> For the complete documentation index, see [llms.txt](https://atomoh.gitbook.io/kubernetes/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://atomoh.gitbook.io/kubernetes/en/quiz-collection/operations-guide/02-infrastructure-advanced-quiz.md).
# Infrastructure Advanced Quiz
> **Related Document**: [Infrastructure Advanced](/kubernetes/en/operations-guide/ops/02-infrastructure-advanced.md)
## Multiple Choice Questions
### 1. What is the primary purpose of NLB weighted target groups in a blue/green deployment?
* A) To reduce costs by using fewer load balancers
* B) To control traffic distribution between cluster versions
* C) To improve SSL termination performance
* D) To eliminate the need for health checks
Show Answer
**Answer: B) To control traffic distribution between cluster versions**
**Explanation:** NLB weighted target groups allow gradual traffic shifting between blue (current) and green (new) clusters. By adjusting weights (e.g., 90:10, 50:50, 0:100), operators can perform controlled rollouts and quickly rollback if issues are detected.
### 2. In a single-zone EKS cluster strategy, why might you deploy data nodes to only one Availability Zone?
* A) To reduce cross-AZ data transfer costs
* B) To simplify DNS configuration
* C) To avoid using multiple subnets
* D) To eliminate the need for persistent volumes
Show Answer
**Answer: A) To reduce cross-AZ data transfer costs**
**Explanation:** Cross-AZ data transfer incurs costs in AWS. For data-intensive workloads with local storage (like databases), keeping all replicas in a single AZ eliminates these costs while relying on application-level replication for durability.
### 3. What Kubernetes feature ensures pods are distributed across different zones or nodes?
* A) PodAffinity
* B) TopologySpreadConstraints
* C) ResourceQuota
* D) LimitRange
Show Answer
**Answer: B) TopologySpreadConstraints**
**Explanation:** TopologySpreadConstraints control how pods are spread across topology domains (zones, nodes, regions). They ensure even distribution for high availability and can be configured with `maxSkew`, `topologyKey`, and `whenUnsatisfiable` parameters.
### 4. How does Route53 weighted routing differ from NLB weighted target groups?
* A) Route53 works at DNS level, NLB works at connection level
* B) Route53 only supports equal weights
* C) NLB doesn't support health checks
* D) Route53 requires VPC peering
Show Answer
**Answer: A) Route53 works at DNS level, NLB works at connection level**
**Explanation:** Route53 weighted routing distributes traffic at DNS resolution time, while NLB weighted target groups distribute at the connection level. DNS-based routing has TTL considerations, while NLB provides more immediate traffic shifting.
### 5. What is the recommended `maxSkew` value for TopologySpreadConstraints in a 3-AZ deployment?
* A) 0
* B) 1
* C) 3
* D) 10
Show Answer
**Answer: B) 1**
**Explanation:** A `maxSkew` of 1 ensures pods are evenly distributed with at most one pod difference between topology domains. This provides good balance while still allowing scheduling flexibility when nodes have resource constraints.
### 6. In blue/green cluster architecture, what should be shared between clusters?
* A) Worker nodes
* B) External DNS and load balancer
* C) etcd storage
* D) Kubernetes API server
Show Answer
**Answer: B) External DNS and load balancer**
**Explanation:** Blue/green clusters are separate EKS clusters that share external infrastructure like DNS records and load balancers. This allows traffic to be shifted between clusters without changing client-facing endpoints.
### 7. What happens when `whenUnsatisfiable: DoNotSchedule` is set in TopologySpreadConstraints?
* A) Pods are scheduled anywhere regardless of constraints
* B) Pods remain pending if constraints cannot be satisfied
* C) Pods are automatically deleted
* D) The constraint is ignored
Show Answer
**Answer: B) Pods remain pending if constraints cannot be satisfied**
**Explanation:** `DoNotSchedule` prevents pod scheduling when the spread constraint would be violated. This ensures strict adherence to topology requirements but may result in pending pods if cluster topology doesn't support the constraint.
### 8. For automated failover between blue/green clusters, what AWS service can be used with health checks?
* A) AWS Config
* B) Route53 health checks with failover routing
* C) AWS Inspector
* D) AWS Trusted Advisor
Show Answer
**Answer: B) Route53 health checks with failover routing**
**Explanation:** Route53 health checks continuously monitor endpoint availability and can automatically switch traffic to a healthy cluster using failover routing policy. This enables automated disaster recovery without manual intervention.
### 9. What is a key consideration when using NLB cross-zone load balancing?
* A) It's always free
* B) It may incur additional data transfer charges
* C) It requires VPC peering
* D) It only works with TCP protocol
Show Answer
**Answer: B) It may incur additional data transfer charges**
**Explanation:** When cross-zone load balancing is enabled, NLB distributes traffic evenly across all registered targets in all enabled AZs, which can result in cross-AZ data transfer charges. Consider this cost when architecting multi-AZ deployments.
### 10. In a zonal cluster deployment (a-zone blue, c-zone green), what is the primary benefit?
* A) Reduced networking complexity
* B) Failure isolation and independent upgrade paths
* C) Lower compute costs
* D) Automatic data replication
Show Answer
**Answer: B) Failure isolation and independent upgrade paths**
**Explanation:** Zonal clusters provide failure domain isolation - an issue in one zone doesn't affect the other cluster. This also enables independent upgrade testing and gradual rollouts, reducing risk during Kubernetes version upgrades.