3
Post-Installation Configuration Tasks

This chapter describes post-installation configuration tasks for Oracle COM Automation feature.

Specific topics discussed are:

• Release 8.1.3 and Later Database Directory Trees
• Configuring Oracle COM Automation Feature
• Configuring the Listener
• Configuring DCOM

Release 8.1.3 and Later Database Directory Trees

The introduction of Optimal Flexible Architecture (OFA) for Oracle8i release 8.1.3 Beta caused changes to the Oracle directory tree. You need to be aware of these changes in order to understand the configuration instructions in the following sections.

Oracle8i Database Release 8.1.3 and Later

When you install Oracle8i Enterprise Edition, all subdirectories are no longer under a top-level ORACLE_HOME directory. There is now a new top-level directory called ORACLE_BASE that is of the form X:\ORACLE where X is any hard drive. If you install an OFA-compliant database using Oracle Universal Installer defaults, ORACLE_BASE is C:\ORACLE. \ORACLE_HOME directories are located under ORACLE_BASE. \ORADATA and \ADMIN directories that contains the database files and database administration files are also located under ORACLE_BASE.

The following configuration instructions reference directory trees that assume that you have already installed a release 8.1.3 or later OFA-compliant Oracle database.

Configuring Oracle COM Automation Feature

To configure Oracle COM Automation feature:

1. Change to the following directory from the MS-DOS command prompt:

C:\> CD ORACLE_BASE\ORACLE_HOME\COM

where ORACLE_BASE\ORACLE_HOME represents your drive letter and the Oracle home directory where Oracle COM Automation feature was installed.
 
2. Start Server Manager:

C:\> SVRMGRL
 
3. Connect to the Oracle database instance as INTERNAL/PASSWORD. The default password for INTERNAL is ORACLE unless it has been changed by a database administrator.

SVRMGR> CONNECT INTERNAL/PASSWORD
 
4. Grant the CREATE LIBRARY privilege to the database user(s) that will use Oracle COM Automation feature. For example:

SVRMGR> GRANT CREATE LIBRARY TO SCOTT;
 
5. Run the COMWRAP.SQL script at the Server Manager prompt:

SVRMGR> CONNECT SCOTT/TIGER
SVRMGR> @ORACLE_BASE\ORACLE_HOME\COM\COMWRAP.SQL

You will receive several "ORA-04043: object XXXX does not exist" messages when you run this script for the first time. These messages are normal.

Configuring the Listener

Since Oracle COM Automation feature relies on external procedure callouts, you must configure the listener and Net8 remote procedure call (RPC) mechanism for the feature to work.

The following examples demonstrate how to configure the LISTENER.ORA and TNSNAMES.ORA files to use inter-process communication (IPC) to invoke external stored procedures. This is the default configuration for both files for this release. If your files are not configured correctly, see Chapter 6 of the Oracle Net8 Administrator's Guide for additional information on how to configure the LISTENER.ORA and TNSNAMES.ORA files for external procedures.

LISTENER.ORA Configuration File

LISTENER =
        (ADDRESS_LIST =
        (ADDRESS=
          (PROTOCOL= IPC)
          (KEY= EXTPROC0)
        )
        )
STARTUP_WAIT_TIME_LISTENER = 0
CONNECT_TIMEOUT_LISTENER = 10
TRACE_LEVEL_LISTENER = OFF
SID_LIST_LISTENER =
  (SID_LIST =
    (SID_DESC =
      (SID_NAME = ORCL)
    )
    (SID_DESC =
      (SID_NAME = extproc)
      (PROGRAM=extproc)
    )
  )
PASSWORDS_LISTENER = (oracle)

TNSNAMES.ORA Configuration File

extproc_connection_data.world =
  (DESCRIPTION =
    (ADDRESS =
        (PROTOCOL=IPC)
        (KEY=EXTPROC0)
    )
    (CONNECT_DATA = (SID=extproc)
    )
  )

ORA-28575: Error Message

An "ORA-28575: unable to open RPC connection to external procedure agent" error message indicates one of two possible problems:

Problem 1

Problem: The listener is not started.

Action: You must start the OracleHOME_NAMETNSListener service from the Control Panel or the MS-DOS command prompt.

To start Oracle services from the Control Panel:

1. Choose Start > Settings > Control Panel.

The Control Panel window appears.
 
2. Double-click Services.

The Services dialog box appears.
 
3. Find OracleHOME_NAMETNSListener in the list and verify that it has a status of Started. If it does not, select it and click Start.

To start Oracle services from the MS-DOS command prompt:

Enter the following command to start an Oracle service at the MS-DOS command prompt:

C:\> NET START SERVICE

where SERVICE is a specific service name, such as OracleHOME_NAMETNSListener.

Problem 2

Problem: The listener is not configured correctly.

Action: You must modify the LISTENER.ORA and TNSNAMES.ORA files. See "Configuring the Listener" for information on how to configure these files.

Configuring DCOM

Oracle COM Automation feature supports the use of DCOM to access remote COM objects over a network. However, in order to use DCOM, you must configure both the computer that is running the Oracle database instance and the computer that contains the remote COM object.

For security purposes, the Oracle listener must run with the same security privileges as a domain user that has access to the remote computer. In order to authenticate that the client has access to the remote computer, DCOM passes the security credentials of the Oracle listener to the remote computer. The remote computer validates the security credentials and allows DCOM to proceed. Normally, the Oracle listener runs as the system user. The system user has no remote privileges; therefore, the system administrator must perform the following steps.

To change the Oracle listener to run as a domain user:
 

1. Choose Start > Settings > Control Panel

 The Control Panel window appears.
 
2. Double-click Services.

The Services dialog box appears.
 
3. Select the OracleHOME_NAMETNSListener service and click Startup.

 
4. Click the This Account radio button.

The Service dialog box appears.
 
5. Enter the name or browse for a domain user. The Oracle listener runs with the security privileges of this user.

 
6. Enter and confirm the password of the domain user that was selected.

 
7. Click OK to save the changes.

The next step is to configure the DCOM security settings of the remote computer. The system administrator must set the DCOM security privileges such that the Oracle listener, operating as a domain user, has sufficient privileges to instantiate and manipulate the remote COM object.

The remote COM object executes with the same privileges as the Oracle listener. If the COM object attempts to perform an action for which it does not have permission, DCOM denies the operation and returns a security violation back to Oracle COM Automation feature. Therefore, it is imperative that the system administrator configure the DCOM security properly and provide Oracle with the necessary permissions.

DCOM enables the administrator to configure the default security for the entire computer or define specific security permissions for a specific COM object. Microsoft provides the DCOMCNFG.EXE tool to configure DCOM security. This tool enables the system administrator to set the access permissions, launch permissions, and configuration permissions for a specific COM object or all COM objects on a computer. For more information on how to use this tool and the implications of each of these permissions, see Microsoft documentation.