在搭建Apache Kafka平台的时候，运行测试代码时抛出以下的错误：

ExceptiException in thread "main" org.I0Itec.zkclient.exception.ZkTimeoutException: Unable to connect to zookeeper server within timeout: 6000

    at org.I0Itec.zkclient.ZkClient.connect(ZkClient.java:876)

    at org.I0Itec.zkclient.ZkClient.<init>(ZkClient.java:98)

    at org.I0Itec.zkclient.ZkClient.<init>(ZkClient.java:84)

    at kafka.producer.ZKBrokerPartitionInfo.<init>(ZKBrokerPartitionInfo.scala:61)

    at kafka.producer.Producer.<init>(Producer.scala:51)

    at kafka.javaapi.producer.Producer.<init>(Producer.scala:32)

    at kafka.javaapi.producer.Producer.<init>(Producer.scala:39)

看到Timeout类型的错误，因为一般网络连接建立都非常快，不会有超时的问题，所以笔者的第一想法是Kafka或Zookeeper的配置出了问题，可是改来改去并没有发现错误。后来仔细看了一下错误提示，考虑是否真的有可能在连接Zookeeper时比较耗时间也说不定，于是将timeout值加大，经测试成功。

下面是修改后的测试代码：

import java.util.Properties;

import kafka.javaapi.producer.Producer;

import kafka.javaapi.producer.ProducerData;

import kafka.producer.ProducerConfig;

public class Test {

    public static void main(String[] args) {

        Properties props = new Properties();

        props.put("zk.connect", "9.186.66.159:2181");

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

        // This is added by myself for changing the default timeout 6000.

        props.put("zk.connectiontimeout.ms", "15000");

        ProducerConfig config = new ProducerConfig(props);

        Producer<String, String> producer = new Producer<String, String>(config);

        // The message is sent to a randomly selected partition registered in ZK

        ProducerData<String, String> data = new ProducerData<String, String>(

                "test-topic", "test-message");

        producer.send(data);

        producer.close();

    }

}