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Overview of Oracle Enterprise Manager

Oracle Enterprise Manager is a system management tool that provides an integrated solution for centrally managing your heterogeneous environment. Combining a graphical console, Oracle Management Servers, Oracle Intelligent Agents, common services, and administrative tools, Oracle Enterprise Manager provides a comprehensive systems management platform for managing Oracle products.

From the client interface, the Oracle Enterprise Manager Console, you can perform the following tasks:

• Centrally administer, diagnose, and tune multiple databases

• Manage Oracle products and services other than databases

• Effectively monitor and respond to the health of your Oracle family of products and third-party services 24 hours a day

• Schedule activities on multiple nodes at varying time intervals

• Monitor networked services for events

• Customize your display by organizing databases and other services into logical administrative groups

This chapter presents an overview of Oracle Enterprise Manager's benefits, architecture, and major components. The chapter is divided into the following sections:

Topic	See Page
Three-Tier Framework	1-2
Benefits of Oracle Enterprise Manager	1-9
The Basic Components	1-9

Three-Tier Framework

Oracle Enterprise Manager architecture consists of a three-tier framework. Unlike a two-tier client-server structure, where a client tier responsible for the presentation of information accesses data from a server, Release 2 of Oracle Enterprise Manager utilizes a three-tier architecture which includes:

• Console and management applications--first tier

• Oracle Management Server(s)--second tier

• Managed nodes containing databases and other services--third tier

With Oracle Enterprise Manager, data-intensive business logic is moved off the client and is recast as shared services on one or more middle-tier Oracle Management Servers, providing reliability, scalability, and fault tolerance for enterprise environments.

Figure 1-1 Three-Tier Architecture

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Clients

The first tier of Oracle Enterprise Manager is comprised of clients such as consoles and management applications, which present graphical user interfaces to administrators for all management tasks. These client components can be installed locally or brought up with a web browser.

The first-tier clients depend on second-tier Oracle Management Servers for the bulk of their application logic. The consoles and management applications communicate with one or more Oracle Management Servers via standard CORBA interfaces and IIOP.

Figure 1-2 First Tier

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Oracle Management Server

The second tier of the Oracle Enterprise Manager framework is comprised of one or more Oracle Management Servers. The Management Server is the core of the Enterprise Manager framework. It provides administrative user accounts, processes management functions such as jobs and events, and manages the flow of information between the Console (first tier) and the managed nodes (third tier).

Figure 1-3 Second Tier

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The Oracle Management Server uses a repository to store all system data, application data, information about the state of managed nodes, and information about any system management packs. A repository is a set of database tables that must be located in any Oracle database accessible to the Oracle Management Server. If necessary, a large enterprise can use more than one Oracle Management Server in the middle tier. Multiple Oracle Management Servers share a repository and provide reliability and fault tolerance for one another.

One of the most important responsibilities of the Oracle Management Server is distributing tasks to the Oracle Intelligent Agents, which run on managed nodes in the third tier. The Intelligent Agents are responsible for the localized execution of tasks and the on-going monitoring of databases and other services on the managed nodes.

Managed Nodes

The third tier of the Oracle Enterprise Manager framework is comprised of managed nodes which contain databases and other managed services. Residing on each node is an Oracle Intelligent Agent, which communicates with the Oracle Management Server(s) and performs tasks sent by consoles and client applications.

Figure 1-4 Third Tier

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The Oracle Intelligent Agent monitors databases and other services in the node for registered events (potential problem occurrences) and scheduled jobs (activities), both sent by the client via the middle-tier Oracle Management Server(s).

Intelligent Agents function independently of the databases and other services they support, and also function independently of the Console, management applications, and Oracle Management Servers. By running independently of other components, Intelligent Agents can perform such tasks as starting up and shutting down a database and staying operational if another part of the system is down.

Intelligent Agents support Simple Network Management Protocol (SNMP), enabling third-party applications to communicate with the Intelligent Agent and be managed along with Oracle services.

