Greach-2018.md

footer: © Object Computing Inc., 2018 slidenumbers: false

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[FIT] Launching the Micro Future

Groovy, Grails and the Micro Future -- by Graeme Rocher

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Agenda

• How we got here
• Microservice Challenges
• Launching the Micro Future
• Grails Roadmap

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Then and Now

• Since 2008, a lot has changed
• 10 years ago Grails 1.0 was released!
• Everybody was building Monoliths
• No Angular, No React, No Docker, No Microservices

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So We Try to Adapt

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• Let's try and fit Monolith focused framework into Micro environment!
• Spring and Grails were never designed for this
• ... No matter how much marketing you hear

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What to do, What to do?

Shall we:

1. Try and convince people that something never designed for Microservices is still ok?
2. Go back to the drawing board

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The Goal

• Create a New Framework designed from the ground-up for Microservices and Server-less Computing
• Blazing fast startup time
• Low Memory Footprint
• As Small As Possible JAR Sizes
• Zero Dependency
• 12 Factor - https://12factor.net

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The Analysis

To meet this goal we performed an analysis of Spring and Grails and the challenges to using them to develop Microservice applications

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What Spring (and Grails) Do

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Spring is an amazing technical achievement and does so many things, but does them at Runtime.

• Reads the byte code of every bean it finds
• Synthesizes new annotations for each annotation on each bean method, constructor, field etc. to support Annotation metadata
• Builds Reflective Metadata for each bean for every method, constructor, field etc.

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So What's the Problem?

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So What's the Problem?

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The Micro Reality

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• With Spring (and Grails) anything beyond "Hello World" becomes fat quickly
• But we love the programming model and productivity so we live with it
• There must be a better way...

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Introducing Micronaut

• Designed from the ground up with Microservices in mind
• Ultra-light weight and Reactive - Based on Netty
• Integrated AOP and Compile-Time DI
• HTTP Client & Server

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[fit] DEMO

• Hello Micronaut

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Hello Micronaut

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@Controller
class HelloController {
    @Get("/hello/{name}")
    String hello(String name) { "Hello $name!" }
}
@Client("/") // Client Generated at Compile Time
interface HelloClient {
  @Get("/hello/{name}")
  String hello(String name)
}

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How Small?

• Smallest Micronaut Hello World JAR is 8MB when written Java or 12MB in Groovy
• Can be run with as little as 10mb Max Heap (24mb for Groovy)
• Startup time is sub-second for Java, around a second for Groovy
• All Dependency Injection, AOP and Proxy generation happens at compile time

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But... How?

• Compile Time Dependency Injection & AOP for Groovy, Java and Kotlin (!)
• AST Transforms for Groovy. Annotation processors for Java/Kotlin
• Annotation metadata produced at Compile Time
• Reflection Free and No Reflection Data Caching

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Not Another HTTP Server!?

• If all we had achieved was another HTTP server Micronaut wouldn't be very interesting
• So what else does it do?

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Natively Cloud Native

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• Service Discovery - Consul and Eureka Supported; Route 53 Planned
• Configuration Sharing - Consul Supported; Amazon & GCP Planned
• Client Side Load Balancing - Integrated or Netflix Ribbon Supported
• Support for Serverless Computing via AWS Lambda

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[fit] DEMO

• Micronaut Pet Store

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The HTTP Server

• Fully Reactive and non-blocking - Reactor and RxJava 2.x support
• Auto configuration for common databases

@Get('/pets')
Single<List<Pet>> pets() {
    petClient.list()
            .onErrorReturnItem(Collections.emptyList())
}

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The HTTP Client

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• Client Implementations Produced at Compile Time
• Service Discovery by Service ID
• Automatic Client Side Load Balancing & Fallback

@Client(id = "pets", path = "/v1")
interface PetClient {
    @Get('/pets')
    Single<List<Pet>> list()
}

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Serverless Computing

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• Write Functions and Run them locally or as regular server applications
• Deploy Functions to AWS Lambda - after warm-up functions execute in milliseconds

@Field @Inject Twitter twitter

@CompileStatic
URL updateStatus(Message status) {
    Status s = twitter.updateStatus(status.text)
    String url = "https://twitter.com/$s.user.screenName/status/${s.id}"
    return new URL(url)
}

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Micronaut Roadmap

• First Milestones in Q2
• GA by the end of the year. Still todo:
• AWS Route 53, Google Metadata Server Support

• Metrics & Distributed Tracing
• JWT Token Auth

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Micronaut - Find Out More

• We have launched a Micronaut website at: http://micronaut.io
• Register at the bottom to get notifications
• Speak to us (OCi) if you wish to use Micronaut in beta form
• Check out Alvaro's talk about Micronaut on Saturday at 9:30am

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What About Grails?

• Grails is awesome, mature and robust ... for Creating Monoliths
• Not every Application needs Microservices
• You will want parts of Micronaut in your Grails apps: HTTP Client, Discovery Client etc.

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Grails Status Update

• Grails 3.3.3 just released
• Users seeing measured improvement in Memory consumption in production
• More 3.3.x releases planned

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Grails 4.0 (Q4 2018)

• Java 8 minimum, Java 9 support, Groovy 2.5
• Spring Boot 2 and Spring 5
• GORM 7.0 (Hibernate 5.2 minimum)
• Micronaut Integration

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Summary

• Micronaut aims to provide the same wow factor for Microservices that Grails did for Monoliths
• Built by the people that made Grails, leveraging over 10 years experience in framework development
• Coming soon in 2018

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[FIT] Q & A