I started with some code to implement an idea I had for SPARK-529, and before going much further (since it's a large and kinda boring change) I'd like to get some feedback from people.
Current code it at: https://github.com/vanzin/spark/tree/SPARK-529 There are still some parts I haven't fully fleshed out yet (see TODO list in the commit message), but that's the basic idea. Let me know if you have any feedback or different ideas. Thanks! -- Marcelo
