Speed matters, and developers are challenged to reduce latency in their applications at every turn. In traditional synchronous programming patterns, users are asked to monitor the spinning wheel as the application moves from one task to the next until a response can be returned. However, developers can reclaim these precious milliseconds by learning to think asynchronously. Asynchronous patterns challenge developers to evaluate what tasks require the client to wait versus what can be done after the fact. When developing serverless applications on AWS this process is made easier by the asynchronous and polling patterns that are native to AWS Lambda. In this session I will demonstrate taking an existing translation application that is synchronous and modifying it to use asynchronous patterns. This will be accomplished using Amazon DynamoDB Streams and the recently released Amazon EventBridge.

1. © 2019, Amazon Web Services, Inc. or its Affiliates. All rights reserved.
Eric Johnson
@edjgeek
Asenkron Düşünme
/serverless/DAYS
Senior Developer Advocate - Serverless
ISTANBUL 2019
Background Image by skeeze from Pixabay
Unicorn image by https://istanbul.serverlessdays.io/
Thinking Asynchronously

2. © 2019, Amazon Web Services, Inc. or its Affiliates. All rights reserved.
Ben kimim?
• Sr. Geliştirici ‘Avukatı’ — Sunucusuz, AWS
• Sunucusuz/Takım/ Otomasyon Geek
• Yazılım Mimarı/Çözüm Mimarı
• Kocası – Brigitte
• Noah, Jake, Owen
Sophie Anne & Gracie Mae'ın babası
• Müzik aşığı
• Pizza/Diyet Dr. Pepper fanatik

3. © 2019, Amazon Web Services, Inc. or its Affiliates. All rights reserved.
Who am I?
• Sr. Developer Advocate – Serverless, AWS
• Serverless / Tooling / Automation Geek
• Software Architect / Solutions Architect
• Husband to Brigitte
• Father to Noah, Jake, Owen
Sophie Anne, & Gracie Mae
• Music lover
• Pizza / Diet Dr. Pepper fanatic

4. © 2019, Amazon Web Services, Inc. or its Affiliates. All rights reserved.
Bugün
neden
buradayız?

5. © 2019, Amazon Web Services, Inc. or its Affiliates. All rights reserved.© 2018, Amazon Web Services, Inc. or its Affiliates. All rights reserved.
Synchronous vs. Asynchronous

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2. Lambda function(s) invoked
SNS topic
1. Data published to a topic
Data
Amazon SNS + Lambda
Simple, flexible, fully managed
pub/sub messaging and mobile
push notification service for high
throughput, highly reliable
message delivery
Messages are published to a topic
Topics can have multiple
subscribers (fanout)
Messages can be filtered and only
sent to certain subscribers
Lambda
function
Lambda
function

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2. Lambda function
invoked based on rule
Amazon EventBridge
1. Data published
to an event bus
Data
Amazon EventBridge + Lambda
Serverless event bus that allows easy
connection between applications, AWS
services, and third-party SaaS
applications
Easily consume events from supported
third-party SaaS applications
Define custom buses or use default bus
Dispatch to 15 AWS services
Generate custom events from your
application
Lambda
function

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1. Message
inserted into
to a queue
Message
Amazon
SQS3. SQS removes
message from
queue on
successful
response from
function
2. Lambda
function invoked
Amazon SQS + Lambda
Simple, flexible, fully managed
message queuing service for
reliably and continuously
exchanging any volume of
messages from anywhere
Processed in batches
At least once delivery
Visibility timeout allows for
handling of failures during
processingLambda
function

9. © 2019, Amazon Web Services, Inc. or its Affiliates. All rights reserved.
2. Lambda
polls stream
Amazon
Kinesis
Stream
1. Data published to a
stream
3. Kinesis returns
stream data
Data
Amazon Kinesis Streams + Lambda
Fully managed, highly scalable service
for collecting and processing real-time
data streams for analytics and machine
learning
Stream consists of shards with a fixed
amount of capacity and throughput
Lambda receives batches (and
potentially batches of batches)
Different applications can consume the
same stream
Lambda
function

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Common patterns

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Common AWS Lambda use cases
Web Apps Backends Data Processing Chatbots Amazon Alexa IT Automation
• Static
websites
• Complex
web apps
• Packages
for Flask
and Express
• Apps &
services
• Mobile
• IoT
• Real time
• MapReduce
• Batch
• Powering
chatbot logic
• Powering
voice-enabled
apps
• Alexa Skills
Kit
• Policy engines
• Extending AWS
services
• Infrastructure
management

