Microsoft Certified: Azure Developer Associate (AZ-204)Develop Azure compute solutionsHard
A media company uses Azure Container Instances (ACI) to run a series of short-lived, burstable containerized tasks for video transcoding. Each task processes a segment of a video, and the number of tasks varies significantly throughout the day. The company wants to optimize costs by only paying for the exact compute resources consumed during the container's execution, without managing any underlying virtual machines or orchestration. Which ACI billing model is most relevant for this scenario?
- APay-as-you-go per second
- BDedicated hosts
- CSpot instances
- DReserved Instances
Show answer & explanationAnswer & explanation
Correct answer: A. Pay-as-you-go per second
Azure Container Instances (ACI) charges on a per-second basis for the CPU and memory resources allocated to your containers, from the moment your container starts until it stops. This 'Pay-as-you-go per second' model is ideal for short-lived, burstable workloads where you only pay for the exact duration and resources consumed, aligning perfectly with the goal of cost optimization without managing VMs.
Why the other options are wrong
- B. Dedicated hosts provide physical servers for exclusive use but are expensive and designed for specific isolation or compliance needs, not cost optimization for burstable tasks.
- C. Spot instances (available for VMs, not directly ACI) offer deep discounts but can be preempted, which might be disruptive for critical video transcoding tasks unless designed for fault tolerance.
- D. Reserved Instances offer discounted rates for continuous, long-term (1 or 3 years) usage, which is not suitable for short-lived, burstable tasks.
ACI Billing Model
Azure Container Instances bills based on the actual duration (per second) and resources (CPU, memory) consumed by your container.
- Pay-as-you-go, per second billing
- Charges for CPU and memory allocated
- Ideal for burstable, short-lived, and unpredictable workloads
- No upfront costs or termination fees
Memory trick: ACI bills by the Second, for exactly what you use.