SAA-C03 Design High-Performing Architectures Practice Question
A distributed system needs extremely low network latency between a set of EC2 instances running the same workload. The team wants the instances to be placed as close together as AWS allows to reduce round-trip time. Which placement strategy should the architect use?
⚠ Common exam trap
A common mix-up: candidates confuse the purpose of placement groups: Cluster is for low latency and high throughput, Spread is for fault tolerance across hardware, and Partition is for large distributed systems needing failure isolation, but only Cluster guarantees physical proximity.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Use a Cluster placement group for the instances that must communicate frequently over low latency.
A Cluster placement group is the correct choice because it places instances in a single Availability Zone within the same rack or logical cluster, providing the lowest possible network latency and maximum throughput (up to 10 Gbps for single-flow traffic) between instances. This is ideal for tightly coupled, latency-sensitive workloads like HPC or real-time distributed systems.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Use a Cluster placement group for the instances that must communicate frequently over low latency.
Why this is correct
Cluster placement groups are designed to place instances close together within a single Availability Zone to minimize network latency. They are the right choice when nodes require high intercommunication performance, such as distributed processing or tightly coupled systems. The scenario’s goal of minimizing round-trip time aligns with the Cluster placement group behavior. It’s also an EC2-native placement option focused on performance.
- ✗
Use a Spread placement group across multiple Availability Zones to maximize fault tolerance.
Why it's wrong here
Spread placement groups maximize resilience by dispersing instances across hardware failure domains, including multiple AZs. While useful for availability, it typically does not optimize for the lowest possible network latency between nodes. The scenario explicitly requires closeness to reduce round-trip time, which is the Cluster placement group strength.
- ✗
Use the default placement strategy without specifying a placement group.
Why it's wrong here
Default placement does not guarantee low-latency proximity between instances. Even though some instances may end up relatively close, it provides no assurance for tight inter-node communication requirements. The system’s need for extremely low latency requires an explicit placement strategy, not reliance on chance.
- ✗
Use a placement group of type Partition to ensure independent failure of each instance.
Why it's wrong here
Partition placement groups are aimed at isolating instances into separate logical partitions, often for large clusters. This improves the ability to isolate failures but does not specifically prioritize minimal latency between all instances in one communication set. The scenario’s primary objective is lower round-trip time, which points to Cluster placement.
Go deeper
Related to this question
About these practice questions
One of 302 original SAA-C03 practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This SAA-C03 practice question is part of Courseiva's free Amazon Web Services certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the SAA-C03 exam.