The following sections introduce Oracle RAC administration using the three tools that you commonly use to manage Oracle RAC databases and instances: the SRVCTL utility, Oracle Enterprise Manager, and SQL*Plus. In many cases, you use these tools the same way to manage Oracle RAC environments as you would use them manage noncluster Oracle databases:

• Administering Oracle RAC with SRVCTL

• Administering Oracle RAC with Oracle Enterprise Manager

• Administering Oracle RAC with SQL*Plus

Use SRVCTL start Oracle RAC databases and instances.

Enter the following SRVCTL syntax from the command line, providing the required database name and instance name, or include multiple instance names to start multiple specific instances:

• To start or stop your entire cluster database, that is, all of the instances and its enabled services, enter the following SRVCTL commands:

  $ srvctl start database -db db_unique_name [-startoption start_options]

  $ srvctl stop database -db db_unique_name [-o stop_options]

  The following SRVCTL command, for example, mounts all of the non-running instances of an Oracle RAC database:

  $ srvctl start database -db orcl -startoption mount

• To start administrator-managed databases, enter a comma-delimited list of instance names:

  $ srvctl start instance -db db_unique_name -instance instance_name_list
    [-startoption start_options]

  In Windows you must enclose a comma-delimited list in double quotation marks ("").

• To start policy-managed databases, enter a single node name:

  $ srvctl start instance -db db_unique_name -node node_name
    [-startoption start_options]

  Note that this command also starts all enabled and non-running services that have AUTOMATIC management policy, and for which the database role matches one of the service's roles.

• To stop one or more instances, enter the following SRVCTL syntax from the command line:

  $ srvctl stop instance -db db_unique_name [-instance "instance_name_list" | 
    -node node_name] [-stopoption stop_options]

  You can enter either a comma-delimited list of instance names to stop several instances or you can enter a node name to stop one instance. In Windows you must enclose a comma-delimited list in double quotation marks ("").

This command also stops the services related to the terminated instances on the nodes where the instances were running. As an example, the following command shuts down the two instances, orcl3 and orcl4, on the orcl database using the immediate stop option:

$ srvctl stop instance -db orcl -instance "orcl3,orcl4" -stopoption immediate

Use SRVCTL to stop instances and Oracle RAC databases.

The procedure for shutting down Oracle RAC instances is identical to shutting down instances in noncluster Oracle databases, with the following exceptions:

• In Oracle RAC, shutting down one instance does not interfere with the operation of other running instances.

• To shut down an Oracle RAC database completely, shut down every instance that has the database open or mounted.

• After a NORMAL or IMMEDIATE shutdown, instance recovery is not required. Recovery is required, however, after you issue the SHUTDOWN ABORT command or after an instance terminates abnormally. An instance that is still running performs instance recovery for the instance that shut down. If no other instances are running, the next instance to open the database performs instance recovery for any instances needing it.

• Using the SHUTDOWN TRANSACTIONAL command with the LOCAL option is useful to shut down a particular Oracle RAC database instance. Transactions on other instances do not block this operation. If you omit the LOCAL option, then this operation waits until transactions on all other instances that started before you ran the SHUTDOWN command either commit or rollback, which is a valid approach, if you intend to shut down all instances of an Oracle RAC database.

  Note:

  SHUTDOWN TRANSACTIONAL and SHUTDOWN TRANSACTIONAL LOCAL both perform the same action on a nonclustered database but the two commands are different on an Oracle RAC database.

Use SRVCTL to shut down an Oracle RAC database or database instance. The respective SRVCTL commands (srvctl stop database or srvctl stop instance) provide shutdown options to perform an optimized transactional shutdown. Use the TRANSACTIONAL stop option with the srvctl stop database command and the TRANSACTIONAL LOCAL stop option with the srvctl stop instance command.

You can use the crsctl stop crs command on the node or the crsctl stop cluster -all command to stop all instances on a node or the entire cluster.

When you want to stop an entire node or cluster (for maintenance purposes, for example), you run either the crsctl stop crs command on the node or the crsctl stop cluster -all command, provided you have the required cluster privileges. These commands stop all database instances running on a server or in the cluster and ensure that their state is recovered after you restart the cluster. Using CRSCTL also enables Oracle Clusterware to relocate services and other resources that can run elsewhere.

Using either of these CRSCTL commands to stop all database instances on a server or in the cluster can lead to the database instances being stopped similar to shutdown abort, which requires an instance recovery on startup. If you use SRVCTL to stop the database instances manually before stopping the cluster, then you can prevent a shutdown abort, but this requires that you manually restart the database instances after restarting Oracle Clusterware.

If you want to start or stop just one instance and you are connected to your local node, then you must first ensure that your current environment includes the SID for the local instance.

Note that any subsequent commands in your session, whether inside or outside a SQL*Plus session, are associated with that same SID.

