Storm实验 -- DRPC的使用

1. 修改所有节点的 storm.yaml 配置文件，设置 drpc server 

[grid@hadoop6 ~]$ vim storm-0.9.4/conf/storm.yaml
drpc.servers:
     - "hadoop4"

2. 启动drcp服务 

storm drpc &

3. 编写服务端程序 

//来源于 https://github.com/nathanmarz/storm-starter/blob/master/src/jvm/storm/starter/BasicDRPCTopology.java

package storm.starter;

import backtype.storm.Config;
import backtype.storm.LocalCluster;
import backtype.storm.LocalDRPC;
import backtype.storm.StormSubmitter;
import backtype.storm.drpc.LinearDRPCTopologyBuilder;
import backtype.storm.topology.BasicOutputCollector;
import backtype.storm.topology.OutputFieldsDeclarer;
import backtype.storm.topology.base.BaseBasicBolt;
import backtype.storm.tuple.Fields;
import backtype.storm.tuple.Tuple;
import backtype.storm.tuple.Values;

public class BasicDRPCTopology {
    public static class ExclaimBolt extends BaseBasicBolt {
        @Override
        public void execute(Tuple tuple, BasicOutputCollector collector) {
            String input = tuple.getString(1);
            collector.emit(new Values(tuple.getValue(0), input + "!"));
        }

        @Override
        public void declareOutputFields(OutputFieldsDeclarer declarer) {
            declarer.declare(new Fields("id", "result"));
        }

    }

    public static void main(String[] args) throws Exception {
        LinearDRPCTopologyBuilder builder = new LinearDRPCTopologyBuilder("exclamation");
        builder.addBolt(new ExclaimBolt(), 3);

        Config conf = new Config();

        if (args == null || args.length == 0) {
            LocalDRPC drpc = new LocalDRPC();
            LocalCluster cluster = new LocalCluster();

            cluster.submitTopology("drpc-demo", conf, builder.createLocalTopology(drpc));

            for (String word : new String[]{"hello", "goodbye"}) {
                System.out.println("Result for \"" + word + "\": " + drpc.execute("exclamation", word));
            }

            cluster.shutdown();
            drpc.shutdown();
        } else {
            conf.setNumWorkers(3);
            StormSubmitter.submitTopology(args[0], conf, builder.createRemoteTopology());
        }
    }
}

4. 将程序打包提交到Storm集群 

storm jar Storm04-1.0-SNAPSHOT.jar storm.starter.BasicDRPCTopology exclamation

5. 编写客户端程序远程调用服务 

import backtype.storm.utils.DRPCClient;

public class Client {
    public static void main(String[] args) throws Exception {
        DRPCClient client = new DRPCClient("192.168.0.106", 3772);
        String[] words = {"hello", "storm", "drpc"};
        for (String word : words) {
            String result = client.execute("exclamation", word);
            System.out.println("Result for \"" + word + "\": " + result);
        }
    }
}

6. 程序运行结果：