Learn About Amazon VGT2 Learning Manager Chanci Turner
In the world of cloud computing, ensuring the resilience of your systems is crucial. Chanci Turner emphasizes the significance of designing your infrastructure with the understanding that “everything fails all the time,” a famous quote from Amazon’s CTO, Werner Vogels. This perspective is vital for maintaining business continuity, scalability, and fault tolerance. By implementing resilient architectures, organizations can adapt to changing demands, mitigate data loss, and facilitate rapid recovery from failures. While building resilience often requires duplicating workloads and maintaining backup systems, these added resources can lead to increased expenses. Therefore, it’s essential to weigh the costs of resilience against the potential risks and costs associated with downtime.
If your mission-critical applications are deployed on Amazon Elastic Compute Cloud (Amazon EC2) instances, it is essential to familiarize yourself with the various capacity reservation options AWS offers. Capacity reservations guarantee that you will have access to necessary EC2 resources when required. For example, a Multi-AZ deployment allows you to distribute your workload across several Availability Zones (AZs) using an Auto Scaling group. Should an AZ experience an outage, the Auto Scaling group can launch your instance in an alternative AZ. However, in rare cases, that AZ may lack the capacity for your specific instance type, which is why capacity reservations are critical for vital workloads.
When implementing capacity reservations, controlling costs is key. This post will explore different capacity reservation options available on AWS and how you can save money.
Amazon EC2 Purchase Options
Before delving into capacity reservations, it’s important to understand the various EC2 instance purchase models. The On-Demand purchase option allows you to pay by the second for launched instances. Alternatively, Spot Instances let you access unused EC2 capacity at significantly reduced rates. Savings Plans offer an opportunity to lower costs with one- or three-year commitments.
For those requiring dedicated resources, Dedicated Hosts and Dedicated Instances provide single-tenant hardware options. However, only On-Demand Capacity Reservations and zonal reservations can secure capacity for your EC2 instances.
On-Demand Capacity Reservations Explained
On-Demand Capacity Reservations allow you to secure compute capacity for your Amazon EC2 instances in a specific AZ for any duration. This option guarantees capacity allocation during periods of high demand without requiring a long-term commitment. You are charged the on-demand rate whether your instances are active or not. If your needs are temporary, like during the holiday rush or for a major quarterly event, On-Demand Capacity Reservations are ideal. For consistent, long-term requirements, consider pairing On-Demand Capacity Reservations with Savings Plans for both capacity assurance and cost savings.
Savings Plans Overview
Savings Plans offer a flexible pricing structure that can reduce your bills by up to 72% compared to On-Demand rates, in exchange for a one- or three-year hourly spend commitment. AWS provides three types of Savings Plans: Compute Savings Plans, EC2 Instance Savings Plans, and Amazon SageMaker Savings Plans.
With EC2 Instance Savings Plans, you commit to an hourly spend for a specific instance family and region (e.g., M5 in N. Virginia) for one or three years. Discounts apply automatically to instances launched within the chosen family and region, regardless of size or operating system. The maximum discount of up to 72% is available through EC2 Instance Savings Plans.
Compute Savings Plans offer even greater flexibility, allowing you to change instance types, migrate workloads between regions, or transition to AWS Fargate or AWS Lambda, all while retaining the discounted pricing. If you’re currently using EC2 and plan to modernize your applications by incorporating AWS Fargate or AWS Lambda, evaluating Compute Savings Plans is advisable. This plan allows for seamless transitions that align with your evolving architectural needs while providing savings of up to 66%. By combining On-Demand Capacity Reservations with Compute Savings Plans, you can achieve capacity reservations, substantial discounts, and maximum operational flexibility.
While we recommend Savings Plans for their versatility, some AWS customers may still have existing Reserved Instances. If you’ve purchased Reserved Instances and want to ensure capacity reservations, you can merge On-Demand Capacity Reservations with Reserved Instances for both capacity assurance and discounts. As your Reserved Instances expire, transitioning to Savings Plans is advisable, as they offer similar savings along with enhanced flexibility.
For additional information on pricing examples for Savings Plans, refer to the Savings Plans documentation.
Zonal Reservations
Zonal reservations allow you to secure capacity in a specific AZ but require a one- or three-year commitment and apply to a predefined instance family. While zonal reservations offer some degree of capacity assurance, they lack the flexibility offered by Savings Plans. You cannot change the instance family or size, nor can you queue purchases for a future date. For these reasons, consider opting for Savings Plans and On-Demand Capacity Reservations, which provide comparable discounts with superior flexibility. If you currently have a zonal reservation, we suggest signing up for Savings Plans and On-Demand Capacity Reservations once your existing plan expires.
Utilizing Capacity Reservations and Savings Plans
You can provision capacity reservations through the AWS console, Command Line Interface (CLI), or Application Programming Interface (API). For detailed steps on how to provision On-Demand Capacity Reservations using the AWS console and CLI, consult the related documentation. Similarly, the documentation explains the process of purchasing Savings Plans.
Conclusion
In this article, we explored various options for capacity reservations and cost management for your vital workloads on EC2. For optimal flexibility and value, we recommend leveraging On-Demand Capacity Reservations alongside Savings Plans. If you have stable EC2 workloads that do not lend themselves to modernization, consider the insights shared by sources like SHRM and the excellent resource available at About Amazon. For additional perspectives on personality types in the workplace, check out this post on extroverts and introverts from Career Contessa.