Anyone use Cayley in prod? An old job used Neo4j, and the graph concept was great for specific use cases. As a lightweight graph store, Cayley was really exciting when it came out, but I haven't had a need for it since I left that job. It strikes me as really well made, and I'd love to hear any war stories.
Tried to use it in production a couple of years ago hosting a mirror copy of Freebase with mixed results:
- There were a couple of issue loading the data that we fixed and contributed back the patch
- Loading the data was really slow, and it got slower every time a new entry was added (Loading the full freebase dump required 1 week on a very beefy machine with SSD. Used LevelDB)
- Then the queries were relatively slow. Without going too much into details, we were using the data to analyze texts and extract entities, and the relationship between them, and even parallelizing the queries, they were relatively slow (depending on complexity between 0.1 and 1 sec on average). We solved the issue implementing a robust caching layer in front of it and carefully planning the queries.
- In general, it was stable and performant enough for a backend service. But we were pushing really the envelope of what it could do.
All in all, I would say that I was happy with it. In comparison, I tried a year earlier to use Neo4J in a similar role and I give up after 2 weeks because I wasn't even able to get it loading part of the dataset without crashing on a similar hardware.
What's the best way to load Freebase in 2017? Cayley with Postgres storage? Or some other RDF/graph DB? Or ElasticSearch? Or dump it in Postgres/MySQL? I am not interested in complex queries, but simple queries that execute reasonable fast.
(Dgraph author) That's a good point. I think I'll load one instance up with the entire Freebase data, run it on freebase.dgraph.io, and blog about how and whys etc. Expect that in the next couple of weeks.
Dgraph follows MongoDB licensing. The clients are all in Apache, and the server code is AGPL. This doesn't affect anyone using Dgraph for commercial purposes; but if they make changes to the server code, they'll have to release them under AGPL. Blog post here: https://open.dgraph.io/post/licensing/
