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Infrastructure Advanced Quiz ​

Related Document: Infrastructure Advanced

Multiple Choice Questions ​

1. What does an NLB weight ratio of 5:5 mean? ​

  • A) Create five nodes in each cluster
  • B) Configure an equal relative distribution of new flows
  • C) Move every existing connection within five seconds
  • D) It is invalid because the total is not 100
Show Answer

Answer: B) Configure an equal relative distribution of new flows

NLB weights are relative integers 0–999. Observed bytes/requests can differ with flow size, stickiness, and the observation window.

2. What matters when lowering an NLB group weight to zero? ​

  • A) Existing connections must survive until natural closure
  • B) The current guide says existing connections also close after a short period, so test reconnection
  • C) Deregistration delay guarantees all transition times
  • D) A successful API response means all traffic already moved
Show Answer

Answer: B) The current guide says existing connections also close after a short period, so test reconnection

Distinguish ordinary weight changes from zero transitions. Configuration acceptance and data-plane convergence are separate; inspect new/active flows, errors, and latency.

3. If blue and green DNS names point to the same shared NLB, what can DNS weights do? ​

  • A) Independently select its target groups
  • B) Pin requests to an AZ by hostname alone
  • C) Select the same LB; they do not choose cluster-specific target groups
  • D) Automatically select the same database replica
Show Answer

Answer: C) Select the same LB; they do not choose cluster-specific target groups

DNS-based selection needs distinct real LB endpoints leading to the intended clusters. Listener weights and DNS record weights operate at different layers.

4. How do you place workloads on Auto Mode nodes in a chosen AZ? ​

  • A) Pod nodeSelector creates nodes by itself
  • B) Put subnet_ids in the NodePool
  • C) Align Pod selection, NodePool requirements, NodeClass subnet selection, and tolerations
  • D) Name the cluster blue
Show Answer

Answer: C) Align Pod selection, NodePool requirements, NodeClass subnet selection, and tolerations

NodeSelector/affinity selects eligible nodes; provisioning constraints and taints/tolerations must also align. Distinguish worker placement from the regional managed control plane.

5. Which TGB ownership model does this externally managed TG example use? ​

  • A) Built-in Auto Mode always has identical deletion behavior
  • B) A separately installed LBC with elbv2.k8s.aws/v1beta1, distinct from built-in Auto Mode
  • C) Only an ARN, with no Service or targetPort prerequisites
  • D) Permanent Pod IPs registered through Terraform
Show Answer

Answer: B) A separately installed LBC with elbv2.k8s.aws/v1beta1, distinct from built-in Auto Mode

Built-in Auto Mode uses eks.amazonaws.com/v1 and documents TG deletion behavior. This recipe uses a separate controller for dynamic registration and networking rules.

6. What does a single PostgreSQL StatefulSet plus a Retain PVC guarantee? ​

  • A) Cross-cluster replication
  • B) Zero-downtime DB failover across AZs
  • C) Every connection remains open
  • D) It does not by itself guarantee HA, backup, or recovery
Show Answer

Answer: D) It does not by itself guarantee HA, backup, or recovery

Retain is a reclamation policy. Replication, backup, writer ownership, and recovery procedures are separate. NLB weights do not relocate EBS volumes across AZs.

7. Why separate alarm-input and decision-notification SNS topics? ​

  • A) Prevent notifications from returning as new input and causing extra executions/errors
  • B) Allow publishing without IAM permission
  • C) Retry Lambda forever
  • D) Eliminate DNS TTL
Show Answer

Answer: A) Prevent notifications from returning as new input and causing extra executions/errors

This handler accepts the SNS envelope. Direct CloudWatch Lambda events differ, so do not wire both invocation paths. A notification failure must not replay an already successful listener mutation.

8. What does the default automatic_failover=false do? ​

  • A) Immediately shift all traffic to Green
  • B) Propose changes without granting ModifyListener permission
  • C) Skip health checks
  • D) Modify every available listener
Show Answer

Answer: B) Propose changes without granting ModifyListener permission

Enable automatic mode only after capacity, SLO, reconnection, and writer coordination are tested. Reserved concurrency=1 does not serialize external Terraform or manual writers.

9. What should a manual transition script do? ​

  • A) Evaluate raw user strings as Bash arithmetic
  • B) Always assume an initial 100/0 state
  • C) Validate weights and destination health, then show and approve the full plan
  • D) Repeat a timer loop with STEP=0
Show Answer

Answer: C) Validate weights and destination health, then show and approve the full plan

Validate numeric bounds first and use the intended variables/backend. Check real SLOs and data compatibility between stages. API/apply success alone does not prove transition completion.

10. Which statement about Route 53 weight and TTL is correct? ​

  • A) Weights are integers 0–255; TTL alone is not a recovery-time guarantee
  • B) Weights are always 0–999
  • C) A 60-second TTL is a 60-second recovery SLA
  • D) If all choices are unhealthy, DNS must return no answer
Show Answer

Answer: A) Weights are integers 0–255; TTL alone is not a recovery-time guarantee

Alias records inherit target TTL. Consider health, resolver caches, connection lifetimes, and fallback behavior. All-zero weights are not a reliable traffic-stop mechanism.