Implementation and usage of Paxos vs Raft in Scylla

ScyllaDB
1

Recently i completed Data modeling course from Scylla University and learned that Initial decision was to use RAFT in scylla and later Paxos protocol was used.

I saw a latest update in scylla open source 6.0 that scylla uses RAFt in its new Tablet based architecture.
while i am not a Database expert, but I am trying to seek clarity and understand if these protocols have different use case in Scylla or Paxos has been replaced with RAFT.

Any insights would be helpful to get clarity.

Thanks.

2

Paxos is used to implement LWT queries in ScyllaDB.
RAFT is used to implement strongly consistent metadata storage: so far this includes schema, topology, tablets metadata and some other internal system tables.
Going forward we will use RAFT for more and more things, one day perhaps we will have a RAFT-based LWT implementation too.

2 Likes
3

Thank you for the clarification.