@Test(timeout = 30000)
public void testDataNodeGetReconfigurableProperties() throws IOException {

  final int port = datanode.getIpcPort();
  final String address = "localhost:" + port;
  final List<String> outs = Lists.newArrayList();
  final List<String> errs = Lists.newArrayList();
  getReconfigurableProperties("datanode", address, outs, errs);
  assertEquals(3, outs.size());
  assertEquals(DFSConfigKeys.DFS_DATANODE_DATA_DIR_KEY, outs.get(1));
}