OEM Grid Control comes with a set of performance and health metrics that allow monitoring of technology components such as applications, application servers, databases, as well as the back-end components on which they rely, such as hosts, operating systems and storage.
The OMS also acts as the user-interface — by generating web-pages for database administrators to view the status of systems and services.
The OMR comprises an instance of the Oracle database that stores the data collected by the OMS.
Installers can make the OMR highly available or fault-tolerant by running it on an Oracle RAC instance across multiple nodes.
The current[update] release of OEM allows for the design and configuration of custom Plug-ins to monitor any application desired.