Microservices on the JVM - a practical overview

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM MicroServices on the JVM A practical
overview Alexander Heusingfeld & Martin Eigenbrodt

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM #MicroServices #buzz • Deﬁned by LOC?
• UI or not UI? • SOA in new clothes?

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM “Micro” Services?

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM “Micro” Services? Monolith

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM “Micro” Services? Monolith A A A
A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A C A A B D Y K

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM “Micro” Services? Monolith System A System
B System C System D A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A C A A B D Y K

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Our approach

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Our approach • build around business
capabilities

capabilities • separate runtime processes

capabilities • separate runtime processes • self-contained

capabilities • separate runtime processes • self-contained • loosely coupled

capabilities • separate runtime processes • self-contained • loosely coupled • independent life cycles

capabilities • separate runtime processes • self-contained • loosely coupled • independent life cycles • decentralised management

capabilities • separate runtime processes • self-contained • loosely coupled • independent life cycles • decentralised management Self-Contained System

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM We’re not talking about…

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM We’re not talking about… • micro
architecture

architecture • slicing howtos

architecture • slicing howtos • communication protocol

System A System B System C

System A System B Persistence Logic UI System C Logic
UI Persistence Logic

System A System B Persistence Logic UI System C HTTP
HTTP Logic UI Persistence Logic

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Challenges

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Challenges • distributed conﬁguration

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Challenges • distributed conﬁguration • service
registration & discovery

registration & discovery • resilience

registration & discovery • resilience • fast, automated deployment

registration & discovery • resilience • fast, automated deployment • metrics

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Frameworks

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Dropwizard

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Dropwizard • Glue Code for well
known libraries • Java

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Dropwizard libraries

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Dropwizard libraries • Jetty

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Dropwizard libraries • Jetty • Jersey

• Metrics

• Metrics • Jackson • Guava • Logback • Hibernate Validator • Apache Http Client • JDBI • Liquibase • Freemarker & Mustache • Joda

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Spring Boot

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Spring Boot • convention over conﬁguration
approach

approach • Java, Groovy or Scala

approach • Java, Groovy or Scala • self-contained jar or war

approach • Java, Groovy or Scala • self-contained jar or war • tackles dependency-hell via pre-packaging

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Spring Cloud

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Spring Cloud • new umbrella project
for cloud connectors

for cloud connectors • On top of Spring Boot

for cloud connectors • On top of Spring Boot • conﬁg server for distributed conﬁguration

for cloud connectors • On top of Spring Boot • conﬁg server for distributed conﬁguration • Eureka annotations for service-discovery

for cloud connectors • On top of Spring Boot • conﬁg server for distributed conﬁguration • Eureka annotations for service-discovery • Hystrix annotations for resilience enhancements

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Play 2

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Play 2 • Java or Scala
• based on Akka • strong async support

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Routing

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM @Path ("/cart") public class ShoppingCartResource {
@GET @Path("{id}") @Timed @Produces(MediaType.TEXT_HTML) public ShoppingCartView shoppingCart(@PathParam("id") String cartId, @Context UriInfo uriInfo) { ImmutableList<String> urls = dao.findItemsForCartId(cartId); ImmutableList<Product> products = catalog.resolveProducts(urls); return new ShoppingCartView(products, uriInfo.getAbsolutePath().toString() ); } ... } Dropwizard

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM @Controller  @RequestMapping(value = ORDERS_RESOURCE)  public class
OrderController {    private @Autowired CounterService counterService;    @RequestMapping(method = RequestMethod.POST)  public String checkoutCart(@RequestParam(value = "products") List<String> productUris) {  counterService.increment("checkouts.withproducts." + productUris.size());    // save products as an order   return "redirect:" ORDERS_RESOURCE + order.getId(); // like “/order/123”  }  } Spring Boot

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM # Routes # List of all
books GET / controllers.BooksController.books # A specific Book GET /books/:id controllers.BooksController.book(id:String) Play

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM object BooksController extends Controller { def
books = Action.async { implicit request => val bestsellerFuture = Bestseller.getBestseller val booksFuture = Books.books for { bestseller <- bestsellerFuture books <- booksFuture } yield { Ok(views.html.books(books.values.toList, bestseller)) } } ... } Play

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Configuration

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Spring Boot @ComponentScan  @EnableAutoConfiguration  public class
OrderApp {    public static void main(String[] args) {  SpringApplication.run(OrderApp.class, args);  }  }

