Set a minimum number of spare instances to make available.

The idea is that up to the instance cap, there will always be this number of instances unused and waiting for builds.

This is different from the minimum number of instances, which only guarantees that n instances exist, not whether there is any available capacity.

If this value is set 1, there will be one instance available, then if that instance is used by a build, another will be provisoned. The idea being that there is always a waiting instance ready for an incoming build. If you have a high rate of incoming builds this value can be set higher.

Note that value is local to this specific AMI and associated configurations.

This setting is ignored while a cloud-level Hot spares by label rule matches one of the labels of this AMI, because such a rule owns the spare count for its whole label group. The minimum number of instances above is unaffected, and so is its time range: a rule holds no spares on this AMI outside the hours it is configured to keep instances in.