@Override
  public synchronized MonitoredRPCHandlerImpl clone() {
    MonitoredRPCHandlerImpl clone = (MonitoredRPCHandlerImpl) super.clone();
    clone.callInfoMap = generateCallInfoMap();
    clone.snapshot = true;
    return clone;
  }
A MonitoredTask implementation designed for use with RPC Handlers handling frequent, short
duration tasks. String concatenations and object allocations are avoided in methods that will be
hit by every RPC call.
hbase-server/src/main/java/org/apache/hadoop/hbase/monitoring/MonitoredRPCHandlerImpl.java