Re-programming the programmer, from Actors to FP

on YouTube ↗30m

" summary

A DNS management service evolves through three rewrites from event sourcing with Akka to an actor-based CQRS on DynamoDB to a functional design using FS2 + SQS. Problems that force changes are replay times for zones with millions of DNS records, Akka split‑brain and nondeterministic actors, and an unwieldy DynamoDB persistence. The final system replaces actors with pure functions, drops thousands of lines of code, reintroduces determinism, supports rate‑limiting via SQS, and achieves active‑active high availability.

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" chapters (35)

1. 0:00Intro
2. 1:17MALIGNED OBJECT ORIENTED PROGRAMMING - MOOP
3. 1:36INJECTS DEPENDENCIES
4. 2:12MOOP - LIKE TO THINK WE HAVE GOOD STRUCTURE
5. 3:24MOOP - ALL THEM DEPENDENCIES NEED MOCKING...
6. 4:57WHAT IS DNS?
7. 6:22APPROACH - SCALA +AKKA
8. 6:41DESIGN - EVENT SOURCING
9. 7:30EVENT SOURCING - COLD LOAD ENTITY
10. 8:02EVENT SOURCING - IN MEMORY STATE
11. 8:22EVENT SOURCING - AKKA PERSISTENCE
12. 8:38EVENT SOURCING - LOAD DNS ZONE
13. 8:53AKKA CLUSTER FOR HA USING GOSSIP
14. 9:49HIGH AVAILABILITY
15. 11:09NEW REQUIREMENTS
16. 11:26EVENT SOURCING CHALLENGES
17. 12:14NEW DESIGN - AKKA + CORS
18. 12:47THROTTLING
19. 13:11ACTOR EVERYTHING
20. 14:18NETWORKING ISSUES
21. 14:41OUR CLUSTER..
22. 14:59SPLIT BRAIN
23. 16:06VERSION 2 - ACTORS
24. 18:02VERSION 2 - ACTOR ISSUES
25. 18:48STATE OF AFFAIRS
26. 19:28REBUILD AGAIN
27. 19:53USE A MESSAGE QUEUE
28. 20:16USE FS2 FOR COMMAND PROCESSING
29. 20:36FS2 DECLARATIVE SYNTAX
30. 20:51REPLACE ACTORS WITH FUNCTIONS
31. 21:56QUERYING IN DYNAMODB
32. 23:11LESSONS LEARNED
33. 24:34THE LAST SLIDE
34. 27:24VERSION 3 - CHANGE DATABASE TO MYSQL
35. 30:17Sponsored by

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