Great talk! Looking at Riak vs MongoDB right now for a production system in fact. The data isn't K/V though and we need rich queries so I'm not sure what our solution will be unfortunately.
Agreed, start with a known entity. Take the one special table that is killing you and move it to a special database (Riak/Cassandra etc) suited for that task only once you understand exactly what you need.
I find it a better course of action to work on properly understanding your data problem and then evaluate the options available instead of just sticking with the stand-by solution ("Well, we've always done x!").
Just like with anything in technology ... there is going to be pain as you escalate the level of complexity and what you are trying to accomplish.
I disagree, based on experience. On the surface, MongoDB did solve our data problem, and we thought we sufficiently researched the technology that it would work, even attending multiple MongoDB conferences and talking to 10gen employees.
The issue was that underlying architectural decisions in MongoDB ended up biting us and limiting us rather significantly. It could be argued that this is because MongoDB is a rather new piece of tech (I disagree, I think MongoDB is fundamentally flawed, but it doesn't matter in this argument).
Because of our experience, going with the standby IS the best choice, until you _need_ something else. Riak was a change necessitated by its fast growth such that horizontally scaling was necessary when you're in an environment such as EC2. Ignoring MongoDB specifically, the IDEA of MongoDB simply isn't correct here, a Dynamo-style K/V store is the correct option, and Riak happens to be a fantastic one.
I recently asked if anyone could point me to an (open source) app on github or wherever that has a 'fluid schema' on a NoSQL system and nobody was able to show me one. Do you have a concrete example I can look at please?
Nothing? For something as common as you say I'd have thought there would be many examples out there. I don't get how this can be touted so often when there's no concrete use cases for this 'feature'.
I think that you would find MongoDB to work nicely for you ... especially with the need for rich queries (which assumes, on my part, that you have more complex data needs, documents, etc.).
With all due respect to the Kiip engineering team, this wasn't a strong case for using Riak over MongoDB ... but rather the general pain that a engineering team feels when horizontally scaling in the cloud.
