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Linux Foundation KCNA Practice Test 45

Question 440

A Pod reports intermittent 502 errors and a nearby network proxy logs upstream timeouts with matching request IDs. Which observable result BEST confirms the desired Kubernetes or cloud native behavior?

  1. Production uses a tested traceable artifact only after required promotion and environment gates succeed.
  2. An incident timeline pinpoints the failing dependency rather than relying on one generic readiness or CPU signal.
  3. Healthy Pods enter ready endpoints only after application dependencies function, without restarting healthy processes unnecessarily.
  4. Engineers identify the failing process message associated with the correct container instance and time window.

Explanation

Correct Answer

B:

An incident timeline pinpoints the failing dependency rather than relying on one generic readiness or CPU signal. This is an observable service outcome, not just evidence that a configuration file was saved. Metrics show trends, logs show event details, and traces show request spans; reliable correlation benefits from consistent identifiers. Workload context: A Pod reports intermittent 502 errors and a nearby network proxy logs upstream timeouts with matching request IDs.

Incorrect Answers

A:

Production uses a tested traceable artifact only after required promotion and environment gates succeed. That result validates CI versus CD pipeline separation rather than the requirement here. Verify instead: An incident timeline pinpoints the failing dependency rather than relying on one generic readiness or CPU signal. Workload context: A Pod reports intermittent 502 errors and a nearby network proxy logs upstream timeouts with matching request IDs.

C:

Healthy Pods enter ready endpoints only after application dependencies function, without restarting healthy processes unnecessarily. That result validates Readiness-probe failure versus process crash rather than the requirement here. Verify instead: An incident timeline pinpoints the failing dependency rather than relying on one generic readiness or CPU signal. Workload context: A Pod reports intermittent 502 errors and a nearby network proxy logs upstream timeouts with matching request IDs.

D:

Engineers identify the failing process message associated with the correct container instance and time window. That result validates kubectl logs current versus previous instance rather than the requirement here. Verify instead: An incident timeline pinpoints the failing dependency rather than relying on one generic readiness or CPU signal. Workload context: A Pod reports intermittent 502 errors and a nearby network proxy logs upstream timeouts with matching request IDs.

Question 441

A stateful Pod requires a particular zone but an Immediate-binding StorageClass allocated a disk elsewhere. Which observable result BEST confirms the desired Kubernetes or cloud native behavior?

  1. Resource pressure is resolved without sustained involuntary eviction or unsafe removal of application persistent data.
  2. Each stateful replica retains its expected identity and corresponding durable storage through controlled replacement.
  3. Storage is provisioned in a suitable placement domain after the first eligible consumer is considered.
  4. Each workload can invoke only required API verbs without accessing unrelated namespaces or cluster secrets.

Explanation

Correct Answer

C:

Storage is provisioned in a suitable placement domain after the first eligible consumer is considered. This is an observable service outcome, not just evidence that a configuration file was saved. A PVC may legitimately remain unbound until a Pod consumes it under WaitForFirstConsumer. Workload context: A stateful Pod requires a particular zone but an Immediate-binding StorageClass allocated a disk elsewhere.

Incorrect Answers

A:

Resource pressure is resolved without sustained involuntary eviction or unsafe removal of application persistent data. That result validates Node pressure and Pod eviction analysis rather than the requirement here. Verify instead: Storage is provisioned in a suitable placement domain after the first eligible consumer is considered. Workload context: A stateful Pod requires a particular zone but an Immediate-binding StorageClass allocated a disk elsewhere.

B:

Each stateful replica retains its expected identity and corresponding durable storage through controlled replacement. That result validates StatefulSet identity and volume templates rather than the requirement here. Verify instead: Storage is provisioned in a suitable placement domain after the first eligible consumer is considered. Workload context: A stateful Pod requires a particular zone but an Immediate-binding StorageClass allocated a disk elsewhere.

D:

Each workload can invoke only required API verbs without accessing unrelated namespaces or cluster secrets. That result validates ServiceAccount and workload RBAC boundaries rather than the requirement here. Verify instead: Storage is provisioned in a suitable placement domain after the first eligible consumer is considered. Workload context: A stateful Pod requires a particular zone but an Immediate-binding StorageClass allocated a disk elsewhere.

Question 442

A worker cannot validate the registry certificate after an internal CA rotation while other nodes still pull images successfully. Which observable result BEST confirms the desired Kubernetes or cloud native behavior?

