Oracle Database 11g : Connecting to Oracle - Use Oracle Configuration Files, Use Administration Tools

1. Use Oracle Configuration Files

Remote applications will look for Oracle Net configuration files to determine how to access the Oracle database server. Configuration files can be found in the ORACLE_HOME/network/admin directory location. Table 1 defines the primary configuration files.

DBAs can use the management tools to modify Oracle Net Services configurations. However, since the configuration files have a simple syntax, it is easy to modify the configuration files directly. The following is an example of the listener.ora file:

# LISTENER.ORA Date: 04/25/2009
LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS_LIST =
        (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC0))
      )
      (ADDRESS_LIST =
        (ADDRESS = (PROTOCOL = TCP)(HOST = eclipse)(PORT = 1521))
      )
    )
  )

Should a DBA want to modify the files directly, the following syntax rules must be followed:

• Comments must begin with a pound sign (#). Anything following the pound sign is treated as a comment.

• Keywords are not case sensitive and cannot contain spaces.

• Spaces are optional around equal (=) signs.

• Values can only contain spaces if they are surrounded by quotes. The values may be case sensitive depending on the operating system and protocol.

• A connect descriptor can be no more than 4KB in length.

• All characters must be part of the network set.

• Care must be taken with parentheses when editing. Troubleshooting a connection problem might be necessary because a simple edit was made to the file and close or open parenthesis was dropped.

2. Use Administration Tools

Oracle Net Services contains a number of user interfaces and tools that simplify the management of the Oracle network, including the following:

• Oracle Enterprise Manager (OEM) / Grid Control

• The OEM console

• Oracle Net Manager

• Oracle Net Configuration Assistant

• Oracle Connection Manager

• Oracle Internet Directory Configuration Assistant

• Command-line utilities

• Oracle Advanced Security

The Oracle Enterprise Manager/Grid Control

Along with database administration, OEM allows configuration of Oracle Net Services. OEM can be used to perform the following administration features:

• The configuration of listeners

• The configuration of naming definitions such as connect descriptors

The Oracle Net Manager

The Oracle Net Manager allows the configuration of Oracle Net Services and can be started from the OEM console, by choosing Tools | Service Management | Oracle Net Manager.

The Oracle Net Manager provides the following administration support:

• Listeners This supports creating and configuring listeners.

• Naming This supports defining simple names. Simple names specify information for connect descriptors and service location information.

• Naming methods This supports the definition of naming methods.

Some of the functionality in OEM is also available in the Oracle Net Manager. Table 2 shows the overlapping functionality and the differences between the two tools.

The following can be used to start Oracle Net Manager manually through UNIX:

$  $ORACLE_HOME/bin/netmgr

Oracle Net Manager can also be started manually through Windows by selecting Start | Programs | Oracle—OraHome11 | Configuration and Migration Tools | Net Manager.

The OEM Console

The Oracle Enterprise Manager Central Console is a web-based interface for managing the entire enterprise from the console. It offers a lot more functionality than the standard Oracle Enterprise Manager that comes with a typical database install. The default ports for running in a nonsecure mode are 7777-7877; default ports for running in a secure mode are 4443-4533.

You can access the OEM Central Console from the following URLs: http://<oms hostname>.<domain>.<port>/em and https://<oms hostname>.<domain>.<port>/em. The OEM Central Console requires the Oracle Management Service unless the Oracle Management Agent is installed separately.

The OEM Components

The OEM console uses the following components installed with the Oracle application server:

• The Oracle Management Service This is a web-based application that runs on the Oracle application server. It provides the user interface for the OEM console, and interfaces with the management agents to process and monitor information.

• The Oracle Management Agent This monitors information from sites that need to be managed and that are loaded into the management service.

• The Oracle Management Repository This contains all the information managed by the Oracle Enterprise Manager.

Before installing the Complete Enterprise Manager, make sure to read the requirements for the complete installation that includes the Oracle Application Server 11g, Web Cache, and the Management Service application as well as verifying additional licensing requirements.

The Oracle Net Configuration Assistant

The Oracle Net Configuration Assistant is used during installation to configure the basic network components. The Oracle Net Configuration Assistant can also be run standalone to modify the same values configured during installation. Configurable components include the following:

• Naming methods

• Net service names (tnsnames.ora)

• Listener names and protocol addresses

• Directory server usage

The following can be used to start the Oracle Net Configuration Assistant manually through UNIX:

$  $ORACLE_HOME/bin/netca

The Oracle Net Configuration Assistant can also be started manually through Windows by selecting Start | Programs | Oracle—OraHome11 | Configuration and Migration Tools | Net Configuration Assistant.

