This document discusses AWS Step Functions and provides an overview of its key features and components. It introduces AWS Step Functions as a way to visually coordinate distributed applications using a series of steps defined as a state machine. It then covers the Amazon State Language used to define state machines, and explains how state machines are executed including starting execution and viewing results. It also discusses how activity tasks can be used to execute applications outside of Lambda in a pull-based manner.

1. AWS Step Functions 実践
AWS Premeir Night #3
クラスメソッド株式会社
菊池 修治

2. • 菊池 修治（きくち しゅうじ）
– クラスメソッド AWS事業
– Solutions Architect
– AWS Certified in All 5!
– SIer à 製造業 à クラスメソッド
– 好きなAWSサービス
• VPC、S3、Step Functions
⾃⼰紹介

3. Agenda
• AWS Step Functions とは
• Amazon State Language
• Step Functions の実⾏
– State Machine の実⾏⽅法
– Activity Task の実⾏

4. Agenda
• AWS Step Functions とは
• Amazon State Language
• Step Functions の実⾏
– State Machine の実⾏⽅法
– Activity Task の実⾏

5. AWS Step Functions
re:Invent 2016 にて発表！

6. AWS Step Functions
• 「Step Functionsやってみた」ブログ公開中
– http://dev.classmethod.jp/referencecat/aws-step-functions/

7. AWS Step Functions
• 分散されたアプリケーションをビジュアルに
コーディネート
– Lambdaなどの複数アプリケーションを⼀連の
ワークフローとして定義・実⾏
– 処理の流れ・ステップをビジュアル化

8. AWS Step Functions

9. AWS Step Functions
• ユースケース
– シーケンシャルなアプリケーションの実⾏
– タスクの並列化
– 処理の条件分岐
– エラーハンドリング
– ⻑時間の実⾏

10. AWS Step Functions
• 利点
– アプリケーション間を疎結合に
– 汎⽤性・再利⽤性の向上
– 実⾏結果の管理

11. AWS Step Functions
• コンポーネント
– State Machine：定義された⼀連のフロー
– State Language：State Machineを定義する⾔語

12. Agenda
• AWS Step Functions とは
• Amazon State Language
• Step Functions の実⾏
– State Machine の実⾏⽅法
– Activity Task の実⾏

13. Amazon State Language
• JSONで記述
{
"Comment": "A Retry example of the Amazon States Language using an AWS Lambda Function",
"StartAt": "HelloWorld",
"States": {
"HelloWorld": {
"Type": "Task",
"Resource": "arn:aws:lambda:REGION:ACCOUNT_ID:function:FUNCTION_NAME",
"Retry": [
{
"ErrorEquals": ["HandledError"],
"IntervalSeconds": 1,
"MaxAttempts": 2,
"BackoffRate": 2.0
},
{
"ErrorEquals": ["States.TaskFailed"],
"IntervalSeconds": 30,
"MaxAttempts": 2,
"BackoffRate": 2.0
},
{
"ErrorEquals": ["States.ALL"],
"IntervalSeconds": 5,
"MaxAttempts": 5,
"BackoffRate": 2.0
}
],
"End": true
}
}
}

14. Amazon State Language
• State (= Step)をつなげてフロー(State Machine)
を作成
• ⼀度作成したState Machineは変更・修正できない

15. Amazon State Language
• 7つの State
– Task ：アプリケーションの実⾏
– Choice ：分岐条件
– Parallel ：Taskの並列実⾏
– Wait ：待ち
– Fail ：異常終了
– Succeed ：正常終了
– Pass ：なにもしない

16. Amazon State Language
• 7つの State
– Task ：アプリケーションの実⾏
– Choice ：分岐条件
– Parallel ：Taskの並列実⾏
– Wait ：待ち
– Fail ：異常終了
– Succeed ：正常終了
– Pass ：なにもしない

17. Amazon State Language
• Task
"TaskState": {
"Comment": "Task State example",
"Type": "Task",
"Resource": "arn:aws:lambda:us-east-1:123456789012:function:HelloFunctio
"Next": "NextState",
"TimeoutSeconds": 300,
"Retry": [
{
"ErrorEquals": [ "ErrorA", "ErrorB" ],
"IntervalSeconds": 1,
"BackoffRate": 2,
"MaxAttempts": 2
}
]
}

18. Amazon State Language
• Task
"TaskState": {
"Comment": "Task State example",
"Type": "Task",
"Resource": "arn:aws:lambda:us-east-1:123456789012:function:HelloFunctio
"Next": "NextState",
"TimeoutSeconds": 300,
"Retry": [
{
"ErrorEquals": [ "ErrorA", "ErrorB" ],
"IntervalSeconds": 1,
"BackoffRate": 2,
"MaxAttempts": 2
}
]
}

19. Amazon State Language
• Task
"TaskState": {
"Comment": "Task State example",
"Type": "Task",
"Resource": "arn:aws:lambda:us-east-1:123456789012:function:HelloFunctio
"Next": "NextState",
"TimeoutSeconds": 300,
"Retry": [
{
"ErrorEquals": [ "ErrorA", "ErrorB" ],
"IntervalSeconds": 1,
"BackoffRate": 2,
"MaxAttempts": 2
}
]
}

20. Amazon State Language
• Task
"TaskState": {
"Comment": "Task State example",
"Type": "Task",
"Resource": "arn:aws:lambda:us-east-1:123456789012:function:HelloFunctio
"Next": "NextState",
"TimeoutSeconds": 300,
"Retry": [
{
"ErrorEquals": [ "ErrorA", "ErrorB" ],
"IntervalSeconds": 1,
"BackoffRate": 2,
"MaxAttempts": 2
}
]
}

21. Amazon State Language
• Choice
"ChoiceState": {
"Type" : "Choice",
"Choices": [
{
"Variable": "$.foo",
"NumericEquals": 1,
"Next": "FirstMatchState"
},
{
"Variable": "$.foo",
"NumericEquals": 2,
"Next": "SecondMatchState”
}
],
"Default": "DefaultState"
},
• StringEquals
• StringLessThan
• StringGreaterThan
• StringLessThanEquals
• StringGreaterThanEquals
• NumericEquals
• NumericLessThan
• NumericGreaterThan
• NumericLessThanEquals
• NumericGreaterThanEquals
• BooleanEquals
• TimestampEquals
• TimestampLessThan
• TimestampGreaterThan
• TimestampLessThanEquals
• TimestampGreaterThanEquals

22. Amazon State Language
• Choice "ChoiceStateX": {
"Type" : "Choice",
"Choices": [
{
"Not": {
"Variable": "$.type",
"StringEquals": "Private”
},
"Next": "Public”
},
{
"And": [
{
"Variable": "$.value",
"NumericGreaterThanEquals": 20
},
{
"Variable": "$.value",
"NumericLessThan": 30
}
],
"Next": "ValueInTwenties”
}
],
"Default": "DefaultState”
},
• Not
• Or
• And

23. Amazon State Language
• Choice "ChoiceStateX": {
"Type" : "Choice",
"Choices": [
{
"Not": {
"Variable": "$.type",
"StringEquals": "Private”
},
"Next": "Public”
},
{
"And": [
{
"Variable": "$.value",
"NumericGreaterThanEquals": 20
},
{
"Variable": "$.value",
"NumericLessThan": 30
}
],
"Next": "ValueInTwenties”
}
],
"Default": "DefaultState”
},
• Not
• Or
• And

24. Amazon State Language
• Choice "ChoiceStateX": {
"Type" : "Choice",
"Choices": [
{
"Not": {
"Variable": "$.type",
"StringEquals": "Private”
},
"Next": "Public”
},
{
"And": [
{
"Variable": "$.value",
"NumericGreaterThanEquals": 20
},
{
"Variable": "$.value",
"NumericLessThan": 30
}
],
"Next": "ValueInTwenties”
}
],
"Default": "DefaultState”
},
• Not
• Or
• And

25. Amazon State Language
• Parallel
– 全ての分岐が完了
してから次のState
へ進む
"Parallel": {
"Type": "Parallel",
"Next": "Final State",
"Branches": [
{
"StartAt": "Wait 20s",
"States": {
"Wait 20s": {
"Type": "Wait",
"Seconds": 20,
"End": true
}
}
},
{
"StartAt": "Wait 10s",
"States": {
"Wait 10s": {
"Type": "Wait",
"Seconds": 10,
"End": true
}
}
}
]
},

26. Amazon State Language
• Wait
– Seconds
– SecondsPath
– Timestamp
– TimestampPath
"wait_ten_seconds" : {
"Type" : "Wait",
"Seconds" : 10,
"Next": "NextState”
}
"wait_until" : {
"Type": "Wait",
"Timestamp": "2016-03-14T01:59:00Z",
"Next": "NextState”
}
"wait_until" : {
"Type": "Wait",
"TimestampPath": "$.expirydate",
"Next": "NextState”
}

27. Agenda
• AWS Step Functions とは
• Amazon State Language
• Step Functions の実⾏
– State Machine の実⾏⽅法
– Activity Task の実⾏

28. State Machine の実⾏
• start-execution API
Step Functions
State Machine
start-execution

29. State Machine の実⾏
• start-execution API
Lambda Step Functions
State Machine
start-execution

30. State Machine の実⾏
• start-execution API
API
Gateway
S3
SNS
Cloud Watch
Event
Lambda Step Functions
State Machine
start-execution

31. State Machine の実⾏
• 実⾏結果
– State Machine ごとに管理

32. State Machine の実⾏
• 実⾏結果
– State Machine の実⾏毎に管理

33. State Machine の実⾏
• 実⾏結果
– State 毎に管理

34. Agenda
• AWS Step Functions とは
• Amazon State Language
• Step Functions の実⾏
– State Machine の実⾏⽅法
– Activity Task の実⾏

35. Activity Taskの実⾏
• Lambda以外のアプリケーションの実⾏
–EC2
–オンプレミス
• Pull型の実⾏
– アプリケーションからポーリング
– LambdaはPush型

36. Activity Taskの実⾏
• Activityの作成

37. Activity Taskの実⾏
• Activityの作成
設定項⽬は名前だけ
ARNが作成される

38. Activity Taskの実⾏
• State Machineの作成
{
"Comment": "An example using a Task state.",
"StartAt": "getGreeting",
"Version": "1.0",
"TimeoutSeconds": 300,
"States":
{
"getGreeting": {
"Type": "Task",
"Resource": "arn:aws:states:eu_central-1:123456789012:activity:get-greeting",
"End": true
}
}
}

39. Activity Taskの実⾏
• アプリケーションからポーリング
– Get-Activity-Task API
Polling
Get-Activity-Task
--Activity ARN
--Worker Name (Option)
Worker
State Machine

40. Activity Taskの実⾏
• State Machine実⾏
Input
TaskToken
In progress
Get-Activity-Task
--Activity ARN
--Worker Name (Option)
Worker
State Machine

41. Activity Taskの実⾏
• 実⾏完了
Success
Send-Task-Success
--Task-Token
--Output
Worker
State Machine

42. Activity Taskの実⾏
• 分散アプリケーション
Workers
State Machines

43. まとめ
• Step Functionsを使うことで分散アプリケーション
による複雑な処理を簡単に定義・実⾏・管理
• マイクロサービス化、サーバレス化
• Lambdaだけでなくサーバ上のアプリケーションも
組み込み可能

44. classmethod.jp44