@Override
  public void close() {
    if (executorService != null) {
      executorService.shutdown();
    }
  }
A metrics reporter for CodahaleMetrics that dumps metrics periodically into
a file in JSON format. Only files on local filesystems are supported.
standalone-metastore/metastore-common/src/main/java/org/apache/hadoop/hive/common/metrics/metrics2/JsonFileMetricsReporter.java