The rollback procedure rolls back HDFS and, the data in HBase is also rolled back automatically as part of this procedure. In addition, HBase metadata stored in ZooKeeper is recovered as part of the ZooKeeper rollback procedure.
If your cluster is configured to use HBase replication, Cloudera recommends that you document all replication peers. If necessary (for example, because the HBase znode has been deleted), you can roll back HBase as part of the HDFS rollback without the ZooKeeper metadata. This metadata can be reconstructed in a fresh ZooKeeper installation, with the exception of the replication peers, which you must add back.