Hadoop - Error: Found interface org.apache.hadoop.mapreduce.TaskAttemptContext

Question

I'm using hadoop to design mapreduce job. I decided to create a custom InputFormat. When I want to run the job on my Hortonworks Sandbox, I got this error :

Error: Found interface org.apache.hadoop.mapreduce.TaskAttemptContext, but class was expected

According to some topics on forums (like here), it is a version problem : in Hadoop 2.x, TaskAttemptContext is an interface, before it was a class.

Here is my pom.xml file :

<dependencies>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.4</version>
    </dependency>

    <dependency>
        <groupId>org.apache.hadoop</groupId>
        <artifactId>hadoop-common</artifactId>
        <version>2.2.0</version>
    </dependency>

    <dependency>
        <groupId>org.apache.hadoop</groupId>
        <artifactId>hadoop-core</artifactId>
        <version>1.2.1</version>
    </dependency>



    <dependency>
        <groupId>jdk.tools</groupId>
        <artifactId>jdk.tools</artifactId>
        <version>${java.version}</version>
        <scope>system</scope>
        <systemPath>${JAVA_HOME}/lib/tools.jar</systemPath>
    </dependency>
    <dependency>
        <groupId>org.apache.mrunit</groupId>
        <artifactId>mrunit</artifactId>
        <version>0.9.0-incubating</version>
        <classifier>hadoop1</classifier>
    </dependency>

</dependencies>

Thanks to help me if you have an idea.

Answer 1

This probably means you compiled your code against an earlier version of Hadoop than you're running on.

This might have something to do with it...

<dependency>
    <groupId>org.apache.hadoop</groupId>
    <artifactId>hadoop-common</artifactId>
    <version>2.2.0</version>
</dependency>

<dependency>
    <groupId>org.apache.hadoop</groupId>
    <artifactId>hadoop-core</artifactId>
    <version>1.2.1</version>
</dependency>

You have two different versions of Hadoop here.