A Brief History of Backend. Ancient hipsters. The Reactive Manifesto introduction. Akka + Scala command-line chat example implementation. https://github.com/vladimir-malyk/akka-command-line-chat

1. Reactive programming
Akka + Scala
vladimir.malyk@gmail.com

2. Backend
Cooperative access:
- data
- computing power

3. Welcome to 1970s
Computing power
and the first hipsters
Teletype Model 33 Terminal
DEC PDP-11

4. 1980s – Mainframe era
Computing power share
Cooperative data access

5. 1980s – Mainframe era
Computing power share
Cooperative data access

6. Mainframe crisis
Computing power share is no longer needed

7. Backend era
Cooperative data access

8. Cooperative data access
web-sites, social networks, online games

9. Cooperative data access
from 6 to 1366 millions
228 times growth by 10 years

10. Cooperative data access

11. Cooperative data access
Reactive programming.
Programming paradigm
oriented around data flows
and the propagation of change.
Execution model
will automatically propagate changes
through the data flow.

13. Message Driven
Reactive:
– data is represented by a message flow
– autonomous message handlers
– async non-blocking message handling
Traditionally:
– data is a mutable shared-state
– locks
– synchronization

14. Responsive
Reactive:
– non-blocking async results delivery
Traditionally:
– blocking synchronous results delivery

15. Resilient
Reactive:
– system is highly available even if some handlers has
crashed
– handlers (new or recovered) and dataflows could be
added without downtime
Traditionally:
– application falls entirely
– maintenance downtime

16. Elastic
Reactive:
– event handlers are distributed over multiple
threads/processes/hosts
– message flow between threads/hosts
– scale out by nature
Traditionally:
– heavy-logic threads
– scale up shared-data

17. Reactive tools

18. Actors

19. Cluster
Netty, GoogleProtobuf,
At-Least-One-Delivery, Vector Clock,
CQRS + Event-Sourcing

20. Back to the past with reactive thrust
Welcome to 1980s telnet
https://github.com/vladimir-malyk/akka-command-line-chat

21. Ask your questions!
https://github.com/vladimir-malyk/akka-command-line-chat