  1. Healthy but initializing Pods avoid traffic and genuinely stuck workloads recover without unnecessary restart loops.
  2. Temporary data is disposable while durable application records remain accessible across Pod recreation.
  3. Eligible nodes retrieve the intended immutable artifact and Pods progress beyond image pull.
  4. The Service has healthy matching backends and forwards to the application process's actual port.

Explanation

Correct Answer

C:

Eligible nodes retrieve the intended immutable artifact and Pods progress beyond image pull. This is an observable service outcome, not just evidence that a configuration file was saved. ImagePullBackOff is a retrieval or authorization problem; changing app readiness probes cannot fix a missing image. Workload context: A worker cannot validate the registry certificate after an internal CA rotation while other nodes still pull images successfully.

Incorrect Answers

A:

Healthy but initializing Pods avoid traffic and genuinely stuck workloads recover without unnecessary restart loops. That result validates Readiness liveness and startup probe behavior rather than the requirement here. Verify instead: Eligible nodes retrieve the intended immutable artifact and Pods progress beyond image pull. Workload context: A worker cannot validate the registry certificate after an internal CA rotation while other nodes still pull images successfully.

B:

Temporary data is disposable while durable application records remain accessible across Pod recreation. That result validates Ephemeral emptyDir versus persistent volumes rather than the requirement here. Verify instead: Eligible nodes retrieve the intended immutable artifact and Pods progress beyond image pull. Workload context: A worker cannot validate the registry certificate after an internal CA rotation while other nodes still pull images successfully.

D:

The Service has healthy matching backends and forwards to the application process's actual port. That result validates Service selector and port mismatch diagnostics rather than the requirement here. Verify instead: Eligible nodes retrieve the intended immutable artifact and Pods progress beyond image pull. Workload context: A worker cannot validate the registry certificate after an internal CA rotation while other nodes still pull images successfully.

Question 443

A node runs containerd but kubelet points at a nonexistent CRI socket and all Pod sandboxes fail. Which evidence should the engineer inspect FIRST to distinguish the likely cause or verify the prerequisite?

  1. Inspect kubectl config current-context, cluster server, user identity and namespace field.
  2. Compare host kernel sharing, namespace isolation, hypervisor boundaries and workload trust requirements.
  3. Inspect kubelet runtime endpoint, CRI protocol support, containerd service status and runtime errors.
  4. Inspect SBOM package inventory, CVE applicability, signature validation and approved exception decisions.

Explanation

Correct Answer

C:

Inspect kubelet runtime endpoint, CRI protocol support, containerd service status and runtime errors. This is the most discriminating evidence for the described failure or requirement. A runtime executes containers; the CRI is its API integration with kubelet rather than the Kubernetes API server. The corresponding implementation is: Use a compatible container runtime via the Kubernetes Container Runtime Interface to create and manage containers on nodes. Workload context: A node runs containerd but kubelet points at a nonexistent CRI socket and all Pod sandboxes fail.

Incorrect Answers

A:

Inspect kubectl config current-context, cluster server, user identity and namespace field. These observations are more relevant to kubectl context and cluster selection, not this case. The distinguishing check is: Inspect kubelet runtime endpoint, CRI protocol support, containerd service status and runtime errors. Workload context: A node runs containerd but kubelet points at a nonexistent CRI socket and all Pod sandboxes fail.

B:

Compare host kernel sharing, namespace isolation, hypervisor boundaries and workload trust requirements. These observations are more relevant to Container versus virtual machine isolation, not this case. The distinguishing check is: Inspect kubelet runtime endpoint, CRI protocol support, containerd service status and runtime errors. Workload context: A node runs containerd but kubelet points at a nonexistent CRI socket and all Pod sandboxes fail.

D:

Inspect SBOM package inventory, CVE applicability, signature validation and approved exception decisions. These observations are more relevant to Image scanning and software bills of materials, not this case. The distinguishing check is: Inspect kubelet runtime endpoint, CRI protocol support, containerd service status and runtime errors. Workload context: A node runs containerd but kubelet points at a nonexistent CRI socket and all Pod sandboxes fail.

Question 444

A stateful app writes records to container writable layers and loses them when a Pod is rescheduled to another node. Which evidence should the engineer inspect FIRST to distinguish the likely cause or verify the prerequisite?

  1. Inspect PVC phase, PV claimRef, capacity, accessModes, storageClassName and volume-mount events.
  2. Inspect namespace labels, Pod selectors, network policy rules, RBAC permissions and effective connectivity tests.
  3. Review storageClass volumeBindingMode, PVC condition, Pod node constraints and CSI topology events.
  4. Inspect PV persistentVolumeReclaimPolicy, underlying disk state, claim release and storage provisioner behavior.

Explanation

Correct Answer

A:

Inspect PVC phase, PV claimRef, capacity, accessModes, storageClassName and volume-mount events. This is the most discriminating evidence for the described failure or requirement. A PVC is a storage request and a PV is a cluster storage resource; neither should be confused with an emptyDir volume. The corresponding implementation is: Use PVCs to request persistent storage and PVs to represent volumes whose lifecycle is separate from ephemeral Pods. Workload context: A stateful app writes records to container writable layers and loses them when a Pod is rescheduled to another node.

Incorrect Answers

B:

Inspect namespace labels, Pod selectors, network policy rules, RBAC permissions and effective connectivity tests. These observations are more relevant to Namespace segmentation with NetworkPolicies, not this case. The distinguishing check is: Inspect PVC phase, PV claimRef, capacity, accessModes, storageClassName and volume-mount events. Workload context: A stateful app writes records to container writable layers and loses them when a Pod is rescheduled to another node.

C:

Review storageClass volumeBindingMode, PVC condition, Pod node constraints and CSI topology events. These observations are more relevant to WaitForFirstConsumer volume binding, not this case. The distinguishing check is: Inspect PVC phase, PV claimRef, capacity, accessModes, storageClassName and volume-mount events. Workload context: A stateful app writes records to container writable layers and loses them when a Pod is rescheduled to another node.

D:

Inspect PV persistentVolumeReclaimPolicy, underlying disk state, claim release and storage provisioner behavior. These observations are more relevant to PV reclaim policy Retain versus Delete, not this case. The distinguishing check is: Inspect PVC phase, PV claimRef, capacity, accessModes, storageClassName and volume-mount events. Workload context: A stateful app writes records to container writable layers and loses them when a Pod is rescheduled to another node.

Question 445

An app in namespace finance resolves api to its own nonexistent finance Service instead of the api Service in payments. Which Kubernetes or cloud native approach BEST addresses the stated requirement?

  1. Check Service selectors and EndpointSlices to distinguish backend discovery from kube-proxy or data-plane forwarding faults.
  2. Use supported Ingress or Gateway API resources together with a running controller to route HTTP traffic by host and path.
  3. Use CoreDNS or the configured cluster DNS service to resolve Service and Pod naming in their correct namespaces.
  4. Choose PV access modes based on how nodes and workloads must mount storage and verify CSI driver capability.

Explanation

Correct Answer

C:

Use CoreDNS or the configured cluster DNS service to resolve Service and Pod naming in their correct namespaces. This response implements the controlling Kubernetes or cloud native principle. Kubernetes DNS uses namespace-aware search paths; a fully qualified Service name avoids ambiguity across namespaces. Check its effect by: Test DNS names, search suffixes, CoreDNS logs, upstream forwarders and service records. Workload context: An app in namespace finance resolves api to its own nonexistent finance Service instead of the api Service in payments.

Incorrect Answers

A:

Check Service selectors and EndpointSlices to distinguish backend discovery from kube-proxy or data-plane forwarding faults. This action addresses Service endpoint routing and kube-proxy instead of the controlling requirement. Service routing depends on endpoints and the cluster's Service dataplane; some clusters replace kube-proxy with an alternate implementation. For this scenario prefer: Use CoreDNS or the configured cluster DNS service to resolve Service and Pod naming in their correct namespaces. Workload context: An app in namespace finance resolves api to its own nonexistent finance Service instead of the api Service in payments.

B:

Use supported Ingress or Gateway API resources together with a running controller to route HTTP traffic by host and path. This action addresses Ingress and Gateway API routing instead of the controlling requirement. Ingress and Gateway API resources describe routing intent; a controller implements data-plane forwarding. For this scenario prefer: Use CoreDNS or the configured cluster DNS service to resolve Service and Pod naming in their correct namespaces. Workload context: An app in namespace finance resolves api to its own nonexistent finance Service instead of the api Service in payments.

D:

Choose PV access modes based on how nodes and workloads must mount storage and verify CSI driver capability. This action addresses ReadWriteOnce and ReadWriteMany semantics instead of the controlling requirement. ReadWriteOnce normally limits read-write mounting to one node, not necessarily exactly one Pod; driver behavior matters. For this scenario prefer: Use CoreDNS or the configured cluster DNS service to resolve Service and Pod naming in their correct namespaces. Workload context: An app in namespace finance resolves api to its own nonexistent finance Service instead of the api Service in payments.

