I evaluated it for a project last year, but decided not to use it. One reason was that at the time, the project seemed to have been abandoned; the author did not respond to issues or pull requests. Another was that based on Google searches, there seemed to be no one else actually using it in production; so even considering getting the commercial ACID support seemed like a big gamble, never mind that I couldn't find any info on how it performed in large clusters, and so on.
That said, it seemed technically brilliant, and fast.
If Escriva can accomplish the same thing with Consus, in a fully open source way, and gain traction enough to keep the project alive, I could see this as something I would consider using. That said, I'm wary of anyone who just abandons projects like that, without telling anyone about it.
Totally agree. I feel like there's a big void in the open-source world for this type of technology that has yet to be filled. There used to be FoundationDB and, well, we all know what happened there. CockroachDB is probably the only other active, open-source project right now that claims to have strong ACID guarantees for multi-database transactions. However, the team is not wholly focused on performance at this stage of development (which some of their early benchmarks demonstrate).
If Consus can retain some of the performance characteristics of Hyperdex while providing completely open source distributed transactions, it will be an absolute game changer.
Consus is a lexicographically sorted key-value store.
Where you will hit performance bottlenecks is when your query planner/executer makes traditional assumptions about performance that do not hold across machines.
A good SQL implementation on top of a kvs should not force you to accommodate it any more than your current "normal" databases subconsciously train you to accommodate your disks (hint: they do).