The document discusses building microservices and Java applications for the cloud using DevOps principles. It introduces the Cloud DHARMA principles for building cloud apps, including being documented, highly cohesive/loosely coupled, automated from commit to cloud, resource aware, monitored, and antifragile. It also discusses moving to microservices architectures, challenges of cloud deployments, and the importance of culture in DevOps.

1. Building Java (micro)services for the Cloud
The DHARMA principles
&&
Chuck Norris Doesn’t Need DevOps…
but Java Developers might benefit
Daniel Bryant
Principal Consultant, Open Credo
daniel.bryant@opencredo.com
@danielbryantuk

2. Who Am I?
• Principal Consultant at OpenCredo
• LJC Associate
 Agile transformations
 DevOps, Cloud and Microservices
 Big Data
• Adopt OpenJDK and JSR
10/11/2014 @danielbryantuk

3. The Current Industry Wish List…
• Service-Oriented Architecture
• Cloud-based deployments
• DevOps Culture
10/11/2014 @danielbryantuk

4. The Current Industry Wish List…
• Service-Oriented Architecture
– muCon 2014 (coming soon via skillsmatter.com)
• Cloud-based deployments
– JavaOne 2014 (coming soon via parleys.com)
• DevOps Culture
– Devoxx UK talk (bit.ly/1BylnZb)
– Previous LJC Event (bit.ly/1elVPJz)
10/11/2014 @danielbryantuk

5. So, what’s all this I hear about small services?…
10/11/2014 @danielbryantuk

6. “Microservices”aka
• “SOA done right”
• “SRP” services
– “Java, The Unix Way” (bit.ly/1cX8VsS)
• “Small” codebase services
– 1000 LOC… 100… 10…?
• “12 Factor apps” (12factor.net)
• My personal opinion…
10/11/2014 @danielbryantuk

7. “Can I fit the service in my head?”
10/11/2014 @danielbryantuk

8. Moving to the Cloud – common problems…
10/11/2014 @danielbryantuk

9. Not respecting the underlying environment
10/11/2014 @danielbryantuk

10. Lack of application/platform monitoring…
10/11/2014 @danielbryantuk

11. Bizarre failure modes…
10/11/2014 @danielbryantuk

12. Difficulty in understanding
the new architecture
10/11/2014 @danielbryantuk

13. Not testing in the Cloud…
(hint: here be dragons!)
10/11/2014 @danielbryantuk

14. We’ve created the “Cloud DHARMA Principles”
to act as a checklist when building Cloud apps
10/11/2014 @danielbryantuk

15. Documented (just enough)
Highly cohesive/loosely coupled (all the way down)
Automated from commit to Cloud
Resource aware
Monitored thoroughly
Antifragile
10/11/2014 @danielbryantuk

16. Documented (just enough)
Highly cohesive/loosely coupled (all the way down)
Automated from commit to Cloud
Resource aware
Monitored thoroughly
Antifragile
10/11/2014 @danielbryantuk

17. API Docs with Swagger
10/11/2014 @danielbryantuk
helloreverb.com/developers/swagger

18. Create a PACT
10/11/2014 @danielbryantuk
github.com/DiUS/pact-jvm

19. Documented (just enough)
Highly cohesive/loosely coupled (all the way down)
Automated from commit to Cloud
Resource aware
Monitored thoroughly
Antifragile
10/11/2014 @danielbryantuk

20. High Cohesion / Loose Coupling
(all the way down…)
• Code
• Architecture
– Components
– Services
• Public API
– PayPal (bit.ly/1hnZNly)
10/11/2014 @danielbryantuk

21. Microservices: Architectural Silver Bullet?
• Enforce service boundaries
– Bounded contexts
– Domain-Driven Design
• Separation of Concerns
– Encapsulate what varies
– Easier to scale/tune independently
• Is this a free-lunch? (bit.ly/1gSw4L7)
10/11/2014 @danielbryantuk

22. No!! It’s all too easy to…
1) Create a distributed monolith
2) Push complexity into orchestration
www.codingthearchitecture.com/2014/07/06/distributed_big_balls_of_mud.html
10/11/2014 @danielbryantuk

23. 10/11/2014 @danielbryantuk

24. Sneak-peak: Smashing the Monolith…
• Business functionality -“Cart Service”
– Noun, verb, SRP (slidesha.re/1owdJhh)
• Technology chunk - “Email Service”
• Vertical Slice - “Service per page”
– Groupon (vimeo.com/105880150)
• Horizontal Slice - “User Repo”
– An anti-pattern?
10/11/2014 @danielbryantuk

25. DZone’s Enterprise Integration Guide
10/11/2014 @danielbryantuk
www.dzone.com/page/research

26. Documented (just enough)
Highly cohesive/loosely coupled (all the way down)
Automated from commit to Cloud
Resource aware
Monitored thoroughly
Antifragile
10/11/2014 @danielbryantuk

27. Thou Shalt Know thy Cloud…
“Everything fails all the time [in the cloud]”
Werner Vogels, CTO, Amazon.com
• Everything is ephemeral
• Volatility
• Noisy (virtual) neighbours
– bit.ly/1w1HQy7
10/11/2014 @danielbryantuk

28. Documented (just enough)
Highly cohesive/loosely coupled (all the way down)
Automated from commit to Cloud
Resource aware
Monitored thoroughly
Antifragile
10/11/2014 @danielbryantuk

29. Antifragile
• The opposite of fragile?
– Robust…
– Antifragile…
• Netflix are best-in-class
– bit.ly/1gs5n3q
• System must be robust first!
10/11/2014 @danielbryantuk

