Exam CKA Topic 2 Question 71 Discussion

See the solution below with Step by Step Explanation.
Explanation:
Solution (Step by Step) :
1. Scale up the StatefulSet:
- Increase the 'replicas' value in the StatefulSet definition from 3 to 4. Apply the change using 'kubectl apply -f mysql-cluster.yaml'

2. Wait for the new pod to be created: - Monitor the pod creation process using 'kubectl get pods -l app=mysql-cluster'. Wait for the new pod to be created and enter a ready state. 3. Join the new pod to the cluster: - In the new pod's shell, execute the following command to join the existing MySQL cluster: Bash mysql -h -u -p -e "CHANGE MASTER TO MASTER PASSWORD=", MASTER DELAY=O" - Replace with the IP address of one of the existing MySQL replicas. - Replace , and '3306' with the appropriate values for your MySQL setup. 4. Verify the new replica is synchronized: - Use "SHOW SLAVE STATUS" command on the new replica to verify that it's successfully replicating data from the existing cluster. Ensure that the 'Slave 10 Running' and 'Slave SQL Running' statuses are both set to 'Yes'. 5. Promote the new replica: - Promote the new replica to a full member of the cluster by updating the StatefulSet definition to include the new pod's hostname. This will typically involve adding a new entry to the 'volumeClaimTemplates' section of the StatefulSet. 6. Test the cluster's health: - Run a series of read and write operations on the database to verify that the new replica is fully integrated and responding correctly. 7. Remove the old pod: - You can now delete the old pod that had the lowest pod index. This will trigger the automatic cleanup of the old volume, ensuring that only the healthy and synchronized replicas remain. By following these steps, you can add a new replica to your MySQL cluster while ensuring minimal downtime and preserving data consistency. ]