Troubleshoot the "ORA-12514" error when installing Oracle plugins

Troubleshoot the "ORA-12514" error when installing Oracle plugins

When installing the Oracle database monitoring plugins, you may encounter the following error:
ORA-12514: TNS:listener does not currently know of service requested in connect descriptor: This error typically occurs during attempts to establish a connection with an Oracle database. It indicates that while the Oracle listener is active, it doesn't recognize the service name or system identifier (SID) provided in the connect string.

Here are the steps you can follow to troubleshoot the issue.
  1. Validate the service name or SID: Ensure that you are using the correct service name or SID in your connection string. Check for any typographical errors.

  2. Confirm listener status: Verify that the Oracle listener service is running and is aware of the database service you are trying to connect to. You can run the following command to see the current status of the listener:
    lsnrctl status
    This command will show you the services that the listener is currently aware of. Ensure the service you're trying to connect to is listed.

  3. Check the TNSNAMES.ORA and LISTENER.ORA files: The TNSNAMES.ORA and LISTENER.ORA files play an integral role in the Oracle connectivity framework. TNSNAMES.ORA defines the network addresses of databases on the network, while LISTENER.ORA contains listener process configurations. Ensure that these files have consistent and correct configurations across client and server systems.

  4. Validate the database instance status: Ensure the Oracle database instance is up and running. If the database is down, the service won't be available to the listener. You can check the status of the Oracle instance using the following command:
    sqlplus / as sysdba

    And then:
    SELECT INSTANCE_NAME, STATUS FROM V$INSTANCE;

  5. Check service registration with the listener: Oracle supports dynamic registration. If the database instance is currently operational but hasn't been automatically registered with the listener, you can manually register it by following the steps below.
    1. Connect to the database using the following command:
      sqlplus / as sysdba
    2. Execute the following command to register the database instance with the listener manually:
      ALTER SYSTEM REGISTER;

  6. Review firewall and network issues: Ensure there aren’t any network or firewall issues that might be preventing the listener from communicating with the Oracle database instance.

  7. Check logs: Examine the listener logs and database alert logs for any additional insights or error messages. By default, the listener log is typically located in the alert_[SID].log file in the Oracle Diagnostic Destination directory.

  8. Restart Oracle: In some cases, restarting the Oracle listener or the database instance resolves the issue.

    First, restart the listener:
    lsnrctl stop lsnrctl start

    If required, then restart the database:
    sqlplus / as sysdba SHUTDOWN IMMEDIATE; STARTUP;

  9. Check Oracle client configuration: If you're trying to connect from a client machine, ensure the Oracle client is correctly installed and the TNSNAMES.ORA file on the client machine is correctly configured. 
Once you've made changes based on the checks above, restart the Site24x7 server monitoring agent or re-register the plugin. Within five minutes, you should be able to view performance metrics in Site24x7.
If the issue persists, reach out to support@site24x7.com with the plugin details.

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