One of the best features of Akka is Akka Cluster. Akka cluster allows for building distributed applications, where one application or service spans multiple nodes. From its initial release in 2013, Akka Cluster needed a node management system to manage the Akka nodes and to provide a resilient and elastic platform. With Kubernetes Akka finally has the node management system that is has been waiting for. Akka Cluster has been designed to gracefully handle nodes leaving and joining a running cluster while continuing to run. Kubernetes adds and removes nodes as needed to increase capacity or to recover from failures. In effect, there is a perfect symbiosis between Akka Cluster and Kubernetes. In this talk, we will look at and demonstrate how Akka Java Cluster and Kubernetes work together and how together they form a beautiful relationship.

1. Hugh McKee (@mckeeh3), Developer Advocate
Akka and Kubernetes:
The beginning of a beautiful relationship

2. Hugh McKee (@mckeeh3), Developer Advocate

3. Hugh McKee (@mckeeh3), Developer Advocate

4. Hugh McKee (@mckeeh3), Developer Advocate

5. The actor model in computer science is a mathematical model of
concurrent computation that treats "actors" as the universal primitives
of concurrent computation. In response to a message that it receives,
an actor can: make local decisions, create more actors, send more
messages, and determine how to respond to the next message
received. Actors may modify their own private state, but can only affect
each other through messages (avoiding the need for any locks).
Wikipedia

6. The actor model in computer science is a mathematical model of
concurrent computation that treats "actors" as the universal primitives
of concurrent computation. In response to a message that it receives,
an actor can: make local decisions, create more actors, send more
messages, and determine how to respond to the next message
received. Actors may modify their own private state, but can only affect
each other through messages (avoiding the need for any locks).
Wikipedia

7. The actor model in computer science is a mathematical model of
concurrent computation that treats "actors" as the universal primitives
of concurrent computation. In response to a message that it receives,
an actor can: make local decisions, create more actors, send more
messages, and determine how to respond to the next message
received. Actors may modify their own private state, but can only affect
each other through messages (avoiding the need for any locks).
Wikipedia

8. The actor model in computer science is a mathematical model of
concurrent computation that treats "actors" as the universal primitives
of concurrent computation. In response to a message that it receives,
an actor can: make local decisions, create more actors, send more
messages, and determine how to respond to the next message
received. Actors may modify their own private state, but can only affect
each other through messages (avoiding the need for any locks).
Wikipedia

9. The actor model in computer science is a mathematical model of
concurrent computation that treats "actors" as the universal primitives
of concurrent computation. In response to a message that it receives,
an actor can: make local decisions, create more actors, send more
messages, and determine how to respond to the next message
received. Actors may modify their own private state, but can only affect
each other through messages (avoiding the need for any locks).
Wikipedia

10. The actor model in computer science is a mathematical model of
concurrent computation that treats "actors" as the universal primitives
of concurrent computation. In response to a message that it receives,
an actor can: make local decisions, create more actors, send more
messages, and determine how to respond to the next message
received. Actors may modify their own private state, but can only affect
each other through messages (avoiding the need for any locks).
Wikipedia

11. The actor model in computer science is a mathematical model of
concurrent computation that treats "actors" as the universal primitives
of concurrent computation. In response to a message that it receives,
an actor can: make local decisions, create more actors, send more
messages, and determine how to respond to the next message
received. Actors may modify their own private state, but can only affect
each other through messages (avoiding the need for any locks).
Wikipedia

12. The actor model in computer science is a mathematical model of
concurrent computation that treats "actors" as the universal primitives
of concurrent computation. In response to a message that it receives,
an actor can: make local decisions, create more actors, send more
messages, and determine how to respond to the next message
received. Actors may modify their own private state, but can only affect
each other through messages (avoiding the need for any locks).
Wikipedia

13. The actor model in computer science is a mathematical model of
concurrent computation that treats "actors" as the universal primitives
of concurrent computation. In response to a message that it receives,
an actor can: make local decisions, create more actors, send more
messages, and determine how to respond to the next message
received. Actors may modify their own private state, but can only affect
each other through messages (avoiding the need for any locks).
Wikipedia

14. The actor model in computer science is a mathematical model of
concurrent computation that treats "actors" as the universal primitives
of concurrent computation. In response to a message that it receives,
an actor can: make local decisions, create more actors, send more
messages, and determine how to respond to the next message
received. Actors may modify their own private state, but can only affect
each other through messages (avoiding the need for any locks).
Wikipedia

