Former Apple employee here. They’ve been using it extensively in production for years. Pretty much all of CloudKit is run using FDB for storage.

Public source for that info, so I don’t get accused of NDA violations - https://youtu.be/HLE8chgw6LI

Timestamp 14:15 touches on CloudKit’s extensive FDB usage.

Nobody here is going to accuse you of violating your NDA :P

I might, but it's mostly because you said that I wouldn't

One of PingCap's (company behind TiKV and TiDB) founders once did his own FoundationDB review [1] - he concluded: "the performance is cool". I'm assuming at that time FDB's performance was superior to TiKV.

[1] https://medium.com/@siddontang/benchmark-foundationdb-with-g...

Disclaimer: I work for PingCAP. That benchmark didn't compare to TiKV. We generally avoid making such comparisions not because our competitors are better but because we know we will always have difficulty fairly benchmarking. Instead we generally do what is shown in that blog post: note in what aspect of a banchmark other databases are showing strength: because that indicates an opportunity to learn.

We don't view ourselves in competition with FoundationDB because most TiKV users want the ability to use TiDB with TiKV for SQL (and MySQL compatibility). If you know you don't ever need that then FDB can be a good choice (but TiKV can be as well).

I've only ever tinkered with tikv, but one advantage that it currently has over fdb is its support of co-processors --the ability for each node in the cluster to run some piece of query logic locally on its own shard of data instead of having all of the data shipped to one node (or even all the way up to the application level) for processing, which is quite bandwidth intensive.

We do, and while I love it, a word of warning: do not allow production FDB clusters to have any member get above 90% storage consumed.