Control spending
Spot Fleet stops launching instances when it has either reached the target capacity or
the maximum amount you’re willing to pay. To control the amount you pay per hour for
your fleet, you can specify the SpotMaxTotalPrice
for Spot Instances and the
OnDemandMaxTotalPrice
for On-Demand Instances. When the maximum total price is
reached, Spot Fleet stops launching instances even if it hasn’t met the target
capacity.
The following examples show two different scenarios. In the first, Spot Fleet stops launching instances when it has met the target capacity. In the second, Spot Fleet stops launching instances when it has reached the maximum amount you’re willing to pay.
Example: Stop launching instances when target capacity is reached
Given a request for m4.large
On-Demand Instances, where:
-
On-Demand Price: $0.10 per hour
-
OnDemandTargetCapacity
: 10 -
OnDemandMaxTotalPrice
: $1.50
Spot Fleet launches 10 On-Demand Instances because the total of $1.00 (10 instances x $0.10) does not
exceed the OnDemandMaxTotalPrice
of $1.50.
Example: Stop launching instances when maximum total price is reached
Given a request for m4.large
On-Demand Instances, where:
-
On-Demand Price: $0.10 per hour
-
OnDemandTargetCapacity
: 10 -
OnDemandMaxTotalPrice
: $0.80
If Spot Fleet launches the On-Demand target capacity (10 On-Demand Instances), the total cost per
hour would be $1.00. This is more than the amount ($0.80) specified for
OnDemandMaxTotalPrice
. To prevent spending more than you're willing
to pay, Spot Fleet launches only 8 On-Demand Instances (below the On-Demand target capacity) because
launching more would exceed the OnDemandMaxTotalPrice
.