Status of ORSeq datatype

[jrfaller]

Hi Carlos!

We are experimenting around the topic of real-time collaborative editors, and I remarked that I only saw existing solutions based upon operation-CRDTs. I came across your amazing articles about delta-state CRDTs (notably Efficient Synchronization of State-Based CRDTs), and I was wondering whether or not it could be a good candidate to implement a real-time collaborative editor. By looking more closely in the various articles, I don't have the impression that you define somewhere a delta-based sequence CRDT. However, in this repository the ORSeq CRDT seems to be the one I have been looking for.

Could you tell me if it's only a prototype or a "stable" implementation. Additionally, do you have some write up about how it works besides the code? Also, if you have already tried something in the same vein, I would be very glad to have your input on the subject 😄

Cheers!

[CBaquero]

Sorry, for the 2-year delay, better late than never.

I made some initial code towards an editable sequence, but it was incorrect and not easy to fix, so it was stopped.
I might come back to this in the future, but nowadays the state of the art is probably in projects like https://automerge.org

Regards,

[jrfaller]

Hi @CBaquero and thanks for the answer! Thanks for pointing out automerge even though it's not clear in their doc if they use operation-based or state-based CRDTs 😄

I hope that you'll find the time to have a second try at this because I really think that a state-based sequence could really ease the development of collaborative editors.

Cheers!

[aep]

Hi i'm from the future, currently binging on CRDT academia.

I think Automerge is directly based on Klepmanns "A Conflict-Free Replicated JSON Datatype".
The current (2024) state of the art is "Extending JSON CRDTs with Move Operations" by Kleppmann.

Bit sad to see @CBaquero not continue the research because that paper was exceptionally good, and lots of the ideas are missing in Kleppmanns series. Notably automerge keeps a full history with tombstones which seems to work fine for its intended use case (collaborative editors) but would be pretty bad in a generic database.

A more direct follow up would be "DSON: JSON CRDT Using Delta-Mutations For Document Stores" from Rinberg et all. code is right here: https://github.com/crdt-ibm-research/json-delta-crdt .

[jrfaller]

Thanks a lot very nice to see that there have been a lot of progress on this topic! Will check this out!