However, listener configuration must be synchronized with the information in the database initialization file. To ensure service registration works properly, the initialization parameter file should contain the following parameters:.
As long as the listener configuration is synchronized with the database configuration, PMON can register service information with a nondefault local listener or a remote listener on another node. Synchronization is simply a matter of specifying the protocol address of the listener in the listener.
Registration to remote listeners, such as in the case of Oracle Real Application Clusters, can be configured for shared server or dedicated server environments. If you set the parameter to null with the statement that follows, then PMON de-registers information with the remote listener with which it had previously registered information.
Configure the listener. Once the listener is configured, the listener can be administered with the Listener Control utility or Oracle Enterprise Manager. This section describes some of the common administrative tasks for the listener, including the following topics:.
In addition to starting the listener, the Listener Control utility verifies connectivity to the listener. Depending upon the current status of the selected listener, the operation will be either Stop or Start.
Click OK to perform the operation. The status output provides basic status information about a listener, including a summary of listener configuration settings, the listening protocol addresses, and a summary of services registered with the listener.
The STATUS command provides basic status information about a listener, including a summary of listener configuration settings, the listening protocol addresses, and a summary of services registered with the listener. Displays a summary of the services registered with the listener and the service handlers allocated to each service. Specifies the name of the instance associated with the service along with its status and number of service handlers associated with the service.
Therefore, the status is non known. The SERVICES command of the Listener Control utility provides detailed information about the services and instances registered with a listener and the service handlers allocated to each instance. The listener blocks all connections to this instance. Identifies the name of the service handler. Dispatchers are named D through D Following this, additional information about the service handler displays, such as whether the service handler is a dispatcher, a local dedicated server, or a remote dedicated server on another node.
This output shows that two database services, sales. Client connection requests to sales. All handlers have a status of ready , indicating that they are ready to receive connections. Client connection requests to hr. When you notice any of the following conditions, review and monitor the listener log file for the following:. Unexpected shutdown of the listener that could indicate a denial-of-service attack. Skip Headers. Previous versions of the listener are not supported for use with an Oracle Database 10g database.
However, it is possible to use a version 10 listener with previous versions of the Oracle database. See Also: "Listener Architecture". Example Example listener. See Also: Oracle Database Net Services Reference for further information about identifying listeners by unique names and creating multiple listener entries in the listener. Customizing Listener Configuration If the default or installed configuration is not adequate for a particular environment, you can use Oracle Net Manager to customize the listener.
See Also: "Oracle Enterprise Manager". Note: You can also configure additional listening addresses with Oracle Net Manager. See topic Create Listener Address in the online Help for further instruction.
See Also: "Oracle Net Manager". For example: Example listener. Note: The default number of concurrent connection requests is operating-system specific. You cannot alter these tablespace names when using the preconfigured database configuration options from OUI. However, you can change the names of the tablespaces if you use the advanced database creation method. As mentioned, each tablespace has one or more data files. The data file names created by the preconfigured database configuration options vary by storage type such as Oracle ASM, or a file system.
The database is configured with two control files that are stored on shared storage. Each instance is configured with at least two redo log files that are stored in the shared storage. If you use a file system, then these files are shared file system files.
The file names of the redo log files that are created with the preconfigured database configuration options vary by storage type. Unless you are using a cluster file system, you must enter the block or raw device names. Oracle Database stores rollback or undo information in undo tablespaces. To manage undo tablespaces, Oracle recommends that you use Automatic Undo Management. Automatic Undo Management is an automated undo tablespace management mode that is easier to administer than manual undo management.
When Oracle ASM and Oracle Managed Files are used along with Automatic Undo Management, an instance that is started for the first time, and thus does not have an undo tablespace, will have its undo tablespace created for it by another instance automatically. The same is also true for redo logs. SPFILEs must be located on shared storage; all instances in a cluster database can access this parameter file. Oracle Database installs a baseline database auditing policy.
This policy covers the access control configuration information stored in Oracle Database database tables, information stored in Oracle Catalog rollback segments, tablespaces, and so on , the use of system privileges, and Oracle Label Security configuration.
Oracle RAC databases provide the important benefits of connection load balancing and failover. Standalone Oracle Databases perform load balancing by distributing connections among local dispatchers. SCAN listeners can run on any node in the cluster. Oracle Database 11 g release 2 and later instances only register with SCAN listeners as remote listeners. Upgraded databases register with SCAN listeners as remote listeners, and also continue to register with all node listeners. SCANs run on the cluster, not on a cluster node.
SCANs provide location independence for the databases, so that client configuration does not have to depend on which nodes are running a particular database. For example, if you configure policy managed server pools in a cluster, then the SCAN enables connections to databases in these server pools regardless of which nodes are allocated to the server pool. Because the SCAN addresses resolve to the cluster, rather than to a node address in the cluster, nodes can be added to or removed from the cluster without affecting the SCAN address configuration.
