Observability tools are used to monitor system behaviour and performance, as well as to troubleshoot issues and identify root causes. Observability tools in SAP BTP, Kyma runtime include Grafana, Prometheus, Loki, and Jaeger, which provide dashboards, metrics, logs, and traces for the workloads running in the cluster1. Distributed tracing is a technique to track the flow of requests across microservices and visualize the latency, errors, and dependencies of each service2. Observability tools help developers and operators to ensure the reliability, availability, and security of their applications and services.
Questions 5
Using the Cloud Events specification, which component must you use to post events to Kyma Eventing?
To post events to Kyma Eventing using the Cloud Events specification, you need to use the service/eventing-event-publisher-proxy component. This component is responsible for validating and forwarding events to the Eventing Controller, which then dispatches them to the subscribers. The other components are not relevant for this purpose. The pod/eventing-event-publisher-proxy is the name of the pod that runs the service, but it is not the component that you use to post events. The pods/eventing-nats-0 and svc/eventing-nats are related to the NATS eventing framework, which is the default eventing backend in Kyma, but they are not the components that you use to post events using the Cloud Events specification. References: Side-by-Side Extensibility Based on SAP BTP, Kyma Runtime - Unit 4 - Lesson 1: Eventing in Kyma, Kyma Documentation - Event Publisher Proxy
Questions 6
Which deployment strategy for new versions avoids downtimes?
A zero downtime deployment is a technique that allows updating an application without interrupting its availability or functionality. It usually involves creating a separate environment for the new version and switching the traffic to it once it is ready. This way, the users do not experience any disruption or errors during the deployment process. A zero downtime deployment can be achieved by using different strategies, such as blue-green deployments, canary deployments, or rolling updates123. References: Zero Downtime Deployment Techniques: Rolling Update, Zero Downtime Deployment Techniques - Blue-Green Deployments, 5 Effective Deployment Strategies To Release Applications In 2021
Questions 7
What happens when you delete a pod managed by a Replica Set?
Options:
A.
The Replica Set will schedule a new pod.
B.
The pod is deleted until the redeployment of the Replica Set.
When you delete a pod managed by a Replica Set, the Replica Set will schedule a new pod to replace the deleted one. This is because the Replica Set’s purpose is to maintain a stable set of replica pods running at any given time. As such, it is often used to guarantee the availability of a specified number of identical pods1. The Replica Set controller monitors the number of pods it owns and creates or deletes pods as needed to reach the desired number. The Replica Set identifies its pods by using a selector that matches the pods’ labels2. Therefore, deleting a pod will reduce the number of pods that match the selector, and trigger the Replica Set to create a new pod with the same pod template3.
References:
1: ReplicaSet | Kubernetes
2: Labels and Selectors | Kubernetes
3: Pods, Deployments and Replica Sets: Kubernetes Resources Explained
