How to Add and Delete a Node in Oracle RAC 19c

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Introduction

In this article, we will explore the process of adding and deleting a node in Oracle RAC 19c. These steps can also be applied to Oracle RAC 12c with minor variations. Oracle RAC (Real Application Clusters) allows you to create a clustered database environment that provides high availability and scalability. By adding or deleting nodes, you can adjust the resources and capacity of your Oracle RAC cluster according to your needs.

Key Points

  • Oracle RAC allows you to create a clustered database environment.
  • Adding and deleting nodes in Oracle RAC can help adjust resources and capacity.
  • This tutorial will focus on Oracle RAC 19c, but the steps are similar for Oracle RAC 12c.

Step-by-Step Guide to Adding a Node

  1. Begin by editing the /etc/hosts file and adding the necessary entry for the new node.
  2. Ping the private IP of the new node to ensure connectivity.
  3. Add the necessary groups on the new node, such as the oracle group and the primary group.
  4. Install the required RPMs on the new node. If you have not configured your repositories, you may need to install from an ISO file.
  5. Configure Oracle ASM on the new node by setting the default user, ownership, and group.
  6. Scan the disk to ensure the visibility of the disks on the new node.
  7. Create the necessary directories, such as the Oracle database directories.
  8. Configure SSH setup for passwordless authentication between the nodes using the keygen method.
  9. Append the authorized keys from one node to the other to enable SSH access.
  10. Verify the SSH setup on both nodes.
  11. Run the cluster verification utility (cluster.verify) on the existing node to check for any errors or compatibility issues.
  12. Repeat the cluster verification utility on the new node.
  13. Fix any errors or issues reported by the cluster verification utility.
  14. Press Enter to continue after fixing the issues.
  15. Add the new node to the cluster by running the addNode.sh script.

Step-by-Step Guide to Deleting a Node

  1. Ensure that all necessary backups have been performed before deleting a node from the Oracle RAC cluster.
  2. Shut down the Oracle services running on the node you want to delete.
  3. Remove the node from the /etc/hosts file and update the network configuration accordingly.
  4. Restart the remaining nodes in the cluster to ensure they are updated with the changes.
  5. Use the Oracle Universal Installer or the runInstaller script to remove the Oracle software and database from the node.
  6. Clean up any remaining files and directories associated with the node.

Conclusion

In this article, we have explored the process of adding and deleting a node in Oracle RAC 19c. The steps provided can also be applied to Oracle RAC 12c with minor variations. By following these steps, you can adjust the resources and capacity of your Oracle RAC cluster according to your needs. It is essential to ensure backups are performed before deleting a node and to carefully follow the steps to avoid any data loss. With Oracle RAC, you can create a robust and scalable database environment for your organization.