George Leopold describes Omid:
The transaction manager utilizes a lock-free approach to support multiple clients and relies on a centralized conflict detection component to resolve write-set collisions among concurrent transactions. Developers added that Omid requires no modifications to the underlying HBase key-value data store.
It also features a simplified API that mimics transaction manager APIs in relational databases. Client and server configuration processes also were simplified to help both application developers and system administrators.
Filing this one under the “What’s old is new again” category.