Cloud resources are automatically discovered by PowerDown and can be started and stopped individually as required. However, it is often convenient to group resources together into a persistent logical group so that member resources can be be powered up or down together.
Resource Groups are an ordered collection of resources and other resource groups that can be managed as a unit.
A resource group depends on other "physical" resources or other resource groups. When you create or modify a resource group, you can specify these dependencies as the group members.
Dependencies can be specified by name or by matching tags. If you specify by name, the dependent resource must continue to exist. If you specify by tag, the set of dependent resources is "dynamic" in that over time, different resources may match those tags and be selected.
When the resource group is powered up or down, a corresponding action is applied to each resource group member in order. If a resource group member is a group itself, then its members will receive the same action. That action is applied in dependency order to the group members and then to the group itself when powering up. The power down sequence is the reverse order.
Please consult the Create Resource Group documentation for details about configuring resource dependencies.
When creating a resource group, you specify the cloud credential that defines the set of resources that can be a member of the group.