Overview
An instance fleet is a configuration that enables you to launch a group of EC2 instances with a variety of instance types. Unlike autoscaling groups that usually deploy similar instance types (for example, multiple T2_micro instances), an instance fleet offers the flexibility to mix different types—such as T2_micro, T3_medium, or M-series—to match your application’s needs.An instance fleet not only allows the use of multiple instance types but also supports integrating different purchasing options (spot, reserved, and on-demand) in one unified configuration.
How Instance Fleets Work
Think of an instance fleet as a military fleet where a primary ship is supported by smaller vessels. Similarly, AWS instance fleets allow you to mix and match various EC2 instances. This setup lets you define separate capacity targets for on-demand and spot instances, ensuring that you can fine-tune your infrastructure based on both performance requirements and cost-effectiveness.
Use Case: AWS EMR
A common use case for instance fleets is with AWS EMR (Elastic MapReduce). When processing large-scale data, the flexibility to blend different EC2 instance types and pricing models allows you to optimize for performance and cost simultaneously.Benefits of Using Instance Fleets
| Feature | Benefit | Example Use Case |
|---|---|---|
| Mixed Instances | Deploy various EC2 instance types in one fleet | Running heterogeneous workloads in an EMR cluster |
| Flexible Purchasing | Combine on-demand, reserved, and spot instances seamlessly | Cost optimization based on real-time market pricing |
| Fine-Tuned Capacity | Define specific targets for instance types and purchasing models | Customizing capacity to meet specific application needs |