When you stop a pay-as-you-go ECS instance in economical mode, you can save on compute costs while retaining its data and configuration. However, a successful restart depends on available instance inventory. During peak hours, an instance in economical mode may fail to restart due to insufficient inventory, which can disrupt your operations. This topic explains how to use a private pool to ensure successful restarts for instances in economical mode.
Procedure
In this example, you have a pay-as-you-go ECS instance, named Instance A, that is in economical mode. The goal is to ensure that you can restart this instance when needed.
Step 1: Set the private pool type of Instance A to Open
-
Go to ECS console - Instances.
In the upper-left corner of the page, select a region and resource group.
-
On the Instance page, click the target instance ID. Click All Actions in the upper-right corner, then search for and click Configure Private Pool.
-
In the Configure Private Pool dialog box, set Private Pool Type to Open and click OK.
Step 2: Create a matching private pool
-
Go to the Create Resource Reservation page.
-
Choose .
-
On the Resource Reservations tab, click Create Resource Reservation.
-
On the Create Resource Reservation page, configure the following parameters.
Parameter
Description
Region/Zone
Select the same region and availability zone as Instance A.
Resource Type
Select the same instance type as Instance A.
Reservation Type
Select Immediate Capacity Reservation.
Expiration Method
Select an option based on your business requirements.
This setting defines the duration of the capacity guarantee.
Private Pool Type
Select Open.
-
After you configure the parameters, click Next: Preview and follow the on-screen instructions to create the Immediate Capacity Reservation.
-
On the Resource Reservations page, click the Private Pools tab. Find the private pool you created and click Details in the Actions column.
-
Verify the association between the instance and the private pool.
On the resource reservation details page, you can see that Instance A is automatically associated with the private pool. This ECS instance can now be stopped and restarted regardless of the available instance inventory.
The status of the associated instance is displayed as Stopped (Not occupying capacity), the private pool status is Reservation in effect, and the available quantity is 1 (0 used out of a total of 1).
FAQ
-
Can I create multiple Immediate Capacity Reservations?
Yes. There is no limit on the number of Immediate Capacity Reservations that you can create. While the reservation is active, you can use the reserved capacity as many times as needed to start your instances.
-
If my Immediate Capacity Reservation is for only one instance, how can I guarantee successful restarts for three instances in economical mode?
If you have three ECS instances and want to ensure that at least one can restart—but you are not sure which one—set the Private Pool Type for all three instances to Open. This allows all three instances to match the resource reservation.
However, because the reservation is for a single instance, it guarantees a restart for only one instance at a time. After one instance restarts and consumes the reservation, the other two instances lose their restart guarantee. If all three instances are stopped, any one of them can use the reservation to restart successfully.