To start or shutdown your local instance, initiate a SQL*Plus session and connect with the SYSRAC or SYSOPER privilege and then issue the required command. For example to start and mount an instance on your local node, run the following commands in your SQL*Plus session:

   CONNECT / AS SYSRAC
   STARTUP MOUNT

You can start multiple instances from a single SQL*Plus session on one node using Oracle Net Services. Connect to each instance in turn by using a Net Services connection string, typically an instance-specific alias from your tnsnames.ora file.

For example, you can use a SQL*Plus session on a local node to perform a transactional shutdown for two instances on remote nodes by connecting to each in turn using the instance's individual alias name. Assume the alias name for the first instance is db1 and that the alias for the second instance is db2. Connect to the first instance and shut it down as follows:

   CONNECT /@db1 AS SYSRAC
   SHUTDOWN TRANSACTIONAL

Then connect to and shutdown the second instance by entering the following from your SQL*Plus session:

   CONNECT /@db2 AS SYSRAC 
   SHUTDOWN TRANSACTIONAL

It is not possible to start or stop multiple instances, simultaneously, with SQL*Plus, so you cannot start or stop all of the instances for a cluster database with a single SQL*Plus command. You may want to create a script that connects to each instance in turn and start it up and shut it down. However, you must maintain this script manually if you add or drop instances.

You can use SRVCTL to verify that instances are running on a particular database.

The following command provides an example of using SRVCTL to check the status of the database instances for the Oracle RAC database named mail:

$ srvctl status database -db mail

This command returns output similar to the following:

Instance mail1 is running on node betal011Instance mail2 is running on node betal010

Additionally, you can check whether PDBs are running in the cluster by checking the availability of their assigned services, as follows:

$ srvctl status service -db db_unique_name -service service_name

You can use SQL*Plus to verify that database instances are running.

1. On any node, from a SQL*Plus prompt, connect to a database instance by using a Net Services connection string, typically an instance-specific alias from your tnsnames.ora file.

   CONNECT /@db1 as SYSRAC
   

2. Query the V$ACTIVE_INSTANCES view, using the following statement:

   CONNECT SYS/as SYSRAC
   Enter password: password
   SELECT * FROM V$ACTIVE_INSTANCES;

   This query returns output similar to the following:

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

The output columns for this example are shown in the following table.

You can change SPFILE settings with Oracle Enterprise Manager or by using the SET clause of the ALTER SYSTEM statement.

The examples in this section appear in ASCII text although the SPFILE is a binary file. Assume that you start an instance with an SPFILE containing the following entries:

*.OPEN_CURSORS=500
prod1.OPEN_CURSORS=1000

The value before the period (.) in an SPFILE entry identifies the instance to which the particular parameter value belongs. When an asterisk (*) precedes the period, the value is applied to all instances that do not have a subsequent, individual value listed in the SPFILE.

For the instance with the Oracle system identifier (SID) prod1, the OPEN_CURSORS parameter is set to 1000 even though it has a database-wide setting of 500. Parameter file entries that have the asterisk (*) wildcard character only affect the instances without an instance-specific entry. This gives you control over parameter settings for instance prod1. These two types of settings can appear in any order in the parameter file.

If another DBA runs the following statement, then Oracle Database updates the setting on all instances except the instance with SID prod1:

ALTER SYSTEM SET OPEN_CURSORS=1500 sid='*' SCOPE=SPFILE;

The SPFILE now has the following entries for OPEN_CURSORS:

*.OPEN_CURSORS=1500
prod1.OPEN_CURSORS=1000

Run the following statement to reset OPEN_CURSORS to its default value for all instances except prod1:

ALTER SYSTEM RESET OPEN_CURSORS SCOPE=SPFILE;

The SPFILE now has just the following entry for prod1:

prod1.OPEN_CURSORS=1000

Run the following statement to reset the OPEN_CURSORS parameter to its default value for instance prod1 only:

ALTER SYSTEM RESET OPEN_CURSORS SCOPE=SPFILE SID='prod1';

Oracle Database searches for your parameter file in a particular order depending on your platform. For Oracle RAC databases, you can easily determine the location of the parameter file by using the srvctl config database command.

On Linux and UNIX platforms, the search order is as follows:

1. $ORACLE_HOME/dbs/spfilesid.ora

2. $ORACLE_HOME/dbs/spfile.ora

3. $ORACLE_HOME/dbs/initsid.ora

On Windows platforms, the search order is as follows:

1. %ORACLE_HOME%\database\spfilesid.ora

2. %ORACLE_HOME%\database\spfile.ora

3. %ORACLE_HOME%\database\initsid.ora

Oracle recommends that you regularly back up the server parameter file for recovery purposes.

Do this using Oracle Enterprise Manager or use the CREATE PFILE statement. For example:

CREATE PFILE='/u01/oracle/dbs/test_init.ora'
FROM SPFILE='/u01/oracle/dbs/test_spfile.ora';

You can use Recovery Manager (RMAN) to create backups of the server parameter file. You can also recover an SPFILE by starting an instance using a client-side initialization parameter file. Then re-create the server parameter file using the CREATE SPFILE statement. Note that if the parameter file that you use for this operation was for a single instance, then the parameter file does not contain instance-specific values, even those that must be unique in Oracle RAC instances. Therefore, ensure that your parameter file contains the appropriate settings as described earlier in this chapter.

To ensure that your SPFILE (and control files) are automatically backed up by RMAN during typical backup operations, use Oracle Enterprise Manager or the RMAN CONTROLFILE AUTOBACKUP statement to enable the RMAN autobackup feature

Certain parameters that are critical at database creation or that affect certain database operations must have the same value for every instance in an Oracle RAC database.

Specify these initialization parameter values in the SPFILE or in the individual PFILEs for each instance. The following list contains the parameters that must be identical on every instance:

• COMPATIBLE
• CLUSTER_DATABASE
• CONTROL_FILES
• DB_BLOCK_SIZE
• DB_DOMAIN
• DB_FILES
• DB_NAME
• DB_RECOVERY_FILE_DEST
• DB_RECOVERY_FILE_DEST_SIZE
• DB_UNIQUE_NAME
• INSTANCE_TYPE (RDBMS or ASM)
• PARALLEL_EXECUTION_MESSAGE_SIZE
• REMOTE_LOGIN_PASSWORDFILE
• UNDO_MANAGEMENT

The following parameters must be identical on every instance only if the parameter value is set to zero:

• DML_LOCKS
• RESULT_CACHE_MAX_SIZE

When it is necessary to set parameters that have unique settings on a policy-managed database, you can ensure that instances always use the same name on particular nodes by running the srvctl modify instance -n node_name -i instance_name command for each server that can be assigned to the database's server pool. Then a unique value of the parameter can be specified for instance_name that is used whenever the database runs on node_name.

Specify the ORACLE_SID environment variable, which consists of the database name and the number of the INSTANCE_NAME assigned to the instance.

Use the CLUSTER_INTERCONNECTS initialization parameter to specify an alternative interconnect to the one Oracle Clusterware is using for the private network. Each instance of the Oracle RAC database gets a unique value when setting the CLUSTER_INTERCONNECTS initialization parameter.

Oracle Database uses the INSTANCE_NUMBER parameter to distinguish among instances at startup and the INSTANCE_NAME parameter to assign redo log groups to specific instances. The instance name can take the form db_unique_name_instance_number and when it has this form of name and number separated by an underscore, the number after the underscore is used as the INSTANCE_NUMBER. With Oracle Database 11.2 using Grid Plug and Play, you no longer have to explicitly assign instance numbers for policy-managed databases and the instance name defaults to db_unique_name_instance_number, where Oracle Database assigns the instance number.

When you specify UNDO_TABLESPACE with automatic undo management enabled, then set this parameter to a unique undo tablespace name for each instance.

If you use the ROLLBACK_SEGMENTS parameters, then Oracle recommends setting unique values for it by using the SID identifier in the SPFILE. However, you must set a unique value for INSTANCE_NUMBER for each instance and you cannot use a default value.

Using the ASM_PREFERRED_READ_FAILURE_GROUPS initialization parameter, you can specify a list of preferred read failure group names. The disks in those failure groups become the preferred read disks. Thus, every node can read from its local disks. This results in higher efficiency and performance and reduced network traffic. The setting for this parameter is instance-specific, and the values need not be the same on all instances.

Oracle recommends that the parameters listed here have identical settings on all instances.

Oracle recommends that you set the values for the parameters in Table 3-4 to the same value on all instances. Although you can have different settings for these parameters on different instances, setting each parameter to the same value on all instances simplifies administration.

The CLUSTER_INTERCONNECTS initialization parameter requires an IP address. It enables you to specify multiple IP addresses, separated by colons. Oracle RAC network traffic is distributed between the specified IP addresses.

Typically, you set the CLUSTER_INTERCONNECTS parameter only in the following situations:

• The cluster is running multiple databases and you need the interconnect traffic to be separated and you do not use Redundant Interconnect Usage.

• You have a single IP address that is made highly available by the operating system, and it does not have a stable interface name (for example, the name can change when you restart).

Do not set the CLUSTER_INTERCONNECTS parameter for the following common configurations:

• If you want to use Redundant Interconnect Usage.

• If you have only one cluster interconnect.

• If the default cluster interconnect meets the bandwidth requirements of your Oracle RAC database, which is typically the case.

