Yarn核心——RPC(2) Hadoop RPC

Hadoop RPC 四步法

(1) 定义协议(2) 实现协议(3) 定义服务端(4) 定义客户端

(1) 定义协议

public interface MethodProtocol extends VersionedProtocol{    public static final long versionID=1L;    int calculate(int v1,int v2) throws IOException;}

(2) 实现协议

public class MethodProtocolImpl implements MethodProtocol{    public int calculate(int v1, int v2) throws IOException {        return  v1+v2;    }    public long getProtocolVersion(String protocol, long clientVersion) throws IOException {        return  MethodProtocol.versionID;    }    public ProtocolSignature getProtocolSignature(String protocol, long clientVersion, int clientMethodsHash) throws IOException {        return new ProtocolSignature(MethodProtocol.versionID,null);    }}

(3) 实现服务端

public class MethodRpcServer {    public static void main(String[] args)  throws Exception{        Configuration conf = new Configuration();        RPC.Builder builder =new RPC.Builder(conf);        builder.setBindAddress("localhost")                .setPort(8888).setProtocol(MethodProtocol.class)                .setInstance(new MethodProtocolImpl());        RPC.Server server=builder.build();        server.start();    }}

(4) 实现客户端

public class MethodRpcClient {    public static void main(String[] args) throws Exception{        MethodProtocol proxy = RPC.getProxy(MethodProtocol.class,MethodProtocol.versionID,                new InetSocketAddress("localhost",8888),new Configuration());        int result = proxy.calculate(1,2);        System.out.println(result);    }}