AWS Certified Associate SAA-C03 Dumps PDF

Explanation (AWS Docs):

To allow private subnets to access the internet, deploy NAT gateways in a public subnet in each AZ for high availability. NAT instances are less scalable and less fault-tolerant.

“To create a highly available architecture, create a NAT gateway in each Availability Zone and configure your routing to use it.”

— NAT Gateway Overview

AWS Certificate Manager (ACM) issues and automatically renews public TLS certificates used by Amazon CloudFront. With DNS validation, ACM creates CNAME records that prove domain control; once validated, renewals occur automatically without manual approval, providing the lowest operational effort. For CloudFront, ACM certificates must be in the US East (N. Virginia) Region. CloudFront security policies (A) configure protocol/cipher requirements, not certificate issuance. OAC (B) secures origin access and is unrelated to certificate management. Email validation (D) requires mailbox approvals and operational handling at issuance/renewal, which is less efficient than DNS validation. Thus, ACM with DNS validation delivers automated creation and renewal with minimal overhead.

The Kubernetes Horizontal Pod Autoscaler (HPA) scales pods, not nodes. When the cluster runs out of node capacity, the HPA cannot schedule more pods.

On Amazon EKS, AWS recommends using the Kubernetes Cluster Autoscaler to automatically adjust the number of nodes in the cluster’s underlying Auto Scaling group based on pending pods.

Cluster Autoscaler watches for pods that cannot be scheduled because of insufficient resources and then scales out nodes automatically with minimal administrative overhead. It also scales in nodes when they are underutilized.

Why others are not correct:

A: Just tracking memory usage does not automatically scale nodes or integrate with Kubernetes scheduling.

C: A custom Lambda-based resizer is unnecessary undifferentiated heavy lifting compared to the native Cluster Autoscaler.

D: An Auto Scaling group is already typically used under EKS, but by itself it does not respond to pod scheduling pressure without Cluster Autoscaler.

Amazon RDS Blue/Green Deployments provide a safe and straightforward way to make database changes with minimal downtime and risk. Blue/Green deployments create an exact copy ( " green " ) of your production environment ( " blue " ) where you can make schema changes and run tests. After validation, you can promote the green environment to production with a single click or API call, achieving near-zero downtime and maximum availability. This is the AWS-recommended method for deploying major database changes in a way that minimizes impact to users and maximizes uptime.

Reference Extract from AWS Documentation / Study Guide:

" Amazon RDS Blue/Green Deployments enable you to make changes to your database environment safely. You can perform schema updates and feature testing in a fully managed staging environment and switch over with minimal downtime, ensuring the highest availability. "

Source: AWS Certified Solutions Architect – Official Study Guide, Database and Migration section; Amazon RDS Blue/Green Deployments Documentation.