There is an ever increasing importance to have responsive Enterprise Applications with low latency. With the increased usage of Distributed Systems architecture, it is more challenging to achieve this. In this talk, we explore how the Actor Model can help in addressing these modern challenges.

1. Caching Entities using Actors
in a Distributed System
Aldrin Seychell
Technical Architect
@aseychell

2. GDG Malta Meetup
Group
https://www.meetup.com/GDGMalta/

3. Enterprise
Applications
@aseychell

6. Actors = Threads
Lightweight Processes

11. Akka
● Actor Model on the
JVM
● Abstract scheduling of actors
● Abstract details of message-passing
● Location transparency through ActorRef
● Elasticity of Java applications
● Remote Actors
● Fault tolerance with exceptions
@aseychell

12. Actor
Hierarchy
https://petabridge.com/
blog/how-actors-recover
-from-failure-hierarchy-a
nd-supervision/
@aseychell

13. Supervision
https://petabridge.co
m/blog/how-actors-re
cover-from-failure-hier
archy-and-supervision
@aseychell

14. Virtual Card 1 Virtual Card 2
Virtual Card 3
Router
Take €10 VC1
Take €25 VC1
Take €15 VC2
Put €50 VC3

15. Entity exists on only ONE node

16. Sharding Entities Sharding
Function

17. Shards place an upper-bound
on the load-balancing problem

20. Tuning
Parameters
- Number of shards
- Sharding Function
- Load Balancing
- Recreating Actors on new nodes
- Remember-Entities?
- Resolving Split-Brain Situations
@aseychell

21. Google
Protocol
Buffers
(aka Protobuf)
“Protocol buffers are a language-neutral,
platform-neutral, extensible mechanism for
serializing structured data.”
https://developers.google.com/protocol-buffers/
message Counter {
int64 id = 1;
int64 value = 2;
}
message CounterOp {
enum Type {
INCREMENT = 0;
DECREMENT = 1;
}
int64 id = 1;
Type type = 2;
}
10101111010101011...
@aseychell

22. Demo - Sharding Counters
https://github.com/aseychell/demo-akka-clustersharding
@aseychell

23. Counter 1 Counter 2
Counter 3
Router
INCREMENT 1
INCREMENT 1
DECREMENT 2
GET 1
GET 2
GET 3

24. Thank you!
@aseychell