doc-exports/docs/dis/api-ref/dis_02_0020.html

Obtaining Data Cursors

Function

This API is used to obtain data cursors.

URI

GET /v2/{project_id}/cursors

Table 1 Path parameters

Parameter	Mandatory	Type	Description
project_id	Yes	String	Project ID.

Table 2 Query parameters

Parameter	Mandatory	Type	Description
stream-name	Yes	String	Name of the stream.
partition-id	Yes	String	Partition ID of the stream. The value can be in either of the following formats: shardId-0000000000 0 For example, if a stream has three partitions, the partition identifiers are 0, 1, and 2, or shardId-0000000000, shardId-0000000001, and shardId-0000000002, respectively.
cursor-type	No	String	Cursor type. AT_SEQUENCE_NUMBER: Data is read from the position denoted by a specific sequence number (that is defined by starting-sequence-number). This is the default cursor type. AFTER_SEQUENCE_NUMBER: Data is read right after the position denoted by a specific sequence number (that is defined by starting-sequence-number). TRIM_HORIZON: Data is read from the earliest data record in the partition. For example, a tenant uses a DIS stream to upload three pieces of data A1, A2, and A3. N days later, A1 has expired and A2 and A3 are still in the validity period. In this case, if the tenant uses TRIM_HORIZON to download the data, the system downloads data from A2. LATEST: Data is read from the latest record in the partition. This setting ensures that you always read the latest record in the partition. AT_TIMESTAMP: Data is read from the position denoted by a specific timestamp. Enumeration values: AT_SEQUENCE_NUMBER AFTER_SEQUENCE_NUMBER TRIM_HORIZON LATEST AT_TIMESTAMP
starting-sequence-number	No	String	Serial number. A sequence number is a unique identifier for each record. DIS automatically allocates a sequence number when the data producer calls the PutRecords operation to add data to the DIS stream. SN of the same partition key usually changes with time. A longer interval between PutRecords requests results in a larger sequence number. The sequence number is closely related to cursor types AT_SEQUENCE_NUMBER and AFTER_SEQUENCE_NUMBER. The two parameters determine the position of the data to be read. Value range: 0 to 9,223,372,036,854,775,807
timestamp	No	Long	Timestamp when the data record starts to be read, which is closely related to cursor type AT_TIMESTAMP. The two parameters determine the position of the data to be read. Note: The timestamp is accurate to milliseconds.

Request Parameters

Table 3 Request header parameters

Parameter	Mandatory	Type	Description
X-Auth-Token	Yes	String	User token. The token can be obtained by calling the IAM API (value of X-Subject-Token in the response header).

Response Parameters

Status code: 200

Table 4 Response body parameters

Parameter	Type	Description
partition_cursor	String	Data cursor. Value range: a string of 1 to 512 characters Note: The validity period of a data cursor is 5 minutes. Minimum: 1 Maximum: 512

Example Requests

Obtaining Data Cursors

GET https://{Endpoint}/v2/{project_id}/cursors

Example Responses

Status code: 200

Normal response.

{
  "partition_cursor" : "eyJnZXRJdGVyYXRvclBhcmFtIjp7InN0cmVhbS1uYW1lIjoianpjIiwicGFydGl0aW9uLWlkIjoiMCIsImN1cnNvci10eXBlIjoiQVRfU0VRVUVOQ0VfTlVNQkVSIiwic3RhcnRpbmctc2VxdWVuY2UtbnVtYmVyIjoiMTAifSwiZ2VuZXJhdGVUaW1lc3RhbXAiOjE1MDYxNTk1NjM0MDV9"
}

Status Codes

Status Code	Description
200	Normal response.

Error Codes

See Error Codes.

Parent topic: Data Management