Consider the following important points when specifying the CLUSTER_INTERCONNECTS initialization parameter:

• The CLUSTER_INTERCONNECTS initialization parameter is useful only in Linux and UNIX environments where UDP IPC is enabled.

• Specify a different value for each instance of the Oracle RAC database when setting the CLUSTER_INTERCONNECTS initialization parameter in the parameter file.

• The IP addresses you specify for the different instances of the same database on different nodes must belong to network adapters that connect to the same interconnect network.

• If you specify multiple IP addresses for this parameter, then list them in the same order for all instances of the same database. For example, if the parameter for the first instance on node1 lists the IP addresses of the alt0:, fta0:, and ics0: devices in that order, then the parameter for the second instance on node2 must list the IP addresses of the equivalent network adapters in the same order.

• If an operating system error occurs while Oracle Database is writing to the interconnect that you specify with the CLUSTER_INTERCONNECTS parameter, then Oracle Database returns an error even if some other interfaces are available. This is because the communication protocols between Oracle Database and the interconnect can vary greatly depending on your platform. See your Oracle Database platform-specific documentation for more information.

Consider setting CLUSTER_INTERCONNECTS when a single cluster interconnect cannot meet your bandwidth requirements. You may need to set this parameter in data warehouse environments with high interconnect bandwidth demands from one or more databases that cannot use Redundant Interconnect Usage.

For example, if you have two databases with high interconnect bandwidth requirements, then you can override the default interconnect provided by your operating system and nominate a different interconnect for each database using the following syntax in each server parameter file where ipn is an IP address in standard dot-decimal format, for example: 144.25.16.214:

Database One: crm1.CLUSTER_INTERCONNECTS = ip1
Database Two: ext1.CLUSTER_INTERCONNECTS = ip2

If you have one database with high bandwidth demands, then you can nominate multiple interconnects using the following syntax:

CLUSTER_INTERCONNECTS = ip1:ip2:...:ipn

Discovering Oracle RAC database and instance targets in Oracle Enterprise Manager enables monitoring and administration.

Oracle Enterprise Manager Cloud Control enables you to use the Oracle Enterprise Manager console interface to discover Oracle Real Application Clusters (Oracle RAC) database and instance targets.

If the Oracle Enterprise Manager Cloud Control agents are installed on a cluster that has an Oracle RAC database, then Oracle RAC database targets are discovered at install time. You can use the console interface to discover targets if a database is created after agents are installed or if a database is not automatically discovered at agent install time.

To discover nodes and instances, use Oracle Enterprise Manager Cloud Control as follows:

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

2. Click the Database tab to view all of the available targets. The column labeled Types shows the Oracle RAC databases using the entry Cluster Database.

3. Add the database target by selecting the target name, then clicking Add. The Add Database Target: Specify Host page appears, which enables you to add databases, listeners, and Oracle Automatic Storage Management (Oracle ASM) as monitored targets.

4. Click the flashlight icon to display the available host names, select a host, then click Continue. The Add Database: Specify Source page appears.

5. Either request Oracle Enterprise Managerr to discover only noncluster databases and listeners, or to discover all cluster databases, noncluster databases, and listeners on the cluster, then click Continue.

6. If this procedure did not discover your reconfigured cluster database and all of its instances, you can use the Targets Discovered on Cluster page to manually configure your cluster database and noncluster databases.

Oracle Enterprise Manager provides a variety of administrative capabilities starting with Oracle Enterprise Manager 12c.

• The Oracle Grid Infrastructure/Oracle RAC Provisioning deployment procedure provisions Oracle RAC 12c and Oracle Grid Infrastructure. This procedure also has a feature called Profiles, which enables you to record the inputs and subsequently use them for repeated deployments.

• Dynamic prerequisites for the new procedures enable Oracle Enterprise Manager, when connected to My Oracle Support, to download the latest prerequisites and tools for Oracle RAC provisioning.

• The existing One-Click Extend Cluster Database capability now supports Oracle RAC 12c stack.

• The existing Delete/Scale down Oracle Real Application Clusters capability is certified with Oracle RAC 12c clusters.

• The existing Oracle Database Provisioning procedure now supports provisioning of single instances of Oracle Database 12c.

• A new deployment procedure—Oracle Grid Infrastructure Provisioning for Standalone Servers—has been introduced to provision Oracle Grid Infrastructure 12c for noncluster databases.

The Cluster Database Home page shows all of the instances in the Oracle RAC database and provides an aggregate collection of several Oracle RAC-specific statistics that are collected by the Automatic Workload Repository (AWR) 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 Oracle RAC database, navigate to the Cluster Database Home page, and click the Administration tab.

This section includes the following topics:

• Administering Jobs in Oracle RAC

• Administering Alerts in Oracle RAC with Oracle Enterprise Manager

• Using Defined Blackouts in Oracle Enterprise Manager