KafkaSpout throws NoClassDefFoundError for log4j

Question

For some reason, I get the following error when trying to run my topology in a Storm cluster:

java.lang.NoClassDefFoundError: Could not initialize class org.apache.log4j.Log4jLoggerFactory
  at org.apache.log4j.Logger.getLogger(Logger.java:39)
  at kafka.utils.Logging$class.logger(Logging.scala:24)
  at kafka.consumer.SimpleConsumer.logger$lzycompute(SimpleConsumer.scala:30)
  at kafka.consumer.SimpleConsumer.logger(SimpleConsumer.scala:30)
  at kafka.utils.Logging$class.info(Logging.scala:67)
  at kafka.consumer.SimpleConsumer.info(SimpleConsumer.scala:30)
  at kafka.consumer.SimpleConsumer.liftedTree1$1(SimpleConsumer.scala:75)
  at kafka.consumer.SimpleConsumer.kafka$consumer$SimpleConsumer$$sendRequest(SimpleConsumer.scala:69)
  at kafka.consumer.SimpleConsumer.getOffsetsBefore(SimpleConsumer.scala:128)
  at kafka.javaapi.consumer.SimpleConsumer.getOffsetsBefore(SimpleConsumer.scala:79)
  at storm.kafka.KafkaUtils.getOffset(KafkaUtils.java:77)
  at storm.kafka.KafkaUtils.getOffset(KafkaUtils.java:67)
  at storm.kafka.PartitionManager.<init>(PartitionManager.java:83)
  at storm.kafka.ZkCoordinator.refresh(ZkCoordinator.java:98)
  at storm.kafka.ZkCoordinator.getMyManagedPartitions(ZkCoordinator.java:69)
  at storm.kafka.KafkaSpout.nextTuple(KafkaSpout.java:135)
  at backtype.storm.daemon.executor$fn__3373$fn__3388$fn__3417.invoke(executor.clj:565)
  at backtype.storm.util$async_loop$fn__464.invoke(util.clj:463) at clojure.lang.AFn.run(AFn.java:24)
  at java.lang.Thread.run(Thread.java:745)cg

What is the problem and how to solve it?

Here are the dependencies that I include:

 <dependencies>
    <dependency>
        <groupId>org.apache.storm</groupId>
        <artifactId>storm-core</artifactId>
        <version>0.9.5</version>
        <scope>provided</scope>
    </dependency>
    <dependency>
        <groupId>org.apache.kafka</groupId>
        <artifactId>kafka_2.10</artifactId>
        <version>0.8.2-beta</version>
    </dependency>
    <dependency>
        <groupId>org.apache.storm</groupId>
        <artifactId>storm-kafka</artifactId>
        <version>0.9.5</version>
    </dependency>
    <dependency>
        <groupId>org.codehaus.jackson</groupId>
        <artifactId>jackson-mapper-asl</artifactId>
        <version>1.9.11</version>
    </dependency>
    <dependency>
        <groupId>org.java-websocket</groupId>
        <artifactId>Java-WebSocket</artifactId>
        <version>1.3.0</version>
    </dependency>
    <dependency>
        <groupId>org.twitter4j</groupId>
        <artifactId>twitter4j-core</artifactId>
        <version>[3.0,)</version>
    </dependency>
    <dependency>
        <groupId>org.twitter4j</groupId>
        <artifactId>twitter4j-stream</artifactId>
        <version>[3.0,)</version>
    </dependency>
</dependencies>

Answer 1

The fact is that you should enable Kafka as follows:

   <dependency>
        <groupId>org.apache.kafka</groupId>
        <artifactId>kafka_2.10</artifactId>
        <version>0.8.1.1</version>
        <exclusions>
            <exclusion>
                <groupId>org.apache.zookeeper</groupId>
                <artifactId>zookeeper</artifactId>
            </exclusion>
            <exclusion>
                <groupId>log4j</groupId>
                <artifactId>log4j</artifactId>
            </exclusion>
        </exclusions>
    </dependency>

For the following reason:

Note that ZooKeeper and log4j dependencies are excluded to prevent version conflicts with Storm dependencies.

Answer 2

Are you using the correct logging structure?

From https://storm.apache.org/2013/12/08/storm090-released.html

Journal Changes

0.9.0 . Storm API slf4j ( loglog logger). Storm API log4j, Storm log4j-over-slf4j.

, API log4j.

, , Storm API slf4j .

, Storm, jar .

Answer 3

I encountered the same problem when I turned on the kafa like you, so I turned on the kafa in a different way according to the exception:

SLF4J: Detected both log4j-over-slf4j.jar AND slf4j-log4j12.jar on the class path, preempting StackOverflowError. SLF4J: See also http://www.slf4j.org/codes.html#log4jDelegationLoop for more details.

You can enable kafka as follows:

<dependency>
        <groupId>org.apache.kafka</groupId>
        <artifactId>kafka_2.10</artifactId>
        <version>${kafka.version}</version>
        <exclusions>
            <exclusion>
                <groupId>org.apache.zookeeper</groupId>
                <artifactId>zookeeper</artifactId>
            </exclusion>
            <exclusion>
                <groupId>org.slf4j</groupId>
                <artifactId>slf4j-log4j12</artifactId>
            </exclusion>
            <exclusion>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
        </exclusion>
    </exclusions>
</dependency>