Oracle Enterprise Manager Installation Guide

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Agent Configuration

Overview

The Intelligent Agent is used to manage an Oracle database on a remote machine. The Intelligent Agent is also a subagent to a master SNMP agent. With the agent properly configured and started, you can use Enterprise Manager to submit jobs to and register events at the node where the agent is running. The agent must be installed on each node you want to manage. The configuration of the Intelligent Agent depends on the version of the agent that is installed.

If you are installing the agent on UNIX, see Configuring an Intelligent Agent on a UNIX platform. If you are installing the agent on Windows NT, see Configuring an Intelligent Agent on Windows NT on page 2-4.

Configuring an Intelligent Agent on a UNIX platform

On Unix systems, the agent is normally installed by the root.sh script as a setuid program, a common Unix practice that allows it to run with root permissions while being invoked by users other than root. The agent must be installed as setuid root so that the agent can run jobs as the users whose name and password are given in the Preferred Credentials for that host. If the agent does not have root permission, all Enterprise Manager jobs are run with the permissions of the user who started the agent.

Note that the agent being set to setuid root does not have the same effect as having the root user start the agent. Having the root user start the agent is incorrect and causes the agent to malfunction. Consult your platform documentation for exact details on setuid programs.

On a Unix system, the user whose credentials are used to run a job should have write permissions in the network/agent directory.

At startup, the agent discovers new services on the machine where it is installed and creates its configuration files, snmp_ro.ora and snmp_rw.ora. If you want to discover a database, a tnsnames.ora file must exist on the node where the 7.3.3 Intelligent Agent is installed. The tnsnames.ora file must contain an entry for the database you want to discover. This file should be located in the $ORACLE_HOME/network/admin directory.

For a listener, a listener.ora file must also exist on the node where the 7.3.3 Intelligent Agent is installed. The listener.ora file should be located in the same directory as the tnsnames.ora file.

If you do not have a tnsnames.ora or listener.ora file, use Network Manager 3.1x to create them. Network Manager can be installed in your 16-bit $ORACLE_HOME from the Oracle Enterprise Manager 1.3.5 CD under the WINDOWS directory. For more information on Network Manager, see the Oracle Network Manager Administrator's Guide and Understanding SQL*Net.

On Unix systems, in addition to the tnsnames.ora and listener.ora files, the agent reads the oratab file. Depending on the platform, the oratab file is located in either the /etc or /var/opt/oracle directory.

There is one Intelligent Agent per node that can monitor all databases you have installed on the system.

If you are using multiple aliases for an Oracle database, the agent uses only the first one it finds during the discovery process. You can re-order the database entries in the tnsnames.ora file if you prefer a different alias name.

When you start the agent, the agent executes a script which reads configuration files, oratab, listener.ora, and tnsnames.ora, for services installed on the node and then generates the services.ora file. When a database or any other new service is installed on the node where the 7.3.3 agent resides, the agent must be restarted to add the new service to the agent configuration file, snmp_ro.ora.

If Oracle Names is in use for the node, snmp.ora must be in $ORACLE_HOME/network/admin, with the parameter NMI.REGISTER_WITH_NAMES set to TRUE. If this flag is detected when the agent starts, the information in the existing snmp.ora is used to discover Oracle services and construct the new configuration files. See Parameters for snmp*.ora Files on page A-9 for more information on configuration files.

Controlling Operations of the UNIX Agent

To start the agent on a Unix machine, enter the following command at the UNIX operating system prompt:

lsnrctl dbsnmp_start

The following warning message might display:

NMS-00001: dbsnmp unable to connect to SNMP master agent

This warning is only a problem if you intend to use the agent with an SNMP master agent, for example, if you want to monitor Oracle through HP OpenView. The agent is capable of running without SNMP.

To stop the agent on the UNIX platform, enter the following command at the system prompt:

lsnrctl dbsnmp_stop

To verify that the agent is running, enter the following command:

ps -aux | grep dbsnmp

The output from the ps command should contain two lines similar to the following:

.../bin/dbsnmp      root       18967 18456 1

Note:
For additional information or restrictions for your platform, see the Intelligent Agent README.

