Explore key differences and best use cases between EC2 Spot, On-Demand, and Reserved Instances with this quiz designed to enhance your understanding of cloud cost optimization and instance purchasing options. Improve decision-making for scalable and economical cloud resource allocation.
Which instance type is most suitable for applications with unpredictable workloads that require servers to be available instantly, such as short-term development or testing environments?
Explanation: On-Demand Instances allow you to start and stop servers as needed without long-term commitment, making them fit for unpredictable workloads. Spot Instances are less reliable due to the chance of interruption, while Reserved Instances require upfront commitment and are cost-effective only if used for longer periods. Designated Instances is not a recognized type.
If you have a steady, predictable workload that will run continuously for at least a year, which instance type typically provides the lowest overall cost?
Explanation: Reserved Instances offer significant discounts compared to On-Demand Instances when workloads are predictable and long-term. Spot Instances can be cheaper but are not suitable for workloads that must always be running since they can be interrupted. Auctioned Instances is not a valid choice. On-Demand Instances are the most flexible but more expensive over time.
In which type of instance can your running servers be interrupted with only a brief warning, possibly resulting in loss of service if not handled properly?
Explanation: Spot Instances can be interrupted when capacity is needed elsewhere, making interruption a key characteristic. Reserved and On-Demand Instances offer guaranteed availability during the purchased or running period. Custom Instances is not an officially recognized term for this feature.
If an organization wants to lock in lower pricing with a one- or three-year commitment but pay some or all costs upfront, which instance type should they use?
Explanation: Reserved Instances allow for upfront or partial upfront payments in exchange for a commitment that reduces cost over the long term. Spot Instances don't require upfront payment but can be terminated, and On-Demand Instances are purely pay-as-you-go with no commitments. Partial-Time Instances is not a valid category.
When customer flexibility and the ability to scale resources up or down at any time without notice are critical, which EC2 instance purchasing option provides this capability?
Explanation: On-Demand Instances allow you to launch or terminate resources at any time, providing maximum flexibility for changing workloads. Reserved Instances involve long-term contracts, while Spot Instances can be interrupted unpredictably. Subscription Instances is not an official term.
A company wants to process large data sets overnight at the lowest possible cost, and occasional job interruptions are not a concern. Which instance purchase option is the best fit?
Explanation: Spot Instances are ideal for workloads that can tolerate interruptions and where cost savings are important, such as big data or batch processing jobs. On-Demand and Reserved Instances guarantee availability but at a higher cost. Priority Instances is not a recognized instance type.
Which instance type is specifically designed to offer cost savings for a client who is certain of their long-term needs and can commit to a specific instance type and region for at least a year?
Explanation: Reserved Instances provide lower pricing for clients willing to commit to a specific type and region for a set term. On-Demand and Spot Instances don’t require a commitment and do not provide equivalent discounts. Scheduled Instances are related to time-based usage but may not offer the same broad savings.
Which instance type is most commonly used with auto scaling to dynamically adjust computing power for unpredictable load spikes without interruption risk?
Explanation: On-Demand Instances fit well with auto scaling for unpredictable spikes, since they guarantee uptime and availability. Spot Instances could be interrupted at any moment, Reserved Instances are meant for steady loads, and Temporary Instances isn’t a standard term.
Which instance type charges you purely for the compute resources you actually use, without any upfront or long-term commitment?
Explanation: On-Demand Instances are pay-as-you-go, meaning you pay only for what you use with no commitments or upfront costs. Reserved Instances require a contractual commitment and may involve upfront payment. Spot Instances charge for use but are subject to interruption and depend on market price. Fixed Instances is not a standard term.
Which statement best describes how pricing works for Spot Instances compared to Reserved or On-Demand Instances?
Explanation: Spot Instance costs are variable, changing based on available capacity and real-time demand, usually offering lower prices. By contrast, Reserved Instances are charged a fixed rate over their term, while On-Demand pricing is constant but set higher. Statement three and four are incorrect as they misrepresent the dynamic nature of spot pricing.