在 AWS Step Function 中使用 Map 状态来迭代一组输入对象。分布式 Map 状态使用 Step Functions 数据库来跨多个实例分发和处理 Map 迭代。每个迭代是由执行器执行的，在执行器之间进行负载平衡。

在这种情况下，“Label”指的是标记 Map 状态中特定迭代的字符串。它用作 Map 任务的唯一标识符，并在 Map 迭代之间传递。

下面是 AWS 文档中 Map 状态包含“Label”的代码示例：

{
  "Comment": "A description of the state machine",
  "StartAt": "Map State Name",
  "States": {
    "Map State Name": {
      "Type": "Map",
      "MaxConcurrency": number,
      "InputPath": "$",
      "OutputPath": "$",
      "Iterator": ,
      "ItemsPath": ,
      "Parameters": ,
      "ResultPath": "$.MapName",
      "Next": "Next State Name",
      "End": true|false
    },
    "Next State Name": {
      "Type": "Task",
      "Resource": "arn:aws:states:::lambda:invoke",
      "Parameters": {
        "FunctionName": "MyFunction",
        "Payload": {
          "Input.$": "$"
        }
      },
      "ResultPath": "$.SomeResult",
      "Retry": [
        {
          "ErrorEquals": [
            "States.TaskFailed"
          ],
          "IntervalSeconds": 2,
          "MaxAttempts": 3,
          "BackoffRate": number
        }
      ],
      "Catch": [
        {
          "ErrorEquals": [
            "States.TaskFailed"
          ],
          "Next": "Alternate State Name"
        }
      ],
      "End": true|false
    },
    "Alternate State Name": {
      "Type": "Task",
      "Resource": "arn:aws:states:::lambda:invoke",
      "Parameters": {
        "FunctionName": "MyOtherFunction",
        "Payload.$": "$.SomeErrorDetails"
      },
      "Next": "Next State Name",
      "ResultPath": "$.SomeOtherResult",
    }
  }
}