The Intelligent Agent also includes a data collection service that collects system performance data (for example, file I/O or CPU usage data) for Capacity Planner and Performance Manager, which are data-analysis applications in the optional Oracle Diagnostics Pack, Oracle Management Pack for Oracle Applications, and Oracle Management Pack for SAP R/3.

Benefits of Oracle Enterprise Manager

Oracle Enterprise Manager enables administrators to maintain the highest level of performance and availability while controlling system management costs. This section describes the major benefits of Oracle Enterprise Manager and its scalability, power, and reliability.

Topic	See Page
Single Point of Management	1-6
Multi-Administrator System	1-7
Scalability for Growing, Distributed Environments	1-7
Extensible Architecture	1-8
Automated Lights-out Administration	1-8
Autonomous Intelligent Agent	1-8
Ease of Use	1-9

Single Point of Management

From the Oracle Enterprise Manager Console, you can manage and administer all your distributed systems, databases, tools, and users from a central location. Through an intuitive graphical user interface that provides powerful and robust system management, the Console gives you a central point of control for the Oracle environment. The easy-to-use interface enables even junior systems administrators to be effective with minimal training.

With Oracle Enterprise Manager, a distributed enterprise can be managed as easily and effectively as a local workgroup, lowering the cost of system ownership. The Oracle Enterprise Manager framework allows the automation and delegation of routine, time-consuming tasks on multiple services. Jobs can be scheduled on multiple nodes simultaneously and groups of services can be monitored together.

Multi-Administrator System

In many enterprises, teams of database administrators must cooperate to manage numerous systems, often remotely. With Oracle Enterprise Manager, database management tasks can be organized and distributed in multi-administrator enterprises, and system data can be safely shared among administrators.

With Oracle Enterprise Manager, system data, application data, and the state of managed services is contained in the Oracle Management Server and a backend repository, which stores all administrative data. (If you are using more than one Oracle Management Server, they share a repository). The Oracle Management Server handles security and distributes notifications and management information to administrators based on the permissions that are set up for them in the repository. Each administrator has an account which provides access to the Oracle Management Server and the central data stored in the repository.

The Oracle Management Server filters information as it flows between different consoles and the services on the managed nodes. Because all administrative data is stored in a central repository, administrators can work together and see the activity of other administrators. This distribution of information reduces redundancy, which saves time and keeps administrative costs down.

Scalability for Growing, Distributed Environments

With its three-tier architecture, Oracle Enterprise Manager is more scalable than ever in maintaining performance and automating routine tasks in rapidly growing, distributed environments. As the number of nodes and managed services in your network increases, or if the current Oracle Management Server is overloaded, you can add more Oracle Management Servers to the middle tier to share and balance the workload. Balancing the workload in the middle tier rather than investing in additional systems management overhead, controls the cost of systems management.

Because multiple Oracle Management Servers share a repository as their back-end store, they provide fault tolerance for each other. If one Oracle Management Server goes down, the clients registered with it can immediately log in again and register with any of the other Oracle Management Servers running with that repository, and work continues seamlessly. Any clients registered with an Oracle Management Server other than the failed one are unaffected.

For failover and scalability of the repository database, Oracle has database solutions such as Oracle Parallel Server, failover, Replication Management, clustering, and others.

Extensible Architecture

Oracle Enterprise Manager's flexible architecture allows new products and additional modules to be written and added to the suite. Oracle Enterprise Manager's use of open standards (CORBA, IIOP, etc.) makes it possible to integrate third-party tools into the Console.

Automated Lights-out Administration

In a large, distributed database environment, the proportion of managed nodes per administrator increases rapidly, requiring tools that can automate tasks. Oracle Enterprise Manager offers automated, "lights-out" task management and proactive service monitoring for pre-set events, which enables control of the enterprise without necessarily needing additional staff to meet increasing system responsibilities.

Using the Job Scheduling System, you can automate routine tasks such as database backups or running reports on a regular basis. Using the Event Management System, you can have remote databases and other services monitored for important occurrences (events) and set up "fixit" jobs that automatically execute in response to events. Monitoring of services for occurrences and automatic problem correction ensures that problems are dealt with before they noticeably impact end users.

