AWS Certified Solutions Architect - Associate SAA-C03 Practice Test 63
Question 620
A newly built AMI passes image creation but produces HTTP 500 responses. The deployment pipeline is about to promote it to every Region's standby Auto Scaling group. What prevents turning a local defect into a DR-wide outage?
- Promote every AMI to all Regions immediately to keep fleet versions synchronized regardless of health.
- Delete the prior AMI before testing the replacement to prevent configuration drift.
- Treat an AMI checksum match as proof that its services will return healthy HTTP responses.
- Gate promotion on canary and workload health tests, retaining the last known-good immutable image for rollback.
Explanation
Correct Answer
D:A tested health gate limits propagation of an invalid artifact; successful image creation does not establish application correctness.
Incorrect Answers
A:Global consistency of an unhealthy image increases the incident blast radius.
B:Removing known-good images eliminates the simplest recovery option if the candidate fails.
C:Checksums establish artifact integrity, not runtime behavior or compatibility with external dependencies.
Question 621
A deployment introduces an incompatible database schema migration, then the team rolls back the web container image. The previous application version still cannot read records in the modified schema. What should the recovery design account for?
- Plan backward-compatible database changes or an independently tested data/schema rollback path, separate from compute-image rollback.
- Repeatedly restart the old container image until the schema automatically reverts.
- Add another load balancer listener to route old code to the same incompatible schema.
- Assume CloudFormation rollback of the EC2 Auto Scaling group restores all external database schema changes.
Explanation
Correct Answer
A:Immutable compute redeployment cannot undo incompatible persistent schema or data transformations already committed.
Incorrect Answers
B:Container restarts do not reverse database DDL or correct transformed data.
C:More listeners do not fix the application-data contract mismatch.
D:Infrastructure rollback does not inherently reverse independent transactional database migrations.
Question 622
A private EC2 API fleet in one AZ uses an Available public NAT gateway to make large numbers of TLS connections to one partner IP and port. Routes, security groups and gateway health are correct, but new connections intermittently fail at peak while existing ones continue. CloudWatch shows ErrorPortAllocation above zero. Which change most directly addresses the exhausted NAT translation resource while retaining private outbound access?
- Raise the ALB target health-check threshold, because ALB target health supplies NAT source ports for outbound partner calls.
- Associate supported secondary IPv4 addresses with the NAT gateway and monitor ErrorPortAllocation, evaluating additional NAT gateways or connection reuse if needed.
- Replace the existing NAT gateway with a VPC internet gateway route directly in the private instances’ route table, keeping instances without public IPv4 addresses.
- Enable an S3 gateway endpoint and expect its route-table prefix list to expand NAT source-port capacity to an external partner destination.
Explanation
Correct Answer
B:A positive ErrorPortAllocation indicates the NAT gateway cannot allocate a source port for another connection. Secondary IPv4 addresses increase per-destination concurrent connection capacity; monitoring and/or traffic distribution must still account for quotas and application patterns.
Incorrect Answers
A:ALB health checks govern backend target readiness and cannot increase the NAT gateway source-port pool for a particular remote destination.
C:An internet gateway is not a replacement for source NAT on private IPv4 instances with no public addresses. The direct route does not give the specified private hosts usable outbound internet access.
D:An S3 gateway endpoint routes supported S3 traffic privately. It does not change the NAT gateway source-port allocation available for an unrelated external API endpoint.
Question 623
A company adds redundant NAT gateways for outbound connectivity in two AZs. Its public checkout site is still served by one EC2 instance behind no health-checked load balancer. What availability claim is defensible?
- The site is multi-AZ highly available because two NAT gateways can accept inbound checkout requests.
- Stop maintaining the checkout instance because NAT gateways can run application code during host failure.
- The egress path is less zonally fragile, but the public service still needs redundant application targets and ingress routing.
- Replace the single web host's HTTP listener with a private endpoint policy and assume the app now spans AZs.
Explanation
Correct Answer
C:NAT gateways support private-to-public outbound flows; they do not duplicate the public application server or replace an ALB.
Incorrect Answers
A:NAT gateways are not general inbound application load balancers for public HTTP clients.
B:NAT gateways provide translation, not customer application compute.
D:Changing an endpoint policy cannot create independent, healthy application replicas.
Question 624
A private analytics fleet has two NAT gateways, one per AZ, but large upstream exports intermittently saturate the available egress path. Engineers regard gateway redundancy as proof of unlimited throughput. What should they validate?
- Only check whether each gateway has a unique name; names determine maximum sustainable Gbps.
- Route every AZ through a single existing NAT gateway to pool connections, without checking its scaling characteristics or cross-AZ transfer charges.
- Disable VPC Flow Logs because removing telemetry automatically removes all gateway bottlenecks.
- Measure real outbound throughput and connection behavior against NAT gateway characteristics, routing and relevant service limits.
Explanation
Correct Answer
D:Redundant AZs improve failover options but do not guarantee a particular rate, packet mix or concurrent connection budget.
Incorrect Answers
A:Identifiers do not establish effective network throughput or load behavior.
B:Consolidating through one gateway can concentrate throughput and connections while adding cross-AZ traffic cost and a failure dependency. It does not verify sustainable egress capacity or solve saturation.
C:Log collection can carry overhead but it does not explain away saturating the NAT network path.
Question 625
A branch office connects to an AWS Transit Gateway through a Site-to-Site VPN. A simulated tunnel loss removes all branch reachability because route preference never shifts to a standby path. Which topology/configuration addresses this?
- Provide redundant VPN tunnels or attachments and test BGP/static route failover with correct transit gateway routing associations.
