Voldemort to LevelDB is what MySQL is to InnoDB: Voldemort is a distributed system that allows multiple engines to be plugged in. Mostly commonly, companies use either BerkeleyDB or MySQL as a storage engine. LinkedIn, Mendeley, EBay and others also use the read only storage engine, where the data is pre-built in Hadoop and loaded into Voldemort.
I am really excited about LevelDB: while there are higher priority projects on my plate right now, we'd very much like to see a LevelDB storage engine. If anyone is interested in contributing one, they're welcome.
The steps are:
1) Creating JNI bindings to LevelDB (or creating a .so version of LevelDB and creating JNA bindings)
2) Implementing the StorageEngine interface with the bindings, including passing in any configuration.
Here is an example of a third party InnoDB/Haildb storage engine for Voldemort: