A basic listener.ora file might look like the
Oracle Net Manager can be used to customize the
Listener.ora parameters for RAC:
The listener.ora file contains the
information needed by the SQL*Net listener file to identify
the instances for which connection requests are being
serviced. If no instances are listed in the listener.ora,
the listener process will wait for the instances to
self-register (instances have been capable of
self-registering since Oracle8i). Below is shown a basic
listener.ora file for use with RAC.
If advanced features such as load
balancing and automatic failover are desired, there are
optional sections of the listener.ora file that must be
present. For example, to configure load balancing, the
listener.ora file (using an instance name of "test") would
be appropriate. The listener file must be the same on the
servers that are participating in the load balancing for
RAC. The second listener, "listener_test1" allows use of
Oracle Enterprise Manager with the instance.
You should never configure the
global_dbname parameter with Oracle RAC if you wish to use
connect time failover or transparent application failover.
Setting this parameter will disable these capabilities.
For the second server, the second
listener would be called "listener_test2", and all instance
specific references would be changed to "test2", while all
server specific references would be changed to "testlinux2".
If a port other than 1521 is utilized,
then the local_listener parameter in that instances local
init.ora file must be set to the same port value. For
example, if we used port 1525 instead of 1521, all
references to port 1521 in the listener.ora would be changed
to 1525, and the following entry would have to be added to
the local init.ora:
queuesize parameter in listener.ora
If it is expected that the listener
will receive large numbers of requests for connection, a
queue may be specified for the process. This enables the
listener to handle larger numbers of simultaneous connection
requests. The number of requests the listener can store
while Oracle works to establish a connection is specified by
the queuesize parameter. The value of this parameter should
be equivalent to the number of expected simultaneous
connections. Below is an example of the queuesize parameter
in the listener.ora file:
(HOST = marvin)
(PORT = 1521)
Use of queuesize can be disadvantageous
since more resources and memory is used. The parameter
pre-allocates resources for anticipated connection requests.
For this reason, if high-volume connections into a dedicated
listener are anticipated, it may be beneficial to implement
the Multi-Threaded Server (MTS) and use pre-spawned Oracle
For example, to configure one or more Listening Protocol
Addresses, use the following steps by accessing the Net
Services Administration page in
Oracle Enterprise Manager:
- From the Administer list, select Listeners
the Oracle home that contains the location of the
- Click Go to access the Listeners page
- Select a listener
- Click Edit to access the Edit Listener page
- In the Addresses section, configure protocol
- Click Add to access the Add
- From the Protocol list, choose
the protocol upon which the listener is configured
- Enter the parameter information
for the selected protocol.
The default port of
1521 should be used when configuring the listener to
listen on TCP/IP. Failure to do so requires
configuration of the local_listener
parameter in the initialization parameter file and
resolving the listener name through a naming method.
- For computers with more than one
IP address, if it is important for the listener to
listen on all available IP addresses, you will need
to configure TCP/IP or TCP/IP with SSL and enter the
host name of the computer in the host field.
- Click OK to add the protocol address to the
This can be repeated as many times as necessary to add
listener protocol addresses.
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