大多數公司在開發應用程序，並將其部署在伺服器時，無論是選擇公有雲還是私有的資料中心，都需要提前了解伺服器、儲存空間、以及資料庫功能等，並部署運行所需的應用程式和軟體，到基礎設施上。 運用無伺服器架構的程式，不需要佈建、維護和管理後端元件伺服器，後端元件包括運算、資料庫、儲存、串流處理、訊息佇列等。可依需求自動擴展，有發生事件才需要調度資源，並照程式實際執行的時間來計算費用，不會有有運算資源閒置浪費的問題。

1. © 2019, Amazon Web Services, Inc. or its Affiliates.© 2019, Amazon Web Services, Inc. or its Affiliates.
Stuart Chen
Solutions Architect
Wild Rydes Workshop
Module 7: Image Processing
2019.7.24

2. © 2019, Amazon Web Services, Inc. or its Affiliates.
What are we building?
OBJECTIVE: Use AWS Step Functions to orchestrate an image processing workflow
AWS
StepFunctions Amazon
S3
Amazon
Rekognition
Amazon
DynamoDB
Facial detection,
validation and
indexing
Generate image
thumbnail
Persist metadata
AWS
Lambda
AWS
Lambda
AWS
Lambda

3. © 2019, Amazon Web Services, Inc. or its Affiliates.
Image Processing module
New feature! Riders have to upload a
selfie
• Easily identify the rider during pickup to provide a good
customer experience.
• Enhances security so bad guys can't spoof to be riders and
get on the unicorns.
• Prevents the same user from signing up for multiple
accounts to abuse new-user promotions.

4. © 2019, Amazon Web Services, Inc. or its Affiliates.
The state machine to build
Multi-step state machine that
leverages several SFN features:
• Lambda task state
• Choice state
• Custom error catching
• Parallel state
• Input/output manipulations
using InputPath and ResultPaths
Task
Choice
Parallel
Fail

5. © 2019, Amazon Web Services, Inc. or its Affiliates.© 2019, Amazon Web Services, Inc. or its Affiliates.
Services used

6. © 2019, Amazon Web Services, Inc. or its Affiliates.
λλ
λ
DBMS
λ
λ
λ
λ
λ
λ λ
λ
λ
Modern app
Amazon
SQS

7. © 2019, Amazon Web Services, Inc. or its Affiliates.
Step Functions overview
“I want to sequence functions”
“I want to select functions based on data”
“I want to run functions in parallel”
“I want to retry functions”
“I want to try/catch/finally”
“I want to run code for hours”

8. © 2019, Amazon Web Services, Inc. or its Affiliates.
Step Functions overview
Visualize in the
console
Define in JSON Monitor
executions

9. © 2019, Amazon Web Services, Inc. or its Affiliates.
{
"Comment": "A Hello World Example",
"StartAt": "HelloWorld",
"States": {
"HelloWorld": {
"Type": "Task",
"Resource": "${lambdaArn}",
"End": true
}
}}
AWS::StepFunctions::StateMachine

10. © 2019, Amazon Web Services, Inc. or its Affiliates.
Seven state types
Task A single unit of work
Choice Adds branching logic
Parallel Fork and join the data across tasks
Wait Delay for a specified time
Fail Stops an execution and marks it as a failure
Succeed Stops an execution successfully
Pass Passes its input to its output

11. © 2019, Amazon Web Services, Inc. or its Affiliates.
Run ML model
Resize image
Task states for any compute
Long poll
Traditional server
Request
Worker requests
tasks from Step
Functions
Step Functions
invokes the Task
Amazon
EC2
Amazon
EKS
AWS
Lambda
Amazon
ECS Amazon
SNS
Amazon
SQS
AWS
Glue
Amazon
SageMaker
Amazon
DynamoDB
AWS
Fargate
AWS
Batch

12. © 2019, Amazon Web Services, Inc. or its Affiliates.
Input/output processing

13. © 2019, Amazon Web Services, Inc. or its Affiliates.
Use ResultPath to Replace Input with Result

14. © 2019, Amazon Web Services, Inc. or its Affiliates.
Use ResultPath to Include Result with Input

15. © 2019, Amazon Web Services, Inc. or its Affiliates.
Use ResultPath to Update a Node in Input with the Result

16. © 2019, Amazon Web Services, Inc. or its Affiliates.© 2019, Amazon Web Services, Inc. or its Affiliates.
Let’s build!
http://bit.ly/WildRydes-Module5