Configuring Spot Optimization
The Spot Optimization panel on the Resource edit page is used to define the desired Spot configuration for an Auto Scale group resource.
In the panel, you can specify either the desired Spot capacity or the desired On-Demand capacity. If you specify the Spot capacity, On-Demand servers will be used for the remainder up to the Auto Scale Group desired number of instances and vice-versa.
You can specify the desired number or percentage of servers. Using a percentage is preferred as it will scale automatically if the total desired number of instances is changed. If you specify a number that exceeds the Scale Current Configuration value for the "Desired" number of instances, it will have no effect beyond the specified "Desired" value.
Note: Don't forget to enable the Enable Spot Optimization checkbox.
Drain Current Requests
Before terminating an instance, it may be necessary to first complete current requests. The Drain Delay field is used to specify a time in seconds to wait before terminating an instance. The default is 20 seconds.
Spot Optimizer with Schedules
PowerDown schedules provide the ability to power down idle or unused cloud resources according to a dynamic schedule. As resources are billed by your cloud provider, by the second, powering down idle resources can significantly lower your cloud costs.
When powering down an Auto Scale group, you can specify how many servers to run for the powered up and powered down states. This includes the number or percentage of Spot or On-Demand servers to use. This is useful when you wish to maintain some level of service when "powered down".
Enter the desired number or percentage of Spot or On-Demand servers in the relevant "Powering Up" and "Powering Down" section of the Scaling panel.