@Override
    public Optional<RegionObserver> getRegionObserver() {
      return Optional.of(this);
    }
A coprocessor that collects metrics from meta table.
<p>
These metrics will be available through the regular Hadoop metrics2 sinks (ganglia, opentsdb,
etc) as well as JMX output.
</p>
@see MetaTableMetrics
hbase-server/src/main/java/org/apache/hadoop/hbase/coprocessor/MetaTableMetrics.java