9 Understanding Discovery

9.1 Introduction to Automatic Discovery

Adding a target to Enterprise Manager through discovery involves two steps:

1. Discovering potential targets on hosts that are managed by Enterprise Manager.

2. Promoting targets to be managed by Enterprise Manager by assigning the target to a Management Agent.

Users can enable automatic discovery of potential targets on a host managed by Enterprise Manager.

To enable auto discovery, Management Agent-side discovery scripts are packaged with the plug-in. When auto discovery is configured on a host, the discovery part of the plug-in (discovery scripts) is deployed on the host.

After auto discovery is configured to run on the managed host, discovery takes place periodically and sends potential targets to the Management repository.

Users can view the targets from the discovery results UI and then take various actions such as promoting the target to be managed by Enterprise Manager.

9.2 What's New in Discovery?

This section describes the new features of discovery:

• You can configure automatic discovery for targets in a plug-in to be run at the Management Agent-side. Currently, automatic discovery is scheduled to run every day.

• After automatic discovery is configured and run, the Management Agent sends the targets back to the Oracle Management Service to be reviewed by the user.

• The user can configure targets that are not yet managed and promote them so that they can by managed by Enterprise Manager.

9.3 Automatic Discovery Overview

This section provides an overview of the components of automatic discovery:

• Plug-in

  The plug-in contains the components required to discover and promote targets of a particular target type. The plug-in includes discovery metadata to register with the discovery framework, discovery scripts, and monitoring scripts.

  Note:

  Only the discovery part of the plug-in (discovery scripts and any content required to run discovery) is deployed when scheduling discovery.

  The complete plug-in (monitoring and discovery) is deployed only when the discovered target is promoted or when a target is manually added.

• Discovery module

  The discovery module defines a set of target types to discover on the hosts to which the plug-in is deployed.

  Specify discovery modules in the discovery metadata XML file. For information about the discovery metadata XML file, see the Enterprise Manager Programmer's Reference.

• Discovery metadata

  Discovery metadata enables you to register automatic discovery with the discovery framework. The Extensibility Development Kit (EDK) provides a discovery XML schema definition (XSD) for registering automatic discovery. For information about defining discovery metadata and a description of the elements, see the Enterprise Manager Programmer's Reference.

• Discovery Content

  Discovery content includes all the Perl scripts and JAR files that are required to discover targets of a particular type.

• Discovery parameters

  A discovery parameter passes input entered from the UI to the discovery script. These discovery parameters are available as environment variables in the discovery script running at the Management Agent. The discovery script uses this information when performing discovery.

  Define discovery parameters in the discovery metadata XML file. For information about the discovery metadata XML file, see the Enterprise Manager Cloud Control Programmer's Reference.

• Discovery schedule

  For plug-ins that are deployed already when Management Agents are installed or deployed to new hosts, and if discovery does not require any user inputs, then discovery is configured automatically and runs every 24 hours.