Oracle Enterprise Manager (OEM) is a set of web-based tools aimed at managing software and hardware produced by Oracle Corporation as well as by some non-Oracle entities.

Oracle Enterprise Manager includes three releases:

Oracle Enterprise Manager Database Control, the oldest and arguably the best-known release, aims to manage Oracle databases. It originated as a Java client able to configure and manage databases.

Oracle Application Server also has a web-interface to manage the application server.

To manage many databases and application servers (according to Oracle Corporation, preferably in a grid solution), the Oracle Enterprise Manager Grid Control can be used. It can manage multiple instances of Oracle deployment platforms; the most recent edition also allows for management and monitoring of other platforms such as Microsoft .NET, Microsoft SQL Server, NetApp filers, BEA Weblogic and others. Partners and IT organizations can build extensions to Oracle Enterprise Manager, and make them available to other Enterprise Manager users via an Oracle hosted web site called Oracle Enterprise Manager Extensibility Exchange.

System monitoring features include monitoring functionality that supports detection and notification of impending IT problems. It monitors Oracle Database instances, Oracle Real Application Clusters, and Oracle Application Server Farms and Clusters. 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 architecture of the OEM for Grid Control has three distinct components:

The OMA runs on the target host and collects information on the hardware, operating system, and applications that run on the target. The OMS runs on one or two servers and collects the data generated by the OMAs. The OMS pulls the information from the OMAs and aggregates the collections into the repository. 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.