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Oracle® Real Application Clusters Administrator's Guide
10g Release 1 (10.1)

Part Number B10765-01
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8 Administrative Options

This chapter describes administrative tasks or options within Oracle tools that are specific to Oracle Real Application Clusters (RAC) and not discussed elsewhere in this book. In some cases, you have a choice of tools to perform a task while other tasks must be executed through a specific tool, such as Enterprise Manager or SRVCTL. The topics in this chapter are:

See Also:

Oracle Enterprise Manager Concepts and the Enterprise Manager online help for more information about Enterprise Manager

Optional Enterprise Manager Tasks in Real Application Clusters

Within Enterprise Manager, RAC-specific administrative tasks generally focus on two levels: tasks that affect an entire cluster database and tasks that affect specific instances. For example, you can use Enterprise Manager to administer storage, the schema, and security at the cluster database level. Or you can perform instance-specific commands such as setting parameters or creating resource plans.

Because there is one Enterprise Manager Agent on each node of a RAC database, you can use any URL for that database to administer it with Enterprise Manager. You can manage all of the following RAC components as targets in your Enterprise Manager framework:

See Also:

Oracle Enterprise Manager Concepts for information about creating administrator accounts, using privileges, defining roles, and so on, and Oracle Enterprise Manager Advanced Configuration for information about configuring Enterprise Manager Grid Control for multiple RAC databases

Using Enterprise Manager to Discover Nodes and Instances

Enterprise Manager automatically detects changes in your configuration, for example, if you add nodes or instances. Enterprise Manager rediscovers pre-existing instances as well as newly added instances. To do this, use Enterprise Manager Grid Control as follows:

  1. Log in to Enterprise Manager Database Control and click the Targets tab.

  2. Click a database name to view all of the available targets. The column labeled Types indicates a RAC database with the entry "Cluster Database".

  3. Add the database target by clicking Add on the right-hand side of the page.

  4. Click the flashlight icon to display the available host names.

  5. Select a host, click Continue, and Enterprise Manager performs discovery to locate and display the cluster database and its associated instances.

If you cannot discover your reconfigured cluster database and all of its instances using this procedure, then manually configure your targets for Enterprise Manager by adding the Oracle home, SID, instances, and so on.

See Also:

The Oracle Real Application Clusters Deployment and Performance Guide for more information about using Enterprise Manager to monitor RAC databases

Enterprise Manager Pages for Real Application Clusters

This section describes the following Enterprise Manager pages for RAC:

Databases Summary Page

This is a top-level page that shows cluster and single-instance databases. If there are cluster databases in your environment, the Databases Summary page displays "Cluster Database" in the Type column. The page also indicates cluster database availability as well as the ratio of active instances to inactive instances. Click a cluster database link and Enterprise Manager displays the Cluster Database Home Page for that database, which is described under the following heading.

Cluster Database Home Page

From the Cluster Database Home Page you can manage the cluster nodes and hosts as well as cluster subcomponents such as instances and listeners. The Cluster Database Home Page is also a summary page for cluster database management that provides an overview of cluster database activity. Enterprise Manager uses a unique database name to identify the cluster database it represents. You can use the Administration tab on this page to perform many activities such as:

  • Create undo tablespaces and redo threads and assign them to specific instances, SPFILE, create a backup

  • Start, stop, and relocate database services at the cluster database level

You can use the Maintenance tab on this page to perform operations such as:

  • Create backup and recovery scenarios

  • Toggle the archive mode on and off

  • Administer recovery settings

  • Manage resource plans for the database and its instances

Cluster Database Instances Pages

Instances pages show instance-specific information similar to the information that you would see on a single-instance Oracle database.

The Databases Overview Page for Real Application Clusters

The Databases Overview Page links to Cluster Home Pages and to the node or instance Home Pages.

The Cluster Home Page for Real Application Clusters

The Cluster Home Page displays an overview of activities and detailed reports at both the cluster and instance levels. The Cluster Home Page has the following sections:

  • General Section—Provides a cluster status overview.

  • Configuration Section—Lists the hardware platform, operating system and version, and Oracle or vendor clusterware version.

  • Cluster Databases Table—Displays the cluster databases associated with a cluster, their availability, and any cluster database alerts. You can access the individual Cluster Database Home Pages from the Cluster Databases Table.

  • Alerts Table—Provides alert information such as severity rating.

  • Hosts Table—Displays information about the hosts or nodes in the cluster.

Instance Pages for Real Application Clusters

The RAC-specific contents of Instance Pages are:

Real Application Clusters Administration Procedures for Enterprise Manager

The Cluster Database Home page shows all the instances in the RAC database and provides an aggregate collection of several RAC-specific statistics that are collected by the Automatic Workload Repository for server manageability.

You do not need to navigate to an instance-specific page to see these details. However, on the Cluster Database Home page, if an instance is down that should be operating, or if an instance has a high number of alerts, then you can drill down to the instance-specific page for each alert.

To perform specific administrative tasks as described in the remainder of this section, log in to the target RAC database, navigate to the Cluster Database Home page, and click the Administration tab.

Administering Enterprise Manager Jobs in Real Application Clusters

You can administer Enterprise Manager jobs at both the database and instance levels. For example, you can create a job at the cluster database level and the job will run on any active instance of the target RAC database. Or you can create a job at the instance level and the job will only run on the specific instance for which you created it. In the event of a failure, recurring jobs can run on a surviving instance.

Creating Enterprise Manager Jobs in Real Application Clusters

Because you can create jobs at the instance level, cluster level, or cluster database level, jobs can run on any available host in the cluster database. This applies to scheduled jobs as well. Enterprise Manager also displays job activity in several categories, namely, Active, History, and Library.

You use the Jobs tab to submit operating system scripts and SQL scripts and to examine scheduled jobs. For example, to create a backup job for a specific RAC database:

  1. Click Targets and click the database for which you want to create the job.

  2. Log in to the target database.

  3. When Enterprise Manager displays the Database Home page, click Maintenance.

  4. Complete the Enterprise Manage Job Wizard panels to create the job.

Administering Alerts in Real Application Clusters with Enterprise Manager

You can use Enterprise Manager to configure alerts for RAC environments. You can also configure specialized tests for RAC databases such as global cache converts, consistent read requests, and so on.

See Also:

The Oracle Real Application Clusters Deployment and Performance Guide for more information about using Enterprise Manager to monitor RAC environments

Enterprise Manager distinguishes between database- and instance-level alerts in RAC environments. Alert thresholds for instance level alerts, such as archive log alerts, can be set at the instance target level. This enables you to receive alerts for the specific instance if performance exceeds your threshold. You can also configure alerts at the database level, such as setting alerts for tablespaces. This enables you to avoid receiving duplicate alerts at each instance.

See Also:

The Oracle Real Application Clusters Deployment and Performance Guide for an example of configuring alerts in RAC and the PL/SQL Packages and Types Reference for information about using packages to configure thresholds

Performing Scheduled Maintenance Using Defined Blackouts in Enterprise Manager

You can define blackouts for all managed targets of a RAC database to prevent alerts from occurring while performing maintenance. You can define blackouts for an entire cluster database or for specific cluster database instances.

Additional Information About SQL*Plus in Real Application Clusters

The following sections describe the use of SQL*Plus in RAC environments:

How SQL*Plus Commands Affect Instances

Most SQL statements affect the current instance. You can use SQL*Plus to start and stop instances in the RAC database. You do not need to run SQL*Plus commands as root on UNIX-based systems or as Administrator on Windows-based systems. You need only the proper database account with the privileges that you normally use for a single-instance Oracle database. Some examples of how SQL*Plus commands affect instances are:

  • The statement ALTER SYSTEM SET CHECKPOINT LOCAL only affects the instance to which you are currently connected, rather than the default instance or all instances.

  • ALTER SYSTEM CHECKPOINT LOCAL affects the current instance.

  • ALTER SYSTEM CHECKPOINT or ALTER SYSTEM CHECKPOINT GLOBAL affects all instances in the cluster database.

  • ALTER SYSTEM SWITCH LOGFILE affects only the current instance.

    • To force a global log switch, use the ALTER SYSTEM ARCHIVE LOG CURRENT statement.

    • The INSTANCE option of ALTER SYSTEM ARCHIVE LOG enables you to archive each online redo log file for a specific instance.

Table 8-1 describes how SQL*Plus commands affect instances.

Table 8-1 How SQL*Plus Commands Affect Instances

SQL*Plus Command Associated Instance
ARCHIVE LOG Always affects the current instance.
CONNECT Affects the default instance if no instance is specified in the CONNECT command.
HOST Affects the node running the SQL*Plus session, regardless of the location of the current and default instances.
RECOVER Does not affect any particular instance, but rather the database.
SHOW INSTANCE Displays information about the current instance, which can be different from the default local instance if you have redirected your commands to a remote instance.
SHOW PARAMETER and SHOW SGA Displays parameter and SGA information from the current instance.
STARTUP and SHUTDOWN Always affects the current instance. These are privileged SQL*Plus commands.

Verifying that Instances are Running

To verify that instances are running, on any node from a SQL*Plus prompt enter:


Oracle returns output similar to the following:

-----------  ----------------- 
           1 db1-sun:db1  
           2 db2-sun:db2  
           3 db3-sun:db3  

The output columns for this example are shown in Table 8-2.

