Leaderless Database Replication

Let’s talk about leaderless database replication where all nodes are peer nodes and can accept both read and write requests.

We contrast this architecture to the leader follower model. We look at both write and read paths and talk about the tradeoffs you need to make when it comes to availability and consistency.

0:00 Intro
00:50 Leaderless Database Features
03:15 Writes
07:25 Reads
11:30 Stale Data
12:30 Read Repair
13:50 Background Process
14:30 Tradeoff
17:08 Database Examples
17:30 Outro & References

#systemDesign #database

[RS-vuum]

Your Videos with Block Diagrams are excellent. Very Clear and Crisp explanation. Keep up your great work

[LuluHou]

thanks a lot! another great video! i have some confusion about data version based staleness judgement though. suppose we have two replicas, the first write was sucessful on replica one, the second write was successful one replice two. then we have both replicas with the same version, but different data. i suppose this could be fixed by process you mentioned to deal with read staleness, but i suppose it wont be real time, so wont exactly fix the issue. another possibility, we could compare with other replicas when we write, but it beats the idea of leaderless and writing to replicas independantly. so i dont know the fix.

[석상주]

Even if the client reads data from X nodes and returns the latest data, that data may not be the latest because you only need X acknowledgements. By chance, all X replica nodes may not have the latest data. But your data will be eventually consistent after sufficient number of reads.

[flashliqu]

Good content and explanation, one minor suggestion, remove the background music :D