Autonomous Intelligent Agent

Because jobs are executed locally at the managed nodes, they can be completed even when a crucial part of the network is down. Localized tasks are dependable because all jobs are processed by the Intelligent Agents on the individual managed nodes.

For example, if you schedule a job to run on a node, the job will be executed locally at the node at the specified time, and will run even if a network outage occurs between the node, the Oracle Management Server, and the Console. If a service on the node is down, the Intelligent Agent stores any jobs to be performed on the service until the service is back up. If the Console is down, the Intelligent Agent stores any information about the status of the job until the Console is back in service and can receive information.

Ease of Use

Oracle Enterprise Manager provides a complete user-friendly system management solution that allows administrators to manage distributed environments with a minimum of effort. With the ability to see operational data in remote managed services, an administrator can more easily make changes and execute commands. The Oracle Enterprise Manager framework is designed to offer high scalability without increasing complexity, allowing an administrator to manage more and more services, confident that the environment is under control.

In addition, all Oracle Enterprise Manager applications have a similar graphical user interface allowing the administrator to manage the Oracle enterprise using the same familiar front end with each application. This interface can be used by both beginning and advanced users, and also can serve as a training tool when used with the Oracle Enterprise Manager wizards and quick tours.

Additionally, the Oracle Management Servers and Consoles require little or no configuration. Manual intervention from the administrator is reduced to an absolute minimum.

The Basic Components

This section describes in further detail the basic components of Oracle Enterprise Manager and contains the following sections:

Topic	See Page
Console	1-9
Oracle Management Server	1-11
Common Services	1-12
DBA Management Pack	1-17

Console

The Oracle Enterprise Manager Console is a client graphical user interface which provides menus, toolbars, and drawers allowing access to Oracle tools as well as utilities available through other vendors. The Console is partitioned into four panes for different administrative purposes. These panes include:

• Navigator pane

• Group pane

• Jobs pane

• Events pane

Figure 1-5 shows the Console screen.

Figure 1-5 Oracle Enterprise Manager Console

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Oracle Management Server

The Oracle Management Server is the middle tier in the Oracle Enterprise Manager framework and provides centralized intelligence and controlled distribution between console clients and managed nodes. A central engine for notification, the Oracle Management Server processes all system management tasks and administers the distribution of these tasks to Intelligent Agents on managed nodes across the enterprise.

Figure 1-6 Management Server as Central Engine for Notification

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When multiple Oracle Management Servers are used, they share and balance the workload, ensuring high performance and scalability.

Common Services

Oracle Enterprise Manager is made up of common services that help you manage the Oracle environment.

These common services include:

• Repository

• Service Discovery

• Job Scheduling System

• Event Management System

• Notification System and Filtering

• Paging/Email Blackouts

• Security

• Generate an Enterprise Report

• Font Control

Repository

A repository is a set of tables in an Oracle database and is used as a back-end store by the Oracle Management Server(s). The Repository contains state information for the managed environment, including the management packs, and is created when you set up an Oracle Management Server using the Oracle Enterprise Manager Configuration Assistant. The repository tables can be installed in any database accessible to the Oracle Management Server.

Whatever the administrator sees on the Console when connected to the Oracle Management Server is determined by the administrator's permissions data stored in the repository.

Service Discovery

Oracle Enterprise Manager automatically discovers (locates) all the databases and other services running on the managed nodes once the nodes are identified. During the discovery process, Intelligent Agents search for services on the nodes they manage, then communicate their findings to the Oracle Management Server. Discovered services are then displayed in a hierarchical tree view in the Navigator window of the Console, displaying a big-picture view of all discovered nodes and their respective services.

Job Scheduling System

The Job Scheduling System enables the automation of standard and repetitive administrative tasks. With the Job Scheduling System, you can create and manage jobs, schedule their execution, and view and share information about defined jobs with other administrators connected to the repository. Upon job completion or failure, the system automatically notifies you and/or other administrators through Console alert (with view permissions), e-mail, or page.

Because a job is an administrative entity (object) within the Oracle Enterprise Manager framework, an owner is always specified for the job as well as basic security parameters, which prevent or allow viewing and modifications by other administrators.

Event Management System

The Event Management System allows the Oracle environment to be monitored for operational occurrences and borderline conditions such as loss of service, shortage of storage, and resource problems such as high CPU usage.

These critical occurrences, called "events", are each made up of one or more "tests" which an Intelligent Agent makes towards a managed service when an event is registered against it. When you register an event through the Console, you define the event condition by selecting one or more tests.

When an event occurs and is detected by an Intelligent Agent, specified administrators are notified by Console alert, e-mail, or page, depending on their permissions and preferred credentials. You can also set up a "fixit" job to run automatically in response to an event.

As in the Job Scheduling System, you can share event information with other administrators connected to the repository. Events are also objects within the Oracle Enterprise Manager framework and are assigned owners and security parameters.

Notification System and Filtering

Administrators can be notified of the status of jobs and events by Console alert, e-mail, or page. When scheduling a job or registering an event, you set up notification procedures and choose which administrators to have notified of job completion or failure or event occurrence. You also can specify different email and page filters to administrators in response to events and job status notifications.

Paging/Email Blackouts

Oracle Enterprise Manager has a paging and email blackout feature, which prevents administrators from being flooded with emails and pages if a managed service is brought down. For example, if a service is brought down on a regular basis for scheduled maintenance, you can specify paging and email "blackouts" for the services during those periods. During a specified blackout, enhanced notification (paging/e-mail) is deactivated while the service is down.

Security

Security parameters in Oracle Enterprise Manager are defined for services, objects, and administrators. All administrator accounts are defined by a Super Administrator who creates and defines the permissions of all the repository's administrators. A Super Administrator can access any object and control its security parameters, including objects owned by other administrators. Security parameters are set up in the Preferences dialog box, shown in Figure 1-7, "Preferences Dialog Box".

Figure 1-7 Preferences Dialog Box

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The following table describes the options available in each tab of the Preferences dialog box.

Preference	Description
General	The General tab is for editing your name and password and enabling or disabling Advanced Mode, which displays advanced DBA features.
Notification	The Notification tab is for configuring the paging server and carriers, and setting up paging and e-mail preferences, including notification filtering. It can also be used to send test pages and e-mails.
Schedule	The Schedule tab is for setting up the notification schedule for an administrator. This tab is for entering the times and dates when you, as an administrator, can be notified of any job or event occurrence.
Default Permissions	The Default Permissions tab is for choosing the default permissions settings for objects that you create (jobs, events, and groups). These permissions affect whether other administrators can access the objects you create, and if they can, whether they have modify permissions or just view permissions. You can also choose whether to have other administrators notified of event and job status. Overriding your default permissions when creating an object is also possible. For example, your default permissions will automatically be applied when you create a job, but you can override these permissions during job creation if you prefer.
Preferred Credentials	The Preferred Credentials tab is for setting up names, passwords, and roles for nodes, listeners, databases, and other services that you administer in the network. With your credentials for these services pre-set, you only need to log into the Console once, and then are transparently logged into a service when you select it anywhere in the Console.

If you try to access an object or service for which your preferred credentials are not set up, the service will try using your Console login information.

Generate an Enterprise Report

Generating an Enterprise Report allows you to create an HTML-based Enterprise Report containing information such as event alerts, scheduled jobs, groups, and discovered services for all managed nodes in your enterprise. For more information, see the Oracle Enterprise Manager online help.

Font Control

You can control font size and style. If the default fonts are too large or small for your display, you can change them from the Console. Any application which is then launched from the Console will display the updated font size.

DBA Management Pack

Bundled with Oracle Enterprise Manager is the DBA Management Pack, which is an integrated set of standard database administration tools to help automate and simplify the common daily tasks of administrators. These supplemental tools focus on specific areas of database administration, helping administrators with their daily and routine tasks of managing databases and other services and keeping them operational.

Oracle Enterprise Manager also contains integrated applications for help in managing the Oracle Environment.