kafka NoClassDefFoundError kafka/Kafka

Question

Regarding Apache-Kafka messaging queue.

I have downloaded Apache Kafka from the Kafka download page. I've extracted it to /opt/apache/installed/kafka-0.7.0-incubating-src.

The quickstart page says you need to start zookeeper and then start Kafka by running:
>bin/kafka-server-start.sh config/server.properties

I'm using a separate Zookeeper server, so i edited config/server.properties to point to that Zookeeper instance.

When i run Kafka, as instructed in the quickstart page, I get the following error:

Exception in thread "main" java.lang.NoClassDefFoundError: kafka/Kafka
Caused by: java.lang.ClassNotFoundException: kafka.Kafka
        at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:252)
        at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320)
Could not find the main class: kafka.Kafka.  Program will exit.

I used telnet to make sure the Zookeeper instance is accessible from the machine that Kafka runs on. Everything is OK.

Why am i getting this error?

Answer 1

You must first build Kafka by running the following commands:

> ./sbt update
> ./sbt package 

Only then will Kafka be ready for use.