private void retryOrThrow(RetryCounter retryCounter, KeeperException e, String opName)
    throws KeeperException {
    if (!retryCounter.shouldRetry()) {
      LOG.error("ZooKeeper {} failed after {} attempts", opName, retryCounter.getMaxAttempts());
      throw e;
    }
    LOG.debug("Retry, connectivity issue (JVM Pause?); quorum={},exception{}=", quorumServers, e);
  }
exists is an idempotent operation. Retry before throwing exception
@return A Stat instance
hbase-zookeeper/src/main/java/org/apache/hadoop/hbase/zookeeper/RecoverableZooKeeper.java