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

AWS Step Functions supports long-running workflows and error retries, making it ideal for a job composed of many tasks. Integration with EventBridge allows automatic triggering from S3 events. This setup is resilient and supports up to 1-year execution duration.

Amazon EFS provides a shared, elastic, low-latency file system that can be mounted concurrently by many EC2 instances across multiple Availability Zones, delivering strong read-after-write consistency so all instances see updates almost immediately. This is the standard pattern for CMS-style workloads that require shared, up-to-date assets with minimal lag. Syncing local copies from S3 (C) introduces polling windows and eventual consistency delays; hourly sync is not near-real time. Copying from a “newest instance” (A) is brittle and not scalable. EBS volumes/snapshots (D) are single-instance, single-AZ block devices and not designed for multi-writer sharing across instances/AZs. EFS’s multi-AZ design and POSIX semantics provide the simplest, most reliable solution with the least operational overhead.

Amazon S3 Glacier Flexible Retrieval is a low-cost archival storage class that supports retrieval of data within minutes (expedited access ~1–5 minutes), making it ideal for audit scenarios where occasional, quick access to archived data is required. In contrast, Glacier Deep Archive takes hours to retrieve.

Aurora Global Database: Provides cross-Region disaster recovery with minimal data loss (<1 second replication latency).

S3 Cross-Region Replication (CRR): Automatically replicates data between buckets in different Regions.

“Aurora Global Database replicates your data with typically under one second of latency to secondary Regions.”

“Amazon S3 Cross-Region Replication automatically replicates objects across buckets in different AWS Regions.”

— Aurora Global Database

— S3 Cross-Region Replication

This meets the multi-Region DR requirement with minimal data loss.

AWS advises using serverless event-driven processing to minimize operational burden and scale automatically with demand. Amazon SQS can be directly configured as an event source for AWS Lambda. With this setup, Lambda polls the queue, invokes the function, and processes messages without requiring the customer to manage infrastructure. Scaling is automatic, based on the volume of messages in the queue. Option A (increasing instance size) still leaves scaling and management challenges. Option B reduces cost when idle but does not address scaling. Option D requires manual triggering and does not meet continuous processing requirements. Migrating the script to Lambda (C) fully eliminates the need for instance management, providing scalability, reliability, and reduced operational overhead.

This solution is the most suitable for running cron jobs on AWS with minimal refactoring, while also supporting the possibility of running jobs in response to future events.

Container Image for Cron Jobs: By containerizing the cron jobs, you can package the environment and dependencies required to run the jobs, ensuring consistency and ease of deployment across different environments.

Amazon EventBridge Scheduler: EventBridge Scheduler allows you to create a recurring schedule that can trigger tasks (like running your cron jobs) at specific times or intervals. It provides fine-grained control over scheduling and integrates seamlessly with AWS services.

AWS Fargate: Fargate is a serverless compute engine for containers that removes the need to manage EC2 instances. It allows you to run containers without worrying about the underlying infrastructure. Fargate is ideal for running jobs that can vary in duration, like cron jobs, as it scales automatically based on the task's requirements.

Why Not Other Options?:

Option A (Lambda): While AWS Lambda could handle short-running cron jobs, it has limitations in terms of execution duration (maximum of 15 minutes) and might not be suitable for jobs that run up to 20 minutes.

Option B (AWS Batch on ECS): AWS Batch is more suitable for batch processing and workloads that require complex job dependencies or orchestration, which might be more than what is needed for simple cron jobs.

Option D (Step Functions with Wait State): While Step Functions provide orchestration capabilities, this approach would introduce unnecessary complexity and overhead compared to the straightforward scheduling with EventBridge and running on Fargate.

AWS References:

Amazon EventBridge Scheduler- Details on how to schedule tasks using Amazon EventBridge Scheduler.

AWS Fargate- Information on how to run containers in a serverless manner using AWS Fargate.

For cost-effectiveness and high availability in Amazon EMR workloads, the best approach is to configure atransient cluster(which runs for the duration of the job and then terminates) withOn-Demand Instancesfor the primary and core nodes, andSpot Instancesfor the task nodes. Here's why:

Primary and core nodes on On-Demand Instances: These nodes are critical because they manage the cluster and store data on HDFS. Running them on On-Demand Instances ensures stability and that no data is lost, as Spot Instances can be interrupted.

