Obtaining Data Cursors

project_id

Yes

String

Project ID.

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.

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).

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

200

Normal response.