Raft - Consensus Algorithm to evereone

Raft talk given at Gophercon Brazil 2016

Transcript

1. Raft @luizbafilho consensus algorithm to everyone
2. Consensus
3. Replicated Log
4. Raft consensus algorithm for managing a replicated log
5. Raft Understandable Complete foundation for implementation Easy to implement
6. Where?
7. Example Server DB DB DB
8. Open-source projects using it Raft
9. Raft Server Consensus Module State Machine x: 3 y: 9 z: 0 Server Log x = 3 y = 1 y = 9 ...
10. Raft Term Timeline Term 1 Term 2 Term 3 Term 4 Election Normal Operation No leader Timeline
11. Raft Messages RequestVotes Term Candidate Id Last Log Index Last Log Term AppendEntries Term Entries Previous Log Index Previous Log Term
12. Leader Election Safety Log Replication
13. Leader Election
14. Follower Candidate Leader starts up times out, starts election times out, new election receives votes from majority of servers discovers current leader or new term discovers server with higher term Leader Election
15. Raft Scope Source: https://raft.github.io/raftscope-replay/index.html
16. Raft Scope Source: https://raft.github.io/raftscope-replay/index.html
17. Raft Scope - Leader Stop Source: https://raft.github.io/raftscope-replay/index.html
18. Raft Scope - Leader Stop Source: https://raft.github.io/raftscope-replay/index.html
19. Raft Scope - Split Votes Source: https://raft.github.io/raftscope-replay/index.html
20. Raft Scope - Split Votes Source: https://raft.github.io/raftscope-replay/index.html
21. Log Replication
22. Client Consensus Module State Machine Server Log Consensus Module State Machine Server Log Consensus Module State Machine Server Log Leader Follower Follower
23. Source: http://bit.ly/2fyk4K5 Log Replication - Happy Path Leader Follower Follower
24. Source: http://bit.ly/2fyk4K5 Log Replication Leader Follower Follower
25. Source: http://bit.ly/2fyk4K5 Log Replication Leader Follower Follower
26. Source: http://bit.ly/2fyk4K5 Log Replication - Network Partition Leader Follower Follower
27. Source: http://bit.ly/2fyk4K5 Log Replication - Network Partition Leader Follower Leader
28. Source: http://bit.ly/2fyk4K5 Log Replication - Network Partition Leader Follower Leader
29. Source: http://bit.ly/2fyk4K5 Log Replication - Network Partition Follower Follower Leader
30. Safety
31. Leader Completeness 1 1 1 2 2 3 3 3 1 1 1 2 2 3 3 1 1 1 2 2 3 3 3 3 1 1 1 2 2 3 3 3 1 1 1 2 2 2 2 2 S1 S2 S3 S4 S5 1 2 3 4 5 6 7 8 9 RequestVotes Term Candidate Id Last Log Index Last Log Term
32. Log Compaction
33. Obrigado! Estamos Contratando! https://talentos.globo.com
34. References • https://raft.github.io/raft.pdf • https://raft.github.io/slides/uiuc2016.pdf • https://raft.github.io/slides/buildstuff2015.pdf • https://speakerdeck.com/vanstee/raft-consensus-for-rubyists • https://raft.github.io/raftscope/index.html