30. Design for Failure
• Distributed Computing Principles
– ‘For young bloods’ (bit.ly/1pKVepz)
– Eight Fallacies… (bit.ly/1zCBet7)
• Design patterns
– Timeouts / retries
– Bulkheads / circuit-breakers
10/11/2014 @danielbryantuk

31. Retries
10/11/2014 @danielbryantuk
github.com/rholder/guava-retrying

32. Circuit-breaker/bulkhead
10/11/2014 @danielbryantuk
github.com/Netflix/Hystrix
projects.spring.io/spring-cloud/

33. Antifragile Patterns: Elastic Scaling
Stateless components
Distributed data stores / caches
10/11/2014 @danielbryantuk

34. Microservices in the Cloud…
Documented (just enough)
Highly cohesive/loosely coupled (all the way down)
Automated from commit to Cloud
Resource aware
Monitored thoroughly
Antifragile
10/11/2014 @danielbryantuk

35. and now to DevOps…
…or as the recruiters like to say
“DeeVoips”, “DevAnOps” and “Dev-Oops”
10/11/2014 @danielbryantuk

36. What’s in a Name?
• “Development / Operations”
• Increasing cohesion between:
– Business
– Development
– Quality Assurance
– Operations
“Bu-Dev-Qa-Ops”?
10/11/2014 @danielbryantuk

37. So, What’s Chuck Norris Doing Here?
10/11/2014 @danielbryantuk

38. Chuck Norris doesn’t need DevOps…
…as a one-man army he codes with
one hand, tests with the other and
deploys with his beard
The rest of us…
…work in teams to develop software
10/11/2014 @danielbryantuk

39. Software Development Teams
• Developers
• Quality Assurance
• Operations
10/11/2014 @danielbryantuk

40. Software Development Teams
• Developers
• Quality Assurance
• Operations
10/11/2014 @danielbryantuk

41. 10/11/2014 @danielbryantuk

42. Software Development Teams
• Developers
• Quality Assurance
• Operations
10/11/2014 @danielbryantuk

43. 10/11/2014 @danielbryantuk

44. Software Development Teams
• Developers
• Quality Assurance
• Operations
10/11/2014 @danielbryantuk

45. 10/11/2014 @danielbryantuk

46. This silo mentality has to stop
10/11/2014 @danielbryantuk

47. Culture is Vital
• Culture drives behaviour, drives culture…
– “Communication, simplicity, feedback, courage”
– Everyone is responsible for delivery
– Continuous experimentation and learning
• Not easy to change culture
– The hardest part of DevOps…
– …but you will learn new things
10/11/2014 @danielbryantuk

48. Changing Culture
• Create an effective team…
• “Habits of highly effective technical teams”
– Martijn Verburg (bit.ly/1aF9SnK)
• “Patterns of Effective Teams”
– Dan North (vimeo.com/68226771)
10/11/2014 @danielbryantuk

49. Chuck Norris doesn’t do QA…
…Chuck Norris can test an entire
application with a single assert
(and get 110% code coverage)
The rest of us…
…need high-quality automated QA
10/11/2014 @danielbryantuk

50. Automating QA
• Intra-component integration testing
– Utilise embedded datastore/middleware
– Cucumber (via ports/adapters/API?)
• Fault-tolerance
– Chris Batey’s Skillscast (bit.ly/1tU6wZj)
– WireMock + Saboteur (wiremock.org)
– “Scassandra” (github.com/scassandra)
10/11/2014 @danielbryantuk

51. Automating QA
• Inter-component integration testing
– The hardest part of SOA…
– Consider ‘synthetic txns’ (active monitoring)
• Service virtualisation
– Mountebank (www.mbtest.org)
– Mock external services (e.g. Spring profiles)
10/11/2014 @danielbryantuk

52. All arrays Chuck Norris creates are of
infinite size…
…as Chuck Norris knows no bounds
The rest of us…
…should manage our resources and
cultivate ‘mechanical sympathy’
10/11/2014 @danielbryantuk

53. Cultivating “Mechanical Sympathy”
• Virtualisation
– Tech Target (bit.ly/1kDVqyG)
• Networking
– ‘Unix and Linux System Administration Handbook’
– AWS docs aws.amazon.com/documentation
• Thinking/Acting Operationally
– You write it, you run it… (“dev on call”)
10/11/2014 @danielbryantuk

54. When Chuck Norris throws Exceptions…
…everybody knows about it because they
land outside of the data center
The rest of us…
…should log all errors (and other vital
information for diagnostic purposes)
10/11/2014 @danielbryantuk

55. Monitor All The Things!
• Infrastructure monitoring
– Nagios / Zabbix
– Codahale, Actuator
• Distributed Tracing
– twitter.github.io/zipkin
• Centralised Logging
– logstash.net
10/11/2014 @danielbryantuk

56. The ‘ELK’ Stack
blog.comperiosearch.com/blog/2014/08/14/elk-one-vagrant-box
10/11/2014 @danielbryantuk

57. “…but what should I graph?”
10/11/2014 @danielbryantuk

58. 10/11/2014 @danielbryantuk
Phrase borrowed from Etsy!

59. 10/11/2014 @danielbryantuk

60. Thanks For Listening
• Massive thanks
– OpenCredo (@OpenCredo)
– notonthehighstreet.com
– RecWorks & The LJC
• Questions / comments?
– daniel.bryant@opencredo.com
– @danielbryantuk
10/11/2014 @danielbryantuk