Question 446

A platform team drains a node hosting local ephemeral data without evaluating whether eviction will discard required state. Which observable result BEST confirms the desired Kubernetes or cloud native behavior?

  1. Each eligible node runs the intended agent and newly added eligible nodes receive it automatically.
  2. Scheduling constraints match verified node attributes without exhausting reserved system resources.
  3. Missing workload replicas are recreated from their controllers and desired counts converge after disruptions.
  4. Workloads relocate where permitted and the maintained node returns to service without unexpected data loss.

Explanation

Correct Answer

D:

Workloads relocate where permitted and the maintained node returns to service without unexpected data loss. This is an observable service outcome, not just evidence that a configuration file was saved. cordon prevents new scheduling while drain attempts safe evictions; existing Pods are not deleted by cordon alone. Workload context: A platform team drains a node hosting local ephemeral data without evaluating whether eviction will discard required state.

Incorrect Answers

A:

Each eligible node runs the intended agent and newly added eligible nodes receive it automatically. That result validates DaemonSet node-local workloads rather than the requirement here. Verify instead: Workloads relocate where permitted and the maintained node returns to service without unexpected data loss. Workload context: A platform team drains a node hosting local ephemeral data without evaluating whether eviction will discard required state.

B:

Scheduling constraints match verified node attributes without exhausting reserved system resources. That result validates Node labels and allocatable inventory rather than the requirement here. Verify instead: Workloads relocate where permitted and the maintained node returns to service without unexpected data loss. Workload context: A platform team drains a node hosting local ephemeral data without evaluating whether eviction will discard required state.

C:

Missing workload replicas are recreated from their controllers and desired counts converge after disruptions. That result validates Controller manager reconciliation loops rather than the requirement here. Verify instead: Workloads relocate where permitted and the maintained node returns to service without unexpected data loss. Workload context: A platform team drains a node hosting local ephemeral data without evaluating whether eviction will discard required state.

Question 447

A namespace lacks the correct registry pull Secret and otherwise healthy Pods remain in ImagePullBackOff. Which observable result BEST confirms the desired Kubernetes or cloud native behavior?

  1. Eligible nodes retrieve the intended immutable artifact and Pods progress beyond image pull.
  2. External clients reach only the intended healthy Service backends and the allocated endpoint matches network policy.
  3. Healthy but initializing Pods avoid traffic and genuinely stuck workloads recover without unnecessary restart loops.
  4. The Service has healthy matching backends and forwards to the application process's actual port.

Explanation

Correct Answer

A:

Eligible nodes retrieve the intended immutable artifact and Pods progress beyond image pull. This is an observable service outcome, not just evidence that a configuration file was saved. ImagePullBackOff is a retrieval or authorization problem; changing app readiness probes cannot fix a missing image. Workload context: A namespace lacks the correct registry pull Secret and otherwise healthy Pods remain in ImagePullBackOff.

Incorrect Answers

B:

External clients reach only the intended healthy Service backends and the allocated endpoint matches network policy. That result validates LoadBalancer Service provisioning rather than the requirement here. Verify instead: Eligible nodes retrieve the intended immutable artifact and Pods progress beyond image pull. Workload context: A namespace lacks the correct registry pull Secret and otherwise healthy Pods remain in ImagePullBackOff.

C:

Healthy but initializing Pods avoid traffic and genuinely stuck workloads recover without unnecessary restart loops. That result validates Readiness liveness and startup probe behavior rather than the requirement here. Verify instead: Eligible nodes retrieve the intended immutable artifact and Pods progress beyond image pull. Workload context: A namespace lacks the correct registry pull Secret and otherwise healthy Pods remain in ImagePullBackOff.

D:

The Service has healthy matching backends and forwards to the application process's actual port. That result validates Service selector and port mismatch diagnostics rather than the requirement here. Verify instead: Eligible nodes retrieve the intended immutable artifact and Pods progress beyond image pull. Workload context: A namespace lacks the correct registry pull Secret and otherwise healthy Pods remain in ImagePullBackOff.

Question 448

A Service has no endpoints because its selector refers to app=backend while replicas carry app=api. Which TWO complementary steps supply the appropriate approach AND the evidence required to validate it? Select TWO.

