Listen Software Solutions' "How To" Series: The Listener Server
By David Nishimoto
Configuration Files
Server
Client
listener.ora
sqlnet.ora
names.ora
tnsnames.ora
sqlnet.ora
tnsnav.ora
tnsnames.ora
Listener.ora
Includes the service names and addresses of all listeners on a machine, the
SIDs for the databases they listen for, and various control parameters used by the listener.
listener_name
Port
1521
Protocols
TCPIP and IPC
SID
Hostname
ADDRESS_LIST
Contains a block of addresses at which the listener will listen for
incoming connections
CONNECT_TIMEOUT_listener_name
Number of seconds to get a valid DB query
LISTENER_address
LOG_DIRECTORY_listener_name
LOG_FILE_listener_name
LOGGING_listener_name
PASSWORDS_listener_name
SAVE_CONFIG_ON_STOP_listener_name
Oracle Name Server
Using the Oracle Name server, the clients do not need to know where the database
is located. The only requirement is for the client to know the address
of the name server. When the user wants a connection, Net 8 connects to
the name server, resolves the address, and connects to the address
given by the name server.
Connecting to the Server
The client uses both the tnsnames.ora file and the sqlnet.ora file
to make a connection with the server. TNSNames contains the names
of services on the network; whereas, sqlnet.ora contains client
profile information and Oracle Name Servers if used.
The server uses the listener.ora file
to create services that listen
for connection requests. The listener
service responds to incoming
requests by routing them to
the appropriate instance. The listener
server uses the listener.ora file to
boot and configure one or more listeners.
A listener service after routing
the connection is ready to respond to
the next request for information
(service name to connection descriptor).
The listener spawns a new process
or redirects the connection to
an existing process. Now the
listener is no longer involved.
LSNRCTL
QUIT
RELOAD
SAVE_CONFIG
SERVICES
SET
SET CONNECTION_TIMEOUT, SET CURRENT_LISTENER, SET PASSWORD,
SET LOG_DIRECTORY, SET LOG_FILE, SET SAVE_CONFIG_ON_STOP,
SET STARTUP_WAITTIME
