For replication, it would be useful to have an SPI that users can implement for executing HBase DDL operations. The base implementation would be whatever is done today, operating on a single HBase instance. Another implementation could call an external service that operates on multiple HBase clusters and sets up replication between the clusters.
Full design at https://wiki.cask.co/display/CE/HBase+DDL+SPI.
Provided SPI hooks that users can implement for performing HBase DDL operations.
All PRs merged. Marking JIRA as fixed.