AWS Spot Instances let users purchase unused Amazon EC2 compute capacities. In other words, spot instances are spare computing capacity that Amazon sells at a massive discount to drive usage. However, in only two minutes, these instances could be terminated and reclaimed for other workloads. This means the application must be fault-tolerant and flexible to handle interruptions in compute availability.
Why use EC2 Spot Instances?
Depending on the selected EC2 instance type, AWS Region, and Availability Zone, AWS claims that Spot Instances can offer a 90 percent cost reduction compared to on-demand pricing.
What is Spot Fleet?
Spot Fleet is a collection of Spot Instances that attempts to maintain the capacity specified by customers. This way, you can run your application on different instance types and save on costs.
Use cases
Spot Instances are preferred for workloads that are not time-sensitive or bound by SLA requirements, including:
Machine learning
Hadoop data processing
Image rendering
Big Data analytics
CI/CD operations
Add customized tags to individual spot instances, and track costs using CloudSpend.