void updateMetricsStore(boolean memstoreRead) {
    if (memstoreRead) {
      memstoreOnlyRowReadsCount.increment();
    } else {
      mixedRowReadsCount.increment();
    }
  }
Returns get maximum ref count of storeFile among all compacted HStore Files for the HStore
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HStore.java