@Override
  public void runReplicationBarrierCleaner() {
    ReplicationBarrierCleaner rbc = this.replicationBarrierCleaner;
    if (rbc != null) {
      rbc.chore();
    }
  }
This method modifies the master's configuration in order to inject replication-related features
hbase-server/src/main/java/org/apache/hadoop/hbase/master/HMaster.java