© 2015, Amazon Web Services, Inc. or its Affiliates. All rights reserved.

Ajay Nair, Senior Product Manager, AWS Lambda

Olivier Klein 奧樂凱, Solutions ArchitectOctober 2015

MBL302

Build Scalable, Serverless

Mobile & IoT Back Ends with AWS Lambda

What to Expect from the Session

• A brief introduction to AWS Lambda

• How to use Amazon Cognito & Amazon Mobile Analytics

• Build an Amazon API Gateway and AWS Lambda CRUD

back end with DynamoDB

• Leverage AWS Lambda to power an event-driven mobile

back end

• Push and alert mobile apps through Amazon SNS

• See how Easy Ten put this approach to work

First, a little bit about Lambda

AWS Lambda

COMPUTE SERVICE

EVENT DRIVEN

Run code

without thinking

about servers

Code only runs

when it needs to

run

AWS Lambda: Benefits

EVENT-DRIVEN SCALESERVERLESS SUBSECOND BILLING

AWS Lambda: Capabilities

BRING YOUR OWN CODE COMPUTE “POWER LEVELS”

FLEXIBLE INVOCATION PATHS GRANULAR PERMISSIONS CONTROL

AWS Lambda: How it works

AUTHOR CONFIGURE

DEPLOY LOG AND MONITOR

Multiple ways to put Lambda to work

AWS

CloudFormation

custom

resources

… and the list will

continue to grow!

Amazon Echo

skillsAmazon SWF

tasks

Customized

notifications with

Amazon SNS

Amazon Cognito

triggers

Amazon S3

triggers

Amazon

Dynamo DB

triggers

Amazon

Kinesis

processors

Microservices

with API

Gateway

Cloud back end for mobile apps

Back-end wish list

What it does

User administration

Content storage

Push notifications

Analyze user behavior

Custom app logic

How it behaves

Cost follows usage

Minimal undifferentiated heavy lifting

Iterative development

Reduced time to market

Instant scale

Reliable and secure

Amazon Cognito

Authenticate & sync

Amazon Mobile Analytics

Analyze user behavior

AWS Lambda

Run business logic

Amazon S3

Amazon DynamoDB

Store content

Store data

Amazon SNS mobile push

notifications

Send push notifications

Back-end architecture on AWS

Mobile SDK

Amazon API Gateway

Sample app: “Find-a-Like”

• Premise: Create a profile with interests

and get notified when like-minded users

are nearby

• Functionalities:

• Create a profile with interests and upload

content

• Track location continuously

• Notify when users with similar interests are

close by

• Log and analyze app usage

Let’s think in layers

Create profile, upload

content, and track usage

Track location and user

interests

Match and alert users

App-centric

“You”

Activity-centric

“What you do”

User base-centric

“Them & me”

1

2

3

Create a profile, upload content,

and track usage

1

Cognito

Mobile Analytics

SNS Mobile Push

Kinesis Recorder DynamoDB Mapper S3 Transfer Manager

SQS Client

AWS global infrastructure (regions, Availability Zones, edge locations)

Core building

block services

Mobile-optimized

connectors

Your mobile app

AWS Mobile SDK (iOS, Android, Unity, Xamarin)

Compute Storage Networking Analytics Databases

Integrated SDK

Lambda

AWS Mobile SDKs

Security model for AWS API calls

Mobile client

IAM PermissionsAWS Security

Token Service

1. Request token

2. Receive temporary

credentials

3. Sign API request

with temporary token

AWS service APIs

4. Make API request

against AWS service API

Authenticate your user: Amazon Cognito

• Generate temporary credentials

and enforce rotation to limit

credential lifetime

• Authenticate user through third-party

authentication provider

• Unique users across multiple

devices and identity providers

• Allows anonymous user access

• Enables security best practices

through IAM roles

Use Cognito for authentication on iOS

//Create and configure Cognito credentials provider

AWSCognitoCredentialsProvider *credentialsP = [AWSCognitoCredentialsProvidercredentialsWithRegionType:AWSRegionUSEast1 accountId:@"0123456789” identityPoolId:@”us-east-1:beeeeeef-beef-beef-beef-beef” unauthRoleArn:@"arn:aws:iam::0123456789:role/Unauth” authRoleArn:@"arn:aws:iam::0123456789:role/Auth"];

//Set Cognito as default credentials provider for all AWS service calls

AWSServiceConfiguration *configuration = [AWSServiceConfigurationconfigurationWithRegion:AWSRegionUSEast1 credentialsProvider:credentialsP];

[AWSServiceManager defaultServiceManager].defaultServiceConfiguration = configuration;

