Kafka介绍之安装配置API

Kafka集群安装步骤：

    1、解压

   2、修改server.properties

             broker.id=1

             zookeeper.connect=weekend05:2181,weekend06:2181,weekend07:2181

  3、将zookeeper集群启动

  4、在每一台节点上启动broker

            bin/kafka-server-start.sh config/server.properties

   5、在kafka集群中创建一个topic

           bin/kafka-topics.sh --create --zookeeper zk_hostname:2181 --replication-factor 3 --partitions 1 --topic topic_name

   6、用一个producer向某一个topic中写入消息

          bin/kafka-console-producer.sh --broker-list broker_hostname:9092 --topic topic_name

    7、用一个comsumer从某一个topic中读取信息

         bin/kafka-console-consumer.sh --zookeeper zk_hostname:2181 --from-beginning --topic topic-name

    8、查看一个topic的分区及副本状态信息

         bin/kafka-topics.sh --describe --zookeeper zk_hostname:2181 --topic topic_name

Java API

     Producer端:

---

               public class ProducerDemo{

                       public static void main(String[] args){

                               //创建Properties实例，设置属性

                              Properties properties = new Properties();

                              //声明zk                            

                             properties.put("zk.connect","zk_hostname:2181,....");

                               //声明broker                           

                              properties.put("metadata.broker.list","broker_hostname:9092,.....");

                              properties.put("serializer.class","kafka.serializer.StringEncoder");

                               //创建ProducerConfig配置实例                             

                              ProducerConfig config = new ProducerConfig(properties);

                               //创建Producer实例                            

                              Producer producer = new Producer(config);

                              //发送消息                         

                              producer.send(new KeyedMessage(topic_name,content));

             }

}

---

Consumer端:

---

         public class ConsumerDemo{

                      public static void main(String[] args){

                             //创建Properties实例，设置属性

                          Properties properties = new Properties();

                          properties.put("zookeeper.connect","zk_hostname:2181,....");

                              //如果生产者和消费者在同一个组中，则不能访问同一组Topic内的数据

                          properties.put("group.id","id_name");

                           //声明ConsumerConnector

                        ConsumerConnector consumer =  Consumer.createJavaConsumerConnector(new ConsumerConfig(properties));

                        MaptopicCountMap = new HashMap();

                        //一次从一个主题中读取数据

                       topicCountMap.put(topic, 1);

                        topicCountMap.put(“topic_name", 1);

                        topicCountMap.put("topic_name1", 1);

                        Map>> consumerMap =

                                         consumer.createMessageStreams(topicCountMap);

                      List> streams = consumerMap.get("topic_name");

                        for(final KafkaStreamkafkaStream : streams){

                                       new Thread(new Runnable() {

                                                 @Override

                                         public void run() {

                                                for(MessageAndMetadatamm : kafkaStream){

                                                        String msg = new String(mm.message());

                                                         System.out.println(msg);

                                                   }

                                    }

                       }).start();

               }

         }

｝

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