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
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#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.

3. Agenda
• What exactly are microservices?
• Are microservices for you?
• Microservices and Java EE
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

11. Pragmatic Java EE Microservices Demo
https://github.com/m-reza-rahman/javaee-pragmatic-microservices
Copyright © 2015 CapTech Ventures, Inc. All rights reserved.

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.

13. Microservices and Java EE
Copyright © 2015 CapTech Ventures, Inc. All rights reserved.
http://microprofile.io

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.

17. Copyright©2015CapTechVentures,Inc.Allrightsreserved.