Complete SAA-C03 Amazon Web Services Materials

The most suitable solution for the company’s requirements is to enable Default Host Configuration Management in Systems Manager to manage the EC2 instances. This solution will allow the company to patch the EC2 instances without disrupting the running applications and without manually creating or modifying IAM roles or users.

Default Host Configuration Management is a feature of AWS Systems Manager that enables Systems Manager to manage EC2 instances automatically as managed instances. A managed instance is an EC2 instance that is configured for use with Systems Manager. The benefits of managing instances with Systems Manager include the following:

Connect to EC2 instances securely using Session Manager.

Perform automated patch scans using Patch Manager.

View detailed information about instances using Systems Manager Inventory.

Track and manage instances using Fleet Manager.

Keep SSM Agent up to date automatically.

Default Host Configuration Management makes it possible to manage EC2 instances without having to manually create an IAM instance profile. Instead, Default Host Configuration Management creates and applies a default IAM role to ensure that Systems Manager has permissions to manage all instances in the Region and account where it is activated.If thepermissions provided are not sufficient for the use case, the default IAM role can be modified or replaced with a custom role1.

The other options are not correct because they either have more operational overhead or do not meet the requirements. Creating a new IAM role, attaching the AmazonSSMManagedInstanceCore policy to the new IAM role, and attaching the new IAM role and the existing IAM role to the EC2 instances is not correct because this solution requires manual creation and management of IAM roles, which adds complexity and cost to the solution.The AmazonSSMManagedInstanceCore policy is a managed policy that grants permissions for Systems Manager core functionality2. Creating an IAM user, attaching the AmazonSSMManagedInstanceCore policy to the IAM user, and configuring Systems Manager to use the IAM user to manage the EC2 instances is not correct because this solution requires manual creation and management of IAM users, which adds complexity and cost to the solution.An IAM user is an identity within an AWS account that has specific permissions for a single person or application3. Removing the existing policies from the existing IAM role and adding the AmazonSSMManagedInstanceCore policy to the existing IAM role is not correct because this solution may disrupt the running applications that rely on the existing policies for accessing RDS databases.An IAM role is an identity within an AWS account that has specific permissions for a service or entity4.

Recycle Bin is a data recovery feature that enables you to restore accidentally deleted Amazon EBS snapshots and EBS-backed AMIs. When using Recycle Bin, if your resources are deleted, they are retained in the Recycle Bin for a time period that you specify before being permanently deleted. You can restore a resource from the Recycle Bin at any timebefore its retention period expires. This solution has the least operational overhead, as you do not need to create, copy, or upload any additional resources. You can also manage tags and permissions for AMIs in the Recycle Bin. AMIs in the Recycle Bin do not incur any additional charges. References:

Recover AMIs from the Recycle Bin

Recover an accidentally deleted Linux AMI

This solution meets the requirements because it requires the least amount of infrastructure management and guarantees exactly-once delivery for application messaging. AWS Lambda is a serverless compute service that lets you run code without provisioning or managing servers. You only pay for the compute time you consume.Lambda scales automatically with the size of your workload. Amazon SQS FIFO queues are designed to ensure that messages are processed exactly once, in the exact order that they are sent. FIFO queues have high availability and deliver messages in a strict first-in, first-out order. You can use Amazon SQS to decouple and scale microservices, distributed systems, and serverless applications. References: AWS Lambda, Amazon SQS FIFO queues

Point-in-time recovery (PITR) for DynamoDB is a feature that enables you to restore your table data to any point in time during the last 35 days. PITR helps protect your table from accidental write or delete operations, such as a test script writing to a production table or a user issuing a wrong command. PITR is easy to use, fully managed, fast, and scalable. You can enable PITR with a single click in the DynamoDB console or with a simple API call. You can restore a table to a new table using the console, the AWS CLI, or the DynamoDB API. PITR does not consume any provisioned table capacity and has no impact on the performance or availability of your production applications. PITR meets the requirements of the company with the least operationaloverhead, as it does not require any manual backup creation, scheduling, or maintenance. It also provides per-second granularity for restoring the table to any point within the last 24 hours.