更新时间:2024-10-21 GMT+08:00

获取数据游标

功能介绍

本接口用于获取数据游标。

调用方法

请参见如何调用API

URI

GET /v2/{project_id}/cursors

表1 路径参数

参数

是否必选

参数类型

描述

project_id

String

项目ID。

表2 Query参数

参数

是否必选

参数类型

描述

stream-name

String

已创建的通道名称。

partition-id

String

通道的分区标识符。可定义为如下两种样式:- shardId-0000000000- 0比如一个通道有三个分区,那么分区标识符分别为0, 1, 2,或者shardId-0000000000, shardId-0000000001, shardId-0000000002

cursor-type

String

游标类型。- AT_SEQUENCE_NUMBER:从特定序列号(即starting-sequence-number定义的序列号)所在的记录开始读取数据。此类型为默认游标类型。- AFTER_SEQUENCE_NUMBER:从特定序列号(即starting-sequence-number定义的序列号)后的记录开始读取数据。- TRIM_HORIZON:从最早被存储至分区的有效记录开始读取。例如,某租户使用DIS的通道,分别上传了三条数据A1,A2,A3。N天后(设定A1已过期,A2和A3仍在有效期范围内),该租户需要下载此三条数据,并选择了TRIM_HORIZON这种下载方式。那么用户可下载的数据将从A2开始读取。- LATEST:从分区中的最新记录开始读取,此设置可以保证你总是读到分区中最新记录。- AT_TIMESTAMP:从特定时间戳(即timestamp定义的时间戳)开始读取。

枚举值:

  • AT_SEQUENCE_NUMBER

  • AFTER_SEQUENCE_NUMBER

  • TRIM_HORIZON

  • LATEST

  • AT_TIMESTAMP

starting-sequence-number

String

序列号。序列号是每个记录的唯一标识符。序列号由DIS在数据生产者调用PutRecords操作以添加数据到DIS数据通道时DIS服务自动分配的。同一分区键的序列号通常会随时间变化增加。PutRecords请求之间的时间段越长,序列号越大。序列号与游标类型AT_SEQUENCE_NUMBER和AFTER_SEQUENCE_NUMBER强相关,二者共同确定读取数据的位置。取值范围:0~9223372036854775807。

timestamp

Long

开始读取数据记录的时间戳,与游标类型AT_TIMESTAMP强相关,二者共同确定读取数据的位置。

说明:

此时间戳精确到毫秒。

请求参数

表3 请求Header参数

参数

是否必选

参数类型

描述

X-Auth-Token

String

用户Token。

通过调用IAM服务获取用户Token接口获取(响应消息头中X-Subject-Token的值)。

响应参数

状态码: 200

表4 响应Body参数

参数

参数类型

描述

partition_cursor

String

数据游标。

取值范围:1~512个字符。

说明:

数据游标有效期为5分钟。

最小长度:1

最大长度:512

请求示例

获取数据游标

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

响应示例

状态码: 200

正常返回

{
  "partition_cursor" : "eyJnZXRJdGVyYXRvclBhcmFtIjp7InN0cmVhbS1uYW1lIjoianpjIiwicGFydGl0aW9uLWlkIjoiMCIsImN1cnNvci10eXBlIjoiQVRfU0VRVUVOQ0VfTlVNQkVSIiwic3RhcnRpbmctc2VxdWVuY2UtbnVtYmVyIjoiMTAifSwiZ2VuZXJhdGVUaW1lc3RhbXAiOjE1MDYxNTk1NjM0MDV9"
}

SDK代码示例

SDK代码示例如下。

Java

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package com.huaweicloud.sdk.test;

import com.huaweicloud.sdk.core.auth.ICredential;
import com.huaweicloud.sdk.core.auth.BasicCredentials;
import com.huaweicloud.sdk.core.exception.ConnectionException;
import com.huaweicloud.sdk.core.exception.RequestTimeoutException;
import com.huaweicloud.sdk.core.exception.ServiceResponseException;
import com.huaweicloud.sdk.dis.v2.region.DisRegion;
import com.huaweicloud.sdk.dis.v2.*;
import com.huaweicloud.sdk.dis.v2.model.*;


public class ShowCursorSolution {

    public static void main(String[] args) {
        // The AK and SK used for authentication are hard-coded or stored in plaintext, which has great security risks. It is recommended that the AK and SK be stored in ciphertext in configuration files or environment variables and decrypted during use to ensure security.
        // In this example, AK and SK are stored in environment variables for authentication. Before running this example, set environment variables CLOUD_SDK_AK and CLOUD_SDK_SK in the local environment
        String ak = System.getenv("CLOUD_SDK_AK");
        String sk = System.getenv("CLOUD_SDK_SK");

