Component Migration

This section describes how to migrate customized components to MapR Hadoop.

MapR Hadoop features the complete Hadoop distribution including components such as Hive. There are a few things to know about migrating Hive, or about migrating custom components you have patched yourself.

Custom Components

If you have applied your own patches to a component and wish to continue to use that customized component with the MapR distribution, you should keep the following considerations in mind:

  • MapR libraries: All Hadoop components must point to MapR for the Hadoop libraries. Change any absolute paths. Do not hardcode hdfs:// or maprfs:// into your applications. This is also true of Hadoop ecosystem components that are not included in the MapR Hadoop distribution (such as Cascading). For more information see Working with MapR-FS.
  • Component compatibility: Before you commit to the migration of a customized component (for example, customized HBase), check the MapR release notes to see if MapR Technologies has issued a patch that satisfies your business requirements. MapR Technologies publishes a list of Hadoop common patches and MapR patches with each release and makes those patches available for our customers to take, build, and deploy.
  • ZooKeeper coordination service: Certain components depend on ZooKeeper. When you migrate your customized component from the HDFS cluster to the MapR cluster, make sure it points correctly to the MapR ZooKeeper service.