The replacement is one of the most common processes in an Elastigroup.
What triggers an instance replacement:
- Predicting an interruption - using our prediction algorithms, identify instance failures and preemptively provision a replacement instance.
- Fixing Strategy - in case the instance On-Demand count of the group is higher than the spot risk percentage/OD Count configuration and the relevant market has spots available, a replacement will be triggered to gracefully switch the instance back to a spot.
- Unhealthy instance - when the Auto-Healing feature is enabled - Auto Healing allows you to select which health check service will automatically perform health checks on your EC2 instances. If an instance fails the health check, it is automatically replaced with a new instance.
Spotinst Prediction process:
Fix strategy process: