Enterprise Manager includes the following components:

• Oracle Management Agent

• Oracle Management Service

• Oracle Management Repository

• Plug-ins

• Enterprise Manager Console

Figure 1-2 shows a sample Enterprise Managerconfiguration and illustrates how these core components fit into the architecture.

The Management Agent is an integral software component that enables you to convert an unmanaged host to a managed host in the Enterprise Manager system. The Management Agent works in conjunction with the plug-ins to monitor the targets running on that managed host.

With the first Oracle Management Service (OMS) you install, by default you receive a Management Agent called the Central Agent. The Central Agent is used for monitoring only the first OMS host, the first OMS, and the other targets running on the first OMS host. To monitor other hosts and the targets running on those hosts, you must install a separate Standalone Management Agent on each of those hosts. Starting with Enterprise Manager 24ai, you can also install Remote Agents that allow you to monitor targets on remote hosts. Remote Agents can significantly reduce the number of agents you need to deploy on your managed environments, therefore simplifying the deployment and maintenance tasks.

Oracle Management Service (OMS) is a Web-based application that orchestrates with the Management Agents and the plug-ins to discover targets, monitor and manage them, and store the collected information in a repository for future reference and analysis. The OMS also renders the user interface for Enterprise Manager.

The OMS is deployed to the middleware home, which is the parent directory that contains Oracle WebLogic Server, OMS, plug-ins, Java Development Kit (JDK), Oracle WT directory, Oracle Common, and other relevant configuration files and directories. While installing the OMS, the Enterprise Manager installation wizard automatically installs Oracle WebLogic Server and JDK. Starting with Enterprise Manager 24ai, you can apply Enterprise Manager software updates without incurring any downtime. The detection of events on all managed targets, alerts, incidents, notifications, or connector processing can continue with no interruptions because all the monitoring components run inside of an independent application container, the Zero Downtime (ZDT) WebLogic container.

The Oracle Management Repository (Management Repository) is a storage location where all the information collected by the Management Agent gets stored. It consists of objects such as database jobs, packages, procedures, views, and tablespaces.

The OMS uploads the monitoring data it receives from the Management Agents to the Management Repository. The Management Repository then organizes the data so that it can be retrieved by the OMS and displayed in the Enterprise Manager console. Since data is stored in the Management Repository, it can be shared between any number of administrators accessing Enterprise Manager.

At the time of installation, the Enterprise Manager installation wizard configures the Management Repository in your existing, certified database. The wizard, however, does not install a new database.

Plug-ins are pluggable entities that offer special management capabilities customized to suit specific target types. In Enterprise Manager, the plug-ins work in conjunction with the OMS and the Management Agent to monitor every target in your environment. Therefore, they are deployed to the OMS as well as the Management Agent. In Enterprise Manager, plug-ins enable you to monitor all types of targets in your environment.

Plug-ins have independent release cycles, so every time you have a new version of an Oracle product released, you will have a new version of the plug-in released to support monitoring of that new product version in Enterprise Manager. An independent release cycle simplifies things because you no longer have to wait to upgrade your Enterprise Manager system to support a new product version; instead you can upgrade your plug-ins to monitor the new product version.

Table 1-1 lists the default plug-ins that are installed with a new Enterprise Manager system. In addition to these plug-ins, you can optionally install other plug-ins available in the software kit (DVD, downloaded software bundle, and so on). The installer offers a screen where you can select the optional plug-ins and install them.

For a complete list of the plug-ins available with Enterprise Manager, see Plug-ins Included In This Release in Oracle Enterprise Manager Release Notes.

Java Virtual Machine Diagnostics (JVMD) Engine enables you to diagnose performance problems in Java applications in the production environment. By eliminating the need to reproduce problems, it reduces the time required to resolve these problems, thus improving application availability and performance.

As part of the Oracle Fusion Middleware plug-in deployment, one JVMD Engine is installed and configured by default on the OMS. For every additional OMS you deploy, you receive one JVMD Engine by default with that OMS.

While JVMD Engine is installed by default on the OMS host, you will still need JVMD Agents to be manually deployed on the targeted JVMs.

Starting with Enterprise Manager 13.5, Oracle Business Intelligence (BI) Publisher is no longer bundled with the EM installation or managed by the EM utilities, EMCTL and EMCLI. BI Publisher, rebranded as Oracle Analytics Server (OAS) must be installed independently of Enterprise Manager and managed by OAS utilities. Update all your EMCTL or EMCLI scripts that make references to BI Publisher verbs.

For more information, see Oracle Analytics Server Technical Brief.

The Enterprise Manager console is the user interface you see after you install Enterprise Manager (Figure 1-1). With the help of the console, you can monitor and administer your entire computing environment from one location on the network. All the systems and services including enterprise application systems, databases, hosts, middleware application servers, listeners, and so on, are easily managed from one central location.

EMCTL is a command-line tool that enables you to execute certain tasks on the OMS and Management Agents. You can use it for tasks such as starting or stopping OMS instances, setting properties on OMS instances, or getting a list of targets being monitored by a specific Management Agent. EMCTL commands are executed on a specific OMS or Management Agent.

The Enterprise Manager Command Line Interface (EM CLI) is a command-line tool that is accessible through classic programming language constructs, enabling tasks to be created and run either from the command-line or programatically. EM CLI enables you to access Enterprise Manager functionality from text-based consoles (shells and command-line windows) for a variety of operating systems.