To verify that a database instance is available, use Oracle Enterprise Manager, SRVCTL, or SQL*Plus.
Oracle Database 2 Day + Real Application Clusters Guide for information about using Oracle Enterprise Manager to view the status of Oracle RAC database 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
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
CONNECT /@db1 as SYSDBA
Query the V$ACTIVE_INSTANCES view, using the following statement:
CONNECT SYS/as SYSDBA Enter password: password SELECT * FROM V$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 Table 3-2.
Table 3-2 Descriptions of V$ACTIVE_INSTANCES Columns
Identifies the instance number.
Identifies the host name and instance name as