The Spot Instance request type.
A one-time Spot Instance request remains active until Amazon EC2 launches the Spot Instance, the request expires, or you cancel the request.
If the Spot price exceeds your maximum price or capacity is not available, your Spot Instance is terminated and the Spot Instance request is closed.
A persistent Spot Instance request remains active until it expires or you cancel it, even if the request is fulfilled.
If the Spot price exceeds your maximum price or capacity is not available, your Spot Instance is interrupted. After your instance is interrupted, when your maximum price exceeds the Spot price or capacity becomes available again, the Spot Instance is started if stopped or resumed if hibernated.