1. 程式人生 > >Kafka 溫故(五):Kafka的消費程式設計模型

Kafka 溫故(五):Kafka的消費程式設計模型

Kafka的消費模型分為兩種:

1.分割槽消費模型

2.分組消費模型

一.分割槽消費模型

二、分組消費模型

Producer :

package cn.outofmemory.kafka;
 
import java.util.Properties;
 
import kafka.javaapi.producer.Producer;
import kafka.producer.KeyedMessage;
import kafka.producer.ProducerConfig;
 
/**
 * Hello world!
 *
 */
public
class KafkaProducer { private final Producer<String, String> producer; public final static String TOPIC = "TEST-TOPIC"; private KafkaProducer(){ Properties props = new Properties(); //此處配置的是kafka的埠 props.put("metadata.broker.list", "192.168.193.148:9092");
//配置value的序列化類 props.put("serializer.class", "kafka.serializer.StringEncoder"); //配置key的序列化類 props.put("key.serializer.class", "kafka.serializer.StringEncoder"); //request.required.acks //0, which means that the producer never waits for an acknowledgement from the broker (the same behavior as 0.7). This option provides the lowest latency but the weakest durability guarantees (some data will be lost when a server fails).
//1, which means that the producer gets an acknowledgement after the leader replica has received the data. This option provides better durability as the client waits until the server acknowledges the request as successful (only messages that were written to the now-dead leader but not yet replicated will be lost). //-1, which means that the producer gets an acknowledgement after all in-sync replicas have received the data. This option provides the best durability, we guarantee that no messages will be lost as long as at least one in sync replica remains. props.put("request.required.acks","-1"); producer = new Producer<String, String>(new ProducerConfig(props)); } void produce() { int messageNo = 1000; final int COUNT = 10000; while (messageNo < COUNT) { String key = String.valueOf(messageNo); String data = "hello kafka message " + key; producer.send(new KeyedMessage<String, String>(TOPIC, key ,data)); System.out.println(data); messageNo ++; } } public static void main( String[] args ) { new KafkaProducer().produce(); } }
Consumer
package cn.outofmemory.kafka;
 
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Properties;
 
import kafka.consumer.ConsumerConfig;
import kafka.consumer.ConsumerIterator;
import kafka.consumer.KafkaStream;
import kafka.javaapi.consumer.ConsumerConnector;
import kafka.serializer.StringDecoder;
import kafka.utils.VerifiableProperties;
 
public class KafkaConsumer {
 
    private final ConsumerConnector consumer;
 
    private KafkaConsumer() {
        Properties props = new Properties();
        //zookeeper 配置
        props.put("zookeeper.connect", "192.168.193.148:2181");
 
        //group 代表一個消費組
        props.put("group.id", "jd-group");
 
        //zk連線超時
        props.put("zookeeper.session.timeout.ms", "4000");
        props.put("zookeeper.sync.time.ms", "200");
        props.put("auto.commit.interval.ms", "1000");
        props.put("auto.offset.reset", "smallest");
        //序列化類
        props.put("serializer.class", "kafka.serializer.StringEncoder");
 
        ConsumerConfig config = new ConsumerConfig(props);
 
        consumer = kafka.consumer.Consumer.createJavaConsumerConnector(config);
    }
 
    void consume() {
        Map<String, Integer> topicCountMap = new HashMap<String, Integer>();
        topicCountMap.put(KafkaProducer.TOPIC, new Integer(1));
 
        StringDecoder keyDecoder = new StringDecoder(new VerifiableProperties());
        StringDecoder valueDecoder = new StringDecoder(new VerifiableProperties());
 
        //獲取到的輸入流
        Map<String, List<KafkaStream<String, String>>> consumerMap = 
                consumer.createMessageStreams(topicCountMap,keyDecoder,valueDecoder);
        KafkaStream<String, String> stream = consumerMap.get(KafkaProducer.TOPIC).get(0);
        ConsumerIterator<String, String> it = stream.iterator();
        //輸出接受到的訊息
        while (it.hasNext())
            System.out.println(it.next().message());
    }
 
    public static void main(String[] args) {
        new KafkaConsumer().consume();
    }
}

 

 kafka 學習告一段落,後面進入的為Spring 溫習。