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Difficulty: MediumOptimizing Compute and Storage Performance

A healthcare company runs a medical image processing application. The application's backend database runs on a single Amazon RDS for PostgreSQL DB instance in a Multi-AZ deployment. The compute layer consists of Amazon EC2 instances in an Auto Scaling group that processes tasks from an Amazon SQS queue. During peak periods, the application experiences performance degradation. A Solutions Architect identifies two main bottlenecks:

1. The database CPU utilization reaches 95%95\% due to a high volume of read-only queries for historical report retrieval.
2. The Auto Scaling group launches new EC2 instances to handle the SQS queue surge, but these instances take more than 88 minutes to bootstrap because they download heavy software packages at startup. This delay causes the Auto Scaling group to launch more instances than required before the existing ones can begin processing tasks.

Which combination of actions will resolve these performance bottlenecks? (Select TWO.)

  1. Create an Amazon RDS PostgreSQL Read Replica and update the application configuration to route read-only queries to the replica endpoint.Answer
  2. Create a custom Amazon Machine Image (AMI) with all application dependencies pre-packaged, and update the Auto Scaling group's launch template to use this AMI.Answer
  3. C
    Configure the application to distribute read-only queries between the primary DB instance and the standby DB instance in the Multi-AZ deployment.
  4. D
    Submit an AWS Support request to pre-warm the Application Load Balancer (ALB) to handle the increased traffic volume and prevent dropped connections during peak periods.
  5. E
    Decrease the Auto Scaling group cooldown period to a value shorter than the EC2 bootstrap time to force the group to launch new instances faster.

Answer

Create an Amazon RDS PostgreSQL Read Replica to handle read-only queries, and build a custom Amazon Machine Image (AMI) containing pre-packaged dependencies to speed up the Auto Scaling group's EC2 instance boot time.
To optimize the compute and storage performance of this queue-based medical application, read-heavy workloads must be offloaded from the primary database and EC2 instance bootstrap times must be reduced. Creating an Amazon RDS PostgreSQL Read Replica allows the read-only queries to be redirected to a dedicated read-only endpoint, relieving CPU pressure on the primary instance. Building a custom Amazon Machine Image (AMI) with all application software and packages pre-installed eliminates the startup delay caused by runtime package downloads, enabling new instances to scale and process SQS messages immediately without triggering over-provisioning.

Step-by-Step Solution

1
Identify the database read bottleneck and determine the capability of RDS Multi-AZ deployments.
Establish that the standby instance cannot serve reads, meaning an Amazon RDS Read Replica must be created to offload queries.
To reduce CPU utilization on the primary database, read queries must be redirected to a dedicated, read-capable replica endpoint.
2
Analyze the EC2 scaling bottleneck caused by slow bootstrapping (8+ minutes).
Build a custom AMI with all software dependencies pre-installed.
Eliminating dependency downloads during instance launch speeds up the boot process so that instances can quickly absorb SQS queue tasks and satisfy scale-out signals.

Key Concept

Scaling read capacity with database replicas and accelerating EC2 scale-out times via custom AMIs to optimize compute and storage performance.
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Topics

Optimizing Compute and Storage Performance