public Set<TableName> filterInsufficientlyReportedTables(
      QuotaSnapshotStore<TableName> tableStore) throws IOException {
      final double percentRegionsReportedThreshold = getRegionReportPercent(getConfiguration());
      Set<TableName> tablesToRemove = new HashSet<>();
      for (TableName table : Iterables.concat(tablesWithTableQuotas, tablesWithNamespaceQuotas)) {
        // Don't recompute a table we've already computed
        if (tablesToRemove.contains(table)) {
          continue;
        }
        final int numRegionsInTable = getNumRegions(table);
        // If the table doesn't exist (no regions), bail out.
        if (numRegionsInTable == 0) {
          if (LOG.isTraceEnabled()) {
            LOG.trace("Filtering " + table + " because no regions were reported");
          }
          tablesToRemove.add(table);
          continue;
        }
        final int reportedRegionsInQuota = getNumReportedRegions(table, tableStore);
        final double ratioReported = ((double) reportedRegionsInQuota) / numRegionsInTable;
        if (ratioReported < percentRegionsReportedThreshold) {
          if (LOG.isTraceEnabled()) {
            LOG.trace("Filtering " + table + " because " + reportedRegionsInQuota + " of "
              + numRegionsInTable + " regions were reported.");
          }
          tablesToRemove.add(table);
        } else if (LOG.isTraceEnabled()) {
          LOG.trace("Retaining " + table + " because " + reportedRegionsInQuota + " of "
            + numRegionsInTable + " regions were reported.");
        }
      }
      for (TableName tableToRemove : tablesToRemove) {
        tablesWithTableQuotas.remove(tableToRemove);
        tablesWithNamespaceQuotas.remove(tableToRemove);
      }
      return tablesToRemove;
    }
Filters out all tables for which the Master currently doesn't have enough region space
reports received from RegionServers yet.
hbase-server/src/main/java/org/apache/hadoop/hbase/quotas/QuotaObserverChore.java