Database Reference
In-Depth Information
Chapter 1
Architecture
Oracle Enterprise Manager 12c provides a scalable and reliable central repository, a console, and services for
managing your all of your Oracle products. Users typically interact with OEM through the OEM console, which has a
rich intuitive graphical interface.
The Enterprise Manager Command-Line Interface (EM CLI) provides access to OEM system functionality outside
of the console. Interactive EM CLI tasks can replace lengthy click-streams in defining EM administrator accounts
and roles, as one example of its usefulness. EM CLI interactive commands can be used in shell scripts or can be CLI
invoked through CLI's own scripting mode in Jython.
This topic explores different ways you can apply these techniques to simplify and automate tasks in your Oracle
environment.
Enterprise Manager Framework
The Oracle Enterprise Manager application runs as a JEE application in a WebLogic Server J2EE domain on a
WebLogic server. This combination is known as the Oracle Management Server, or OMS.
Java processes running on the OMS gather and process XML file uploads that come from EM agents on your
remote hosts. That information is posted to a repository database, where it is stored in the SYSMAN schema.
When you view a page on your OEM console, the data is assembled from the repository database for
presentation. In the same way, commands that you issue from the console are processed through the OMS to update
repository information (metric collection or notifications, for instance) or manipulate managed targets either through
a call to the EM agent or through an authenticated connection to a remote database or host.
Each command issued by the console executes a Java program. The console solicits and assembles data as well
as the input commands required for those routines to execute. Much of the manipulative and query code base can be
accessed through EM CLI.
The EM CLI program is itself a lightweight Java program that performs the same activities as the console pages
but runs an immediate execution of OMS modules using values passed as command-line inputs; it is often employed
in shell scripts or Jython programs.
EM CLI Verbs
Interface commands are referred to as
verbs
. Each verb performs a single task and either succeeds with reasonable
feedback or comes back with a quick and obvious failure message.
Many verbs require input values on the command line. As with a PL/SQL package, your input must be passed to
the OMS using very specific syntax. The values are always preceded by a filter keyword, and most input requires your
strings to be wrapped in double-quotes.