  1. Use ClusterIP for private service access and NodePort only when node-level external ports are intentionally needed.
  2. Check Service selectors and EndpointSlices to distinguish backend discovery from kube-proxy or data-plane forwarding faults.
  3. Inspect CNI configuration, Pod CIDRs, node route tables, overlay/underlay links and CNI daemon logs.
  4. Noncompliant Pod specifications are rejected under enforcement without unexpectedly blocking approved workloads.
  5. Inspect Service selector, Pod readiness, EndpointSlice addresses, kube-proxy or eBPF service programming and target ports.

Explanation

Correct Answers

B:

Check Service selectors and EndpointSlices to distinguish backend discovery from kube-proxy or data-plane forwarding faults. This response implements the controlling Kubernetes or cloud native principle. Service routing depends on endpoints and the cluster's Service dataplane; some clusters replace kube-proxy with an alternate implementation. Check its effect by: Inspect Service selector, Pod readiness, EndpointSlice addresses, kube-proxy or eBPF service programming and target ports. This is the implementation part of the required paired answer. Workload context: A Service has no endpoints because its selector refers to app=backend while replicas carry app=api.

E:

Inspect Service selector, Pod readiness, EndpointSlice addresses, kube-proxy or eBPF service programming and target ports. This is the most discriminating evidence for the described failure or requirement. Service routing depends on endpoints and the cluster's Service dataplane; some clusters replace kube-proxy with an alternate implementation. The corresponding implementation is: Check Service selectors and EndpointSlices to distinguish backend discovery from kube-proxy or data-plane forwarding faults. This is the diagnostic evidence part of the paired answer. Workload context: A Service has no endpoints because its selector refers to app=backend while replicas carry app=api.

Incorrect Answers

A:

Use ClusterIP for private service access and NodePort only when node-level external ports are intentionally needed. This step belongs to ClusterIP and NodePort Service exposure rather than the complementary implementation and evidence pair. The intended approach is: Check Service selectors and EndpointSlices to distinguish backend discovery from kube-proxy or data-plane forwarding faults. Validate with: Inspect Service selector, Pod readiness, EndpointSlice addresses, kube-proxy or eBPF service programming and target ports. Workload context: A Service has no endpoints because its selector refers to app=backend while replicas carry app=api.

C:

Inspect CNI configuration, Pod CIDRs, node route tables, overlay/underlay links and CNI daemon logs. This step belongs to CNI Pod networking implementation rather than the complementary implementation and evidence pair. The intended approach is: Check Service selectors and EndpointSlices to distinguish backend discovery from kube-proxy or data-plane forwarding faults. Validate with: Inspect Service selector, Pod readiness, EndpointSlice addresses, kube-proxy or eBPF service programming and target ports. Workload context: A Service has no endpoints because its selector refers to app=backend while replicas carry app=api.

D:

Noncompliant Pod specifications are rejected under enforcement without unexpectedly blocking approved workloads. This step belongs to Pod Security Admission and namespaces rather than the complementary implementation and evidence pair. The intended approach is: Check Service selectors and EndpointSlices to distinguish backend discovery from kube-proxy or data-plane forwarding faults. Validate with: Inspect Service selector, Pod readiness, EndpointSlice addresses, kube-proxy or eBPF service programming and target ports. Workload context: A Service has no endpoints because its selector refers to app=backend while replicas carry app=api.

Question 449

A workload expects a ConfigMap-mounted configuration file to update after restart yet uses an immutable environment variable without rollout. Which TWO complementary steps supply the appropriate approach AND the evidence required to validate it? Select TWO.

  1. Inspect resource status, conditions, events, generation, owner references and logs from the relevant container.
  2. Cluster state can be recovered from a tested snapshot with quorum intact and application volumes handled separately.
  3. Maintain accurate node labels, allocatable resources and topology information to support workload placement and capacity analysis.
  4. Store non-sensitive configuration in ConfigMaps and sensitive values in Secrets with access control and encryption controls.
  5. Inspect ConfigMap/Secret references, RBAC, API audit records, encryption-at-rest settings and mount or environment behavior.

Explanation

Correct Answers

D:

Store non-sensitive configuration in ConfigMaps and sensitive values in Secrets with access control and encryption controls. This response implements the controlling Kubernetes or cloud native principle. Kubernetes Secret data is base64-encoded by default, not inherently encrypted or a substitute for managed secret governance. Check its effect by: Inspect ConfigMap/Secret references, RBAC, API audit records, encryption-at-rest settings and mount or environment behavior. This is the implementation part of the required paired answer. Workload context: A workload expects a ConfigMap-mounted configuration file to update after restart yet uses an immutable environment variable without rollout.

