Data Warehouse and Databases

There are two PostgresSQL databases in Oracle Linux Virtualization Manager. The engine configuration creates a database called engine. If you elect to install the ovirt-engine-dwh package, a second database called ovirt_engine_history is created:

• The engine database (engine) stores persistent information about the state of the Oracle Linux Virtualization Manager environment, its configuration, and its performance. The historical configuration information and statistical metrics are collected every minute.
• The data warehouse database is a management history database (ovirt_engine_history) that can be used by any application to retrieve historical configuration information and statistical metrics for data centers, clusters, and hosts.

The data warehouse service (ovirt-engine-dwd):

• Extracts data from the engine database, performs ETL, and inserts it into the ovirt_engine_history database.

• Tracks three types of changes:

  • When new entity is added to the engine database, ovirt-engine-dwd service replicates the change to the ovirt_engine_history database.
  • When an existing entity is updated, ovirt-engine-dwd service replicates the change to the ovirt_engine_history database.
  • When an entity is removed from the engine database, a new entry in the ovirt_engine_history database flags the corresponding entity as removed.

Both the history and engine databases can run on a remote host to reduce the load on the engine host. Running these databases on a remote host is a technology preview feature. For more information, see Technology Preview in the Oracle Linux Virtualization Manager: Release Notes.