SAP Updated C_KYMD_01 Exam Questions and Answers by enola

• A DaemonSet ensures that all (or some) Nodes run a copy of a Pod. As nodes are added to the cluster, Pods are added to them. As nodes are removed from the cluster, those Pods are garbage collected. Deleting a DaemonSet will clean up the Pods it created2.
• Some typical uses of a DaemonSet are: running a cluster storage daemon on every node, running a logs collection daemon on every node, running a node monitoring daemon on every node2.
• DaemonSets are ideal in a variety of real-world use cases: Running Node monitoring agents, Running log collection agents, Running network plugins, Running service meshes3.

References:

• Kubernetes DaemonSet - What It is & How to Use It (Example)
• DaemonSet | Kubernetes
• Kubernetes Daemonset: A Practical Guide - Spot.io

• The kyma-gateway is a custom-configured Istio Ingress Gateway that is installed in the kyma-system namespace. It is the central point of contact for all external traffic that enters the Kyma cluster.
• The kyma-gateway uses the Envoy Proxy as an application-based service proxy to handle the traffic and to forward it to the correct Service. Envoy Proxy is a high-performance proxy developed in C++ to mediate all inbound and outbound traffic for all services in the service mesh.
• Envoy Proxy supports dynamic service discovery, load balancing, TLS termination, HTTP/2 and gRPC proxies, health checks, staged rollouts, fault injection, and rich metrics.

References:

• Using the API Gateway to Expose Services
• Extending on-premise systems via Kyma runtime
• SAP BTP, Kyma Runtime API Gateway future architecture based on Istio
• Exposing a Service in Kyma with API Rules

A Kubernetes cluster consists of two types of components: the control plane and the worker nodes. The control plane is responsible for managing the cluster state and orchestrating the containerized applications. The worker nodes are the machines that run the applications in pods. Some of the components of the architecture of a Kubernetes cluster are:

• kubelet: The kubelet is an agent that runs on each worker node and communicates with the control plane. The kubelet ensures that the pods and containers are running as expected, and reports the node status and resource usage to the control plane1.
• kube-proxy: The kube-proxy is a network proxy that runs on each worker node and enables the service abstraction. The kube-proxy maintains the network rules on the nodes, and allows the pods to communicate with each other and with external services2.
• etcd: The etcd is a distributed key-value store that stores the cluster configuration and state. The etcd is the source of truth for the cluster, and is accessed by the control plane components. The etcd is designed to be consistent, reliable, and secure3.

References:

• 1: Kubernetes Components | Kubernetes
• 2: Services, Load Balancing, and Networking | Kubernetes
• 3: etcd | Kubernetes

Stateless workloads are workloads that do not store any data or application state on the host that serves the requests. Instead, they rely on the information provided by the client or an external service, such as a database, to process each request independently. Stateless workloads do not keep any references to past transactions or interactions, and they can be handled by any available server. Stateless workloads are more scalable, fault-tolerant, and easier to manage than stateful workloads, which require persistent storage and session management. Some examples of stateless workloads are web servers, print servers, or microservices. References: Stateful vs stateless - Red Hat, Create stateless workloads | Google Distributed Cloud Hosted - Google Cloud, Stateless vs Stateful Kubernetes - WEKA