. }
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