SAP C_KYMD_01 Exam With Confidence Using Practice Dumps

• A headless service is defined by setting the clusterIP field to None in the service spec. This tells Kubernetes not to allocate a cluster IP for the service, and to create DNS records only.
• For StatefulSets, you can use a headless service to control the domain of the pods. The pods that belong to a StatefulSet have a unique identity that is comprised of an ordinal, a stable network identity, and stable storage. The identity sticks to the pod, regardless of which node it’s (re)scheduled on.
• Each pod in a StatefulSet derives its hostname from the name of the StatefulSet and the ordinal of the pod. The pattern for the constructed hostname is (statefulsetname)−(ordinal). The example above will create three pods named web-0,web-1,web-2.
• A StatefulSet can use a headless service to provide network identity for its pods. The service is responsible for creating a DNS record for each pod in the form (podname).(governing service domain). For the previous example, the headless service named nginx will create DNS records for web-0.nginx, web-1.nginx, and web-2.nginx.

References:

• Headless Services
• StatefulSets
• Is it required to use a headless service for statefulsets?

 Some of the features of Kubernetes are:

• Immutability and self-healing: Kubernetes treats pods as immutable, meaning that they are not modified after they are created. Instead, pods are replaced with new ones when they need to be updated or repaired. This ensures that the pods are always in a consistent and predictable state. Kubernetes also monitors the health and availability of the pods and automatically restarts, reschedules, or replicates them if they fail or become unresponsive1.
• Extensibility and ecosystem: Kubernetes is designed to be extensible and modular, allowing users to customize and extend its functionality according to their needs. Kubernetes supports various extensions, such as custom resources, operators, admission controllers, schedulers, network plugins, storage plugins, and more. Kubernetes also has a large and vibrant ecosystem of tools, services, and applications that are built on top of or integrate with it2.
• Automated rollouts and rollbacks: Kubernetes enables users to deploy and update their applications with zero downtime, using declarative configuration and rolling updates. Kubernetes ensures that only a certain number of pods are changed at a time, and that the new pods are ready before terminating the old ones. Kubernetes also tracks the history of each update and allows users to roll back to a previous version if something goes wrong3.

References:

• 1: Pods | Kubernetes
• 2: Extending Kubernetes | Kubernetes
• 3: Deployments | Kubernetes

Kyma Eventing simplifies the process of publishing and subscribing to events in the cluster. Publishing events means sending information about a change in the state of the application or the system to the Eventing backend. Subscribing to events means registering interest for a specific event type from a specific source. Kyma Eventing allows users to publish events by sending HTTP requests to the Event Publisher Proxy component, which validates and forwards the events to the NATS backend. Kyma Eventing also allows users to subscribe to events by creating Subscription custom resources that specify the event source, type, and the HTTP endpoint of the service that will receive the events. Kyma Eventing handles the delivery of the events from the NATS backend to the subscribers with the help of the Eventing Controller and the Eventing Dispatcher components. References: