AWS Lambdaの裏側をなるだけ詳しく解説してみる - https://www.keisuke69.net/entry/2020/09/29/131203

aws-lambda.uml

@startuml
skinparam monochrome true
skinparam backgroundColor #EEEEEE

control ALB as LB
actor "Front\nEnd" as FE
actor "Counting\nService" as CS
actor "Worker\nManager" as WM
actor Worker as W
actor "Placement\nService" as PS
actor Poller as P
actor "State Manager\nStream Tracker" as SM
actor "Leasing\nService" as LS
collections SQS as Q

group 同期実行
    LB -> FE
    activate LB
    activate FE
    FE -> WM: |Request|\n- Reserve Sandbox
    deactivate FE
    activate WM
    alt 初回呼出
        WM -> PS
        deactivate WM
        activate PS
        PS -> W
        deactivate PS
        activate W
    end
    W -> W: |Invoke|
    deactivate W
end


group 非同期実行/スケールアップ
    LB -> FE
    deactivate LB
    activate FE
    FE -> Q: |SendMessage|
    deactivate FE
    activate Q

    group スケールアップ
        SM -> Q: Workを探索
        activate SM
        alt 関数の同時実行数の設定が小さい場合
            SM -> LS
            activate LS
            LS -> P: Pollerの割当を作成\n(Poller Assignment Dataに書込)
            activate P
        else
            SM -> Q: 新たにdedicatedなキューを作成
            deactivate SM
        end
    end

    LS -> P: ヘルスチェック
    deactivate LS

    P -> Q: |ReceiveMessage|\n|DeleteMessage|
    deactivate Q
    P -> FE: |Invoke|
    deactivate P
    activate FE

    group 非同期実行
        FE -> WM: |Request|\n- Reserve Sandbox
        deactivate FE
        activate WM
        alt 初回呼出
            WM -> PS
            deactivate WM
            activate PS
            PS -> W
            deactivate PS
            activate W
        end
        W -> W: |Invoke|
        deactivate W
    end
end

@enduml

plantuml.svg