Task nodes on Spot Instances: Task nodes handle additional processing and can be used with Spot Instances to reduce costs. Spot Instances are much cheaper but can be interrupted, which is fine for non-critical tasks as the framework can handle retries.

Atransient clusteris more cost-effective than a long-running cluster for workloads that only run for 6 hours a day. Transient clusters automatically terminate after the workload completes, saving costs by not keeping the cluster running when it's not needed.

Option A: A long-running cluster may result in unnecessary costs when the cluster isn't being used.

Option C: Running core nodes on Spot Instances risks data loss if the Spot Instances are interrupted, violating the requirement for zero data loss.

Option D: Running both core and task nodes on Spot Instances is highly risky for data-critical workloads.

AWS References:

Amazon EMR Cluster Management

Using Spot Instances in EMR

AmazonSES (Simple Email Service)allows for the automatic ingestion of incoming emails. By setting up email receiving in SES and creating a rule set with a receipt rule, you can configure SES to invoke anAWS Lambda functionwhenever an email is received. The Lambda function can then process the email body and attachments, saving any attachments to an Amazon S3 bucket. This solution is highly scalable, cost-effective, and provides near real-time processing of emails with minimal operational overhead.

Option B (Content filtering): This only filters emails based on content and does not provide the functionality to save attachments to S3.

Option C (S3 Event Notifications): While SES can store emails in S3, SES with Lambda offers more flexibility for processing attachments in real-time.

Option D (EventBridge rule): EventBridge cannot directly listen for incoming emails, making this solution incorrect.

AWS References:

Receiving Email with Amazon SES

Invoking Lambda from SES

AWS Application Migration Service (AWS MGN) is the recommended tool for a lift-and-shift strategy, especially for time-sensitive migrations. It automates the replication of on-premises VMs to AWS, minimizing the effort required for migration and testing.

Key steps:

Replication with AWS MGN: The AWS Replication Agent is installed on the VMs to continuously replicate data to AWS, allowing you to manage migration easily.

Testing and Cutover: Initial replication allows for testing in AWS before performing the final cutover, ensuring that the migration process is smooth and data integrity is maintained.

AWS Documentation: AWS MGN is recommended for migrating virtual machines to the cloud with minimal downtime and disruption​​.

The best practice for secure access control in AWS is to use IAM roles with least-privilege policies, granting only the permissions necessary to perform required tasks. Assigning roles individually ensures that developers cannot overstep their intended access boundaries.

Sharing credentials or using permanent access keys increases the risk of security breaches. Cognito is primarily intended for managing user access to applications, not AWS infrastructure. Thus, Option B best meets security and access control requirements.

Amazon RDS Proxy helps manage and pool database connections from serverless compute like AWS Lambda, significantly reducing the stress on the database during unpredictable traffic surges. It improves scalability and resiliency by efficiently managing connections, protecting the database from being overwhelmed, and enabling failover handling.

Option A is the most cost-effective and operationally efficient approach to handling unpredictable surges and improving resilience without requiring major application changes.

Option B involves a migration to DynamoDB, which is a significant architectural change and costlier initially. Option C is manual connection cleanup, insufficient for unpredictable surges. Option D increases resources but does not solve connection storm problems efficiently and is more costly.

To track costs by department, you must activate the custom department tag as a cost allocation tag in the AWS Organizations management account. Once activated, Cost Explorer and cost and usage reports can group costs by this tag for all linked accounts. The most operationally efficient way is to activate only the relevant department tag and create a cost and usage report grouped by that tag.

AWS Documentation Extract:

“To use a tag for cost allocation, you must activate it in the AWS Billing and Cost Management console. After activation, you can use the tag to group costs in Cost Explorer and reports.”

(Source: AWS Cost Management documentation)

A, E: aws:createdBy is not related to department cost grouping and is unnecessary.

B: Applying extra filters is optional; D is more direct and operationally efficient.

The best practice for granting AWS service access to EC2 instances is to assign IAM roles with the least privilege necessary. IAM roles attached to EC2 instances provide temporary credentials automatically rotated by AWS, avoiding hard-coded credentials in the application code.

Option C adheres to security best practices by assigning an IAM role scoped with the minimum permissions needed to access the S3 bucket.

Option A grants administrative access, which violates least privilege principles. Options B and D use IAM users with static credentials, increasing the risk of credential exposure and requiring manual rotation, which is not recommended.