private void startReplicationService() throws IOException {
    if (sameReplicationSourceAndSink && this.replicationSourceHandler != null) {
      this.replicationSourceHandler.startReplicationService();
    } else {
      if (this.replicationSourceHandler != null) {
        this.replicationSourceHandler.startReplicationService();
      }
      if (this.replicationSinkHandler != null) {
        this.replicationSinkHandler.startReplicationService();
      }
    }
  }
Start up replication source and sink handlers.
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegionServer.java