2019独角兽企业重金招聘Python工程师标准>>> 
1、当kafka 客户端连接如下异常
Exception in thread "main"
java.util.concurrent.ExecutionException: org.apache.kafka.common.errors.TimeoutException: Failed to update metadata after 60000 ms.
at org.apache.kafka.clients.producer.KafkaProducer$FutureFailure.
at org.apache.kafka.clients.producer.KafkaProducer.doSend(KafkaProducer.java:764)
at org.apache.kafka.clients.producer.KafkaProducer.send(KafkaProducer.java:701)
at org.apache.kafka.clients.producer.KafkaProducer.send(KafkaProducer.java:609)
at com.KafkaProducerExample.main(KafkaProducerExample.java:53)
Caused by: org.apache.kafka.common.errors.TimeoutException: Failed to update metadata after 60000 ms.
问题原因：
1. java client 包与kafka server 版本不一致
2、/kafka_2.11-0.9.0.0/config/server.properties
listerners 需配置ip ,不能配置主机名，因本地Hosts中不存在对应的Ip配置，导致producer 无法连接
官网默认提示 设置host.name advertised.host.name 为Ip 时可以通过ip连接，但经过测试，此配置失败。只有通过修改Listerners 后成功。
3、查看zk中得配置信息，
查看配置 get /brokers/ids/0 当时ip时，可以正常连接。
4、java client 连接实例（生成者）
Properties props = new Properties();
props.put("bootstrap.servers", "192.168.2.176:9092");
props.put("acks", "all");
props.put("retries", 0);
props.put("batch.size", 16384);
props.put("linger.ms", 10);
props.put("buffer.memory", 33554432);
props.put("key.serializer", "org.apache.kafka.common.serialization.StringSerializer");
props.put("value.serializer", "org.apache.kafka.common.serialization.StringSerializer");
Producer producer = new KafkaProducer<>(props);
for (int i = 0; i < 100; i++) {
System.out.println(i);
Future future = producer.send(new ProducerRecord("kafka1", Integer.toString(i), Integer.toString(i)));
System.out.println(future.get());
// System.out.println(future.get());
}
producer.close();
消费者实例，不用配置zk连接也可以消费了
public static void main(String[] args) {
Properties props = new Properties();
props.put("bootstrap.servers", "192.168.2.176:9092");
props.put("group.id", "test");
props.put("enable.auto.commit", "true");
props.put("auto.commit.interval.ms", "1000");
props.put("session.timeout.ms", "30000");
props.put("key.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");
props.put("value.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");
KafkaConsumer consumer = new KafkaConsumer(props);
consumer.subscribe(Arrays.asList("kafka1"));
while (true) {
ConsumerRecords records = consumer.poll(100);
for (ConsumerRecord record : records)
System.out.printf("offset = %d, key = %s, value = %s\n", record.offset(), record.key(), record.value());
}
}
依赖版本
org.apache.kafka kafka-clients 0.9.0.0