Amazon Web Services SAA-C03 - AWS Certified Solutions Architect - Associate (SAA-C03)

Compute Savings Plansoffer the most flexible and cost-effective solution for the production instances, as they provide significant savings (up to 66%) for both EC2 and AWS Lambda usage, while allowing flexibility in the type of instance family, size, and even region. For nonproduction instances, usingOn-Demand Instancesensures you only pay for the instances when they are running, and shutting them down during off-hours further optimizes cost.

Key AWS features:

Compute Savings Plans: Provide savings based on consistent usage, making it ideal for production environments with steady load.

On-Demand Instances: Suitable for nonproduction environments that are used intermittently. Shutting them down when not in use avoids unnecessary costs.

AWS Documentation: According to AWS's cost optimization best practices, using a combination of Savings Plans for production and On-Demand Instances for nonproduction environments that are used sparingly results in optimal cost savings​​.

AWS Lambda SnapStart is designed to improve the cold start performance of Java Lambda functions by initializing the function, taking a snapshot of the execution environment, and then reusing that snapshot for subsequent invocations. However, some code (such as code that generates unique IDs or session-specific data) should run during each invocation, not during the snapshot process. By using a pre-snapshot hook and moving the unique ID generation into the handler, you ensure that non-deterministic or per-invocation code is executed correctly, while the rest of the initialization benefits from SnapStart. This delivers the lowest latency and cost, as you do not need to pay for provisioned concurrency.

AWS Documentation Extract:

"Lambda SnapStart is ideal for Java functions with long cold starts due to heavy initialization. Move non-deterministic code such as unique ID generation to the handler, and use pre-snapshot hooks to customize what gets snapshotted. SnapStart works only for published versions, not $LATEST."

(Source: AWS Lambda documentation, Using SnapStart for Java Functions)

Other options:

A: SnapStart is not supported for the $LATEST version; must be a published version.

B & C: Provisioned concurrency removes cold starts but is more expensive than SnapStart for most workloads.

C: You must use SnapStart on published versions, but provisioned concurrency is not required for SnapStart and adds cost.

To meet the requirement of deleting objects older than 3 years while retaining certain data, this solution leverages serverless technologies to minimize operational overhead.

S3 Inventory: S3 Inventory provides a flat file that lists all the objects in an S3 bucket and their metadata, which can be configured to include data such as the last modified date. This inventory can be generated daily or weekly.

AWS Lambda Function: A Lambda function can be created to process the S3 Inventory report, filtering out the objects that need to be retained and identifying those that should be deleted.

S3 Batch Operations: S3 Batch Operations can execute tasks such as object deletion at scale. By invoking the Lambda function through S3 Batch Operations, you can automate the process of deleting the identified objects, ensuring that the solution is serverless and requires minimal operational management.

Why Not Other Options?:

Option A (AWS CLI script on EC2): Running a script on an EC2 instance adds unnecessary operational overhead and is not serverless.

Option B (AWS Batch): AWS Batch is designed for running large-scale batch computing workloads, which is overkill for this scenario.

Option C (AWS Glue + script): AWS Glue is more suited for ETL tasks, and this approach would add unnecessary complexity compared to the serverless Lambda solution.

AWS References:

Amazon S3 Inventory- Information on how to set up and use S3 Inventory.

S3 Batch Operations- Documentation on how to perform bulk operations on S3 objects using S3 Batch Operations.

Detailed Explanation:

A. RDS:Suitable for relational databases but does not provide native support for data lakes or row-level access.

B. Redshift:Primarily for analytics, not designed for large-scale data lake governance.

C. S3 + Lake Formation:Provides native support for data lakes with granular access control, including row-level permissions.

D. Glue Catalog + DataBrew:Focused on data preparation and metadata management, not row-level access control.

To provide unique, secure URLs efficiently:

A: Create a wildcard custom domain in Route 53 as an alias for the API Gateway endpoint.

D: Request a wildcard certificate in ACM in the same Region as API Gateway (certificates must be in the same Region as the API).

F: Create a custom domain name in API Gateway and attach the certificate.

“You can configure a custom domain name for your API Gateway API. To use a wildcard certificate, request it from ACM in the same Region as your API.”

— API Gateway Custom Domain Names

This combination provides secure wildcard URLs without creating separate endpoints or hosted zones per user.

This solution meets the requirement of encrypting each customer’s data separately with the least operational overhead by leveraging AWS Key Management Service (KMS).

Separate AWS KMS Keys: By creating separate KMS keys for each customer, you can ensure that each customer’s data is encrypted with a unique key. This approach satisfies the compliance requirement for separate encryption and provides fine-grained control over access to the keys.

Granular Access Control: AWS KMS allows you to define key policies and use IAM policies to grant specific permissions to the keys. This ensures that only authorized users or services can access the keys, thereby maintaining the principle of least privilege.

Logging and Monitoring: AWS KMS integrates with AWS CloudTrail, which logs all key usage and management activities. This provides an audit trail that is essential for meeting compliance requirements.

