@Override
  protected long getLogFileSize0() {
    long logFileSize = 0;
    for (WALProvider provider : cached.values()) {
      logFileSize += provider.getLogFileSize();
    }
    return logFileSize;
  }
A group-provider mapping, make sure one-one rather than many-one mapping
hbase-server/src/main/java/org/apache/hadoop/hbase/wal/RegionGroupingProvider.java