How to leverage the spot instances to optimise your EKS costs

Introduction

Welcome to the first part of our two-part series on using Spot EC2 Instances for EKS (Elastic Kubernetes Service) in AWS (Amazon Web Services). In this blog post, we will explore the idea of spot instances, their behavior, and cost efficiency, which make them an attractive choice for running workloads on EKS.

What are Spot EC2 Instances?

Spot instances are a type of Amazon EC2 instance that allows you to take advantage of unused EC2 capacity in the AWS cloud. These instances are available at up to a 90% discount compared to On-Demand prices, which can result in significant cost savings for running your workloads.

Spot instances are often used for workloads that can be interrupted, such as batch processing, big data analytics, machine learning training, or web services with flexible start and end times. They are also a great fit for stateless applications or applications that can quickly recover from interruptions.

Behavior of Spot Instances

Spot instances are subject to termination when the demand for computing capacity increases or when the Spot price goes above your maximum bid price. This means that your instances might be terminated with just a 2-minute notification, which can be disruptive for certain workloads. However, they are a great option for fault-tolerant and flexible applications that can handle such interruptions.

Cost Efficiency

The primary advantage of using spot instances is their cost efficiency. As mentioned earlier, spot instances can offer up to a 90% discount compared to On-Demand instances. This can lead to significant cost savings for your organization, especially if you are running workloads that can tolerate interruptions.

Spot instances can be further optimized by using spot fleets, which is a collection of Spot instances that are automatically launched and managed by AWS. Spot fleets enable you to define a target capacity and the desired mix of instance types, allowing you to optimize your costs and maintain workload availability even if some instances are terminated.

Integrating Spot Instances with EKS

EKS is an AWS-managed Kubernetes service that makes it easy to run containerized applications using Kubernetes. By using spot instances with EKS, you can optimize your costs while maintaining the flexibility, scalability, and resilience that Kubernetes provides. This is particularly advantageous for large-scale deployments, where cost savings can add up quickly. There is a huge benefit related to Spot instances but under specific circumstances, namely when using stateless services. In case of the mixed services the EKS cluster can be a hibrid, using the standard EC2 nodes with reservations for the statefull services like databases or message queues and Spot instances for the stateless services.

In the next part of this series, we will explore how to set up and manage spot instances with EKS, covering topics such as node groups, cluster autoscaling, and best practices for optimizing your spot instance usage.

Conclusion

Spot instances offer a cost-effective solution for running workloads on AWS, particularly for fault-tolerant and flexible applications. By integrating spot instances with EKS, you can optimize your costs while taking advantage of the robust features provided by Kubernetes. Stay tuned for the second part of this series, where we will dive deeper into the practical aspects of using spot instances with EKS.