Relationship Between Loader and Other Components

The components that interact with Loader include HDFS, HBase, MapReduce, and ZooKeeper.

Loader works as a client to use certain functions of these components, such as storing data to HDFS and HBase and reading data from HDFS and HBase tables. In addition, Loader functions as an MapReduce client to import or export data.

Loader imports or exports jobs in parallel using MapReduce jobs. Some job import or export may involve only the Map operations, while some may involve both Map and Reduce operations.