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Spring Boot • opinionated preset @ComponentScan 
@EnableAutoConfiguration  public class OrderApp {    public static void main(String[] args) {  SpringApplication.run(OrderApp.class, args);  }  }

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Spring Boot • opinionated preset •
HTTP resource “/env” shows all properties @ComponentScan  @EnableAutoConfiguration  public class OrderApp {    public static void main(String[] args) {  SpringApplication.run(OrderApp.class, args);  }  }

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Spring Boot • opinionated preset •
HTTP resource “/env” shows all properties • overwrite via application.properties or CLI parameter @ComponentScan  @EnableAutoConfiguration  public class OrderApp {    public static void main(String[] args) {  SpringApplication.run(OrderApp.class, args);  }  }

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Play - Typesafe Config

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Play - Typesafe Config • Conﬁg
Library used by akka, play and other

Library used by akka, play and other • HOCON - JSON Data Model + syntactic sugar

Library used by akka, play and other • HOCON - JSON Data Model + syntactic sugar • override via system property

Library used by akka, play and other • HOCON - JSON Data Model + syntactic sugar • override via system property • rich merge and include possibilities

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Http Client

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM public Product resolveProduct(String url) { Product
product = client.resource(url) .accept(MediaType.APPLICATION_JSON).get(Product.class); return product; } Dropwizard

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM public Product resolveProduct(String url) { final
RestTemplate restTemplate = new RestTemplate();  return restTemplate.getForEntity(url, Product.class);  } Spring Boot

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM WS.url(apiUrl).get.map { response => response.json.as[List[Bestseller]] }.recover
{ case e => List() } Play

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Service Discovery

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Registry Service Client register & heartbeat
lookup call

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM @ComponentScan  @EnableAutoConfiguration  @EnableEurekaServer  public class EurekaServerApp
{    public static void main(String[] args) {  SpringApplication.run(EurekaServerApp.class, args);  }  }

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM @ComponentScan  @EnableAutoConfiguration  @EnableEurekaServer  public class EurekaServerApp
{    public static void main(String[] args) {  SpringApplication.run(EurekaServerApp.class, args);  }  } @ComponentScan  @EnableAutoConfiguration  @EnableEurekaClient  public class OrdersApp {    public static void main(String[] args) {  SpringApplication.run(OrdersApp.class, args);  }  }

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Resilience

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Resilience • isolate Failure • apply
graceful degradation • be responsive in case of failure

Request service Request service http://en.wikipedia.org/wiki/Circuit_breaker Request service closed open half-
open

> Provides Command-oriented Integration of Services > Introduces Circuit Breaker,
Bulkheads and Isolation > Decouples from Service-dependencies > Provides metrics-facility to protect from failures

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM public class CommandInDropwizard extends TenacityCommand<Product> {
@Override protected Product run() throws Exception { Product product = client.resource(url) .accept(MediaType.APPLICATION_JSON).get(Product.class); return product; } protected Product getFallback() { return FALLBACK_PRODUCT } } Hystrix & Dropwizard

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM ResolveProductCommand command = new ResolveProductCommand(client, url);
Product product = command.execute(); Hystrix & Dropwizard

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM @HystrixCommand(fallbackMethod = “fallbackProduct") private Pair<String, ResponseEntity<Product>>
resolveProduct(String productUri) {  final RestTemplate restTemplate = new RestTemplate();  return new Pair(productUri, restTemplate.getForEntity(productUri, Product.class));  } private Pair<String, ResponseEntity<Product>> fallbackProduct(String productUri) {  final Product product = new Product(productUri, null, BigDecimal.ZERO);  final ResponseEntity<Product> response = new ResponseEntity<Product>(product, PARTIAL_CONTENT);  return new Pair(productUri, response);  } Spring Cloud Hystrix

resolveProduct(String productUri) {  final RestTemplate restTemplate = new RestTemplate();  return new Pair(productUri, restTemplate.getForEntity(productUri, Product.class));  } private Pair<String, ResponseEntity<Product>> fallbackProduct(String productUri) {  final Product product = new Product(productUri, null, BigDecimal.ZERO);  final ResponseEntity<Product> response = new ResponseEntity<Product>(product, PARTIAL_CONTENT);  return new Pair(productUri, response);  } Spring Cloud Hystrix wrapped in command -> async!

