Starting today, you can proactively manage the EC2 Spot Instance lifecycle by using the new Capacity Rebalancing feature for Amazon EC2 Auto Scaling, EC2 Fleet, and Spot Fleet. Capacity Rebalancing helps you maintain workload availability by proactively augmenting your fleet with a new Spot Instance before a running instance receives a two-minute interruption notice. Previously, EC2 Auto Scaling, EC2 Fleet, and Spot Fleet replaced Spot Instances only after they were interrupted. Now, with Capacity Rebalancing, these services attempt to proactively replace Spot Instances when they receive the new EC2 Instance rebalance recommendation, rather than waiting until they receive a two-minute in interruption notice.
Source:: Amazon AWS