Programming AWS Lambda: Build and Deploy Serverless Applications with Java

Foreword....6 Preface....8 About This Book....8 Why We Wrote This Book....8 Who This Book Is For....9 Why You Need This Book....10 Using the End-of-Chapter Exercises....10 Conventions Used in This Book....11 Using Code Examples....12 O’Reilly Online Learning....13 How to Contact Us....13 Acknowledgments....14 1. Introduction to Serverless, Amazon Web Services, and AWS Lambda....16 A Quick History Lesson....16 The Cloud Grows....18 Enter Serverless....19 Backend as a Service....19 Functions as a Service....20 Differentiating Serverless....21 What Is AWS?....22 Types of Service....23 Capacity....23 Who Uses AWS?....25 How Do You Use AWS?....25 What Is AWS Lambda?....26 Functions as a Service....27 FaaS as Implemented by Lambda....28 Why Lambda?....30 What Does a Lambda Application Look Like?....31 AWS Lambda in the Java World....35 Summary....36 Exercises....37 2. Getting Started with AWS Lambda....39 Quick Guide to the AWS Console....39 Regions....40 Identity and Access Management....42 Lambda Hello World (as Quickly as Possible)....42 Setting Up Your Development Environment....46 AWS Command Line Interface....46 Java Setup....53 AWS SAM CLI Installation....55 Lambda Hello World (the Proper Way)....55 Creating Your First Java Lambda Project....56 Building Hello World....57 Creating the Lambda Function....58 Summary....61 Exercises....62 3. Programming AWS Lambda Functions....63 Core Concepts: Runtime Model, Invocation....63 The Lambda Execution Environment....64 Invocation Types....65 Introduction to Logging....69 Input, Output....71 Lambda Function Method Signatures....71 Configuring the Handler Function in the SAM Template....73 Basic Types....73 Lists and Maps....75 POJOs and Ecosystem Types....77 Streams....79 Context....81 Timeout....83 Memory and CPU....85 Environment Variables....90 Summary....91 Exercises....92 4. Operating AWS Lambda Functions....93 Build and Package....93 Uberjars....94 Assembling a ZIP File....95 Reproducible Builds....101 Deploy....103 Infrastructure as Code....104 CloudFormation and the Serverless Application Model....105 Security....108 The Principle of Least Privilege....109 Identity and Access Management....111 Summary....118 Exercises....118 5. Building Serverless Applications....120 Lambda Event Sources....121 Writing Code to Work with Input and Output for Event Sources....121 Configuring a Lambda Event Source....126 Understanding Different Event Source Semantics....127 Example: Building a Serverless API....129 Behavior....129 Architecture....130 Lambda Code....133 Build and Package Using the AWS SDK BOM....144 Infrastructure....146 Deployment....149 Example: Building a Serverless Data Pipeline....154 Behavior....155 Architecture....155 Lambda Code....160 Build and Package Using Multiple Modules and Isolated Artifacts....167 Infrastructure....174 Deployment....177 Summary....179 Exercises....180 6. Testing....182 The Test Pyramid....182 Unit Tests....183 Functional Tests....183 End-to-End Tests....184 Refactoring for Testing....184 Revisiting BulkEventsLambda....185 Refactoring BulkEventsLambda....188 Add Constructors....189 Isolate Side Effects....189 Split Methods....191 Testing BulkEventsLambda....192 Unit Testing....192 Functional Testing....195 End-to-End Testing....200 Local Cloud Testing....205 Cloud Test Environments....208 Summary....210 Exercise....211 7. Logging, Metrics, and Tracing....212 Logging....212 CloudWatch Logs....213 LambdaLogger....214 Java Logging Frameworks....216 Structured Logging....221 Structured Logging in Java....223 CloudWatch Logs Insights....225 Metrics....228 CloudWatch Metrics....228 Lambda Platform Metrics....229 Business Metrics....230 Alarms....232 Distributed Tracing....234 Finding Errors....237 Summary....240 Exercises....241 8. Advanced AWS Lambda....242 Error Handling....242 Classes of Error....242 The Various Behaviors of Lambda Error Processing....243 Deep Dive into Asynchronous Event Source Errors....245 Handling Kinesis and DynamoDB Stream Errors....252 Tracing Errors with X-Ray....253 Error Handling Strategies....253 Scaling....255 Observing Lambda Scaling....255 Scaling Limits and Throttling....257 Thread Safety....259 Vertical Scaling....261 Versions and Aliases, Traffic Shifting....261 Lambda Versions....262 Lambda Aliases....262 Traffic Shifting....263 When (Not) to Use Versions and Aliases....265 Cold Starts....266 What Is a Cold Start?....267 When Does a Cold Start Occur?....267 Identifying Cold Starts....269 Impact of Cold Starts....270 Mitigating Cold Starts....271 Provisioned Concurrency....275 Cold Start Summary....280 State....280 Persistent Application State....281 Caching....283 Lambda and Java Application Frameworks....285 Virtual Private Clouds....288 Architectural Concerns of Using Lambda with a VPCs....289 Configuring Lambda to Use a VPC....290 Alternatives....291 Layers and Runtimes....292 What Are Layers?....292 When to Use, and Not Use, Layers....293 Custom Runtimes....295 Summary....297 Exercises....298 9. Advanced Serverless Architecture....300 Serverless Architecture “Gotchas”....300 At-Least-Once Delivery....300 Impacts of Lambda Scaling on Downstream Systems....304 The “Fine Print” of Lambda Event Sources....311 New Patterns of Architecture Enabled by Serverless Thinking....312 Published Components with the Serverless Application Repository....312 Globally Distributed Applications....314 Summary....323 Exercises....323 10. Conclusion....325 Index....328