resolveProduct(String productUri) {  final RestTemplate restTemplate = new RestTemplate();  return new Pair(productUri, restTemplate.getForEntity(productUri, Product.class));  } private Pair<String, ResponseEntity<Product>> fallbackProduct(String productUri) {  final Product product = new Product(productUri, null, BigDecimal.ZERO);  final ResponseEntity<Product> response = new ResponseEntity<Product>(product, PARTIAL_CONTENT);  return new Pair(productUri, response);  } Spring Cloud Hystrix

resolveProduct(String productUri) {  final RestTemplate restTemplate = new RestTemplate();  return new Pair(productUri, restTemplate.getForEntity(productUri, Product.class));  } private Pair<String, ResponseEntity<Product>> fallbackProduct(String productUri) {  final Product product = new Product(productUri, null, BigDecimal.ZERO);  final ResponseEntity<Product> response = new ResponseEntity<Product>(product, PARTIAL_CONTENT);  return new Pair(productUri, response);  } Spring Cloud Hystrix method reference? :(

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM val apiUrl = "..." val breaker
= CircuitBreaker(Akka.system().scheduler, maxFailures = 5, callTimeout = 2.seconds, resetTimeout = 1.minute) def getBestseller : Future[List[Bestseller]] = { breaker.withCircuitBreaker( WS.url(apiUrl).get.map { response => response.json.as[List[Bestseller]] }).recover { case e => List() } } Play - Circuit Breaker

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Deployment

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Spring Boot - Packaging ./gradlew distZip
./gradlew build

./gradlew build ZIP + shell-script

./gradlew build ZIP + shell-script executable JAR

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Play - Packaging sbt dist sbt
debian:packageBin sbt rpm:packageBin

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Metrics

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Dropwizard • “Metrics” Integrated with Dropwizard
• @Timed on Resources • HTTP Client is already instrumented • JVM Data

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM "cart.resources.ShoppingCartResource.shoppingCart": { "count": 22, "max": 0.136162,
"mean": 0.01208109090909091, "min": 0.00093, "p50": 0.008174500000000001, "p75": 0.011782250000000001, "p95": 0.11783499999999976, "p98": 0.136162, "p99": 0.136162, "p999": 0.136162, "stddev": 0.02813530239821426, "m15_rate": 1.8524577712890011, "m1_rate": 0.18057796798879996, "m5_rate": 1.315746847992022, "mean_rate": 0.133050618509084, "duration_units": "seconds", "rate_units": "calls/second" } "org.apache.http.client.HttpClient.cart.get-requests": { "count": 11, "max": 0.062107, "mean": 0.013355909090909092, "min": 0.005750000000000001, "p50": 0.009454, "p75": 0.010427, "p95": 0.062107, "p98": 0.062107, "p99": 0.062107, "p999": 0.062107, "stddev": 0.016285873488729705, "m15_rate": 0, "m1_rate": 0, "m5_rate": 0, "mean_rate": 2.9714422786532126, "duration_units": "seconds", "rate_units": "calls/second" }

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Dropwizard Metrics • Exposed over HTTP
(as Json) • Exposed as jmx • Others available: stdout, csv, slf4j, ganglia, graphite

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Spring Boot Metrics • Prepackaged Spring
Boot starter module • enables HTTP resources for metrics • conﬁgurable via application.properties http://docs.spring.io/spring-boot/docs/current-SNAPSHOT/reference/htmlsingle/#production-ready

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Using a counter metric in your
Java code… …will display it in the /metrics JSON counterService.increment("checkouts.withproducts." + productUris.size()); GET /metrics HTTP/1.1 { "counter.checkouts.withproducts.3": 4, ... }

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Conclusion

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Take Aways

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Take Aways • MicroServices aren’t micro!

• Only “micro” regarding business scope

• Only “micro” regarding business scope • micro services = distributed systems deep dive

• Only “micro” regarding business scope • micro services = distributed systems deep dive • no framework is a silver bullet

@goldstift @eigenbrodtm #DV14 #MicroservicesJVM Thanks for your attention • Questions?
Martin Eigenbrodt, @eigenbrodtm Alexander Heusingfeld, @goldstift https://www.innoq.com/en/timeline/

Microservices on the JVM - a practical overview

Microservices on the JVM - a practical overview

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