Reduce Latency in AWS SAP by Placing Instances in Same AZ
An SAP system on AWS is experiencing high latency between the application server and the database server. Both servers are in the same VPC but in different Availability Zones. Which action should the administrator take to reduce latency?
Quick Answer
The correct action is to move the application and database servers to the same Availability Zone. This directly reduces latency between EC2 instances in different AZs by eliminating the physical distance and network hops required for cross-AZ traffic, which typically adds 1-2 milliseconds of latency due to the transit through Availability Zone gateways. On the AWS Certified SAP on AWS Specialty PAS-C01 exam, this scenario tests your understanding of how network architecture impacts SAP performance, often appearing as a distractor where candidates might incorrectly choose larger instances or placement groups. A common trap is assuming that compute power alone fixes latency, but for SAP workloads, proximity within a single AZ is the most immediate and cost-effective solution. Remember the memory tip: "Same AZ, same delay—cross AZ, cross your fingers."
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
✓
Move the application and database servers to the same Availability Zone
Moving both servers to the same Availability Zone (Option B) reduces network latency because data does not have to traverse the AZ boundary, which adds extra network hops and latency. Creating a placement group (Option A) can help co-locate instances but does not guarantee they are in the same AZ unless specified, and even then, moving to the same AZ is simpler. Upgrading instance types (Option C) does not affect network latency. AWS Direct Connect (Option D) is for connecting on-premises networks to AWS, not for inter-instance communication within a VPC.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Create a placement group and launch both instances in it
Why it's wrong here
Placement group may help but same AZ is more effective.
- ✓
Move the application and database servers to the same Availability Zone
Why this is correct
Reduces network latency.
- ✗
Upgrade the instance types to compute-optimized instances
Why it's wrong here
Does not directly reduce network latency.
- ✗
Use AWS Direct Connect to connect the servers
Why it's wrong here
Direct Connect is for on-premises to AWS, not within AWS.
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Variation 1. An SAP system on AWS is experiencing high latency between the application and database tiers. Both tiers are in the same VPC but in different Availability Zones. What is the most effective way to reduce latency?
hard- ✓ A.Move both tiers into the same Availability Zone.
- B.Add an Application Load Balancer between tiers.
- C.Increase the bandwidth of the EC2 instances.
- D.Enable AWS Direct Connect.
Why A: Placing both tiers in the same Availability Zone eliminates cross-AZ data transfer latency. AWS data transfer between AZs incurs additional latency compared to within the same AZ. Option B (adding an Application Load Balancer) would add network hops and potentially increase latency. Option C (increasing bandwidth) does not reduce latency; bandwidth affects throughput, not latency. Option D (AWS Direct Connect) is used for on-premises connectivity, not for communication within AWS.
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This PAS-C01 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 PAS-C01 exam.