The document discusses the Akka toolkit, focusing on Akka Streams and Akka HTTP, emphasizing their capabilities for building concurrent and distributed applications. It highlights key features such as actors, message passing, flow transformations, and the importance of back-pressure in streaming operations. The document also includes practical examples like streaming earthquake events via WebSocket, demonstrating data transformation and flow composition.

1. Akka-streams & Akka-http
Pierangelo Cecchetto
Java/Scala developer @
@pierangelocecc
https://github.com/pierangeloc

2. Akka-streams & Akka-http
- Akka
- Akka-streams
- Akka-http
- Examples and code

3. Akka
Akka 101
● Toolkit to build concurrent apps
● “ “ “ distributed “
● Actors can be created/disposed at will
● Small memory footprint
● Hierarchical failure / supervision management
supervises

4. Akka
● Actors’ mailbox can be unbounded or bounded but dropping
● Actors interaction: can be complex
● Message passing === messages flow
● Messages are handled in an untyped fashion*
* This is being addressed with Typed Actors
Akka

5. Akka-Streams:
- Sequence of ephemeral elements
- Possibly unbounded
- Can be transformed/mapped
- Immutable, reusable, shareable
- Use bounded buffers
- Compose to build complex streams
- Explicit materialization of a blueprint
Akka-streams

6. Akka-streams
Akka-streams foundations / 1
Actors based
Synthesized by actors

7. Akka-streams
Tools of the trade

8. Akka-streams
Flow Transformations
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9. Flow Transformations
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Flow Composition
- Graph builder
- Fan in
- , ,
- Fan out
- ,
Akka-streams

10. Akka-streams
Basic composition

11. Akka-streams
Materialization: Simple example

12. Akka-streams
Materialization: Simple example
Concisely:

13. Akka-http
- Streams: back-pressure & buffers

14. Akka-http
- Streams: back-pressure & buffers
- TCP: back-pressure & buffers

15. Akka-http
- Streams: back-pressure & buffers
- TCP: back-pressure & buffers
- Streams everywhere:

16. Akka-http
- Streams: back-pressure & buffers
- TCP: back-pressure & buffers
- Streams everywhere:

17. Akka-http
- Streams: back-pressure & buffers
- TCP: back-pressure & buffers
- Streams everywhere:
Think in Streams!

18. Akka-http
Routing

19. Akka-http
Routing Serving

20. Akka-http
Thinking in Streams
example: Stream earthquakes events on a websocket

21. Earthquakes replay
Earthquakes stream
websocket

22. Earthquakes replay
Earthquakes stream
websocket

23. Earthquakes replay
- Data transformation

24. Earthquakes replay
- Data transformation

25. Earthquakes replay
- Data transformation

26. Earthquakes replay
- Data transformation
- Rate transformation