kafka quick start

http://kafka.apache.org/quickstart

Step 1: Download the code

Download the 1.1.0 release and un-tar it.

1 2	> tar -xzf kafka_2.11-1.1.0.tgz > cd kafka_2.11-1.1.0

Step 2: Start the server

Kafka uses ZooKeeper so you need to first start a ZooKeeper server if you don't already have one. You can use the convenience script packaged with kafka to get a quick-and-dirty single-node ZooKeeper instance.

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> bin/zookeeper-server-start.sh config/zookeeper.properties [2013-04-22 15:01:37,495] INFO Reading configuration from: config/zookeeper.properties (org.apache.zookeeper.server.quorum.QuorumPeerConfig) ...

Now start the Kafka server:

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> bin/kafka-server-start.sh config/server.properties [2013-04-22 15:01:47,028] INFO Verifying properties (kafka.utils.VerifiableProperties) [2013-04-22 15:01:47,051] INFO Property socket.send.buffer.bytes is overridden to 1048576 (kafka.utils.VerifiableProperties) ...

Step 3: Create a topic

Let's create a topic named "test" with a single partition and only one replica:

1	> bin/kafka-topics.sh --create --zookeeper localhost:2181 --replication-factor 1 --partitions 1 --topic test

We can now see that topic if we run the list topic command:

1 2	> bin/kafka-topics.sh --list --zookeeper localhost:2181 test

Alternatively, instead of manually creating topics you can also configure your brokers to auto-create topics when a non-existent topic is published to.

Step 4: Send some messages

Kafka comes with a command line client that will take input from a file or from standard input and send it out as messages to the Kafka cluster. By default, each line will be sent as a separate message.

Run the producer and then type a few messages into the console to send to the server.

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> bin/kafka-console-producer.sh --broker-list localhost:9092 --topic test This is a message This is another message

Step 5: Start a consumer

Kafka also has a command line consumer that will dump out messages to standard output.

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> bin/kafka-console-consumer.sh --bootstrap-server localhost:9092 --topic test --from-beginning This is a message This is another message

If you have each of the above commands running in a different terminal then you should now be able to type messages into the producer terminal and see them appear in the consumer terminal.

All of the command line tools have additional options; running the command with no arguments will display usage information documenting them in more detail.

遇到问题：

启动失败并提示如下错误：

 FATAL [KafkaServer id=0] Fatal error during KafkaServer startup. Prepare to shutdown (kafka.server.KafkaServer)nager)999) by writing to Zk with path version 2 (kafka.coordinator.java.net.UnknownHostException: server38: server38: 未知的名称或服务
        at java.base/java.net.InetAddress.getLocalHost(Unknown Source)
        at kafka.server.KafkaHealthcheck$$anonfun$1.apply(KafkaHealthcheck.scala:63)
        at kafka.server.KafkaHealthcheck$$anonfun$1.apply(KafkaHealthcheck.scala:61)
        at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:234)
        at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:234)
        at scala.collection.mutable.ResizableArray$class.foreach(ResizableArray.scala:59)
        at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:48)
        at scala.collection.TraversableLike$class.map(TraversableLike.scala:234)
        at scala.collection.AbstractTraversable.map(Traversable.scala:104)
        at kafka.server.KafkaHealthcheck.register(KafkaHealthcheck.scala:61)

表示解析不了server38这个host！

使用hostname可以看到，我们机器的hostname就是server38

修改/etc/hosts文件，增加一行如下内容即可：

127.0.0.1 server38 localhost