Create your profile: Cognito Sync

• Create your app profile and save it

locally in the Cognito data store

• Cognito will synchronize the data sets

across all your user’s devices

• Cognito data sets are key/value pairs

AWSCognito *syncClient = [AWSCognito defaultCognito];

AWSCognitoDataset *subs = [syncClientopenOrCreateDataset:@”UserProfile"];

[dataset setString:”Oli" forKey:@”name"];[dataset setString:”50km" forKey:@”interestRadius"];

[dataset synchronize];

Upload a profile picture: S3 Transfer Utility

• Amazon S3 to store and share UGC

directly from the mobile device

• S3 Transfer Utility provides:

• Ability to continue transferring data in

the background when your app is

not running

• Ability to upload binary data instead

of having to first save it as a file on

the device

Amazon S3

S3 Transfer Utility: iOS code

NSData *dataToUpload = // The data to upload

AWSS3TransferUtility *transferUtility = [AWSS3TransferUtility defaultS3TransferUtility];

[[transferUtility uploadData:dataToUpload

bucket:@"YourBucketName"

key:@"YourObjectKeyName"

contentType:@"text/plain"

expression:expression

completionHander:completionHandler] continueWithBlock:^id(AWSTask *task) {

if (task.result) {

AWSS3TransferUtilityUploadTask *uploadTask = task.result;

// Do something with uploadTask

}

}

Track app usage: Amazon Mobile Analytics

• Allows you to collect, visualize, and

understand your mobile app usage

• Scales seamlessly to billions of events

per day

• You retain full control and ownership

of the data

Amazon Mobile

Analytics

AWSMobileAnalytics *analytics = [AWSMobileAnalytics

mobileAnalyticsForAppId:@"yourAppId” identityPoolId: @"cognitoId"];

Let’s think in layers

Create profile, upload

content, and track usage

Track location and user

interests

Match and alert users

App-centric

“You”

Activity-centric

“What you do”

User base-centric

“Them & me”

1

2

3

Track location and user interests

2

How to collect location and interests?

Back-end logic DatabaseMobile

“Location Tracker” and “Interest” microservice

Amazon

Lambda

Amazon API

Gateway

Amazon

DynamoDB

• /location

• /interests

• reportLocation()

• likeInterest()

• createInterest()

• listInterest()

Microservice

• location-table

• interest-table

Concepts first: Geohash

GeoHash is a lat/long

geocode system that

subdivides space into

buckets on a grid.

Can be numerical

(e.g.6093522776912656819)

Divide the planet earth

into six cells

(A,B,C,D,E,F) like the

six faces of a cube.

Divide each cell into

child cells, and divide

child cells into more

child cells. The red dot

here would thus be

A224.

Works with

DynamoDB!

How does it work?

Geo library for Amazon DynamoDB

• Java library to easily create and query

geospatial data in DynamoDB using GeoHashes

GeoPoint point = new GeoPoint(47.62, -122.34);

// find places 250m of Seattle’s Space NeedleQueryRadiusRequest request = new

QueryRadiusRequest(point, 250);

QueryRadiusResult result = geoDataManager.queryRadius(request);

https://github.com/awslabs/dynamodb-geo

Works with

Lambda!

Amazon API Gateway

• Fully managed and scalable RESTful

API gateway service

• Powered through our content

delivery network via our 53 global

edge locations

• Provides DDoS protection and

throttling capabilities

• Multiple API stages which you define

(e.g. dev, test, prod)

AWS Lambda

Amazon API

Gateway

Amazon

EC2

AWS API

On-prem

server

When to choose API Gateway vs. direct SDK?

• Amazon API Gateway adds an additional

layer between your mobile users and your

logic and data stores in order to:

• Allow back-end logic to be interchanged

without mobile app code modifications

• Ability to throttle individual users or requests

• Protect against DDoS attacks including

counterfeit requests (Layer 7) and SYN floods

(Layer 3)

• Provide a caching layer for your calls

Let’s think in layers

Create profile, upload

content, and track usage

Track location and user

interests

Match and alert users

App-centric

“You”

Activity-centric

“What you do”

User base-centric

“Them & me”

1

2

3

Match and alert users

3

DynamoDB

streams

Cognito

Sync trigger

S3 event

notification

AWS Lambda: Event-driven compute

Find a proximity match based on interests

/location

REST API

Profile

(proximity

setting)

Interest table

AWS SDK call

reportLocation()

Invoke

findMatch()

DynamoDB Streams

GeoHash table

AWS SDK call

Interest tablelikeInterest()

/interest

DynamoDB Streams processor: findMatch()

exports.handler = function(event, context) {

// Process all the records in the stream

event.Records.forEach(function(record) {

var newLocation = record.dynamodb.NewImage.geohash.S;

if (findProximityMatch(newLocation)) {

// Found match!

