我试图用hadoopipc在它们之间创建一个简单的父子进程。结果是程序执行并打印结果，但它没有退出。这是它的代码。

interface Protocol extends VersionedProtocol{
  public static final long versionID = 1L;
  IntWritable getInput();
}

public final class JavaProcess implements Protocol{
  Server server;

  public JavaProcess() {
  String rpcAddr = "localhost";
  int rpcPort = 8989;
  Configuration conf = new Configuration();
  try {
    server = RPC.getServer(this, rpcAddr, rpcPort, conf);
    server.start();

  } catch (IOException e) {
    e.printStackTrace();
  }
}

public int exec(Class klass) throws IOException,InterruptedException {
  String javaHome = System.getProperty("java.home");
  String javaBin = javaHome +
      File.separator + "bin" +
      File.separator + "java";
  String classpath = System.getProperty("java.class.path");
  String className = klass.getCanonicalName();

  ProcessBuilder builder = new ProcessBuilder(
      javaBin, "-cp", classpath, className);

  Process process = builder.start();
  int exit_code = process.waitFor();
  server.stop();

  System.out.println("completed process");
  return exit_code;
}

public static void main(String...args) throws IOException, InterruptedException{
  int status = new JavaProcess().exec(JavaProcessChild.class);
  System.out.println(status);
}

@Override
public IntWritable getInput() {
  return new IntWritable(10);
}

@Override
public long getProtocolVersion(String paramString, long paramLong)
    throws IOException {
  return Protocol.versionID;
 }
}

下面是子进程类。然而，我已经意识到，这是由于rpc.getserver（）在服务器端，它的罪魁祸首。是已知的hadoop错误，还是我遗漏了什么？

public class JavaProcessChild{

  public static void main(String...args){
    Protocol umbilical = null;
    try {
       Configuration defaultConf = new Configuration();
       InetSocketAddress addr = new InetSocketAddress("localhost", 8989);
       umbilical = (Protocol) RPC.waitForProxy(Protocol.class, Protocol.versionID,
            addr, defaultConf);
       IntWritable input = umbilical.getInput();

       JavaProcessChild my = new JavaProcessChild();

      if(input!=null && input.equals(new IntWritable(10))){
        Thread.sleep(10000);
      }
      else{
        Thread.sleep(1000);
      }
    } catch (Throwable e) {
      e.printStackTrace();
   } finally{
      if(umbilical != null){
        RPC.stopProxy(umbilical);
      }
  }
}
}