Database Reference
In-Depth Information
Figure 12-2.
User interface for managing agents within EM12c
For the EM12c release, agents were completely rewritten from the ground up for greater reliability, availability,
and performance (see the upcoming section on plug-ins for details on how this was achieved). The only downside
of this change is that you must use an EM12c agent to talk to the EM12c Oracle Management Service. Backward
compatibility between 12c and earlier agents was lost because of the number of changes that were made in the
new release.
Oracle Management Service
The
Oracle Management Service (OMS)
is a web-based application that communicates with the agents and the Oracle
Management Repository to collect and store information about all the targets on the various agents. (Note that the
information itself is stored in the Oracle Management Repository, not the OMS.) The OMS is also responsible for
rendering the user interface for the console.
The OMS is installed into an Oracle middleware home, which also contains the Oracle WebLogic Server
(including the WebLogic Server administration console), an Oracle Management agent for the middleware tier, the
management service instance base directory, the Java Development Kit (JDK), and other configuration files. You
can install the OMS into an existing WebLogic Server (WLS) configuration if it exists, but usually it is better from an
availability perspective to have it installed in a dedicated WLS home.
Oracle Management Repository
The
Oracle Management Repository
(also called the
repository
or
OMR
) is an Oracle database that stores all the
information collected by the various management agents. It is composed of database users, tablespaces, tables, views,
indexes, packages, procedures, and database jobs.
Unlike the OMS, the installation process for the OMR requires that a database already exists for the repository.
This means you need to have created the database somewhere in your environment prior to installing the OMS.
Again, it is typically recommended for the repository to be created in a dedicated database.
