SE-Radio Episode 252: Christopher Meiklejohn on CRDTs

Use Cases

CRDTs, or conflict-free replicated data types, have found successful applications across various domains. Christopher Meiklejohn highlights their use in the React distributed database by Basho, which supports CRDTs like counters, sets, and dictionaries, enabling high availability in systems like Bet365's gambling platform and Riot Games' chat functionality for League of Legends 1. These systems benefit from CRDTs' ability to handle concurrent modifications without conflicts, ensuring seamless user experiences. Meiklejohn also notes that SoundCloud uses CRDTs for modeling timelines, while Rovio Entertainment employs them in leaderboards and advertisement counters 2.

It's great to know that Angry Birds is driving innovation in database technology.

--- Robert Blumen

CRDTs are particularly effective in scenarios requiring high availability, such as Amazon's shopping cart, where they mitigate latency issues and prevent abandoned purchases 3.

   

Challenges

Implementing CRDTs presents significant technical challenges, particularly in ensuring correct data resolution and handling network failures. Christopher Meiklejohn explains that CRDTs require careful design to avoid anomalies, such as items reappearing in shopping carts due to asynchronous propagation 4. Debugging these complex structures often involves advanced techniques like model checking and formal verification to ensure reliability. Despite these challenges, CRDTs offer a promising approach to building eventually consistent applications.

Implementing these things is really hard.

--- Christopher Meiklejohn

Programming with CRDTs remains difficult, as developers seek effective ways to compose them into larger applications. Meiklejohn is involved in research to develop programming abstractions that support CRDTs at the language level, aiming to simplify their integration into software systems 5.