        ICredential auth = new BasicCredentials()
                .withAk(ak)
                .withSk(sk);

        DisClient client = DisClient.newBuilder()
                .withCredential(auth)
                .withRegion(DisRegion.valueOf("<YOUR REGION>"))
                .build();
        ShowCursorRequest request = new ShowCursorRequest();
        request.withStreamName("<stream-name>");
        request.withPartitionId("<partition-id>");
        request.withCursorType(ShowCursorRequest.CursorTypeEnum.fromValue("<cursor-type>"));
        request.withStartingSequenceNumber("<starting-sequence-number>");
        request.withTimestamp(<timestamp>L);
        try {
            ShowCursorResponse response = client.showCursor(request);
            System.out.println(response.toString());
        } catch (ConnectionException e) {
            e.printStackTrace();
        } catch (RequestTimeoutException e) {
            e.printStackTrace();
        } catch (ServiceResponseException e) {
            e.printStackTrace();
            System.out.println(e.getHttpStatusCode());
            System.out.println(e.getRequestId());
            System.out.println(e.getErrorCode());
            System.out.println(e.getErrorMsg());
        }
    }
}

Python

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# coding: utf-8

import os
from huaweicloudsdkcore.auth.credentials import BasicCredentials
from huaweicloudsdkdis.v2.region.dis_region import DisRegion
from huaweicloudsdkcore.exceptions import exceptions
from huaweicloudsdkdis.v2 import *

if __name__ == "__main__":
    # The AK and SK used for authentication are hard-coded or stored in plaintext, which has great security risks. It is recommended that the AK and SK be stored in ciphertext in configuration files or environment variables and decrypted during use to ensure security.
    # In this example, AK and SK are stored in environment variables for authentication. Before running this example, set environment variables CLOUD_SDK_AK and CLOUD_SDK_SK in the local environment
    ak = os.environ["CLOUD_SDK_AK"]
    sk = os.environ["CLOUD_SDK_SK"]

    credentials = BasicCredentials(ak, sk)

    client = DisClient.new_builder() \
        .with_credentials(credentials) \
        .with_region(DisRegion.value_of("<YOUR REGION>")) \
        .build()

    try:
        request = ShowCursorRequest()
        request.stream_name = "<stream-name>"
        request.partition_id = "<partition-id>"
        request.cursor_type = "<cursor-type>"
        request.starting_sequence_number = "<starting-sequence-number>"
        request.timestamp = <timestamp>
        response = client.show_cursor(request)
        print(response)
    except exceptions.ClientRequestException as e:
        print(e.status_code)
        print(e.request_id)
        print(e.error_code)
        print(e.error_msg)

Go

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package main

import (
	"fmt"
	"github.com/huaweicloud/huaweicloud-sdk-go-v3/core/auth/basic"
    dis "github.com/huaweicloud/huaweicloud-sdk-go-v3/services/dis/v2"
	"github.com/huaweicloud/huaweicloud-sdk-go-v3/services/dis/v2/model"
    region "github.com/huaweicloud/huaweicloud-sdk-go-v3/services/dis/v2/region"
)

func main() {
    // The AK and SK used for authentication are hard-coded or stored in plaintext, which has great security risks. It is recommended that the AK and SK be stored in ciphertext in configuration files or environment variables and decrypted during use to ensure security.
    // In this example, AK and SK are stored in environment variables for authentication. Before running this example, set environment variables CLOUD_SDK_AK and CLOUD_SDK_SK in the local environment
    ak := os.Getenv("CLOUD_SDK_AK")
    sk := os.Getenv("CLOUD_SDK_SK")

    auth := basic.NewCredentialsBuilder().
        WithAk(ak).
        WithSk(sk).
        Build()

    client := dis.NewDisClient(
        dis.DisClientBuilder().
            WithRegion(region.ValueOf("<YOUR REGION>")).
            WithCredential(auth).
            Build())

    request := &model.ShowCursorRequest{}
	request.StreamName = "<stream-name>"
	request.PartitionId = "<partition-id>"
	cursorTypeRequest:= model.GetShowCursorRequestCursorTypeEnum().<CURSOR_TYPE>
	request.CursorType = &cursorTypeRequest
	startingSequenceNumberRequest:= "<starting-sequence-number>"
	request.StartingSequenceNumber = &startingSequenceNumberRequest
	timestampRequest:= int64(<timestamp>)
	request.Timestamp = &timestampRequest
	response, err := client.ShowCursor(request)
	if err == nil {
        fmt.Printf("%+v\n", response)
    } else {
        fmt.Println(err)
    }
}

更多

更多编程语言的SDK代码示例,请参见API Explorer的代码示例页签,可生成自动对应的SDK代码示例。

状态码

状态码

描述

200

正常返回

错误码

请参见错误码