Migration assumptions and prerequisites

Before you upgrade your CDH cluster to Cloudera Private Cloud Base or migrate content from Navigator to Apache Atlas, ensure that you have collected all the credentials and set expectations for the time required for completing the migration process.

The prerequisites in this section help you to prepare in advance to migration.

In addition to the prerequisites outlined for the Cloudera Manager and Cloudera upgrades, you shall need the following for the Navigator to Atlas migration:

Deleted entities in Navigator. Check the Navigator Administration page to make sure that a successful purge has run recently. If not, consider running a purge before the migration. See Managing Metadata Storage with Purge.
Role to host assignments. Before you begin upgrading to Cloudera, make a plan for where you will install the Atlas server. In addition, Atlas depends on the HBase, Kafka, and Solr services; your plan should include host assignments for installing the components of these services. See Runtime Cluster Hosts and Role Assignments.
Resources for Atlas service. Atlas requires 16 GB of Java heap (Atlas Max Heapsize property) and 4 Solr shards (Initial Solr Shards for Atlas Collections property). Make sure the host you choose for Atlas has enough resources for all the services' requirements.

caution

You must note about the default values for Initial Solr Shards for Atlas Collections in your Cloudera Manager UI. Before you commence the Atlas initialization process, based on your performance requirements, you must decide the actual (correct) values for Initial Solr Shards for Atlas Collections in your Cloudera Manager instance. Cloudera recommends to set 4 Solr shards (Initial Solr Shards for Atlas Collections property). Also, you must not update or modify these values after the Atlas initialization has commenced. Additionally, note that once the Atlas initialization process is completed, modifying the value of Initial Solr Shards for Atlas Collections or Initial Solr Replication Factor for Collections will not have any effect on the collections for Atlas in Solr.

Resources for Solr service. During migration, Solr running to serve as Atlas' index requires 12 GB of Java heap (Java Heap Size of Solr Server in Bytes property). You can reset this to make sure the host you chose for Atlas has enough resources for all the services' requirements.
Navigator credentials. The migration requires the username and password for a Navigator user with administrator privileges.
Local disk space needed for intermediate processing. The first two phases of the Navigator-to-Atlas migration produce intermediate files in the /tmp folder in the local file system where Atlas is installed. See Estimating migration time and resources required.
Local disk space for migration staging files. The first two phases of the Navigator-to-Atlas migration produce staging files on the local disk where Atlas is installed. See Estimating migration time and resources required.
Time estimates for migration phases. Each phase of the migration runs independently from the upgrade. You can trigger them to run when convenient. See Estimating migration time and resources required.