Exam C1000-138 Topic 4 Question 79 Discussion

To achieve a high availability strategy with a target of four nines (99.99%) for an IBM Kubernetes Services cluster, you need to deploy multiple worker nodes across at least three availability zones within a single region. This configuration ensures that even if one or two zones experience failures, the cluster remains operational, thus meeting the 99.99% uptime objective.
High Availability in IBM Cloud Kubernetes Service: Deploying worker nodes across multiple availability zones provides redundancy and fault tolerance. By having at least three zones, the Kubernetes cluster can tolerate failures in up to two zones while still maintaining functionality.
Comparison of Options:
A (Single worker node in a single zone): Insufficient for high availability as any zone failure would result in downtime.
B (Multiple nodes in a single zone): Provides redundancy but still vulnerable to zone-wide outages, not meeting 99.99% uptime.
C (Multiple nodes in at least three zones across multiple regions): While this offers high availability, it exceeds the requirements stated for achieving 99.99% within a single region.
Reference:
IBM Kubernetes Service Documentation
IBM Cloud High Availability Best Practices
IBM Cloud Architect Exam Study Guide