我在一个Windows主机上安装了两个Kafka 2.1.0代理。默认复制因子设置为2。所有其他设置均为默认设置。
即使我关闭了其中一个代理,生产者也可以编写消息以进行日志记录。但是在这种情况下,使用者停止使用消息。即使重新启动它,也不会分配分区。它只是写来记录此警告:
主要-org.apache.kafka.clients.NetworkClient:[Consumer clientId = consumer-1,groupId = sout]无法建立到节点-2(/192.168.0.1:19092)的连接。经纪人可能不可用。
消费者:
import org.apache.kafka.clients.consumer.*;
import org.apache.kafka.common.TopicPartition;
import org.apache.kafka.common.serialization.StringDeserializer;
import java.time.Duration;
import java.util.Collection;
import java.util.Collections;
import java.util.Properties;
public final class PumpToConsoleSimple {
private static final Duration pollTimeout = Duration.ofSeconds(10);
public static void main(String[] args) {
final Properties consumerProperties = new Properties();
consumerProperties.put(ConsumerConfig.ENABLE_AUTO_COMMIT_CONFIG, false);
consumerProperties.put(ConsumerConfig.GROUP_ID_CONFIG, "sout");
consumerProperties.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
consumerProperties.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
consumerProperties.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, "192.168.0.1:9092,192.168.0.1:19092");
consumerProperties.put(ConsumerConfig.MAX_POLL_RECORDS_CONFIG, 1000);
try (final KafkaConsumer<String, String> kafkaConsumer = new KafkaConsumer<>(consumerProperties)) {
kafkaConsumer.subscribe(Collections.singleton("test"), new ConsumerRebalanceListener() {
@Override
public void onPartitionsRevoked(Collection<TopicPartition> partitions) {
//do nothing
}
@Override
public void onPartitionsAssigned(Collection<TopicPartition> partitions) {
System.out.println("Partitions were assigned");
kafkaConsumer.seekToBeginning(partitions);
}
});
while (true) {
final ConsumerRecords<String, String> consumerRecords = kafkaConsumer.poll(pollTimeout);
consumerRecords.forEach(r -> System.out.println(r.value()));
kafkaConsumer.commitSync();
}
}
}
}
制作人:
import org.apache.kafka.clients.producer.KafkaProducer;
import org.apache.kafka.clients.producer.ProducerConfig;
import org.apache.kafka.clients.producer.ProducerRecord;
import org.apache.kafka.common.serialization.StringSerializer;
import java.time.Duration;
import java.util.Properties;
import java.util.concurrent.locks.LockSupport;
public final class OnceInASecondProducerSimple {
public static void main(String[] args) {
final Properties producerProperties = new Properties();
producerProperties.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
producerProperties.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
producerProperties.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, "192.168.0.1:9092,192.168.0.1:19092");
long counter = 0;
while (true) {
try (KafkaProducer<String, String> producer = new KafkaProducer<>(producerProperties)) {
producer.send(new ProducerRecord<>("test", "msg" + counter++));
}
LockSupport.parkNanos(Duration.ofSeconds(1).getNano());
}
}
}
只有在我再次启动代理之后,消费者才能继续工作。
我错过了什么?如何为Kafka消费者获得高可用性?
答案 0 :(得分:1)
通过__consumer_offsets
脚本检查偏移量主题kafka-topics
的状态。失败的代理必须是您组的协调者,并且__consumer_offsets的复制因子可能为1,因此使用者无法找到该协调者。即使重新启动使用者,它仍然无法查找协调器。
在您的情况下,您可以提高__consumer_offsets的复制因子,然后重试它是否按预期工作。