E:

Inspect ConfigMap/Secret references, RBAC, API audit records, encryption-at-rest settings and mount or environment behavior. This is the most discriminating evidence for the described failure or requirement. Kubernetes Secret data is base64-encoded by default, not inherently encrypted or a substitute for managed secret governance. The corresponding implementation is: Store non-sensitive configuration in ConfigMaps and sensitive values in Secrets with access control and encryption controls. This is the diagnostic evidence part of the paired answer. Workload context: A workload expects a ConfigMap-mounted configuration file to update after restart yet uses an immutable environment variable without rollout.

Incorrect Answers

A:

Inspect resource status, conditions, events, generation, owner references and logs from the relevant container. This step belongs to kubectl inspect and describe diagnostics rather than the complementary implementation and evidence pair. The intended approach is: Store non-sensitive configuration in ConfigMaps and sensitive values in Secrets with access control and encryption controls. Validate with: Inspect ConfigMap/Secret references, RBAC, API audit records, encryption-at-rest settings and mount or environment behavior. Workload context: A workload expects a ConfigMap-mounted configuration file to update after restart yet uses an immutable environment variable without rollout.

B:

Cluster state can be recovered from a tested snapshot with quorum intact and application volumes handled separately. This step belongs to etcd consistency and cluster state rather than the complementary implementation and evidence pair. The intended approach is: Store non-sensitive configuration in ConfigMaps and sensitive values in Secrets with access control and encryption controls. Validate with: Inspect ConfigMap/Secret references, RBAC, API audit records, encryption-at-rest settings and mount or environment behavior. Workload context: A workload expects a ConfigMap-mounted configuration file to update after restart yet uses an immutable environment variable without rollout.

C:

Maintain accurate node labels, allocatable resources and topology information to support workload placement and capacity analysis. This step belongs to Node labels and allocatable inventory rather than the complementary implementation and evidence pair. The intended approach is: Store non-sensitive configuration in ConfigMaps and sensitive values in Secrets with access control and encryption controls. Validate with: Inspect ConfigMap/Secret references, RBAC, API audit records, encryption-at-rest settings and mount or environment behavior. Workload context: A workload expects a ConfigMap-mounted configuration file to update after restart yet uses an immutable environment variable without rollout.

Question 450

A Java client caches a removed Pod address indefinitely despite a stable Kubernetes Service record being available. Which evidence should the engineer inspect FIRST to distinguish the likely cause or verify the prerequisite?

  1. Test DNS names, search suffixes, CoreDNS logs, upstream forwarders and service records.
  2. Inspect Pod pull events, image tag existence, registry TLS, imagePullSecrets and service-account references.
  3. Inspect external IP status, controller events, security groups, health checks and upstream target availability.
  4. Inspect Service metadata, selected Pod labels, EndpointSlice readiness, containerPort and actual listening sockets.

Explanation

Correct Answer

A:

Test DNS names, search suffixes, CoreDNS logs, upstream forwarders and service records. This is the most discriminating evidence for the described failure or requirement. Kubernetes DNS uses namespace-aware search paths; a fully qualified Service name avoids ambiguity across namespaces. The corresponding implementation is: Use CoreDNS or the configured cluster DNS service to resolve Service and Pod naming in their correct namespaces. Workload context: A Java client caches a removed Pod address indefinitely despite a stable Kubernetes Service record being available.

Incorrect Answers

B:

Inspect Pod pull events, image tag existence, registry TLS, imagePullSecrets and service-account references. These observations are more relevant to ImagePullBackOff registry and auth errors, not this case. The distinguishing check is: Test DNS names, search suffixes, CoreDNS logs, upstream forwarders and service records. Workload context: A Java client caches a removed Pod address indefinitely despite a stable Kubernetes Service record being available.

C:

Inspect external IP status, controller events, security groups, health checks and upstream target availability. These observations are more relevant to LoadBalancer Service provisioning, not this case. The distinguishing check is: Test DNS names, search suffixes, CoreDNS logs, upstream forwarders and service records. Workload context: A Java client caches a removed Pod address indefinitely despite a stable Kubernetes Service record being available.

D:

Inspect Service metadata, selected Pod labels, EndpointSlice readiness, containerPort and actual listening sockets. These observations are more relevant to Service selector and port mismatch diagnostics, not this case. The distinguishing check is: Test DNS names, search suffixes, CoreDNS logs, upstream forwarders and service records. Workload context: A Java client caches a removed Pod address indefinitely despite a stable Kubernetes Service record being available.

Kubernetes and Cloud Native Associate (KCNA) Practice Tests