@Override
    public String toString() {
      return "HCatClient: thread: " + Thread.currentThread().getId() + " users=" + users.get()
        + " expired=" + expiredFromCache + " closed=" + isClosed;
    }
Close the underlying objects irrespective of whether they are in use or not.
metastore/src/java/org/apache/hadoop/hive/metastore/HiveClientCache.java