我正在嘗試使用Hadoop IPC在IPC之間創建一個簡單的父子進程。事實證明,程序執行並打印結果,但不會退出。這是它的代碼。Hadoop RPC服務器不會停止
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;
}
}
這裏是子進程類。不過我已經意識到這是由於服務器端的RPC.getServer()導致它的罪魁禍首。這是一些已知的hadoop錯誤,或者我失去了一些東西?
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);
}
}
}
}