0.Kafka服务器配置
3个broker
1个topic,6个partition,副本因子是2
2个consumer,每个consumer三个线程并发读取
1. Producer
package kafka.examples.multibrokers.producers; import java.util.Properties; import java.util.Random; import kafka.javaapi.producer.Producer; import kafka.producer.KeyedMessage; import kafka.producer.ProducerConfig; public class MultiBrokerProducer { private static Producer<String, String> producer; private static Properties props = new Properties(); static { props.put("metadata.broker.list", "192.168.26.140:9092,192.168.26.140:9093,192.168.26.140:9094"); props.put("serializer.class", "kafka.serializer.StringEncoder"); props.put("partitioner.class", "kafka.examples.multibrokers.partitioner.TopicPartitioner"); props.put("request.required.acks", "1"); ProducerConfig config = new ProducerConfig(props); producer = new Producer<String, String>(config); } public static void main(String[] args) { Random rnd = new Random(); String topic = "learn.topic.p8.r2"; for (long i = 0; i < 10000; i++) { String key = "" + rnd.nextInt(255); String msg = "The " + i + " message is for key - " + key; KeyedMessage<String, String> data = new KeyedMessage<String, String>(topic, key, msg); producer.send(data); System.out.println(i); } producer.close(); } }
2. Partitioner
package kafka.examples.multibrokers.partitioner; import kafka.producer.Partitioner; import kafka.utils.VerifiableProperties; import java.util.Random; public class TopicPartitioner implements Partitioner { public TopicPartitioner(VerifiableProperties props) { } @Override public int partition(Object key, int numPartitions) { int hashCode; if (key == null) { hashCode = new Random().nextInt(255); } else { hashCode = key.hashCode(); } if (numPartitions <= 0) { return 0; } return hashCode % numPartitions; } }
3. Consumer
package kafka.examples.multibrokers.consumers; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.Properties; import java.util.concurrent.CountDownLatch; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import kafka.consumer.Consumer; import kafka.consumer.ConsumerConfig; import kafka.consumer.ConsumerIterator; import kafka.consumer.KafkaStream; import kafka.javaapi.consumer.ConsumerConnector; public class MultiThreadHLConsumer { private ExecutorService executor; private final ConsumerConnector consumer; private final String topic; public MultiThreadHLConsumer(String zookeeper, String groupId, String topic) { Properties props = new Properties(); props.put("zookeeper.connect", zookeeper); props.put("group.id", groupId); props.put("zookeeper.session.timeout.ms", "500"); props.put("zookeeper.sync.time.ms", "250"); props.put("auto.commit.interval.ms", "1000"); consumer = Consumer.createJavaConsumerConnector(new ConsumerConfig(props)); this.topic = topic; } public void doConsume(int threadCount) { Map<String, Integer> topicCount = new HashMap<String, Integer>(); // Define thread count for each topic topicCount.put(topic, new Integer(threadCount)); // Here we have used a single topic but we can also add multiple topics to topicCount MAP Map<String, List<KafkaStream<byte[], byte[]>>> consumerStreams = consumer.createMessageStreams(topicCount); List<KafkaStream<byte[], byte[]>> streams = consumerStreams.get(topic); System.out.println("streams length: " + streams.size()); // Launching the thread pool executor = Executors.newFixedThreadPool(threadCount); //Creating an object messages consumption final CountDownLatch latch = new CountDownLatch(3); for (final KafkaStream stream : streams) { executor.submit(new Runnable() { @Override public void run() { ConsumerIterator<byte[], byte[]> consumerIte = stream.iterator(); while (consumerIte.hasNext()) { System.out.println("Message from thread :: " + Thread.currentThread().getName() + " -- " + new String(consumerIte.next().message())); } latch.countDown(); } }); } try { latch.await(); } catch (InterruptedException e) { e.printStackTrace(); } if (consumer != null) { consumer.shutdown(); } if (executor != null) executor.shutdown(); } public static void main(String[] args) { String topic = "learn.topic.p8.r2"; int threadCount = 3; MultiThreadHLConsumer simpleHLConsumer = new MultiThreadHLConsumer("192.168.26.140:2181", "learn.topic.p8.r2.consumers.group", topic); simpleHLConsumer.doConsume(threadCount); } }
4. 注意的问题