Oracle recommends that the SCAN resolves to three addresses, to provide high availability and scalability. Oracle RAC provides failover with the node VIP addresses by configuring multiple listeners on multiple nodes to manage client connection requests for the same database service. If a node fails, then the service connecting to the VIP is relocated transparently to a surviving node, enabling fast notification of the failure to the clients connecting through the VIP.
If the application and client are configured with transparent application failover options, then the client is reconnected to the surviving node. Clients configured to use IP addresses for Oracle Database releases prior to Oracle Database 11 g release 2 can continue to use their existing connection addresses; using SCANs is not required. The database registers with the SCAN listener through the remote listener parameter in the init.
Connection load balancing and failover increase availability by taking advantage of the redundant resources within a cluster database. You do not need to alter this setting. For example, if the name of the cluster is mycluster, and the domain is example. By default, DBCA configures your environment with dedicated servers. In this case, Oracle Database uses both dedicated and shared server processing. You can configure two types of listeners in the listener. The GNS daemon listens for registrations.
Valid nodes and subnets can be specified for registration, and excluded nodes can also be specified for registration. By default, every incoming connection for registration at the listener is subjected to IP-based filtering.
A connection is only allowed if it originates from the local machine. If the other nodes and subnets are specified for registration, then the local machine and the ones specified are allowed. The following parameters can be set in the listener. Presence of a host name in the list results in all IP addresses mapped to it being invited. Nodes not specified on the list are allowed to register with the listener.
This section describes some of the administrative tasks for the listener. It contains the following topics:. In addition to starting the listener, the Listener Control utility verifies connectivity to the listener. The following procedure describes how to start or stop a listener from Oracle Enterprise Manager Cloud Control:.
Select Listeners from the Administer list, and then select the Oracle home that contains the location of the configuration files. Depending on the current status of the selected listener, select either Stop or Start , and then click OK. The Oracle Restart feature enhances availability for the processes and applications in a single-instance database environment. The Oracle Restart agents monitor the health of added components by periodically running check operations and restarting the components when necessary.
You can add the listener as a component to the Oracle Restart configuration. The listener is then automatically started by Oracle Restart when it fails or is not running. For example, if you restart the database instance after a planned restart of the computer, then Oracle Restart restarts the listener. Adding a listener as an entry to the grid infrastructure enables the agent to monitor the listener.
Similarly, removing a listener removes as an entry. Use the srvctl command at the operating system command line as follows:. In the following example, the first command starts the default listener, and the second command starts listener1 and listener2 :. In the following example, the first command stops the default listener, and the second command stops listener1 and listener2 :.
The status output provides basic status information about a listener, a summary of listener configuration settings, the listening protocol addresses, and a summary of services registered with the listener. To show the status the listener from the command line, enter the following command:.
A summary of the services registered with the listener and the service handlers allocated to each service. The listener blocks all connections to this instance. Therefore, the status is not known. The following procedure describes how to show the status of a listener using Oracle Enterprise Manager Cloud Control:. The SERVICES command of the Listener Control utility provides detailed information about the services and instances registered with a listener and the service handlers allocated to each instance.
To show information about the services and instances from the command line, enter:. This output shows that two database services, sales.
Client connection requests to sales. All handlers have a status of ready , indicating that they are ready to receive connections. Client connection requests to hr. Therefore, the status is non known. The name of the service handler. Dispatchers are named D through D When you notice any of the following conditions, review the listener log file for error information:. Unexpected shutdown of the listener that could indicate a denial-of-service attack.
This does not cause a loss of security because authentication is enforced through local operating system authentication. See Also: Chapter 2, "Identifying and Accessing the Database" for a description of how the listener is used during an initial connection request Chapter 4, "Understanding the Communication Layers" for an architectural overview of the listener.
Overview of Oracle Net Listener Note: The release of the listener must be the same as or later than the latest release of all Oracle databases being serviced through the listener. Configuring Dynamic Service Registration Service registration allows processes, such as an Oracle database, to identify their available services to the listener, which then acts as a port mapper for those services.
Example Registering a Local Listener in a Dedicated Server Environment On the host where the local listener resides, configure the listener. Registering Information with a Remote Listener A remote listener is a listener residing on one computer that redirects connections to a database instance on another computer. Registering Information with All Listeners in a Network A network may contain multiple local and remote listeners.
Example Using Two Networks on a Subnet Assume there are two distinct networks, network1 and network2. Example Configuring Multiple Listeners Assume that multiple listeners are listening on a network named sales-network. The following conditions are true: A database configured for dedicated server connections resides on host sales1-server. The following procedure describes how to register information with all listeners in a dedicated server environment: On the hosts where the remote listeners reside in this example, sales2-server and sales3-server , configure the listener.
Notes: Multiple addresses are supported, but connect-time failover and client load balancing features are not supported. Customizing Oracle Net Listener Configuration If the default or installed configuration is not adequate for a particular environment, then you can use Oracle Net Manager to customize the listener.
To specify the listener queue size, do the following: Specify the QUEUESIZE parameter at the end of the protocol address with its value set to the expected number of concurrent requests.
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