Apache Kafka中用户消费消息的延迟

Question

我正在使用Kafka0.8.0并尝试实现下面提到的场景。

JCA API（充当生产者并将数据发送到）------>消费者------>HBase

当我使用JCA客户端获取数据时，我会立即将每个消息发送给消费者。例如，一旦生产者发送第1号消息，我就想从消费者那里获取相同的消息并将其“放入”HBase。但是我的消费者在一些随机的n条消息之后开始获取消息。我想让生产者和消费者同步，这样他们两个开始一起工作。

我使用过：

1个经纪人

1个单选题

1单一生产者和高水平消费者

谁能建议我需要做些什么来实现同样的目标吗？

编辑：

添加一些相关的代码段。

consumer.java

public class Consumer extends Thread {
    private final ConsumerConnector consumer;
    private final String topic;
    PrintWriter pw = null;
    int t = 0;
    StringDecoder kd = new StringDecoder(null);
    Map<String, Integer> topicCountMap = new HashMap<String, Integer>();
    Map<String, List<KafkaStream<String, Signal>>> consumerMap;
    KafkaStream<String, Signal> stream;
    ConsumerIterator<String, Signal> it;

    public Consumer(String topic) {
        consumer = kafka.consumer.Consumer.createJavaConsumerConnector(createConsumerConfig());

        this.topic = topic;
        topicCountMap.put(topic, new Integer(1));
        consumerMap = consumer.createMessageStreams(topicCountMap, kd, new Serializer(
                new VerifiableProperties()));
        stream = consumerMap.get(topic).get(0);
        it = stream.iterator();

    }

    private static ConsumerConfig createConsumerConfig() {
        Properties props = new Properties();
        props.put("zookeeper.connect", KafkaProperties.zkConnect);
        props.put("group.id", KafkaProperties.groupId);
        props.put("zookeeper.session.timeout.ms", "400");
        props.put("zookeeper.sync.time.ms", "200");
        props.put("auto.commit.interval.ms", "1000");
        props.put("fetch.size", "1024");

        return new ConsumerConfig(props);

    }

    synchronized public void run() {

        while (it.hasNext()) {
            t = (it.next().message()).getChannelid();
            System.out.println("In Consumer received msg" + t);
        }
    }
}

Producer.java

public class Producer {
    public final kafka.javaapi.producer.Producer<String, Signal> producer;
    private final String topic;
    private final Properties props = new Properties();

    public Producer(String topic)
    {
        props.put("serializer.class", "org.bigdata.kafka.Serializer");
        props.put("key.serializer.class", "kafka.serializer.StringEncoder");
        props.put("metadata.broker.list", "localhost:9092");
        // Use random partitioner. Don't need the key type. Just set it to Integer.
        // The message is of type userdefined Object .
        producer = new kafka.javaapi.producer.Producer<String,Signal(newProducerConfig(props));
        this.topic = topic;
    }
}

KafkaProperties.java

public interface KafkaProperties {
    final static String zkConnect = "127.0.0.1:2181";
    final static String groupId = "group1";
    final static String topic = "test00";
    final static String kafkaServerURL = "localhost";
    final static int kafkaServerPort = 9092;
    final static int kafkaProducerBufferSize = 64 * 1024;
    final static int connectionTimeOut = 100000;
    final static int reconnectInterval = 10000;
    final static String clientId = "SimpleConsumerDemoClient";
}

     producer sending msg1

     producer sending msg2

     producer sending msg3

     producer sending msg4

     producer sending msg5

     producer sending msg6

     producer sending msg7

     producer sending msg8

     producer sending msg9

     producer sending msg10

     producer sending msg11

     producer sending msg12
     In Consumer received msg12

     producer sending msg13
     In Consumer received msg13

     producer sending msg14
     In Consumer received msg14

     producer sending msg15
     In Consumer received msg15

     producer sending msg16
     In Consumer received msg16

     producer sending msg17
     In Consumer received msg17

     producer sending msg18
     In Consumer received msg18

     producer sending msg19
     In Consumer received msg19

     producer sending msg20
     In Consumer received msg20

     producer sending msg21
     In Consumer received msg21

编辑：添加监听器功能，监听器将消息发送给消费者。并且我使用的是默认的生产者配置没有覆盖它

public synchronized void onValueChanged(final MonitorEvent event_) {


    // Get the value from the DBR
    try {
        final DBR dbr = event_.getDBR();

        final String[] val = (String[]) dbr.getValue();

        producer1.producer.send(new KeyedMessage<String, Signal>         
                    (KafkaProperties.topic,new Signal(messageNo)));
        System.out.println("producer sending msg"+messageNo);

        messageNo++;


    } catch (Exception ex) {
        ex.printStackTrace();
    }
}

Answer 1

>

尝试将props.put（“request.required.acks”，“1”）添加到生成器配置中。默认情况下，producer不会等待ACK，消息传递也不保证。因此，如果您在测试之前启动broker，那么producer可能会在broker完全初始化之前开始发送消息，并且前几个消息可能会丢失。

尝试将props.put（“auto.offset.reset”,“smallest”）添加到使用者配置中。它等于kafka-console-consumer.sh的--from-beginary选项。如果您的使用者启动的时间比producer晚，并且Zookeeper中没有保存偏移量数据，那么默认情况下，它将只开始使用新消息（请参见文档中的使用者配置）。