The Oracle Internet Directory Configuration Assistant

The Oracle Internet Directory Configuration Assistant can be used to configure the Oracle Internet Directory. The directory configuration file ldap.ora can be configured with the Oracle Internet Directory Configuration Assistant or the Oracle Net Configuration Assistant. The ldap.ora file can reside in different locations depending on which tool created the ldap.ora file:

• If created by the OID Configuration Assistant, the ldap.ora file is stored in the ORACLE_HOME/ldap/admin directory.

• If created by the Oracle Net Configuration Assistant, the ldap.ora file is stored in the ORACLE_HOME/network/admin directory.

• The ldap.ora file location can be manually specified with the LDAP_ADMIN or TNS_ADMIN environmental variables.

Command-Line Utilities

The Listener Control utility can be used to start and stop listeners, check their status, and perform tracing and other management operations. The syntax is

lsnrctl  command [listener_name]

Listener commands can also be executed from within the Listener Control utility. The listener name is the one defined in the listener.ora file, but a default listener named LISTENER can be used instead. If LISTENER is used, a listener name does not need to be specified.

The following shows how to stop the listener. Here, executing the lsnrctl command generates an LSNRCTL prompt:

$ lsnrctl
LSNRCTL> stop
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC0)))
The command completed successfully

The next example shows a sample of the type of information displayed when starting the listener:

LSNRCTL> start

starting tnslsnr: please wait...
 TNSLSNR for 32-bit Windows: Version 11.1.0.6.0 -
System parameter file is C:\oracle\ora11\network\admin\listener.ora
Log messages written to C:\oracle\ora11\network\log\listener.log
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=eclipse)
              (PORT=1521)))
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC0)))
STATUS of the LISTENER
------------------------
Alias                     LISTENER
Version                   TNSLSNR for 32-bit Windows:Version 11.1.0.6.0
Start Date                03-FEB-2009 21:26:56
Uptime                    0 days 0 hr. 0 min. 2 sec
Trace Level               off
Security                  OFF
SNMP                      OFF
Listener Parameter File   C:\oracle\ora11\network\admin\listener.ora
Listener Log File         C:\oracle\ora11\network\log\listener.log
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=eclipse)(PORT=1521)))
Services Summary...
Service "cust" has 1 instance(s).
  Instance "cust", status UNKNOWN, has 1 handler(s) for this service...
The command completed successfully

					  

The status command displays detailed information on the status of the listener. Information includes the start time of the listener, the location of log and configuration files, and so on.

LSNRCTL> status

The services command lists dispatchers in a shared server environment and dedicated servers in a dedicated server environment:

LSNRCTL> services

Here is a list of listener commands:

• change_password

• exit

• help

• quit

• reload

• save_config

• services

• set

• show

• spawn

• start

• status

• stop

• trace

• version

The set command can be used to modify different parameter values for a listener. The set command, by itself, will display the parameter values that can be modified:

LSNRCTL> set
password                           rawmode
displaymode                        trc_file
trc_directory                      trc_level
log_file                           log_directory
log_status                          current_listener
inbound_connect_timeout             startup_waittime
save_config_on_stop

The Oracle Advanced Security Option

The Oracle Advanced Security option supports data encryption, enhanced authentication, integrity checking, single sign-on, and the Distributed Computing Environment (DCE). The Oracle Net Manager is used to configure Oracle Advanced Security options.

Dispatchers

The DISPATCHERS parameter can be set to define how dispatchers will work with the shared server architecture. Dispatchers must be defined to work with different protocols, as shown in the following:

DISPATCHERS="(PROTOCOL=tcp)(DISPATCHERS=6)(CONNECTIONS=1000)"
DISPATCHERS="(PROTOCOL=tcps)(DISPATCHERS=6)(CONNECTIONS=1000)"

Connection pooling can also be defined as shown next:

DISPATCHERS="(PROTOCOL=tcp)(DISPATCHERS=6)(POOL=on) (TICK=1)
             (CONNECTIONS=1000)(SESSIONS=5000)"
DISPATCHERS="(PROTOCOL=tcps)(DISPATCHERS=6)(POOL=on) (TICK=1)
             (CONNECTIONS=1000)(SESSIONS=5000)"