@VisibleForTesting
  public static String replaceWhitespace(String input) {
    if (input == null) {
      return input;
    }
    return input.replaceAll("\\s+", "_");
  }
Collect and publish ACID and compaction related metrics.
Everything should be behind 2 feature flags: {@link MetastoreConf.ConfVars#METRICS_ENABLED} and
{@link MetastoreConf.ConfVars#METASTORE_ACIDMETRICS_THREAD_ON}.
standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/metrics/AcidMetricService.java