@Override
  public long getRPCPacketLength() {
    if (getState() != State.RUNNING || packet == null) {
      // no RPC is currently running, or we don't have an RPC's packet info
      return -1L;
    }
    return packet.getSerializedSize();
  }
Produces a string representation of the method currently being serviced by this Handler.
@return A human-readable string representation of the method call.
hbase-server/src/main/java/org/apache/hadoop/hbase/monitoring/MonitoredRPCHandlerImpl.java