In practice today, Rethink's sharding is very similar to Mongo's sharding. This won't remain the case for long -- you'll soon be able to add and remove shards l

In practice today, Rethink's sharding is very similar to Mongo's sharding. This won't remain the case for long -- you'll soon be able to add and remove shards live if that's a requirement in your application. The architecture's already in place, but there are some loose ends we have to tie up to expose this functionality to users.