}

});

context.succeed();

};

We found a match. Now what?

Amazon SNS mobile push notifications

• Amazon SNS is a fully

managed, cross-platform

mobile push intermediary

service

• Fully scalable to millions

of devices

• Allows you to create

topics (e.g. per geo,

interest, usage pattern,

etc.)

Amazon SNS

Apple APNS

Google GCM

Amazon ADM

Windows WNS and

MPNS

Baidu CP

Android phones and tablets

Apple iPhones and iPads

Kindle Fire devices

Android phones and tablets in China

iOS

Windows phone devices

Amazon

SNS

Found a match: Notify user!

AWS SDK call

findMatch()

DynamoDB Streams

GeoHash table

Interest table

Amazon SNS

But what if I adjust my profile?

Interest Radius

Cognito Sync Trigger – AWS Lambda Code

exports.handler = function(event, context) {

if (event.eventType === 'SyncTrigger') {

event.datasetRecords.forEach(function(item) {

if (item.interestRadius.op == 'replace') {

// New interest radius set - process findMatch()

var params = {

FunctionName: 'findMatch',

InvocationType: 'Event', //makes it async

Payload: '{"user":'+ item.identityId +'}’};

lambda.invoke(params, function(err, data) {[..]});

}

}

}

context.succeed(event);

};

Let’s think in Layers

Create profile, upload

content and track usage

Track location and user

interests

Match and alert users

App-centric

“You”

Activity-centric

“What you do”

User base-centric

“Them & me”

1

2

3

Mobile AppMobile

SDKAmazon

API

Gateway

AWS

Lambda

Amazon

S3

Amazon

DynamoDB

Amazon

Cognito

Amazon Mobile

Analytics

Amazon

SNS

Final architecture

Customer story: Easy TenKirill Potekhin, Backend Team Lead

Vasily Sochinsky, CTO

easy ten

Users have learned

170 000 000+new words

1 200 000+downloads

Mobile app that helps you learn

10 new, foreign words a day • Featured in 85+ countries

• Top 5 grossing apps overall (Russia)

• Top 8 grossing apps overall (Brazil)

Screenshots

Legacy approach

• Large monolithic application running on multiple

EC2 instances (expensive)

• Complex deployment process; single-line

modification required the whole project to

be redeployed

• Constant operational pain with DevOps team

• Unable to iterate quickly trying to balance

concerns over scalability and resiliency with new

features

Current approach

• Completely serverless microservice framework based

on Lambda, DynamoDB, Amazon Kinesis, and Cognito

• Full coverage of business requirements in this

architecture

• No dedicated DevOps, streamlined deployment

• Each engineer can build complete microservice

prototype from scratch in matter of hours

• AWS manages scalability, resiliency, and security for us

at lower costs

• Client AWS SDK instead of self-made solutions

Lambda consumer

S3

Mobile

Analytics

DynamoDB

SQS

Amazon

EMR

Amazon

Cognito

Amazon

KinesisMobile app

Lambda interface

S3 dump

DynamoDB log

Amazon

Redshift

Microservice Core

What’s next?

• API Gateway for more flexible integration

• DynamoDB Streams for data replication

across different regions and usage metrics

• SWF for complex multi-step tasks on

Lambda

Recap and next steps

Back-end wish list: ACHIEVED

What it does

User administration

Content storage

Push notifications

Analyze user behavior

Custom app logic

How it behaves

Cost follows usage

Minimal undifferentiated heavy lifting

Iterative development

Reduced time to market

Instant scale

Reliable

More to explore

• Test your app on AWS Device Farm

• Export Amazon Mobile Analytics data to Amazon

Redshift

• Customize your notifications with SNS +

Lambda

• Watermark your pictures using S3 + Lambda

Amazon

Device Farm

Amazon

Redshift

Next steps

1. Download the AWS Mobile SDK and create your first

AWS-backed iOS or Android app.

2. Go to console.aws.amazon.com/lambda and create

your first Lambda function. (The first 1M requests are

on us.)

3. Stay up-to-date with AWS Mobile and Lambda on the

Mobile blog and the Compute blog.

Thank you!Ajay Nair, Senior Product Manager, AWS Lambda

Olivier Klein 奧樂凱, Solutions Architect

Visit http://aws.amazon.com/lambda, the

AWS Compute blog, or the Lambda forum to

learn more and get started using Lambda.

Remember to complete

your evaluations!

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