Company
Date Published
Author
Russell Brown
Word count
2414
Language
English
Hacker News points
None

Summary

Ditto's Delta State CRDTs provide an efficient approach to data synchronization in ad hoc mesh networks by utilizing state-based Conflict-free Replicated Data Types (CRDTs) that support concurrent updates without requiring a central server or predefined set of peers. Unlike operation-based CRDTs, which necessitate exact message delivery and impose significant channel constraints, state-based CRDTs only require that all data eventually reaches all peers, allowing for flexible, asynchronous communication. Ditto's system employs version vectors to maintain causal consistency across documents, ensuring that changes made to data are coherently integrated regardless of the order of receipt. The innovative use of diffs allows for the transmission of minimal state changes, reducing the need for extensive buffering and making the system more adaptable to devices with varying storage capacities. This approach is particularly beneficial for peer-to-peer applications, as it ensures data convergence and consistency even when peers are intermittently connected. Additionally, Ditto's replication protocol supports efficient diff generation and merging by leveraging CRDT Maps' tree structures, with tombstones used to manage the deletion of properties, thereby maintaining the integrity and consistency of the distributed database.