Category Archives: How-to

How-to: Include Third-Party Libraries in Your MapReduce Job

Categories: Hadoop HBase How-to MapReduce

“My library is in the classpath but I still get a Class Not Found exception in a MapReduce job” – If you have this problem this blog is for you.

Java requires third-party and user-defined classes to be on the command line’s “classpath” option when the JVM is launched. The hadoop wrapper shell script does exactly this for you by building the classpath from the core libraries located in /usr/lib/hadoop-0.20/ and /usr/lib/hadoop-0.20/lib/ directories.

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