SAP Certified Development Associate C_KYMD_01 Full Course Free

The command kubectl get services lists all the services in the current namespace1. The get command is used to display one or more resources in Kubernetes2. The services argument specifies the type of resource to list. To list services in a differentnamespace, you can use the --namespace or -n flag3. References: Kubectl commands to list services, deployments and pods from namespace …, kubectl Cheat Sheet | Kubernetes, How to get the current namespace of current context using kubectl - Stack Overflow

 A one off/non parallel job is a workload type that runs a single task to completion and then terminates. This is suitable for running a database migration on SAP BTP, Kyma runtime, as it does not require scaling, persistence, or parallelism. A parallel job, on the other hand, is a workload type that runs multiple tasks in parallel and then terminates. This is useful for batch processing or data analysis, but not for database migration. A StatefulSet is a workload type that runs one or more pods that maintain a stable identity and persistent storage. This is useful for stateful applications such as databases or message brokers, but not for database migration. A DaemonSet is a workload type that runs one pod on each node in the cluster. This is useful for providing node-level services such as logging or monitoring, but not for database migration. References: Workload Concepts, Kubernetes Workloads

 You can check which SAP BTP services are available to create in your subaccount by visiting the SAP BTP Service Marketplace. The Service Marketplace is a page in the SAP BTP cockpit that lists all the services and applications that you can use in your subaccount. You can browse, search, filter, and sort the services and applications by categories, such as databases, analytics, integration, or security. You can also see the details, documentation, and pricing of each service and application, and create instances or subscriptions from the Service Marketplace. The Service Marketplace shows only the services and applications that you have entitlements for in your subaccount. You can manage your entitlements from the Entitlements page in the SAP BTP cockpit. References: SAP BTP Service Marketplace, Create a Service Instance in SAP BTP, Add a New Entitlement to Your Subaccount

• 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?