Common parameters-阿里云帮助中心

Common parameters are required for all API calls. They include common request parameters and common response parameters.

Common request parameters

Common request parameters are required for every API call.

Name	Type	Required	Description
Format	String	No	The format of the return value. Valid values: JSON and XML. The default value is XML.
Version	String	Yes	The version number of the API. The format is YYYY-MM-DD. The version number for this release is 2014-08-15.
AccessKeyId	String	Yes	The AccessKey ID issued by Alibaba Cloud for you to access the service.
Signature	String	Yes	The signature string. For more information about how to calculate a signature, see Signature mechanism.
SignatureMethod	string	Yes	The signature method. Only HMAC-SHA1 is supported.
Timestamp	String	Yes	The timestamp of the request. The format must follow the ISO 8601 standard and use UTC. The format is `YYYY-MM-DDThh:mm:ssZ`. For example, `2013-08-15T12:00:00Z` is 20:00:00 on August 15, 2013 (UTC+8).
SignatureVersion	String	Yes	The version of the signature algorithm. The current version is 1.0.
SignatureNonce	String	Yes	A unique random number used to prevent replay attacks. You must use a different random number for each request.

Common response parameters

Each API call returns a unique request ID (RequestId), regardless of whether the call is successful.

Request example

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

Response examples

After you call an API, the system returns data in a unified format. An HTTP status code in the 2xx range indicates that the call is successful. An HTTP status code in the 4xx or 5xx range indicates that the call failed. For successful calls, data is returned in XML or JSON format. You can specify the response format in the request. The default format is XML. For readability, the response examples in this document are formatted. The actual responses do not contain line breaks or indents.

Successful response

XML format

<?xml version="1.0" encoding="utf-8"?> 
<!--The root node of the result-->
<APIName+Response>
    <!--The request ID tag-->
    <RequestId>4C467B38-3910-447D-87BC-AC049166F216</RequestId>
    <!--The response data-->
</APIName+Response>

JSON format

{
    "RequestId": "4C467B38-3910-447D-87BC-AC049166F216",
    /* The response data */
}

Error response

If an API call fails, no data is returned. You can identify the cause of the error based on the client-side error codes.

If a call fails, the response includes an HTTP status code in the 4xx or 5xx range. The response body contains the specific error code and error message. The response body also includes a globally unique request ID (RequestId) and the ID of the site that you accessed (HostId). If you cannot identify the cause of the error, contact an Alibaba Cloud customer service representative. Provide the HostId and RequestId to help us resolve the issue.

XML format

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

Error response

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