@Override
  public String getClient() {
    return clientAddress + ":" + remotePort;
  }
If an RPC call is currently running, produces a String representation of the connection from
which it was received.
@return A human-readable string representation of the address and port of the client.
hbase-server/src/main/java/org/apache/hadoop/hbase/monitoring/MonitoredRPCHandlerImpl.java