4. Improvements

When using Ambari Blueprints, component topology is validated based on dependency and cardinality information provided in the associated Ambari Stack definition. In addition to validation, some components (mostly clients) are auto-deployed if not present in the topology, which is specified in the corresponding Stack definition as well. Topology validation is performed by default during blueprint creation. To create a blueprint that does not validate, a user can disable topology validation in the URL via '?validate_topology=false'.

During host registration (either during cluster install or add hosts), if using a Custom JDK Path, Ambari will check that the path exists on the host.

Host Check - Hostname Resolution

During host registration (either during cluster install or add hosts), Ambari will check that on each host, the other hosts in the cluster are resolvable.

Host Check - Hostname Reverse Lookup

During host registration (either during cluster install or add hosts), Ambari will check that host reverse lookup can be performed correctly.

Test External Database Connections

Ability to perform “test database connection” when using an external database for Hive Metastore or Oozie.

Simplified External Database JDBC Driver Setup

If you plan to use an external database for Hive Metastore or Oozie, during Ambari Server setup, provide the JDBC driver. Ambari can then copy the driver to the appropriate host during cluster install. Learn more about JDBC Driver Setup here. Learn more about using an external database for Hive here, and for Oozie here.

Manage Stack Repositories from Ambari Web

Ability to manage Stack repository Base URLs from the Ambari Web. Learn more here.