Certified Kubernetes Application Developer (CKAD) Practice Test

Which service type is often utilized for exposing an application when load balancing is required?

1. ClusterIP

2. NodePort

3. LoadBalancer

4. ExternalName

The correct answer is: LoadBalancer

The LoadBalancer service type is specifically designed to expose an application to external traffic while also providing load balancing capabilities. When a LoadBalancer service is created, it provisions a cloud load balancer that routes traffic to the underlying pods based on the defined service configuration. This makes it particularly suitable for applications that require a stable endpoint to handle a large number of incoming requests efficiently. The LoadBalancer service type works well in cloud environments where the cloud provider can allocate external IP addresses and manage the load balancing infrastructure automatically. This service type helps distribute traffic to multiple pods, ensuring high availability and fault tolerance for the application. In contrast, the other options serve different purposes. ClusterIP is used for internal service discovery within the cluster and does not expose the application externally. NodePort also exposes the application outside the cluster, but it does so by opening a specific port on each node, which might not offer the same level of load balancing out of the box. Finally, ExternalName is used for mapping a service to an external DNS name but does not provide any real load balancing. Therefore, the LoadBalancer type is the most suited for applications that need to be exposed with load balancing capabilities.