Table 8-2 Descriptions of V$ACTIVE_INSTANCES Columns

Column Description
INST_NUMBER Identifies the instance number.
INST_NAME Identifies the host name and instance name.

Quiescing Real Application Clusters Databases

The procedure for quiescing RAC databases is identical to quiescing a single-instance database. You use the ALTER SYSTEM QUIESCE RESTRICTED statement from one instance. You cannot open the database from any instance while the database is in the process of being quiesced. Once all non-DBA sessions become inactive, the ALTER SYSTEM QUIESCE RESTRICTED statement finishes, and the database is considered as in a quiesced state. In an Oracle RAC environment, this statement affects all instances, not just the one from which the statement is issued.

To successfully issue the ALTER SYSTEM QUIESCE RESTRICTED statement in a RAC environment, you must have the Database Resource Manager feature activated, and it must have been activated since instance startup for all instances in the cluster database. It is through the facilities of the Database Resource Manager that non-DBA sessions are prevented from becoming active. Also, while this statement is in effect, any attempt to change the current resource plan will be queued until after the system is unquiesced.

These conditions apply to RAC:

Quiesced State and Cold Backups

You cannot use the quiesced state to take a cold backup. This is because Oracle background processes may still perform updates for Oracle internal purposes even while the database is in quiesced state. In addition, the file headers of online datafiles continue to look like they are being accessed. They do not look the same as if a clean shutdown were done. You can still take online backups while the database is in a quiesced state. Refer to the Oracle Database Administrator's Guide for details on the quiesce database feature and the Oracle Database Reference for more information about the ALTER SYSTEM QUIESCE RESTRICTED syntax.

Administering System and Network Interfaces with the OIFCFG (Oracle Interface Configuration) Tool

This section describes the following Oracle Interface Configuration (OIFCFG) topics:

Use the OIFCFG command-line tool in single-instance Oracle databases and in RAC database environments to:

The Oracle Universal Installer (OUI) also uses OIFCFG to identify and display the interfaces available on the system.

Defining Network Interfaces with OIFCFG

The specification for a network interface uniquely identifies it using the interface name, its associated subnet, and interface type. The interface type indicates the purpose for which the network is configured. The supported interface types are:

  • Public—An interface that can be used for communication with components external to RAC instances, such as Oracle Net and Virtual Internet Protocol (VIP) addresses

  • Cluster interconnect—A private interface used for the cluster interconnect to provide inter-instance or Cache Fusion communication

  • Storage—A disk interface used for high-speed file I/O

A network interface can be stored as a global interface or as a node-specific interface. An interface is stored as a global interface when all the nodes of a RAC cluster have the same interface connected to the same subnet (recommended). It is stored as a node-specific interface only when there are some nodes in the cluster that have a different set of interfaces and subnets. If an interface is configured as both a global and a node-specific interface, the node-specific definition takes precedence over the global definition. A network interface specification is in the form of:


For example, the following identifies qfe0 as a cluster interconnect located at the address


Syntax and Commands for the OIFCFG Command-Line Tool

Use the oifcfg -help command to display online help for OIFCFG. The elements of OIFCFG commands, some of which are optional depending on the command, are:

  • nodename Name of the host, as known to a communications network

  • if_name Name by which the interface is configured in the system

  • subnet Subnet address of the interface

  • if_type Type of interface: public, cluster_interconnect, or storage

You can use OIFCFG to list the interface names and the subnets of all the interfaces available on the local node by executing the iflist keyword as shown in this example:

oifcfg iflist

You can also retrieve specific OIFCFG information with a getif command using the following syntax:

oifcfg getif [ [-global | -node <nodename>] [-if <if_name>[/<subnet>]] [-type <if_type>] ]

To store a new interface use the setif keyword. For example, to store the interface hme0, with the subnet, as a global interface (to be used as an interconnect for all the RAC instances in your cluster), you would use the command:

oifcfg setif -global hme0/

For a cluster interconnect that exists between only two nodes, for example rac1 and rac2, you could create the cms0 interface with the following commands, assuming and are the subnet addresses for the interconnect on rac1 and rac2 respectively:

oifcfg setif -node rac1 cms0/
oifcfg setif -node rac2 cms0/

Use the OIFCFG delif command to delete the stored configuration for global or node-specific interfaces. A specific node-specific or global interface can be deleted by supplying the interface name, with an optional subnet, on the command line. Without the -node or -global options, the delif keyword deletes either the given interface or all the global and node-specific interfaces on all the nodes in the cluster. For example, the following command deletes the global interface named qfe0 for the subnet

oifcfg delif -global qfe0/

On the other hand, the next command deletes all the global interfaces stored with OIFCFG:

oifcfg delif -global