TwoStore is designed for repositories that have outgrown the default storage configuration that is shipped with Fedora, but which do not yet require the extensive machinery of gridded or cloud-based storage.
It's based on a simple Adler32-based hash and TwoStore, a special Akubra BlobStore that acts as a binary switch between two other BlobStores. TwoStores are used to assemble other BlobStores into a manually-balanced binary tree of stores.
One of the attractive qualities of TwoStore implementations is that growth in the tree of stores causes more of the hash to be consumed to traverse that same in-memory tree, and not consumed inside a persisting store, where seeking operations are typically much more expensive.
