AWS Solutions Architect Associate Practice Test

Which feature optimizes performance for a compute cluster requiring low inter-node latency?

1. Multiple Availability Zones

2. AWS Direct Connect

3. EC2 Dedicated Instances

4. Placement Groups

The correct answer is: Placement Groups

Placement Groups are designed specifically to optimize the performance of workloads that require low inter-node latency in a compute cluster. This feature allows you to specify how your instances are placed on underlying hardware in an AWS region to achieve the best possible performance for communication between instances. When you use placement groups, you can configure your instances to be physically located close to each other within the AWS data center. This proximity reduces the inter-node latency, maximizing network throughput and minimizing latency for applications that depend on fast inter-instance communication. For workloads such as high-performance computing (HPC), in-memory databases, or real-time data processing, this low-latency communication is crucial for achieving optimal performance. In contrast, other options like Multiple Availability Zones, AWS Direct Connect, and EC2 Dedicated Instances serve different purposes and may not provide the same level of low-latency inter-node communication. Multiple Availability Zones are more about fault tolerance and high availability rather than performance optimization, while AWS Direct Connect is a service for establishing a dedicated network connection from your premises to AWS. EC2 Dedicated Instances offer hardware isolation but do not optimize for low inter-node latency like placement groups do.