Abstract: A processing system including at least one processor may provide a first instance of a plurality of instances of a database distributed at a plurality of different nodes, and a first instance of a plurality of instances of a middleware module distributed at the plurality of different nodes, the first instance of the middleware module associated with the first instance of the database. The first instance of the middleware module may be configured to receive a request from a first client to perform a transaction relating to a range of keys, confirm an ownership of the first client of the range of keys, execute operations of the transaction over the first instance of the database, and write a first entry to a first instance of an entry consistent store, the first entry recording a change of at least a value in the database resulting from executing the operations of the transaction.