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Server Side Configuration
You configure
LISTENER in your Database Server to listen
and establish connections for incoming
client requests. You can have multiple
listeners running on a database server. You
should configure a listener with one or more
protocol addresses that specifies its
listening port numbers. A client must be
configured with the same type of protocol
addresses to converse with the listener. On
the client side, the PMAN background process
provides information to the listener about
its instance. Its job is to make sure that
if a user process got disconnected, clean
the entire remaining task.
You connect to
the Oracle database either through a
dedicated server or shared server.
Configuring a Listener
The listener�s
configuration file is stored in listener.ora,
which is located in the default directory $ORACLE_HOME/network/admin
on UNIX and %ORACLE_HOMEon Windows. If you
are going to relocate the configuration file
make sure to set the TNS_ADMIN environment
variable.
An example of
listener.ora:
LISTENER4MYDBS=
(DESCRIPTION=
(ADDRESS_LIST=
(ADDRESS=(PROTOCOL=tcp)
(HOST=mycomupter) (PORT=1521))
(ADDRESS=(PROTOCOL=ipc)
(KEY=extproc))
)
)
SID_LIST_LISTENER4MYDBS=
(SID_LIST=
(SID_DESC=
(GLOBAL_DBNAME=mydbs.company)
(ORACLE_HOME=/u01/app/oracle/product/9.2.0)
(PROGRAM=extproc)
(SID_NAME=mydbs)
)
)
LISTENER4MYDBS
is just a listener name and can be any name.
The listening location area (ADDRESS=)
specifies where a listener is listening for
a connection.
For each
address you may use a different protocol
type such as TCP, NMP, IPC, SPX and etc. If
you use TCP, you should specify the host
name (or an IP address) and the port number
to be used. If you use NMP (Named Pipes) for
a network using Novel, you should specify
your Machine Name and the Pipe Name. If you
use IPC (Interprocess Communication), you
should specific the library name that will
be accessed on the same node. The IPC
protocol will be used only when client and
server run on the same machine or node. If
you use SPX, the IPX/SPX Microsoft protocol,
you should specify a service name. For other
protocol, you may have to specify the
relevant information for establishing the
Oracle connectivity.
The resets of
above parameter are very much
self-explanatory.
Also, you can
have the following control parameter
settings:
ADMIN_RESTRICTIONS_ listener4mydbs=TRUE
It will
restrict any modification to the listener
dynamically using the SET command.
PASSWARDS_ listener4mydbs=(X6Z76H07Y34D)
It enforces to
enter the password for stopping the
listener.
LOG_DIRECTORY_ listener4mydbs=$ORACLE_HOME/network/admin
It defines a
log directory destination.
LOG_FILE_ listener4mydbs=listener4mydbs.log
It defines a
log file name.
LOGGING_ listener4mydbs=ON
It enables or
disables logging.
TRACE_DIRECTORY_ listener4mydbs=$ORACLE_HOME/network/admin/trace
It defines a
trace directory destination.
TRACE_FILE_ listener4mydbs=listener4mydbs.trc
It defines a
trace file name.
TRACE_LEVEL_ listener4mydbs=(OFF|ADMIN|USER|SUPPORT)
It enable or
disable (OFF) a trace for debugging
purposes. You use the SUPPORT level only
when requested by Oracle Support. The USER
level provides user trace and the ADMIN
level provides administration information.
Listener Control Commands
# lsnrctl
command
listener_name
General
format.
# lsnrctl
help
It will list
lsnrctl commands.
# lsnrctl
stop
listener4mydbs
It stops the
listener.
# lsnrctl
start
listener4mydbs
It starts
listener.
# lsnrctl
reload
listener4mydbs
It reloads the
modified listener file.
# lsnrctl
status
listener4mydbs
It displays
the listener�s status.
# lsnrctl
services
It displays
the registered services.
# lsnrctl
It will enable
listener utility.
LSNRCTL>
You can use
listener utility to use the SHOW and SET
commands. For example setting password.
LSNRCTL> SET
PASSWORD
Configuring Service Registration
The
SERVICE_NAMES and the INSTANCE_NAME
parameter must be set in the database
initialization parameter file (PFILE).
SERVICE_NAMES= mydbs.company
INSTANCE_NAME=mydbs
Questions:
Q: How do you
configure a LISTENER in your database
server?
Q: Can you
have multiple listeners running on a
database server?
Q: How do you
configure a LISTENER with one or more
protocol?
Q: Describe
the PAMN background process jobs?
Q: Describe
the following listener configuration file (listener.ora).
LISTENER4MYDBS=
(DESCRIPTION=
(ADDRESS_LIST=
(ADDRESS=(PROTOCOL=tcp)
(HOST=mycomupter) (PORT=1521))
(ADDRESS=(PROTOCOL=ipc)
(KEY=extproc))
)
)
SID_LIST_LISTENER4MYDBS=
(SID_LIST=
(SID_DESC=
(GLOBAL_DBNAME=mydbs.company)
(ORACLE_HOME=/u01/app/oracle/product/9.2.0)
(PROGRAM=extproc)
(SID_NAME=mydbs)
)
)
Q: How can you
assign a password to you listener?
Q: How do you
turn on the trace utility on a listener on
the user level?
Q: How do you
start a listener?
Q: How do you
stop a listener?
Q: What does
the reload command do in the listener? |
