Microservices allow for scaling agile processes. This presentation shows what Microservices are, what agility is and introduces Self-contained Systems (SCS). Finally, it shows how SCS can help to scale agile processes.

1. Microservices:
Architecture to Scale
Agile
Eberhard Wolff
Fellow, innoQ
@ewolff

2. http://continuous-delivery-buch.de/

3. http://microservices-buch.de/ http://microservices-book.com/

4. http://microservices-book.com/primer.html
FREE!!!!

5. > Microservices
> Agility
> Self-contained Systems
> SCS to scale agile

6. Microservices

7. Server Server
Microservices:
Definition
> Independent deployment units
> E.g. process, VMs, Docker containers
> Any technology
> Any infrastructure
Micro
Service
Micro
Service

8. Components Collaborate
Micro
Service
Micro
Service
Link
Data Replication
REST
Messaging

9. Possible Microservices
Architecture
iOS Android Web
Order Search Catalog
BillingCustomer
Backend Backend Backend

10. Real-World Example
> Team = one person
> Microservices-based system
> Reasons
> Fast and easy deployment
> Clear separation

11. Microservices can do
more than scaling
agile!

12. Agility

13. Iterations
> Work in iterations
> Not following a fixed plan
> “Waterfall” paper 1970
(Royce): Do it twice!
> I.e. iterations are a well-
known idea for very long

14. No Iterations
Goal
Goal

15. Iterations
Goal
Goal
Goal
Goal

16. Cross-functional Team
> Need lots of skill to develop
features
> Have all skills in the team
> Direct communication is
better

17. Self Organization
> Team knows best how to
solve problems
> Let them decide

18. Scaling

19. Scaling
> Do more
> Get more stories
implemented
> ...and running in
production
TODO IN PROGRESS DONE

20. Scaling
> Do more
> Add more people
> Let the work in parallel
> Build more teams

21. Organizational
Approaches
Scrum of
Scrums
Scaled Agile
Framework
(SAFe)
Large Scale
Scrum( LeSS) Agile Path

22. Organizational
Approaches
Scrum of
Scrums
Scaled Agile
Framework
(SAFe)
Large Scale
Scrum( LeSS) Agile Path
Not my
expertise

23. Communication
> Agile means communication
> Instead of written requirements
> ...story cards
> + direct communication

24. # Persons vs.
Potential Links

25. # Persons vs.
Potential Links
0
100
200
300
0 10 20 30

26. Communication is great!
Need more persons

27. Depedencies and
Coordination are
Problems!

28. Dependencies
> Feature across teams
> Team must wait for other teams‘ results

29. time
Team Sprint
Team Sprint
Team Sprint
3 sprints

30. Functionalities
Technology and
Architecture
What Do You
Communicate About?
Releases

31. Can we limit the need
for communication?

32. Challenges for
Scaling Agile
> Dependencies cause delays
> Too much communication about
functionalities...
> ...releasing software,
> ...and technologies

33. Self-contained
System

34. Deployment
monolith
Graphics by Roman Stranghöhner, innoQ
http://scs-architecture.org

35. Cut Deployment
monolith along
domains …

36. … wrap domain in
separate web
application …

37. Self-contained
System (SCS) –
individually
deployable

38. SCS =
user interface+
business logic+
data storage

39. Web user interface

40. optional API e.g. for
mobile

41. Self-contained
Systems
should be integrated
in the web interface

42. Hyperlinks to navigate between
systems.
System 1 System 2

43. Dynamic inclusion of content
served by another application
System 1 System 2

44. Logic only shared over
a well defined
interface.

45. Business logic can
consist of
microservices

46. Avoid synchronous
remote calls

47. Remote API calls
should be
asynchronous

48. Every SCS brings its
own data storage
with its own
(potentially
redundant) data

49. Technical decisions can
be made independently
from other systems
(programming language,
frameworks, tooling,
platform)

50. Domained scoped
SCS enables the
development,
operation and
maintenance of an
domain by a
single team.
Team 1
Team 2 Team 3

51. 1 SCS
= 1 Domain
= 1 Web App
= 1 Team
= 1-n Microservices

52. SCS?
iOS Android Web
Order Search Catalog
BillingCustomer
Backend Backend Backend

53. SCS?
iOS Android Web
Order Search Catalog
BillingCustomer
Backend Backend Backend

54. SCS to Scale Agile

55. Challenges for
Scaling Agile
> Dependencies cause delays
> Too much communication about
functionalities...
> ...releasing software,
> ...and technologies

56. Challenges for
Scaling Agile
> Dependencies cause delays
> Too much communication about
functionalities...
> ...releasing software,
> ...and technologies

57. Conway‘s Law
Architecture
copies
communication structures
of the organization

58. Conway‘s Law: Impact
Architecture
and
communication structures
in the organization
are the same thing.

59. Conway’s Law as a
Limit
> Organization drives architecture
> Teams of experts
> i.e. UI, logic & database team
> Three technical artifacts

60. Logic
UI
Database
Change
Order
Process!

61. time
DB
Team Sprint
Logic
Team Sprint
GUI
Team Sprint
3 sprints

62. Domained scoped
SCS enables the
development of a
domain by a
single team
– no coordination
Order Team =
UI+Logic+Database

63. Challenges for Scaling
Agile
> Dependencies cause delays
> Too much communication about
functionalities...
> ...releasing software,
> ...and technologies

64. Deployment Monolith
Stories
Technical Coordination
Coordinating Releases

65. Self-contained
System (SCS) –
individually
deployable

66. Technical decisions can
be made independently
from other systems
(programming language,
frameworks, tooling,
platform)

67. SCS
Stories
Technical
Coordination
Stories
Technical
Coordination
Stories
Technical
Coordination
Order Billing Search
Release Release Release

68. Impact on Teams
> More self-organization
> Decide about technologies,
releases etc.
> Need to be more cross-
functional
> E.g. ops skills become more
important

69. Conclusion

70. How to scale agile?

71. Define
architecture to
limit
communication
needs

72. Conclusion: SCS &
Microservices
> Microservices have many advantages
> SCS are a way to use Microservices
> …for large projects
> …to scale agile

73. Conclusion: SCS &
Agility
> Domain in one SCS
> less dependencies
> less delays
> less communication about functionalities
> Technological freedom
> less communication about technologies
> Independent releases
> no need to coordinate releases

74. Challenges

75. Challenges
> UI integration
> ...in particular for mobile / Single Page App
> Architecture more important
> Architecture = organization

76. Meta-Conclusion

77. How To Think About
Architecture
> Process has an impact on architecture
> Software architecture & organization are the
same

78. Thank You!
@ewolff
http://scs-architecture.org
(Creative Commons)