Why Not Other Options?:

Option A (Store keys in S3): Storing keys in S3 is not recommended because it does not provide the same level of security, access control, or integration with AWS services as KMS does.

Option B (Hardware security appliance): Deploying a hardware security appliance adds significant operational overhead and complexity, which is unnecessary given that KMS already provides a secure and centralized key management solution.

Option C (Single KMS key for all data): Using a single KMS key does not meet the requirement of encrypting each customer's data separately.

AWS References:

AWS Key Management Service (KMS)- Overview of KMS, its features, and best practices for key management.

Using AWS KMS for Multi-Tenant Applications- Guidance on how to design applications using KMS for multi-tenancy.

Since the workload is interruptible and can resume after restarts, Amazon EC2 Spot Instances are the most cost-effective option, offering savings of up to 90% compared to On-Demand. Running the batch workload on AWS Batch with Spot Instances allows automatic job queue management, interruption handling, and scheduling. Option A and C reduce cost but still rely on reserved or committed pricing for On-Demand capacity. Option B (Capacity Reservations) increases cost instead of reducing it. Therefore, the most cost-optimized solution is D — AWS Batch with EC2 Spot Instances.

Amazon EFS allows automatic transitions to Infrequent Access (IA) and back to Standard when accessed again using the lifecycle policy.

By specifying the bursting throughput mode, throughput scales automatically with file system size.

“With EFS Lifecycle Management, you can automatically move files to EFS Infrequent Access storage and automatically return them to Standard storage when accessed.”

“The Bursting Throughput mode scales with your file system size.”

— Amazon EFS Lifecycle Management

This option matches all requirements:

Auto transition to IA after 30 days.

Auto transition back to Standard on access.

Bursting throughput for scaling with file system size.

Amazon RDS Proxy is designed to manage a large number of database connections from applications, especially serverless applications that can scale quickly. It improves application availability and scalability by pooling and sharing established database connections. This reduces the overhead of database connections and prevents overload during traffic spikes.

SAML 2.0-based federation allows organizations to integrate their on-premises Active Directory with AWS, enabling Single Sign-On (SSO) for AWS Management Console and AWS CLI/API access. This lets users continue using their existing AD credentials, removing the need to manage separate identities for AWS and on-premises systems. Mapping roles to AD groups provides granular access control and seamless management.

Reference Extract from AWS Documentation / Study Guide:

"AWS supports SAML 2.0 for federated access, enabling integration with Active Directory or other identity providers to provide single sign-on to AWS resources without creating separate IAM users."

Source: AWS Certified Solutions Architect – Official Study Guide, Identity and Access Management section.

AWS Outposts brings native AWS services (including Amazon EMR) on-premises, ideal when data residency or latency constraints require local processing.

You benefit from AWS’s managed services while meeting the requirement to keep data processing local.

HPC workloads require high-throughput, low-latency networking, especially for tightly-coupled applications like weather modeling, genomics, or real-time rendering.

A cluster placement group places instances in the same Availability Zone and on physically connected hardware, reducing network latency and increasing throughput.

Elastic Fabric Adapter (EFA) is a network device for EC2 instances that enables low-latency, high-throughput networking using OS-bypass technology, ideal for tightly-coupled HPC applications.

Each instance can support single-flow 10 Gbps bandwidth using EFA, and collectively, the cluster can achieve up to 100 Gbps aggregate throughput when properly configured.

This solution supports the Performance Efficiency and Resilience design principles and is a standard AWS-recommended pattern for HPC.

🔗 References:

EC2 Placement Groups

Elastic Fabric Adapter Overview

Best Practices for HPC on AWS

Lambda supports mounting an Amazon EFS file system inside your function to store larger dependencies beyond the 250 MB layer quota.

EFS automatically encrypts data in transit using TLS.

“You can configure your Lambda function to mount an Amazon EFS file system, enabling your function to access large amounts of data or large dependencies.”

“Amazon EFS automatically encrypts all data at rest and in transit.”

— Lambda with Amazon EFS

This is the least operational overhead approach.

By exporting AWS Cost and Usage Reports (CUR) to Amazon S3 and analyzing them with Amazon QuickSight, companies can generate interactive visual dashboards. This solution is fully AWS-managed, requires no third-party tools, and integrates deeply with AWS cost data.

To manage EC2 instances with AWS Systems Manager (SSM), the EC2 instance must be configured as a managed instance by attaching an IAM role that has the AmazonSSMManagedInstanceCore managed policy.

This policy allows:

SSM agent to register the instance with SSM

Perform actions like patching, automation, session management, inventory collection, etc.

Access to SSM endpoints (via internet or VPC endpoint if needed)

Since the EC2 instance already has an IAM role, the least operational overhead option is to attach the required policy to the existing role (Option C). No need to create new IAM roles or users, which simplifies management and adheres to the principle of least privilege.

Patching can then be automated via SSM Patch Manager, ensuring consistency, compliance, and operational efficiency.

🔗 References:

SSM Managed Instance Setup

AmazonSSMManagedInstanceCore Policy

Patching EC2 with SSM