This presentation shows the properties, advantages and challenges of microservices. It then discusses alternative architectures beyond microservices.

1. Beyond Microservices
Eberhard Wolff
@ewolff
http://ewolff.com
Fellow

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

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

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

5. What are
Microservices?

6. Modules Processes
Independent
Continuous
Delivery Pipeline
Standardized
Operations
Resilience
Microservices

7. Why Microservices?
!

8. Technological
Benefits
"

9. Decoupling
> Originally: Changing
a module does not
influence other
modules.
> i.e. independent
development

10. Microservice Decoupling
> Independent scaling
> Independent
technical decisions
> Decoupled crashes
> Security: firewalls etc

11. Clean Architecture

12. Developer

13. Developer

14. REST REST

15. ECommerce
System
Order
Catalog
Billing
Search

16. ECommerce
System
Order
Catalog
Billing
Search

17. ECommerce
System
Catalog
Billing
Search

18. ECommerce
System
Order
Catalog
Billing
Search
Replace if messed up.

19. Replaceability
> Small components hard to mess up
> Each module can be replaced
> …small green field project
> ...different technology stack possible

20. Continuous Delivery

21. Microservices
ECommerce
System
3rd party
systems
Database

22. Microservices
3rd party
systems
Database
Order
Catalog
Billing
Search

23. Order
Billing
Customer
Commit
Stage
Automated
Acceptance
Testing
Automated
Capacity
Testing
Manual
Explorative
Testing
Release
Commit
Stage
Automated
Acceptance
Testing
Automated
Capacity
Testing
Manual
Explorative
Testing
Release
Commit
Stage
Automated
Acceptance
Testing
Automated
Capacity
Testing
Manual
Explorative
Testing
Release

24. Build Pipeline for
Microservices
> Build pipeline per Microservice
> Smaller
> Easier to set up
> Less features (3rd party systems)
> Faster Feedback: Less tests

25. Decoupled
Development
Decoupled
Scalability
Decoupled
Technical
decisions
Decoupled
Crashes
Security
Architecture
Firewalls
Replaceability
Continuous
Delivery
Technological Benefits

26. Organizational
Benefits
"

27. Deployment Monolith
Stories
Technical Coordination
Coordinating Releases

28. Microservice
Stories
Technical
Coordination
Stories
Technical
Coordination
Stories
Technical
Coordination
Order Billing Search
Release Release Release

29. Inverse Conway Maneuver
> Architecture drives organization
> Cross-functional team (database, logic, UI)
> Team responsible for Bounded Context(s)

30. Take one huge project
and make it several
small projects…

31. Self-organization
> With so much independence…
> ...teams can decide for themselves.
> Self-organization

32. Inverse Conway
Maneuver
Independent
Technologies
Independent
Bounded
Contexts
Self-
organization
Organizational Benefits

33. Microservices:
Challenges
#

34. Consistency
Order
Invoice
Delivery
What about
order #42?
✅
✅
❌

35. Consistency
Order
Invoice
Delivery
Order #42
is cancelled!
✅
✅
⁉
Goods might be delivered
if order arrives
after cancellation.

36. This is quite common
without
microservices.

37. Customer Order Catalog
Domino Effect

38. Customer Order Catalog
Domino Effect

39. Customer Order Catalog
Domino Effect

40. Customer Order Catalog
Domino Effect

41. Build resilient
microservices!

42. Refactorings
> Move code to a new service: Easy
> Move code from service to service
> Might be a port to a different language
> Hard

43. Global Refactorings
> Really hard: Global restructuring
> i.e. moving everything to a different place.
> …but that is always hard…
> ...and the result of a major screwup.
> Do you want to optimize for this?

44. Many New Technologies
> Microservices framework
> Service discovery
> Routing / API Gateway
> Continuous Delivery pipeline
> Docker
> Docker scheduler (Kubernetes)
> ....