Configuring an Intelligent Agent on Windows NT

For a listener, a listener.ora file must also exist on the node where the 7.3.3 Intelligent Agent is installed. The listener.ora file should be located in the same directory as the tnsnames.ora file.

There is one Intelligent Agent per node that can monitor all databases you have installed on the system.

When you start the agent, the agent executes a script which reads configuration files, listener.ora, tnsnames.ora, and the NT Registry, for services installed on the node and then generates the services.ora file. When a database or any other new service is installed on the node where the 7.3.3 agent resides, the agent must be restarted to add the new service to the agent configuration file, snmp_ro.ora.

If Oracle Names is in use for the node, snmp.ora must be in $ORACLE_HOME\network\admin, with the parameter NMI.REGISTER_WITH_NAMES set to TRUE. If this flag is detected when the agent starts, the information in the existing snmp.ora is used to discover Oracle services and construct the new configuration files. See Parameters for snmp*.ora Files on page A-9 for more information on configuration files.

Creating a Windows NT User Account for Running Jobs

On the Windows NT machine where the agent is installed, you need to create an NT user account with the name and password that is used to send jobs from the Console.

To create a Windows NT user account, perform the following steps:

With the User Manager function of the Windows NT Administrator Tools, create a user on the NT machine. See the Windows NT documentation for information on the tools.

: Do not use system for the user name. Make sure the "User Must Change Password At Next Logon" option box is not checked.

2.

Use the User Rights option of the Policies menu of the User Manager NT utility to grant the "Log on as batch job" advanced user right to this user. You need to check the Show Advanced Rights box to display this right.

Controlling Operations of the NT Agent

To start or stop the agent on Windows NT, perform the following steps:

1.: Double-click the Services icon in the Control Panel folder.
2.: Select the OracleAgent service.
3.: Click the Start push-button to start the agent. Or click the Stop push-button to stop the agent.

When the agent is installed, the start-up is set to Manual. When the agent is shut down, all outstanding jobs are killed and failure reports are sent to the Console.

You can also start or stop the Agent from the DOS command prompt. To start the agent from the DOS prompt, enter the following command:

net start oracleagent

To stop the agent from the DOS prompt, enter the following command:

net stop oracleagent

To verify that the agent is running, enter the following command at the DOS prompt:

lsnrctl dbsnmp_status

Agent Configuration for Previous Releases

For releases previous to release 7.3.3 of Intelligent Agent, the primary configuration file for the agent (dbsnmp) is the snmp.ora file on the node where the agent resides.

Before starting the agent, the snmp.ora configuration file must be set up for your system. If SQL*Net version 2.3 has been installed and configured with the SQL*Net configuration tool, Network Manager 3.1, the file has already been configured for your system.

Refer to Appendix A, Configuration Files for examples of the configuration files that are needed.

Additional Information:
For more information on the snmp.ora configuration file, see the Oracle Network Manager Administrator's Guide, Oracle SNMP Support Reference Guide, and Oracle Network Products Messages Manual.

Roles and Users Required by the Agent

When an Oracle database is installed, the catsnmp.sql script is automatically run to create the necessary dbsnmp user account and the SNMPAGENT role for the Intelligent Agent. The agent uses the user/password provided by the Enterprise Manager Console to run all the event and job scripts. Each user wishing to monitor events on the agent node should be granted the SNMPAGENT role, otherwise the event registration is likely to fail. catsnmp.sql is located in the \ORACLE_HOME\rdbms\admin directory on Windows systems. The catsnmp.sql script is run by catalog.sql.

To determine whether the SNMPAGENT role exists in a database, enter the following SQL command:

SELECT * FROM dba_roles;

If the SNMPAGENT role does not appear, run the catsnmp.sql script on the database. To run the script, you must log in as SYS.