1. Event Driven Architecture
in practice
Domenico Musto
@mimmozzo domenico.musto@gmail.com

2. Who am I ?

3. What do I do ?
.NET
Web REST
AgileAutomation Testing
C#
Team leading
Ruby

4. Agenda
• SOA
• EDA
• Communication patterns
• Advantages
• Disadvantages
• Q & A

5. Where is Agile going ?

7. PROCESS MATTERS

8. CODE MATTERS

9. Agile = no work upfront

10. Agile = no work upfront
No work upfront = no architecture planning

11. Architecture is not design

12. Agile = no work upfront
No work upfront = no architecture planning

13. Agile = no work upfront
No work upfront = no architecture planning
Agile = no design upfront

14. We can start now

15. A big code base…

16. • Build time
• Difficult to test
• No real boundaries

17. Does not scale

18. Event Driven Architecture

19. • Architecture is mainly business driven
• Business capabilities

20. Business capability
• Owns a part of the system
• Well defined responsibilities
• Owns a model (set of entities)
• Set of components (services, api)
• Isolated database
• Isolated deploy

23. SOA

24. FILES
DISCUSSIONS MEETINGS
TASKS
SOA FLOW

25. FILES
DISCUSSIONS MEETINGS
TASKS
SOA FLOW

26. FILES
DISCUSSIONS MEETINGS
TASKS
SOA FLOW

27. FILES
DISCUSSIONS MEETINGS
TASKS
SOA FLOW

28. EDA FLOW
FILES DISCUSSIONS MEETINGSTASKS
COMMUNICATION CHANNEL

29. Upload document with SOA
FILESCLIENT
Upload document
TASKS NOTIFICATION PREVIEW

30. Upload document with EDA
FILESCLIENT
Upload document
COMMUNICATION CHANNEL
TASKS NOTIFICATION PREVIEW

31. Communication patterns
• Database
• Files
• Messaging

32. Channels
• Logical address
• Datatype

33. • Events
• Commands
• Document Messages
Types of messages

34. A simple event
• ID
• Past sequence
• Informing the outside world that something
happened

35. NewDocumentUploaded
{
Id:1,
DocumentId:100
}

36. Commands
SendEmail
{
Id: 100,
To: ‘domenico.musto@gmail.com’,
From: ‘info@huddle.com’,
Subject: ‘Welcome to huddle’,
Content: ‘Enjoy’
}

37. Document Message
UserRegistered
{
Id: 100,
Name: ‘Domenico’,
LastName: ‘Musto’,
Email: ‘domenico.musto@gmail.com’,
Twitter: ‘@mimmozzo’,
Avatar: ‘http://my.huddle.net/mimmozzo/avatar’
}

38. Reference Data

39. COMM. CHANNEL
NOTIFICATION
NewDocumentUploaded
{
Id:1,
DocumentId:100,
WorkspaceId:200
}
FILES

40. PEOPLE
COMM.CHANNEL
UserRegistered
{
Id: 100,
Name: ‘Domenico’,
LastName: ‘Musto’,
Email: ‘domenico.musto@gmail.com’,
Address: ‘London’,
Twitter: ‘@mimmozzo’,
Avatar: ‘http://my.huddle.net/mimmozzo/avatar’
}

41. COMM. CHANNEL
NOTIFICATION
Recipient
Id : int
Email : string

42. Eventual consistency

43. PEOPLE
COMM.CHANNEL
UserUpdated
{
Id: 100,
Email: ‘mynewemail@gmail.com’
SomeField: ‘some_value’
}
NOTIFICATION

44. COMM. CHANNEL
NOTIFICATION
RECIPIENTS

45. Messages order

46. Versioning

47. PEOPLE
COMM.CHANNEL
UserUpdated
{
Id: 100,
Email: ‘mynewemail@gmail.com’,
SomeField: ‘some_value’,
Version: 3
}
COMM. CHANNEL
NOTIFICATION
Recipient
Id : 100
Email : ‘oldmail@gmail.com’
Version: 1

48. PEOPLE
COMM.CHANNEL
UserUpdated
{
Id: 100,
Email: ‘mynewemail@gmail.com’,
SomeField: ‘some_value’,
Version: 2
}
COMM. CHANNEL
NOTIFICATION
Recipient
Id : 100
Email : ‘email@gmail.com’
Version: 3

49. Idempotency

50. Ability to replay messages

51. Events publisher

52. PEOPLE PEOPLE
EVENTS
PEOPLE EVENT
PUBLISHER
COMMUNICATION CHANNEL

53. Testing

54. Our infrastructure
• RabbitMQ
• Reactive Extensions
• JSON as message format

55. Business monitoring

56. Big picture

57. Thanks.
@mimmozzo domenico.musto@gmail.com