Presented by Bernd Rücker, Co-Founder of Camunda With microservices (or serverless functions) whole architectures are cut into smaller pieces that are ideally loosely coupled. In this talk I will discuss what this means for business processes that typically span more than one microservice. I will tackle questions like: How can we ensure visibility of cross-microservice flows and provide status and error monitoring? How do we guarantee that overall flows always complete, even if single services fail? How can do this without introducing tight coupling or harming service autonomy? What does this mean for your architecture and the role of workflow automation technology within it?

1. @berndruecker
The Role of Workflows
in Microservices

2. Microservices…
Service
B
Some
Service
Some
Service Some
Service
Service
C
Service
A
Service
D
Monolith
Functionality
A
Functionality
B
Functionality
C
Functionality
D

3. Some
Service
Some
Service
Some
Service
Some
Service
Some
Service
Some
Service
Some
Service
Microservices…

4. Data, data, data, …
Source: Microservices orchestration survey,
July 2018, 354 responses

5. 92 %

6. Why?

7. Photo by born1945, available under Creative Commons BY 2.0 license.

8. How to get something out of it?
Photo by pxhere, available under Creative Commons CC0 1.0 License.

10. Sample architecture: De-coupled services with event backbone
Checkout Inventory
Payment Shipment
e.g. Kafka, …

11. Sample
Checkout
Payment
Inventory
Shipment
Order
Placed
Payment
Received
Goods
Fetched

12. Peer-to-peer communication
Checkout
Payment
Inventory
Shipment

13. The danger is that it's very easy to make
nicely decoupled systems with event
notification, without realizing that you're
losing sight of that larger-scale flow, and
thus set yourself up for trouble in future
years.
https://martinfowler.com/articles/201701-event-driven.html

14. The danger is that it's very easy to make
nicely decoupled systems with event
notification, without realizing that you're
losing sight of that larger-scale flow, and
thus set yourself up for trouble in future
years.
https://martinfowler.com/articles/201701-event-driven.html

15. The danger is that it's very easy to make
nicely decoupled systems with event
notification, without realizing that you're
losing sight of that larger-scale flow, and
thus set yourself up for trouble in future
years.
https://martinfowler.com/articles/201701-event-driven.html

16. Challenges?

17. What we wanted
Photo by Lijian Zhang, available under Creative Commons SA 2.0 License and Pedobear19 / CC BY-SA 4.0

18. Microservice pioneers
have become aware

19. Workflow automation | orchestration
is an essential building block
in microservice architectures
Of course I am opinioated – but I truly believe this!

20. Workflow automation | orchestration
is an essential building block
in microservice architectures
Of course I am opinioated – but I truly believe this!
Orchestration is not a central thing!
„It is not BPEL“

21. Finding the right balance
22
Observe Microservice Paradigms
● Loose Coupling
● Autonomy
● Event Collaboration
Ensure Flow Manageability
• End-To-End Visibility
• Meet Business Process SLA
• Support Continuous Process
Improvement

22. Different levels of leveraging workflow automation
Manage
the flow
Track
the flow
Non-invasive to event-driven-architecture
Additionally to choreography
Limited in power
Needs to be incorporated
Mixture of choreography and orchestration
Leverage full potential

23. Tracking
Checkout Inventory
Payment Shipment
Kafka
Workflow
Engine

24. Tracking + BI
Checkout Inventory
Payment Shipment
Kafka
Workflow
Engine
Camunda
Optimize
Other reporting
/ BI solutions

25. Tracking + BI
Checkout Inventory
Payment Shipment
Kafka
Workflow
Engine
Camunda
Optimize
Other reporting
/ BIO solutions

26. Tracking + BI
Checkout Inventory
Payment Shipment
Kafka
Workflow
Engine
Camunda
Optimize
Other reporting
/ BI solutions
This is totally non-invasive
But also limited in power

27. Start acting upon certain events

28. Why so shy?
Photo by LuidmilaKot, available under Creative Commons CC0 1.0 License.

29. Changing the flow
Checkout
Payment
Inventory
Shipment
Fetch the goods
before the
payment

30. Changing the flow
Checkout
Payment
Inventory
Shipment
Fetch the goods
before the
payment

31. Photo by born1945, available under Creative Commons BY 2.0 license.

32. Order
Checkout
Payment
Inventory
Shipment
Important responsibilities need a home

33. Order
Checkout
Payment
Inventory
Shipment

34. Distributed systems

35. Distributed systems

36. Distributed systems

37. Order
Checkout
Payment
Inventory
Shipment
Stateful orchestration
This orchestration
requires state

38. BPMN supports integration use cases
Aggregator
Re-Sequencer
Combined with timeouts:
Zeebe supports Message TTL

39. BPMN supports integration use cases
Compensation

40. Order
Checkout
Payment
Inventory
Shipment
Every service owns its workflow!

41. Central workflow engine or …
Checkout Inventory
Payment Shipment
Workflow
Engine
Order
Owned heredeployed here
Owned here

42. …decentral workflow engine
Checkout Inventory
Payment Shipment
Workflow
Engine
OrderWorkflow
Engine

43. Same architecture with REST
Checkout Inventory
Payment Shipment
Workflow
Engine
Order
Workflow
Engine

44. Challenge Monitoring
Checkout Inventory
Payment Shipment
Workflow
Engine
Order
Workflow
Engine
Monitor
e.g.
Elastic
Links back
Optimize

45. Same architecture with REST
Checkout Inventory
Payment Shipment
Workflow
Engine
Order
Workflow
Engine

46. Work distribution via workflow engine
Checkout Inventory
Payment Shipment Order
Workflow Engine
Start Workflow
Owns workflow
definition
External Task Worker

47. Hybrid architectures
Order
Credit
Card
Customer
Credit
Payment
Pub/Sub
e.g. Message Bus
Pub/Sub
Work Distribution
e.g. External Task
Request/Response
e.g. REST

48. Recap
• Microservices have its merits
• You need to balance orchestration and chorography
• Distributed systems need stateful orchestration
• Visibility is essential to survive
• Track, monitor or manage the flow – depending on your scenario
• Workflow automation is an essential building block,
make sure to use BPMN

49. 1
4
5
Continuous Process Improvement
Technical Workflow Implementation
Operating mission-critical Processes
Broad-scale Adoption of Automation
Automated Enterprise
Adoption Journey
Value
Time / Invest
1
2
3
4
5
2
3

50. Microservices
Certified
Microservices
Certified

51. Love to see code?

52. Thank you!

53. bernd.ruecker@camunda.com
@berndruecker
https://berndruecker.io
https://medium.com/berndruecker
https://github.com/berndruecker
https://www.infoq.com/articles/events-
workflow-automation
Contact:
Slides:
Blog:
Code:
https://www.infoworld.com/article/3254777/
application-development/
3-common-pitfalls-of-microservices-
integrationand-how-to-avoid-them.html
https://thenewstack.io/5-workflow-automation-
use-cases-you-might-not-have-considered/