AZ-204 Develop Azure compute solutions Practice Question
Which THREE considerations are important when designing a solution using Azure Functions with a Consumption plan for a latency-sensitive application?
⚠ Common exam trap
A common mix-up: candidates confuse the features of the Consumption plan with those of the Premium plan, mistakenly thinking Always-on or pre-warmed instances are available in the Consumption plan, when they are exclusive to higher-tier plans.
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
✓
Cold start latency may impact initial requests.
Option A is correct because on the Consumption plan, function apps scale to zero when idle, so the first request after an idle period triggers a cold start that adds latency to that initial invocation. Option B is correct because the Consumption plan enforces a maximum function execution timeout of 10 minutes (default 5 minutes), which constrains long-running latency-sensitive workloads. Option C is correct because Consumption-plan scaling is event-driven and not instantaneous, so bursts of traffic can cause temporary latency spikes while new instances are provisioned. Option D is incorrect because Always On is a feature of App Service plans (and Premium/ Dedicated), not the Consumption plan, and cannot be enabled there. Option E is incorrect because pre-warmed instances are a Premium plan capability, not available on the Consumption plan.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Cold start latency may impact initial requests.
Why this is correct
In the Azure Functions Consumption plan, instances are dynamically allocated and deallocated based on demand. When a function has been idle for a period, its underlying host instance may be shut down. The "cold start" refers to the latency incurred when the first request arrives, requiring the Azure platform to spin up a new instance, load the function code, and initialize the runtime environment, which can significantly delay the initial response.
- ✓
Function execution timeout is limited to 10 minutes.
Why this is correct
For Azure Functions running on the Consumption plan, the default execution timeout is 5 minutes. While this can be configured up to a maximum of 10 minutes using the functionTimeout setting in the host.json file, any function execution exceeding this limit will be terminated. This constraint is a critical design consideration for long-running processes, necessitating alternative patterns like durable functions or external orchestrators.
- ✓
Scaling may not be instantaneous, causing latency spikes.
Why this is correct
Azure Functions on the Consumption plan automatically scale out by adding more instances as demand increases. However, this scaling process is not instantaneous; it takes time for new instances to be provisioned and become ready to process requests. During sudden bursts of traffic, before sufficient instances are available, requests may queue or experience increased latency, leading to temporary performance spikes until the platform fully scales out.
- ✗
Always-on feature must be enabled to avoid cold starts.
Why it's wrong here
The "Always On" feature is designed for Azure App Service plans (including Premium and Dedicated Function App plans) to keep the application continuously loaded, thereby preventing cold starts. However, this feature is explicitly not available for Azure Functions running on the Consumption plan, which is designed for serverless, event-driven scaling and cost optimization. Therefore, enabling Always On is not an option to mitigate cold starts in a Consumption plan function app.
- ✗
Pre-warmed instances can be configured to reduce latency.
Why it's wrong here
Pre-warmed instances are a feature of the Azure Functions Premium plan, allowing you to specify a minimum number of instances that are always kept ready to serve requests, significantly reducing cold start latency. This capability is not available or configurable within the Consumption plan, which dynamically provisions and de-provisions instances purely based on real-time demand and event triggers. Consequently, pre-warmed instances cannot be used to reduce latency in a Consumption plan function app.
Quick reference
Cloud Service Model Comparison
| Model | You Manage | Provider Manages | Examples |
|---|---|---|---|
| IaaS | OS, runtime, apps, data | Hardware, hypervisor, networking | EC2, Azure VMs, GCP Compute Engine |
| PaaS | Apps and data | OS, runtime, middleware, hardware | Elastic Beanstalk, Azure App Service |
| SaaS | Data and settings only | Everything else | Microsoft 365, Salesforce, Workday |
| FaaS / Serverless | Function code only | Infra, scaling, runtime | Lambda, Azure Functions, Cloud Run |
| CaaS | Containers and apps | Kubernetes, OS, hardware | EKS, AKS, GKE |
Go deeper
Related to this question
Learn chapter
Azure Static Web Apps
Key term
Durable Functions
Durable Functions is an extension of Azure Functions that lets you write stateful workflows in code, managing complex sequences of tasks, retries, and delays automatically.
Key term
Azure Functions Bindings
Azure Functions Bindings are declarative connections that link your serverless function code to Azure services or external resources, handling input and output data automatically without writing extra networking or authentication code.
About these practice questions
This AZ-204 question is part of Courseiva's 883-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This AZ-204 practice question is part of Courseiva's free Microsoft 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 AZ-204 exam.