Jeff’s Note #
Unlike generic exam dumps, ADH analyzes this scenario through the lens of a Real-World Site Reliability Engineer (SRE).
For SOA-C02 candidates, the confusion often lies in choosing the right load balancing technology that supports static IPs per Availability Zone and handles massive, bursty traffic patterns. In production, this is about knowing exactly how AWS Load Balancers differ in IP behavior and scaling characteristics across multi-AZ deployments. Let’s drill down.
The Certification Drill (Simulated Question) #
Scenario #
CloudFleet Logistics, a global shipping tech company, is architecting a resilient front-end application deployed across multiple AWS Availability Zones. The application runs on EC2 instances behind a load balancing layer. The system must gracefully scale to handle millions of requests per second during sudden demand spikes. Additionally, CloudFleet requires that each Availability Zone has a dedicated static IP address exposed to external clients, enabling strict firewall rules and whitelisting. The SysOps team must select a load balancing solution that distributes traffic efficiently under fluctuating loads, provides resilience across AZs, and satisfies the single static IP per AZ requirement.
The Requirement: #
Which AWS service or feature best satisfies these requirements?
The Options #
- A) Amazon Simple Queue Service (Amazon SQS) queue
- B) Application Load Balancer (ALB)
- C) AWS Global Accelerator
- D) Network Load Balancer (NLB)
Google adsense #
leave a comment:
Correct Answer #
D) Network Load Balancer (NLB)
Quick Insight: The SOA-C02 Imperative #
- For SysOps: NLB supports static Elastic IP allocation per AZ, enabling consistent IP addresses which are critical for firewall rules. It also handles millions of requests with ultra-low latency under heavy burst conditions, unlike ALB which does not expose static IPs by default.
Content Locked: The Expert Analysis #
You’ve identified the answer. But do you know the implementation details that separate a Junior from a Senior?
The Expert’s Analysis #
Correct Answer #
Option D: Network Load Balancer (NLB)
The Winning Logic #
NLB is the only AWS load balancer type that supports static, elastic IP addresses assigned per Availability Zone, which satisfies the requirement for a single static IP per AZ. This is critical for scenarios where whitelisting or IP-based firewall rules are enforced externally.
In addition, NLB operates at the transport layer (L4) providing ultra-low latency and can handle millions of requests per second with sudden bursts, making it highly suitable for high-throughput, variable traffic workloads spread across multiple AZs.
Unlike ALB (which works at L7), NLB also supports TCP and UDP protocols and provides high availability seamlessly across AZs.
The Trap (Distractor Analysis): #
-
Why not A: Amazon SQS?
SQS is a message queue, not a load balancing solution; it does not distribute traffic to EC2 instances directly or provide static IPs. -
Why not B: Application Load Balancer?
ALB does not provide static IP addresses; its endpoints are DNS names with dynamically changing IPs, so it cannot satisfy firewall or static IP requirements per AZ. Additionally, ALB is optimized for HTTP/HTTPS traffic, but the question emphasizes static IP and burst handling. -
Why not C: AWS Global Accelerator?
Global Accelerator does offer static IP addresses for global applications, but it provides two global static IPs (not one per AZ) and acts as a front-door accelerator rather than an internal load balancer distributing traffic directly at the EC2 level per AZ. Also, it adds an extra networking layer and is more suited for global, multi-region applications rather than purely multi-AZ within a region.
The Technical Blueprint #
# Example CLI command to create Network Load Balancer with Elastic IP per AZ
aws elbv2 create-load-balancer \
--name cloudfleet-nlb \
--type network \
--subnets subnet-az1 subnet-az2 subnet-az3 \
--scheme internet-facing \
--ip-address-type ipv4
# Allocate Elastic IPs per subnet and attach as static IPs for NLB (using NetworkInterfaces)
# This must be done via console or CloudFormation with AllocationIds mapped appropriately.
The Comparative Analysis #
| Option | Operational Overhead | Automation Level | Impact / Suitability |
|---|---|---|---|
| A) SQS | High (app redesign needed) | High (decoupling, async) | Not a load balancer; no static IP |
| B) ALB | Medium | High (HTTP-based routing) | No static IP, DNS only |
| C) Global Accelerator | Medium | Medium | 2 global static IPs, not per AZ |
| D) NLB | Low | High | Static IP per AZ, ultra-low latency, suitable for bursty traffic |
Real-World Application (Practitioner Insight) #
Exam Rule #
For the exam, always pick NLB when you see requirements that include static IP addresses per Availability Zone with high throughput and TCP/UDP support.
Real World #
In real production, sometimes Global Accelerator is used on top of NLB or ALB for global traffic acceleration, but that adds complexity and doesn’t provide static IPs per AZ, just global IPs.
(CTA) Stop Guessing, Start Mastering #
Disclaimer
This is a study note based on simulated scenarios for the SOA-C02 exam.