12. © 2019, Amazon Web Services, Inc. or its Affiliates. All rights reserved.
Common AWS Lambda use cases
Web Apps
• Static
websites
• Complex
web apps
• Packages
for Flask
and Express
We are focusing
on web apps
today

13. © 2019, Amazon Web Services, Inc. or its Affiliates. All rights reserved.
A common serverless web application
AWS Cloud
Amazon API
Gateway
Amazon
DynamoDB
Lambda
function(s)
Host BucketAmazon
CloudFront
Amazon
Cognito
User

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The “big Lambda function” approach
AWS Cloud
Amazon API
Gateway
Amazon
DynamoDB
Lambda function
User

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The “big Lambda function” approach
AWS Cloud
Amazon API
Gateway
Amazon
DynamoDB
Lambda function
User
One Lambda function
handles all business logic
• Ok for small applications
• Can get bloated as logic
gets complex

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The “many Lambda functions” approach
AWS Cloud
Amazon
DynamoDB
User Amazon API
Gateway

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The “many Lambda functions” approach
AWS Cloud
Amazon
DynamoDB
User Amazon API
Gateway
Multiple Lambda functions
• Single responsibility
• Easier to manage
• Logical splits
• Domain objects
• Resource
• Methods

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What happens when the functions need to talk?
AWS Cloud
Amazon API
Gateway
Amazon
DynamoDB
User
Communication between functions

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Coupling is baaaad
AWS Cloud
Amazon API
Gateway
Amazon
DynamoDB
User
Communication between functions

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Translation Demo
Synchronous “big Lambda function” example

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Event data
{
"data":”Hello, welcome to my translation demo.",
"culture":[”fr-FR","tr-TR”,“de-DE”,”fr-CA”]
}

22. © 2019, Amazon Web Services, Inc. or its Affiliates. All rights reserved.
Synchronous demo
AWS Cloud
Amazon API
Gateway
Lambda
function
Bucket
Amazon
Cognito
User
Amazon Translate
Each culture is sent to Amazon
Translate as a separate request1

23. © 2019, Amazon Web Services, Inc. or its Affiliates. All rights reserved.
Synchronous demo
AWS Cloud
Amazon API
Gateway
Lambda
function
Bucket
Amazon
Cognito
User
Amazon Polly
Amazon Translate
Each translation is sent to
Amazon Polly for audio
rendering
2

24. © 2019, Amazon Web Services, Inc. or its Affiliates. All rights reserved.
Synchronous demo
AWS Cloud
Amazon API
Gateway
Lambda
function
Bucket
Amazon
Cognito
User
Amazon Polly
Amazon Translate
Audio Bucket
Audio files are save to an
Amazon S3 bucket3

25. © 2019, Amazon Web Services, Inc. or its Affiliates. All rights reserved.
Synchronous demo
AWS Cloud
Amazon API
Gateway
Amazon
DynamoDB
Lambda
function
Bucket
Amazon
Cognito
User
Amazon Polly
Amazon Translate
Audio Bucket
All records are written to Amazon
DynamoDB4

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Resulting Data
DynamoDB
S3

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Show me
the demo!!
http://bit.ly/serv-translate

28. © 2019, Amazon Web Services, Inc. or its Affiliates. All rights reserved.© 2018, Amazon Web Services, Inc. or its Affiliates. All rights reserved.
Translation Demo
Asynchronous “many Lambda functions” example

29. © 2019, Amazon Web Services, Inc. or its Affiliates. All rights reserved.
Asynchronous options
Amazon EventBridge
Amazon Simple Queue
Service
Amazon Simple
Notification Service
Amazon Kinesis
Data Streams

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Our demo will use these asynchronous options
Amazon EventBridge
Amazon Kinesis
Data Streams

31. © 2019, Amazon Web Services, Inc. or its Affiliates. All rights reserved.
Our demo will use these asynchronous options
Amazon EventBridge
Amazon DynamoDB
Streams
DynamoDB uses Kinesis under
the hood for streams

32. © 2019, Amazon Web Services, Inc. or its Affiliates. All rights reserved.
Our demo will use these asynchronous options
Amazon EventBridge
Amazon DynamoDB
Streams
Amazon Simple Storage
Service (S3)
We will also use
an S3 bucket
event

33. © 2019, Amazon Web Services, Inc. or its Affiliates. All rights reserved.
Asynchronous demo
AWS Cloud
Amazon API
Gateway
Amazon
DynamoDB
Endpoint
Bucket
Amazon
Cognito
User
Original request is written to
Amazon DynamoDB1

34. © 2019, Amazon Web Services, Inc. or its Affiliates. All rights reserved.
Asynchronous demo
AWS Cloud
Amazon API
Gateway
Amazon
DynamoDB
Endpoint
Bucket
Amazon
Cognito
User
Stream
Reader
EventBridge
DynamoDB Streams then triggers
a stream reader Lambda function
which parses the translation
requests
2

35. © 2019, Amazon Web Services, Inc. or its Affiliates. All rights reserved.
Asynchronous demo
AWS Cloud
Amazon API
Gateway
Amazon
DynamoDB
Endpoint
Bucket
Amazon
Cognito
User
Amazon TranslateStream
Reader
EventBridge Translate
The translations are then saved
to DynamoDB as separate
records
3

36. © 2019, Amazon Web Services, Inc. or its Affiliates. All rights reserved.
Asynchronous demo
AWS Cloud
Amazon API
Gateway
Amazon
DynamoDB
Endpoint
Bucket
Amazon
Cognito
User
Amazon Polly
Amazon Translate
Audio Bucket
Stream
Reader
EventBridge
Audio
Translate
Each translation triggers the Stream Reader function which
creates an audio request and sends it to Amazon Polly who
saves the resulting file to an S3 bucket
4

37. © 2019, Amazon Web Services, Inc. or its Affiliates. All rights reserved.
Asynchronous demo
AWS Cloud
Amazon API
Gateway
Amazon
DynamoDB
Endpoint
Bucket
Amazon
Cognito
User
Amazon Polly
Amazon Translate
Audio Bucket
Stream
Reader
EventBridge
Finalize
Audio
Translate
The bucket triggers a Lambda function
that adds an ACL to the file and saves the
record to DynamoDB
5

38. © 2019, Amazon Web Services, Inc. or its Affiliates. All rights reserved.
http://bit.ly/serv-translate
Show me
the demo!!

39. © 2019, Amazon Web Services, Inc. or its Affiliates. All rights reserved.
Asynchronous demo upgrade
AWS Cloud
Amazon API
Gateway
Amazon
DynamoDB
Endpoint
Bucket
Amazon
Cognito
User
Amazon Polly
Amazon Translate
Audio Bucket
Stream
Reader
EventBridge
Finalize
Audio
Translate
What if I wanted to add another step?

40. © 2019, Amazon Web Services, Inc. or its Affiliates. All rights reserved.
Asynchronous demo upgrade
AWS Cloud
Amazon API
Gateway
Amazon
DynamoDB
Endpoint
Bucket
Amazon
Cognito
User
Amazon Polly
Amazon Translate
Audio Bucket
Stream
Reader
EventBridge
Finalize
Audio
Translate
For example: Sentiment analysis
with Amazon Comprehend

41. © 2019, Amazon Web Services, Inc. or its Affiliates. All rights reserved.
Asynchronous demo upgrade
AWS Cloud
Amazon API
Gateway
Amazon
DynamoDB
Endpoint
Bucket
Amazon
Cognito
User
Amazon Polly
Amazon Translate
Audio Bucket
Stream
Reader
EventBridge
Finalize
Audio
Translate

42. © 2019, Amazon Web Services, Inc. or its Affiliates. All rights reserved.
Asynchronous demo upgrade
AWS Cloud
Amazon API
Gateway
Amazon
DynamoDB
Endpoint
Bucket
Amazon
Cognito
User
Amazon Polly
Amazon Translate
Audio Bucket
Stream
Reader
Finalize
Audio
TranslateEventBridge
Amazon ComprehendSentiment
Options
• Add a new target to an
existing rule
• Create a separate event
for Comprehension in
EventBridge

43. © 2019, Amazon Web Services, Inc. or its Affiliates. All rights reserved.
What we have built
AWS Cloud
Amazon API
Gateway
Amazon
DynamoDB
Endpoint
Bucket
Amazon
Cognito
User
Amazon Polly
Amazon Translate
Audio Bucket
Stream
Reader
Finalize
Audio
TranslateEventBridge
Amazon ComprehendSentiment

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Questions?
https://pixabay.com/illustrations/questions-font-who-what-how-why-2245264/

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Eric Johnson
@edjgeek
Image Source: https://pixabay.com/illustrations/thank-you-polaroid-letters-2490552/