45. Challenges
Consistency Fail safeness
Large scale
refactoring
New
Technologies

46. Microservices are an
all or nothing
approach.

47. Microservices are an
all or nothing
approach.

48. Which benefits are
important?
Which challenges
acceptable?

49. Moving beyond
Microservices:
Rightsize the
achitecture!

50. Alternative
Approaches

51. Centralized DB

52. Billing
Order
Process
CRM
OrderOrder Order
True Microservices

53. Shared Database
Order Schema
Billing
Order
Process
CRM

54. Modules
--
Processes
++
Independent
Continuous
Delivery Pipeline
+
Standardized
Operations
-
Resilience
-
Shared Database:
Microservices

55. Decoupled
Development
--
Decoupled
Scalability
+
Decoupled
Technical
decisions
+
Decoupled
Crashes
+
Security
-
Architecture
Firewalls
-
Replaceability
--
Continuous
Delivery
-
Technological Benefits

56. Inverse Conway
Maneuver
-
Independent
Technologies
+
Independent
Bounded Contexts
--
Self-organization
-
Organizational Benefits

57. Challenges
Consistency
++
Fail safeness
-
Large scale
refactoring
-
New
Technologies
-
-

58. Centralized Database
is a bad idea.

59. Layered

60. Layered
iOS Android Web
Order Product Delivery
InvoiceCustomer

61. Layered: Issues
> Changing a business process cause many
changes
> …in Frontend and many backend
> Lots of communication between teams and
components

62. Modules
++
Processes
++
Independent
Continuous
Delivery Pipeline
++
Standardized
Operations
++
Resilience
+
Microservices

63. Decoupled
Development
-
Decoupled
Scalability
-
Decoupled
Technical decisions
++
Decoupled Crashes
+
Security
+
Architecture
Firewalls
+
Replaceability
+
Continuous Delivery
-
Technological Benefits

64. Inverse Conway
Maneuver
--
Independent
Technologies
++
Independent
Bounded Contexts
--
Self-organization
--
Organizational Benefits

65. Challenges
Consistency
+
Performance
--
Fail safeness
--
Large scale
refactoring
--
New Technologies
--

66. Layered:
More challenges,
less benefits,
same effort

67. Bounded Context
Microlith
SCS

68. Order
Shipping address
Tracking #
Items
Item Categories
Priority shipping
Customs #
Account #
...
Credit card #
Order #

69. My Domain Model is a
mess!

70. Bounded Context
> Domain model is only valid for one context
> There is no universal data model!
> See all failed SOA attempts

71. Order
Shipping address
Tracking #
Items
Item Categories
Priority shipping
Customs #
Account #
...
Credit card #
Order #
Customs
Order
Recommen-
dations
Order
Tracking
Order
Shipping
address
Tracking #
Item
Categories
Priority
shipping
Customs #
Payment
Order
Account #
Credit card #

72. Self-contained Systems
Search Invoice LogisticsCheckout
Web Web Web Web
See http://scs-architecture.org

73. Modules
++
Processes
++
Independent
Continuous
Delivery Pipeline
++
Standardized
Operations
++
Resilience
+
Microservices

74. Decoupled
Development
++
Decoupled
Scalability
++
Decoupled
Technical decisions
++
Decoupled Crashes
++
Security
++
Architecture
Firewalls
+
Replaceability
+
Continuous Delivery
++
Technological Benefits

75. Inverse Conway
Maneuver
++
Independent
Technologies
++
Independent
Bounded Contexts
++
Self-organization
++
Organizational Benefits

76. Challenges
Consistency
+
Performance
++
Fail safeness
++
Large scale
refactoring
+
New
Technologies
+

77. Microservices as they
should be.

78. Modules with
Maven
Architecture Management
OSGi
WAR

79. Build order /
Architecture
management
Build order /
Architecture
management

80. Modules
+
Processes
--
Independent
Continuous
Delivery Pipeline
-
Standardized
Operations
++
Resilience
-
Microservices

81. Decoupled
Development
+
Decoupled
Scalability
--
Decoupled
Technical decisions
--
Decoupled Crashes
--
Security
--
Architecture
Firewalls
++
Replaceability
+
Continuous Delivery
+
Technological Benefits

82. Inverse Conway
Maneuver
+
Independent
Technologies
--
Independent
Bounded Contexts
++
Self-organization
-
Organizational Benefits

83. Challenges
Consistency
-
Performance
++
Fail safeness
-
Large scale
refactoring
++
New
Technologies
++

84. Clean architecture
with a lot less
technical challenges!

85. Conclusion

86. Conclusion
> Microservices are a set of architecture
decision
> Architecture is about trade-offs
> Architecture is different for each project
> Go beyond microservices by picking the
best decisions!
> …and gain most benefits

87. Usually bad tradeoffs
> Centralized database
> Layered model

88. Usually good tradeoffs
> SCS, Bounded Context, Microlith
> Strongly separated modules