Step Functions 実務Tips

Step Functions 実務Tips

AWS CLI

# ステートマシン作成
aws stepfunctions create-state-machine \
  --name my-state-machine \
  --definition file://state-machine.json \
  --role-arn arn:aws:iam::123456789012:role/StepFunctionsRole

# 実行開始
aws stepfunctions start-execution \
  --state-machine-arn arn:aws:states:ap-northeast-1:123456789012:stateMachine:my-state-machine \
  --input '{"orderId": "12345"}'

# 実行履歴確認
aws stepfunctions describe-execution \
  --execution-arn arn:aws:states:ap-northeast-1:123456789012:execution:my-state-machine:exec-id

# 実行停止
aws stepfunctions stop-execution \
  --execution-arn arn:aws:states:ap-northeast-1:123456789012:execution:my-state-machine:exec-id

ステートマシン定義例

{
  "Comment": "Order Processing Workflow",
  "StartAt": "ValidateOrder",
  "States": {
    "ValidateOrder": {
      "Type": "Task",
      "Resource": "arn:aws:lambda:ap-northeast-1:123456789012:function:ValidateOrder",
      "Retry": [
        {
          "ErrorEquals": ["States.TaskFailed"],
          "IntervalSeconds": 2,
          "MaxAttempts": 3,
          "BackoffRate": 2.0
        }
      ],
      "Catch": [
        {
          "ErrorEquals": ["ValidationError"],
          "Next": "OrderFailed"
        }
      ],
      "Next": "ProcessPayment"
    },
    "ProcessPayment": {
      "Type": "Task",
      "Resource": "arn:aws:lambda:ap-northeast-1:123456789012:function:ProcessPayment",
      "Next": "SendNotification"
    },
    "SendNotification": {
      "Type": "Task",
      "Resource": "arn:aws:states:::sns:publish",
      "Parameters": {
        "TopicArn": "arn:aws:sns:ap-northeast-1:123456789012:OrderTopic",
        "Message.$": "$.result"
      },
      "End": true
    },
    "OrderFailed": {
      "Type": "Fail",
      "Error": "OrderValidationFailed",
      "Cause": "Order validation failed"
    }
  }
}

ベストプラクティス

設計:
  - ステート数最小化
  - エラーハンドリング実装
  - タイムアウト設定

パフォーマンス:
  - Parallel活用
  - Express（高スループット）
  - Lambda最適化

コスト:
  - ステート遷移数削減
  - Express（短時間処理）