public void updateGet(HRegion region, long time, long blockBytesScanned) {
    if (region.getMetricsTableRequests() != null) {
      region.getMetricsTableRequests().updateGet(time, blockBytesScanned);
    }
    if (time > slowMetricTime) {
      serverSource.incrSlowGet();
    }
    serverSource.updateGet(time, blockBytesScanned);
    userAggregate.updateGet(time, blockBytesScanned);
  }
Maintains regionserver statistics and publishes them through the metrics interfaces. This class
has a number of metrics variables that are publicly accessible; these variables (objects) have
methods to update their values. Batch your updates rather than call on each instance else all
threads will do nothing but contend trying to maintain metric counters!
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/MetricsRegionServer.java