maven - Differences between Hadoop-common, Hadoop-core and Hadoop-client?

Question

I am newer to Hadoop, and want to know what is the differences between Hadoop-common, Hadoop-core and Hadoop-client?

By the way,for a given class, how do I know which artifact contains it in Maven ? For example, which one contains the org.apache.hadoop.io.Text?

Answer 1

To help provide some additional details regarding the differences between Hadoop-common, Hadoop-core and Hadoop-client, from a high-level perspective:

• Hadoop-common refers to the commonly used utilities and libraries that support the Hadoop modules.
• Hadoop-core is the same as Hadoop-common; It was renamed to Hadoop-common in July 2009, per https://hadoop.apache.org/.
• Hadoop-client refers to the client libraries used to communicate with Hadoop's common components (HDFS, MapReduce, YARN) including but not limited to logging and codecs for example.

Generally speaking, for developers who build apps that submit to YARN, run a MR job, or access files from HDFS use Hadoop-client libraries.