Monitoring the Hosting Platform - Expert Consolidation in Oracle Database 12c - page 298

Managing Database Targets
Managing and monitoring databases is at the core of what Enterprise Manager really is made for. In the following
section you will learn how to add a host to the Enterprise Manager configuration, and how to discover targets. The first
step towards monitoring a target is to install an agent on a host. Using that agent you can then discover targets, either
manually or using an automated process. Once the targets are added you can group them into administrative groups,
allowing monitoring templates to be added automatically.

Deploying an Agent to a New Host
The agent deployment can be performed either via the OEM console, or alternatively from the command line. The
command line installation is more suitable for a mass deployment of the agent, and it will be covered here. When
installing the agent you will notice a slightly different directory structure than the previous versions of the agent.
During the installation you need to define an agent base directory, which contains all agent related files. There are
three directories of higher importance:

• The agent home directory

• The agent instance directory

•
The agent instance directory contains all configuration files, and especially the all-important sysman directory
containing the log files for the agent. The instance home is not to be confused with the agent home directory, which
is below $AGENT_BASE/core/ version . The agent home contains the binaries used to run the agent on the server, but
confusingly the emctl executable recommended for use with the agent is in the instance home. The plugins directory
contains the plugins currently installed for the agent.
You can make use of the Enterprise Manager command line interface for mass-deploying the agent. Log in as the
OMS software owner on an arbitrary management host. You then create a zip file with the agent software for a specific
platform. If you wanted to create the deploy image for the Linux x86-64 agent, you should follow these steps:

The plugins directory

[oracle@oem12oms1 ~]$ emcli login -username=sysman
Enter password

Login successful

Once logged in you can query the agents currently available on the management host:

[oracle@oem12oms1 ~]$ emcli get_supported_platforms
Getting list of platforms ...
Check the logs at /u01/app/oracle/oem12/gc_inst/em/EMGC_OMS1/sysman/emcli/ 
setup/.emcli/agent.log
About to access self-update code path to retrieve the platforms list..
Getting Platforms list ...
-----------------------------------------------
Version = 12.1.0.2.0
Platform = Linux x86-64
-----------------------------------------------
Platforms list displayed successfully.