I think at one point the employees of Basho knew how to write distributed DBs - Riak is the most advanced AP DB from a distributed systems theory perspective. However, in recent months, their CEO, CTO and Chief Architect have left, as well as many of their prominent engineers. Worryingly, the new CTO seems content to make inane comments about "Data Gravity" [0].
I think Riak's theory is fine, but theory isn't enough. And they may have succumbed to the Osborne effect with Riak 2.0.
Here's what I mean. Think of all the nice things you expect to come out of Riak's theoretical basis -- bulletproof distributed writes, for example.
Well, the default last-write-wins writes aren't bulletproof. They clearly fail Jepsen [1]. And if you turned off last-write-wins, then you'd have to handle siblings -- and how you were supposed to handle them without introducing inconsistency was quite unspecified. Riak clients gave you no help there.
Or, as the Jepsen article says, you could use CRDTs. Before 2.0, Riak had exactly one CRDT, the counter.
Something that might be appealing to some is built-in MapReduce. On the forums, people would warn you not to actually use it unless you didn't actually want availability after all. I don't know if they ever sorted that out.
Another supposedly nice thing was Riak Search. A distributed DB with full-text search out of the box -- that sounds great, right? But there were two things called Riak Search, and the first one just plain didn't work. They deprecated it before it had a replacement, but the replacement was supposed to come in 2.0.
So, Osborne effect. When people gradually discovered that Riak 1.x was bad, and the response was "but Riak 2.0 will be great!", that's a great reason not to use 1.x. 2.0 took a very, very long time, enough time for customers and potential customers, including us, to find other solutions.
So it looks like the conflict resolution strategies being recommended are "pick one arbitrarily", or in an advanced section, "keep the longer list"?
Not that it matters to me anymore, but it does sound like having all data in CRDTs is the only way to pass Jepsen. (Or to have your data be immutable, in which case Jepsen doesn't apply.)
Indeed. We're evaluating Riak CS and Swift. In a vacuum, I'd choose Riak CS any day. Knowing all of the drama at Basho, we're in a holding pattern at best and leaning (reluctantly) towards Swift.
Basho needs to sell damn fast or just call it a day and open source the enterprise version.
[0] - http://www.kdnuggets.com/2015/03/interview-dave-mccrory-bash...