Down-to-Earth Microservices with Java EE

1. Others Talk, We Listen. Down-to-Earth Microservices with Java EE Reza Rahman Senior Architect rrahman@captechconsulting.com @reza_rahman

2. CapTech Full-service US national IT consulting firm that focuses on client best interests, trust, servant leadership, culture, professionalism and technical excellence. #28 in Vault's Consulting Top 50 #3 Best Consulting Internship #9 Best Overall Internship #1 in Meeting Client’s Needs #7 Best Firm to Work For #1 in Career Development Ranked for the 7th Consecutive Year Copyright © 2015 CapTech Ventures, Inc. All rights reserved.

4. What’s in a Name? • “Microservices” very vague • Big hurdle to practical adoption by average Joe developer • Poor naming regime, including “monolith” • Overloaded by commercial interests • Simple concept with a long history • UNIX, CORBA, Jini, RMI, EJB 1/2, COM/DCOM, OSGi, SOAP/ESB • An intellectually honest name could be “Son of SOA” Copyright © 2015 CapTech Ventures, Inc. All rights reserved.

5. What’s in a Name? • Decomposing larger systems into smaller independently deployable parts • Purists distance themselves from SOAP, ESB • Purists embrace mostly REST and messaging • Purists take for granted testing, DevOps, continuous delivery • Purists focus on (ridiculously) fine grained services Copyright © 2015 CapTech Ventures, Inc. All rights reserved.

6. The Promise • As systems grow, they become harder to maintain without modularity • Ideal size for “monolithic” team is somewhere around 10-12 engineers • Distributed systems can enforce better modularity • Greater agility – maybe • Easier to scale – maybe • Polyglot programming – maybe Copyright © 2015 CapTech Ventures, Inc. All rights reserved.

7. The Reality • Long well-understood downsides of distributed systems • Significantly more complex administration, deployment and monitoring • Significantly harder testing, debugging, diagnostics, reliability, consistency • Code duplication - the challenges of finding module boundaries • Higher skill and automation requirements for development and operations • “Distributed big ball of mud” • “Fallacies of distributed computing” Copyright © 2015 CapTech Ventures, Inc. All rights reserved.

8. The Reality • The Bottom Line • Majority of systems probably just fine as “monoliths” • Majority of systems needing microservices would be considered “hybrids” by purists • Few practical enterprise systems can or need to achieve “microservices nirvana” • Business and system needs most of the time make decomposition lines obvious Copyright © 2015 CapTech Ventures, Inc. All rights reserved. DDD Bounded Context

9. A Picture Says a Thousand Words… For most ordinary “blue collar” IT organizations “microservices nirvana” is probably more like microservices hell. Copyright © 2015 CapTech Ventures, Inc. All rights reserved.

10. Microservices and Vanilla Java EE Copyright © 2015 CapTech Ventures, Inc. All rights reserved. JAX-RSJAX-RS JSFJSF JMSJMS WebSocketWebSocket JSONJSON CDICDI Bean Validation Bean Validation EJB 3EJB 3 JPAJPA AdministrationAdministration MonitoringMonitoring High Availability High Availability SecuritySecurity ResourcesResources

12. Microservices Buzzword Bingo • Fat jars, uber jars, “containerless”, microframeworks • WildFly Swarm, Payara Micro, WebSphere Liberty, KumuluzEE, TomEE embedded, Spring Boot • Containers • Docker • Cloud, IaaS, PaaS • AWS, OpenShift, Oracle Cloud, BlueMix, Cloud Foundry • Dynamic discovery, client-side load-balancing, circuit-breakers/bulkheads, health-check/metrics • Ribbon, Hystrix, RxJava, NetFlixOSS Copyright © 2015 CapTech Ventures, Inc. All rights reserved.

14. Java EE 9 • Dynamic configuration, health-check, OAuth, OpenID • Fat jars, Java SE 9 modules • Dynamic discovery, circuit-breakers/bulkheads/client-side load-balancing • NoSQL, state management, eventual consistency, events Copyright © 2015 CapTech Ventures, Inc. All rights reserved.

15. Summary • Microservices newest incarnation of ideas with a long history, the last major incarnation being SOA. • Microservices is a valuable architectural technique that is pretty technology agnostic. • Microservices are not necessarily for everyone, not necessary always and not necessarily all-at-once. • Vanilla Java EE is a very capable platform for pragmatic microservices more relevant to ordinary IT organizations, “monoliths” and everything in between. • The Java EE ecosystem is already stepping up to support even the niche of microservices nirvana. Copyright © 2015 CapTech Ventures, Inc. All rights reserved.

16. Resources • Microservices Premium by Martin Fowler • https://martinfowler.com/bliki/MicroservicePremium.html • Microservices is SOA, for those who know what SOA is • http://service-architecture.blogspot.com/2014/03/microservices-is-soa-for-those • Java EE Tutorials • http://docs.oracle.com/javaee/7/tutorial/doc/home.htm • Pragmatic Microservices Lab • https://github.com/m-reza-rahman/pragmatic-microservices-lab Copyright © 2015 CapTech Ventures, Inc. All rights reserved.