Everybody wants to copy Google apparently; there are a variety of Spanner or Percolator clones although some of them do not meet the original guarantees of their reference systems.

FoundationDB also forged its own path and is worth studying.

This is such a niche subcategory of distributed databases [1], that it's a miracle even a few of them exist and you want more implementations. Intuitively distributed systems try to avoid consensus/coordination, as doing those things over public internet is not that useful.

[1] https://trends.google.com/trends/explore?date=2016-09-20%202... compare that to some other distributed database https://trends.google.com/trends/explore?date=2016-09-20%202...

The property that attracts the most mission critical use cases is the ability to keep transactions rolling without loss of guarantees, even while hitting the typical cloud failure modes. Some applications can't make tradeoffs between correctness and global availability, for them FaunaDB's mainframe-like capabilities are key.

For the average application, the benefit is that you don't need to write code to address database drift / eventual consistency. I expect Fauna-like systems to gain popularity as more developers come to expect cloud-native solutions to offer global ACID transactions.

Well, I don't expect distributed ACID transactions to ever become a thing developers expect. I see people try them, but leave unhappy because of the unexpectedly bad latency and performance. Hence the lack of growth in trends.

Furthermore, eventual consistency was never problematic, it was just a myth. It was never hard, certainly not harder than ACID transactions in all those MVCC systems. So not much to benefit from for an average application. And today with all the research in strong eventual consistency applications can have all that correctness without coordination and without sacrificing performance, latency and availability. This is where the opportunity for distributed databases still exists, performance and latency are sellable.

There's a few other research projects based on the same concept of a distributed log and an explicit sequencer such as Corfu: https://github.com/CorfuDB/CorfuDB

As far as why it's not more prevalent, all of this research is work from the last decade or less, and it takes a long time to develop a database ready for production use.