Serverless for (JavaScript) Developers Danilo Poccia @danilop danilop Technical Evangelist

Danilo Poccia With AWS Lambda, you write your code and upload it to the AWS cloud. AWS Lambda responds to the events triggered by your application or your users, and auto- matically manages the underlying computer resources for you. Back-end tasks like analyzing a new document or processing requests from a mobile app are easy to implement. Your ap- plication is divided into small functions, leading naturally to a reactive architecture and the adoption of microservices. AWS Lambda in Action is an example-driven tutorial that teaches you how to build applications that use an event-driven approach on the back-end. Starting with an overview of AWS Lambda, the book moves on to show you common examples and patterns that you can use to call Lambda functions from a web page or a mobile app. The second part of the book puts these smaller examples together to build larger applications. By the end, you’ll be ready to create applications that take advantage of the high availability, security, performance, and scalability of AWS. What’s Inside ● Create a simple API ● Create an event-driven media sharing application ● Secure access to your application in the cloud ● Use functions from different clients like web pages or mobile apps ● Connect your application with external services Requires basic knowledge of JavaScript. Some examples are also provided in Python. No AWS experience is assumed. Danilo Poccia is a technical evangelist at Amazon Web Services and a frequent speaker at public events and workshops. To download their free eBook in PDF, ePub, and Kindle formats, owners of this book should visit www.manning.com/books/aws-lambda-in-action $49.99 / Can $57.99 [INCLUDING eBOOK] AWS Lambda IN ACTION SOFTWARE DEVELOPMENT/CLOUD Danilo Poccia M A N N I N G AWS Lambda IN ACTION MANNING “Clear and concise … the code samples are as well structured as the writing.” —From the Foreword by James Governor, RedMonk “A superb guide to an important aspect of AWS.” —Ben Leibert, VillageReach “Step-by-step examples and clear prose make this the go-to book for AWS Lambda!.” —Dan Kacenjar, Wolters Kluwer “Like Lambda itself, this book is easy to follow, concise, and very functional.” —Christopher Haupt, New Relic M A N N I N G SEE INSERT Danilo Poccia FOREWORD BY James Governor Event-driven serverless applications

Function

greetingsOnDemand

Function

Function

Client Application Function invoke

Client Application Function Database Files invoke read/write

Client Application Function2 Database Files Function1 Function3 invoke event trigger event trigger read/write

Business Logic Client Application Function2 Database Files Function1 Function3 invoke event trigger event trigger read/write

Data Persistence Business Logic Client Application Function2 Database Files Function1 Function3 invoke event trigger event trigger read/write

Data Persistence Business Logic Client Application Functions Functions Functions Repositories Repositories Repositories API read/write event trigger

Data Persistence Business Logic Client Application Functions Functions Functions Repositories Repositories Repositories API read/write event trigger read/write

Data Persistence Business Logic Client Application Functions Functions Functions API Gateway Repositories Repositories Repositories API read/write event trigger read/write

greetingsAPI

How do I start?

No Servers to Manage Continuous Scaling Subsecond Metering AWS Lambda

1 Million requests per month 400,000 GB-seconds per month Free Tier AWS Lambda

https://github.com/awslabs/aws-serverless-auth-reference-app Serverless reference app and backend API, showcasing authentication and authorization patterns using Amazon Cognito, Amazon API Gateway, AWS Lambda, and AWS IAM

aws-serverless-auth-reference-app

https://serverless.com

Building An Infinitely Scalable Online Recording Campaign For David Guetta & UEFA

Do I need to rebuild everything?

https://github.com/awslabs/aws-serverless-express This library enables you to utilize AWS Lambda and Amazon API Gateway to respond to web and API requests using your existing Node.js application framework

aws-serverless-express

How to go beyond the timeout?

function processList(itemList, context) { var item = itemList.shift(); processItem(item, () => { if (itemList.length === 0) { console.log('Finished'); } else if (context.getRemainingTimeInMillis() > TIME_THRESHOLD) { // Process remaning items processList(itemList, context); } else { console.log('Not finished'); // Time is running out, // invoke self asynchrounously to process remaning items invokeSelf(itemList, context); } }); }

What about larger apps?

https://github.com/awslabs/serverless-application-model

> Serverless Continuous Integration and Deployment GitHub Amazon S3 AWS CodeCommit AWS CodeBuild AWS CodeBuild third-party tools AWS CloudFormation Commit Build Test Deploy to Prod AWS CodePipeline + SAM

serverless-application-model

AWS Step Functions Sequential Steps Branching Steps (Choice of Path) Parallel Steps

https://states-language.net/spec.html

AWS Step Functions

Event-Driven Architecture

Name Email Create New User Submit Check the “Name” syntax is right (only letters and spaces) Check the “Email” syntax is right (something@some.domain) Create the new user using provided Name and Email User Interface Actions

Name Email Create New User Submit Check the “Name” syntax is right (only letters and spaces) Check the “Email” syntax is right (something@some.domain) Create the new user using provided Name and Email User Interface Actions Observers Target Action

Generate thumbnails Keep another database in sync Process streaming data Services Functions Platform Target Action Kinesis Stream DynamoDB Table S3 Bucket

area = length x width

area = length x width Procedural Programming “This is a function!”

area = length x width Procedural Programming “This is a function!” Reactive Programming “This is data binding!”

A B Event-Driven Design For Services ”Service A triggers B" or better ”Service B is caused by A"

A B C D E F ? ? What is causing services E and F?

A B C D E F New services (E, F) are triggered caused by C

A B C D E F It can be cyclic Think of acknowledgements

Each service has local visibility A B C D E F

What I need to know (input events) 1 A B C D E F

What I need to do (internal logic) 2 A B C D E F

Who I need to notify (output events) 3 A B C D E F

Who I need to notify (output events) What I need to know (input events) What I need to do (internal logic) 1 2 3 B

Distributed Data Flow Vs Centralised Workflow

Choreography Vs Orchestration

Microservices Distributed Systems

Monolith Service Service μ μ μ space (distribution, mobility) time (concurrency, latency) μ μ μ μ “Distributed in Time and Space” [Jonas Bonér]

“…a diagram of two microservices and their shared database” Data should drive the boundaries

A C I D tomic onsistent solated urable

A C I D tomic onsistent solated urable A C I D ssociative ommutative dempotent istributed ACID 2.0

Scale from Prototype to Production

Responsive Resilient Elastic Message Driven The Reactive Manifesto

Asynchronous communication is not enforced by serverless architectures Responsive Resilient Elastic Message Driven The Reactive Manifesto

Lambda Everywhere

AWS Greengrass

AWS Snowball Edge

AWS Snowball Edge

AWS Snowmobile

Lambda@Edge

Build Apps With Services, Not Servers

https://aws.amazon.com/lambda https://github.com/awslabs/aws-serverless-auth-reference-app https://github.com/awslabs/aws-serverless-express https://serverless.com https://github.com/awslabs/serverless-application-model https://states-language.net/spec.html https://github.com/danilop/AWS_Lambda_in_Action For Your Reference

Thank You! Danilo Poccia @danilop danilop Technical Evangelist