Storm 确保消息被完成处理

storm确保消息如何被完成处理

1.发送的tuple需要携带msgId
        collector.emit(new Values(line),index);

2.bolt中需要对tuple进行确认(ack() | fail())

3.实现spout的ack()和fail()方法

package com.mao.storm.ensure;

import org.apache.storm.spout.SpoutOutputCollector;
import org.apache.storm.task.TopologyContext;
import org.apache.storm.topology.IRichSpout;
import org.apache.storm.topology.OutputFieldsDeclarer;
import org.apache.storm.tuple.Fields;
import org.apache.storm.tuple.Values;

import java.util.*;

/**
 * Spout
 */
public class WordCountSpout implements IRichSpout{
    private TopologyContext context ;
    private SpoutOutputCollector collector ;

    private List<String> states ;

    private Random r = new Random();

    private int index = 0;

    //消息集合, 存放所有消息
    private Map<Long,String> messages = new HashMap<Long, String>();

    //失败消息
    private Map<Long,Integer> failMessages = new HashMap<Long, Integer>();

    public void open(Map conf, TopologyContext context, SpoutOutputCollector collector) {
        this.context = context ;
        this.collector = collector ;
        states = new ArrayList<String>();
        states.add("hello world tom");
        states.add("hello world tomas");
        states.add("hello world tomasLee");
        states.add("hello world tomson");
    }

    public void close() {

    }

    public void activate() {

    }

    public void deactivate() {

    }

    public void nextTuple() {
        if(index < 3){
            String line = states.get(r.nextInt(4));
            //取出时间戳
            long ts = System.currentTimeMillis() ;
            messages.put(ts,line);

            //发送元组，使用ts作为消息id
            collector.emit(new Values(line),ts);
            System.out.println(this + " nextTuple() : " + line + " : " + ts);
            index ++ ;
        }
    }

    /**
     * 消息发送成功回调处理
     */
    public void ack(Object msgId) {
        //成功处理，删除失败重试.
        Long ts = (Long)msgId ;
        failMessages.remove(ts) ;
        messages.remove(ts) ;
    }

    /**
     * 消息发送失败处理
     */
    public void fail(Object msgId) {
        //时间戳作为msgId
        Long ts = (Long)msgId;
        //判断消息是否重试了3次
        Integer retryCount = failMessages.get(ts);
        retryCount = (retryCount == null ? 0 : retryCount) ;

        //超过最大重试次数
        if(retryCount >= 3){
            failMessages.remove(ts) ;
            messages.remove(ts) ;
        }
        else{
            //重试
            collector.emit(new Values(messages.get(ts)),ts);
            System.out.println(this + " fail() : " + messages.get(ts) + " : " + ts);
            retryCount ++ ;
            failMessages.put(ts,retryCount);
        }
    }

    public void declareOutputFields(OutputFieldsDeclarer declarer) {
        declarer.declare(new Fields("line"));
    }

    public Map<String, Object> getComponentConfiguration() {
        return null;
    }
}

package com.mao.storm.ensure;

import org.apache.storm.task.OutputCollector;
import org.apache.storm.task.TopologyContext;
import org.apache.storm.topology.IRichBolt;
import org.apache.storm.topology.OutputFieldsDeclarer;
import org.apache.storm.tuple.Fields;
import org.apache.storm.tuple.Tuple;

import java.util.Map;
import java.util.Random;

/**
 */
public class SplitBolt implements IRichBolt {

    private TopologyContext context ;
    private OutputCollector collector ;

    public void prepare(Map stormConf, TopologyContext context, OutputCollector collector) {
        this.context = context ;
        this.collector = collector ;
    }

    public void execute(Tuple tuple) {
        String line = tuple.getString(0);

        if(new Random().nextBoolean()){
            //确认
            collector.ack(tuple);
            System.out.println(this + " : ack() : " + line + " : "+ tuple.getMessageId().toString());
        }
        else{
            //失败
            collector.fail(tuple);
            System.out.println(this + " : fail : " + line + " : " + tuple.getMessageId().toString());
        }
    }

    public void cleanup() {

    }

    public void declareOutputFields(OutputFieldsDeclarer declarer) {
        declarer.declare(new Fields("word","count"));

    }

    public Map<String, Object> getComponentConfiguration() {
        return null;
    }
}

package com.mao.storm.ensure;

import org.apache.storm.Config;
import org.apache.storm.LocalCluster;
import org.apache.storm.topology.TopologyBuilder;

/**
 * App
 */
public class App {
    public static void main(String[] args) throws Exception {
        TopologyBuilder builder = new TopologyBuilder();
        //设置Spout
        builder.setSpout("wcspout", new WordCountSpout()).setNumTasks(1);
        //设置creator-Bolt
        builder.setBolt("split-bolt", new SplitBolt(),2).shuffleGrouping("wcspout").setNumTasks(2);

        Config conf = new Config();
        conf.setNumWorkers(2);
        conf.setDebug(true);

        /**
         * 本地模式storm
         */
        LocalCluster cluster = new LocalCluster();
        cluster.submitTopology("wc", conf, builder.createTopology());
        System.out.println("hello world llll");
    }
}