© 2015, Amazon Web Services, Inc. or its Affiliates. All rights reserved.
Presenter: Vyom Nagrani, Sr. Product Manager, AWS Lambda
Q&A Moderator: Ajay Nair, Sr. Product Manager, AWS Lambda
August 18th, 2015
Best Practices: Building Serverless
Backends with AWS Lambda and
Amazon API Gateway

Amazon API Gateway: Build, Deploy, and Manage APIs
SDK Generation for iOS, Android and JavaScript
Create and distribute API Keys to developers
Leverage AWS Sigv4 to authorize access to APIs
Swagger support
Utilizes AWS Lambda
Request / Response data transformation

Benefits of API Gateway for creating RESTful
endpoints for deploying services
Manage deployments to
multiple versions and
environments
Define and host APIs
Leverage Identity and
Access Management to
authorize access to your
cloud resources
Leverage AWS Auth
DDoS protection and
request throttling to
safeguard your backend
Manage network traffic
1 2 3

AWS Lambda: A compute service that runs your code
in response to events
Lambda functions: Stateless, trigger-based code execution
Triggered by events:
• Direct Sync and Async invocations
• Put to an Amazon S3 bucket
• API Gateway call
• And many more …
Makes it easy to
• Build back-end services that perform at scale
• Perform data-driven auditing, analysis, and notification

High performance at any scale;
Cost-effective and efficient
No Infrastructure to manage
Pay only for what you use: Lambda
automatically matches capacity to
your request rate. Purchase
compute in 100ms increments.
Bring Your Own Code
“Productivity focused compute platform to build powerful, dynamic, modular
applications in the cloud”
Run code in a choice of standard
languages. Use threads, processes,
files, and shell scripts normally.
Focus on business logic, not
infrastructure. You upload code; AWS
Lambda handles everything else.
Benefits of AWS Lambda for building a server-less data
processing engine
1 2 3

API Gateway + Lambda = Frontend + Backend !
Internet
Mobile Apps
Websites
Services
API
Gateway
AWS
API Gateway
Cache
Endpoints on
Amazon EC2
Any other publicly
accessible endpoint
Amazon
CloudWatch
Monitoring
Amazon
CloudFront
AWS Lambda
functions

Walkthrough of a simple CRUD backend with a
RESTful API endpoint using AWS Lambda
Amazon API
Gateway
AWS Lambda Amazon
DynamoDB
API call from
client app
Request/Response CRUD Operations

AWS Console walkthrough of a simple CRUD backend
with a RESTful API endpoint using Lambda

AWS Console walkthrough of a simple CRUD backend
with a RESTful API endpoint using Lambda

CRUD operations with DynamoDB
‘echo’ and ‘pong’ for testing
Error handling for incorrect inputs
Remove operation code from event

AWS Console walkthrough of a simple CRUD backend
with a RESTful API endpoint using Lambda

AWS Console walkthrough of a simple CRUD backend
with a RESTful API endpoint using Lambda

AWS Console walkthrough of a simple CRUD backend
with a RESTful API endpoint using Lambda

AWS Console walkthrough of a simple CRUD backend
with a RESTful API endpoint using Lambda

AWS Console walkthrough of a simple CRUD backend
with a RESTful API endpoint using Lambda

AWS Console walkthrough of a simple CRUD backend
with a RESTful API endpoint using Lambda

AWS Console walkthrough of a simple CRUD backend
with a RESTful API endpoint using Lambda

AWS Console walkthrough of a simple CRUD backend
with a RESTful API endpoint using Lambda

AWS Console walkthrough of a simple CRUD backend
with a RESTful API endpoint using Lambda

AWS Console walkthrough of a simple CRUD backend
with a RESTful API endpoint using Lambda

AWS Console walkthrough of a simple CRUD backend
with a RESTful API endpoint using Lambda

AWS Console walkthrough of a simple CRUD backend
with a RESTful API endpoint using Lambda

Demo site: A simple CRUD backend with a RESTful API
endpoint using Amazon API Gateway and AWS Lambda
http://squirrelbin.com/

Attaching Lambda functions to RESTful HTTP Endpoints
• 1:1 Mapping: Every API call triggers a stateless Lambda function
• Add caching to API calls to return a cached response instead for duplicate requests
• API Gateway concepts: An API is defined as a set of resources and methods
• Resource: A logical entity that can be accessed within an API
• Method: The combination of a resource path and an HTTP verb such as GET/POST
• Automatic Scaling: Both API Gateway and Lambda scale automatically with calls
• Safety throttle of 100 concurrent Lambda functions, can be increased by AWS Support Center
• User defined standard-rate limit and a burst-rate limit per second for each API method

Best practices for creating Lambda functions
• Memory: CPU proportional to the memory configured
• Increasing memory makes your code execute faster (if CPU bound)
• Timeout: Increasing timeout allows for longer functions, but more wait in case of errors
• Retries: For API Gateway, Lambda doesn’t retry the function execution, but the
Gateway generated SDKs retry throttled requests
• Permission model: API Gateway synchronously triggers Lambda, so assign API
Gateway a resource policy to invoke Lambda.

Monitoring and Debugging Lambda functions
• Console Dashboard
• Lists all Lambda functions
• Easy editing of resources,
event sources and other
settings
• At-a-glance metrics
• Metrics in CloudWatch
• Requests
• Errors
• Latency
• Throttles
• Logging in CloudWatch Logs

Using API Gateway Input/Output Transforms
Filter output results
• Remove private or unnecessary data
• Filter dataset size to improve API
performance
GET to POST
• Read all query string parameters from your
GET request, and create a body to make a
POST to your backend
JSON to XML
• Receive JSON input and transform it to XML
for your backend
• Receive JSON from a Lambda function and
transform it to XML

Managing different versions of your API stack
• Operate multiple API versions and
multiple stages for each version
simultaneously
• Clone an existing API to start working
on the next major version
• Set up custom domain names to point
directly to a stage
• Version Lambda functions, and
associate API stage with Lambda
function version alias
COMING
SOON!

Three Next Steps
1. Create and test your first API. With a few clicks in the AWS Management Console,
you can create an API that acts as a “front door” for applications to access data,
business logic, or functionality from your back-end services.
2. Create and test your first Lambda function. With AWS Lambda, there are no new
languages, tools, or frameworks to learn. You can use any third party library, even
native ones.
3. Select Lambda as your backend for your API … This gives you an endpoint for your
function which can respond to REST calls like GET, PUT and POST without
managing any servers.

Thank you!
Visit http://aws.amazon.com/api-gateway, the
AWS blog, and the API Gateway forum to learn
more and get started using API Gateway.
Visit http://aws.amazon.com/lambda, the
AWS Compute blog, and the Lambda forum
to learn more and get started using Lambda.

AWS re:Invent 2015 – October 6-9
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Details:
Wednesday, October 7
9:00am - 10:30am PT: Andrew Jassy, Sr. Vice President, AWS
11:00am - 5:15pm PT: 5 of the most popular breakout sessions (to be announced)
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11:00am - 6:15pm PT: 6 of the most popular breakout sessions (to be announced)
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