15. The actor model in computer science is a mathematical model of
concurrent computation that treats "actors" as the universal primitives
of concurrent computation. In response to a message that it receives,
an actor can: make local decisions, create more actors, send more
messages, and determine how to respond to the next message
received. Actors may modify their own private state, but can only affect
each other through messages (avoiding the need for any locks).
Wikipedia

16. The actor model in computer science is a mathematical model of
concurrent computation that treats "actors" as the universal primitives
of concurrent computation. In response to a message that it receives,
an actor can: make local decisions, create more actors, send more
messages, and determine how to respond to the next message
received. Actors may modify their own private state, but can only affect
each other through messages (avoiding the need for any locks).
Wikipedia

17. Akka cluster and Kubernetes
Live demo

18. “Crop Circle”
Shows
Running Pods / JVMs

19. “Crop Circle”
Shows
Running Pods / JVMs
POD / JVM
POD / JVM
POD / JVM

20. Entity
Shard
Singleton
HTTP Server
Pod

21. Entities added as needed
Inactive entities shutdown

22. Microservice Application

23. Resilience and Scale Demo

24. The enabler of these characteristics is a Cloud-Ready Message Driven Model.
Lightbend codified these principles into the Reactive Manifesto in 2013; 24,000+ signatories around the world so far.
Responsive Resilient Elastic
React to
Users
React to
Failures
React to
Load Variance
Low latency / High
performance
Real-time / NRT
Graceful, Non-catastrophic
Recovery
Self-Healing
Responsive in the face of
changing loads
Reactive Systems

25. Java Maven K8
Project Review

26. Clustered Entity Actors

27. You
entity 64
Load Balancer
Me
entity 17
Other
entity 76

28. You
entity 64
Load Balancer
Me
entity 17
Other
entity 76

29. Clustered Entity Actors
Code Review

30. Load Balancer
Pod 1

31. Load Balancer
Pod 2Pod 1 Pod 3

32. Load Balancer
Pod 2Pod 1 Pod 3

34. Distributed Actors
Cluster Aware
Actors

35. Distributed Actors
Cluster Aware
Actors

36. Distributed Actors
Cluster Aware
Actors

37. Distributed Actors
Cluster Aware
Actors

38. Distributed Actors
Cluster Aware
Actors

39. Distributed Actors
Cluster Aware
Actors

40. Cluster Aware Actors
Code Review

41. Shard Distribution
Akka Cluster Singleton

42. Shard Distribution
Akka Cluster Singleton

43. Shard Distribution
Akka Cluster Singleton

44. Entity Distributed Sharding
Akka Cluster Sharding

45. Entity Distributed
Sharding
Akka Cluster Sharding

46. Event Sourcing & CQRS
Akka Persistence & Persistence Query

47. Event Sourcing & CQRS
Akka Persistence &
Persistence Query

48. User ID Time Event
You 64 08:11 Add Item 1567
Me 17 08:15 Add Item 3254
Other 76 08:16 Add Item 8359
You 64 08:20 Add Item 2632
Me 17 08:20 Add Item 4983
Other 76 08:24 Change Item 8359
You 64 08:25 Remove Item 1567
You 64 08:26 Add shipping address
Other 76 08:30 Add Item 2438
Me 17 08:33 Add shipping address
Me 17 08:33 Add billing address
You 64 08:35 Add billing address
Event Sourcing & CQRS

49. You
entity 64
Load Balancer
Me
entity 17
Other
entity 76

50. Akka Reactive Systems and Kubernetes
Responsive Resilient Elastic
React to
Users
React to
Failures
React to
Load Variance
Low latency / High
performance
Real-time / NRT
Graceful, Non-catastrophic
Recovery
Self-Healing
Responsive in the face of
changing loads
a beautiful relationship

51. /akka-java-cluster-openshift
/akka-java-cluster.git
/akka-java-cluster-aware.git
/akka-java-cluster-singleton.git
/akka-java-cluster-sharding.git
/akka-java-cluster-persistence.git
/akka-java-cluster-persistence-query.git
https://github.com/mckeeh3…

52. Upgrade your grey matter!
Get the free O’Reilly book by Hugh McKee,
Developer Advocate at Lightbend
https://www.lightbend.com/ebooks

53. Hugh McKee (@mckeeh3), Developer Advocate
hugh.mckee@lightbend.com
Akka and Kubernetes:
The beginning of a beautiful relationship