- Create an additional standby VPN attachment but do not associate or propagate its routes to the transit-gateway route table that serves the branch.
- Enable BGP on the backup customer gateway but keep route filters that reject the standby prefixes after primary failure.
- Increase S3 object versioning to retain more files during the tunnel outage.
Explanation
Correct Answer
A:VPN redundancy only helps when surviving tunnel routes are actually installed and selected following a failure.
Incorrect Answers
B:A second attachment provides potential redundancy, but a missing route-table association or route propagation can leave the surviving path unreachable when the primary tunnel fails.
C:Dynamic routing helps only when usable backup prefixes are exchanged and installed. Filtering the surviving route prevents traffic from failing over even though a second tunnel exists.
D:Object histories do not supply a second network path to the branch.
Question 626
A bank orders two Direct Connect private virtual interfaces on one physical Direct Connect connection and calls the hybrid network fully redundant. What risk remains?
- Two VIFs on one physical circuit guarantee immunity to that circuit's failure.
- The single physical circuit and location remain shared failure domains; use genuinely independent connections/locations for the required HA level.
- Placing the VIFs in different AWS accounts makes the same cable physically redundant.
- Setting an S3 bucket replica in another AZ replaces the branch's Direct Connect connection.
Explanation
Correct Answer
B:Multiple VIFs on one port provide logical separation but not independent power, cabling or physical transport.
Incorrect Answers
A:Both logical interfaces fail when the common physical transport is lost.
C:Account separation does not create another physical path for the VIF packets.
D:Object replication cannot provide private network connectivity after a circuit outage.
Question 627
An enterprise adds a backup Site-to-Site VPN to its Transit Gateway, but the shared services VPC remains unreachable over the backup route during a Direct Connect outage. The VPN BGP session is up; TGW attachment associations and route propagation were not verified. What should it inspect?
- Increase the shared-services database instance size to allow more BGP packets.
- Set every application's DNS TTL to zero without correcting the missing transit routes.
- Check transit gateway route-table associations, route propagation and return paths for both the primary and failover attachments.
- Move the VPN configuration into an S3 lifecycle rule and leave TGW tables untouched.
Explanation
Correct Answer
C:A live tunnel is insufficient if the TGW route tables do not select a destination route or the return route is missing.
Incorrect Answers
A:Database sizing has no effect on transit gateway route propagation.
B:DNS lookup frequency cannot route packets over an unassociated VPN attachment.
D:S3 lifecycle actions do not install routes or associate transit gateway network attachments.
Question 628
A team deploys a Transit Gateway with redundant VPC attachments across two AZs in one Region, then claims it provides a connection to the standby VPC in a separate Region without any inter-Region network configuration. What is missing?
- Create a transit gateway in the standby Region with the same ASN and copied route tables, without establishing gateway peering or another inter-Region link.
- Add another VPC attachment to the primary transit gateway and set a static route for the remote CIDR without a supported inter-Region attachment.
- Attach an S3 interface endpoint to the transit gateway and expect it to carry arbitrary VPC-to-VPC traffic across Regions.
- Plan and configure the supported cross-Region connectivity, routing and recovery dependencies rather than relying on regional attachment redundancy.
Explanation
Correct Answer
D:Regional Transit Gateway attachments provide availability within that Region only. Configure an explicit inter-Region TGW peering or other supported connectivity, associated TGW/VPC route tables, security policy and recovery traffic tests to reach the standby network.
Incorrect Answers
A:Matching ASN or route configuration does not create a physical or logical path between two independent regional transit gateways.
B:A route to a CIDR is not useful unless an attachment connects to that destination; a primary-Region VPC attachment alone cannot reach the standby Region.
C:S3 private endpoints provide service-specific connectivity and do not create general inter-Region routing between the application VPCs.
Question 629
An architecture diagram shows ALB targets across three AZs and an Auto Scaling group, but no one has tested an entire AZ becoming unhealthy. Leadership wants evidence that clients stay served. What is the useful drill?
- In a controlled environment, withdraw or fail all targets in one AZ and observe health routing, replacement capacity and client errors.
- Review the diagram again and treat three drawn AZ labels as proof of a passed failover test.
- Increase the maximum number of tags on the ALB without exercising a failure.
- Validate only a single target's DNS lookup and assume all other components will fail over.
Explanation
Correct Answer
A:A deliberate zonal impairment tests the actual health-check and scale-out behavior, not just the documented intent.
Incorrect Answers
B:Topology diagrams cannot reveal misconfigured health checks, quotas or delayed replacement.
C:Tag quantities do not demonstrate load balancer target failover.
D:One lookup cannot establish application-level continuity when all targets in an AZ disappear.
Question 630
An RDS Multi-AZ database is expected to fail over within an agreed outage window. The application has long-lived pooled connections and DNS caching. The database successfully promotes, but clients never reconnect without manual restarts. What should be tested and fixed?
- Increase the read replica count but leave clients pinned to stale writer connections.
- Exercise real database failover and verify client DNS refresh, connection retry/pool reset and transaction recovery behavior.
- Make the DNS cache TTL infinite so the application uses the original writer endpoint indefinitely.
- Disable database monitoring because Multi-AZ guarantees every connection remains uninterrupted.
Explanation
Correct Answer
B:DB promotion is only one step; applications must discover and establish valid sessions to the new writer endpoint.
Incorrect Answers
A:Extra readers do not repair application writer-reconnection logic.
C:Indefinite endpoint caching blocks timely adaptation when the writer changes.
D:Failover can drop active sessions and still needs application recovery logic and visibility.