11–20 of 89 posts
Here's a video from J On The Beach this year on the details around the Just-Right Consistency approach that might help answer some questions: https://www.youtube.com/watch?v=Vd2I9v3pYpA
Looking forward to Kyle Kingsbury’s Jepsen review.
Jepsen goes into detail about general CRDTs here: https://aphyr.com/posts/285-jepsen-riak
Member of the SyncFree Consortium (and committer to Antidote) here. Here's a video from J On The Beach this year on the details around the Just-Right Consistency approach that might help answer some questions: https://www.youtube.com/watch?v=Vd2I9v3pYpA
Lasp (previously on HN):
https://news.ycombinator.com/item?id=14300763
https://news.ycombinator.com/item?id=15444156
SyncFree project review results:
http://cordis.europa.eu/result/rcn/197514_en.html
Legion:
https://syncfree.lip6.fr/index.php/2-uncategorised/54-legion
SyncFree homepage:
The video lists pros/cons for strongly consistent and eventually consistent databases, but only has pros for a "just right consistency" database. What are the cons?
Your application works as well as if it was executed fully in strong consistency, but with improved scalability for the set of operations that can execute in an eventual consistent model.
Earlier quoted context omitted.
Jepsen goes into detail about general CRDTs here: https://aphyr.com/posts/285-jepsen-riak
Yes, but devil's in the details. The fact CRDTs are provably able to have specific consistency guarantees doesn't mean a particular implementation does it correctly in all contexts. Without testing, "We built this (city) on CRDTs" isn't very useful.
If you look at the Jepsen posts for Cassandra and Riak, for example, you can see that the general characteristics are fairly similar.
- Built in Erlang
- Great explainer videos
- Well documented CRDTs that you accept
- Team of university related researches in CRDTs.
I'll be looking through your guys stuff more. But good job! We need more people like you guys out there.
The video lists pros/cons for strongly consistent and eventually consistent databases, but only has pros for a "just right consistency" database. What are the cons?
The idea of the "just right consistency" is that it brings the best of both worlds, without any drawbacks. Your application works as well as if it was executed fully in strong consistency, but with improved scalability for the set of operations that can execute in an eventual consistent model. https://www.youtube.com/watch?v=HJjWqNDh-GA
This has that "too good to be true" vibe, and I can't find much information on the authors or the Syncfree Consortium organization that backs the project besides their own website. Is this at the cost of fast writes or flexible schema? The pitch video doesn't seem to mention any cons, yet seems to avoid mentioning the type of data or mutations supported. I guess I'll go read their publications.
It's at the cost of playing by the rules of CRDTs. Making CRDTs consequence-free is ongoing research.
Earlier quoted context omitted.
The idea of the "just right consistency" is that it brings the best of both worlds, without any drawbacks. Your application works as well as if it was executed fully in strong consistency, but with improved scalability for the set of operations that can execute in an eventual consistent model. https://www.youtube.com/watch?v=HJjWqNDh-GA
The biggest drawback is that only some operations can be supported. E.g., without strong consistency you can detect double-spending from an account but you can't prevent it, because the validity of an operation can't depend on operations a datacenter hasn't seen.
Earlier quoted context omitted.
Jepsen goes into detail about general CRDTs here: https://aphyr.com/posts/285-jepsen-riak
Yes, but devil's in the details. The fact CRDTs are provably able to have specific consistency guarantees doesn't mean a particular implementation does it correctly in all contexts. Without testing, "We built this (city) on CRDTs" isn't very useful.
No one's arguing that a Jepsen test shouldn't be done. Just that it'll probably be very different in character from more invented industry technology.