Where do I download all of the necessary classes to write Hadoop MapReduce jobs? [closed]
I assume you're using java...
Here you can download it.http://hadoop.apache.org/common/releases.html#Download
If you're on 20.X, you'll just need to import (putting it into your classpath) the hadoop-0.20.X-core.jar in the "root" folder. If > 20.X you have to use three jars: hadoop-common-0.21.0.jar, hadoop-hdfs-0.21.0.jar, hadoop-mapred-0.21.0.
Obviously you have to replace the 'x' with the suffix of the version you're using.