@Override
  public void setConf(Configuration config) {
    this.conf = config;
    this.connection = null;
    try {
      this.connection = ConnectionFactory.createConnection(conf);
    } catch (IOException ioe) {
      LOG.error("Couldn't establish connection", ioe);
    }
  }
Implementation of a file cleaner that checks if an hfile is still referenced by backup before
deleting it from hfile archive directory.
hbase-backup/src/main/java/org/apache/hadoop/hbase/backup/BackupHFileCleaner.java