@Override
  public void updateCompactionOutputSize(boolean isMajor, long bytes) {
    compactionOutputSizeHisto.add(bytes);
    compactedOutputBytes.incr(bytes);
    if (isMajor) {
      majorCompactionOutputSizeHisto.add(bytes);
      majorCompactedOutputBytes.incr(bytes);
    }
  }
Hadoop2 implementation of MetricsRegionServerSource. Implements BaseSource through
BaseSourceImpl, following the pattern
hbase-hadoop-compat/src/main/java/org/apache/hadoop/hbase/regionserver/MetricsRegionServerSourceImpl.java