EC2 Spot Fleet Interruption behavior with Capacity rebalance 'Launch before Terminate' strategy

Question

While requesting a fleet, I select Maintain request type with termination behavior Hibernation and then choose Capacity rebalance with "Launch before Terminate" Replacement strategy .. The "Launch before Terminate" option in the console describes it as "Replacement instances will be launched and instances marked for rebalance will be automatically terminated after the termination delay " if this strategy always terminates is there any significance of what is chosen as the interruption behavior ?

spot_fleet

![spot_fleet](/media/postImages/original/IMN5NOPz6qTnC9reLg8CD8vg)

Answer

Hello,

When employing the "Launch before Terminate" replacement strategy alongside a capacity rebalance, the choice of interruption behaviour has minimal impact, as instances flagged for the termination will proceed with termination after the specified delay period, regardless of the selected interruption behaviour.

In other words, the interruption behaviour doesn't change the result when using "Launch before Terminate". The marked instances will terminate after the delay to ensure available replacement capacity. The selection only impacts what state the instances enter temporarily during the delay period, but they will terminate in the end regardless

Thanks

EC2 Spot Fleet Interruption behavior with Capacity rebalance 'Launch before Terminate' strategy

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