To configure an automatic response to changing demands for resources, you can scale out VMs, which is also called horizontal autoscaling. To scale out, the platform clones the base VM and deploys the clones. To scale in, the platform will delete clone VMs but it will just undeploy the base VM. Scaling operations are subject to all standard platform constraints, such as privileges and allocation limits.
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Privilege: Manage scaling groups, Manage workflow for scaling groups |
To use autoscaling do these steps:
Before you begin:
To create a scaling group:
When you save the scaling group, Abiquo will mark the VM icon with the scaling group symbol and display the scaling group name. If the minimum number of deployed VMs are not present and the scaling group is not in maintenance, Abiquo will create clones of the base machine and deploy them to reach the minimum size. The number in the bottom right-hand corner of the icon is the number of running VMs in the scaling group, including the base machine.
To open the scaling group and check its parameters, click the scaling group symbol in the top right-hand corner of the VM icon.
To trigger autoscaling operations, create an action plan with a scaling action for the VM with the scaling group. Then create triggers to run the action plan. See Manage Action Plans. When scaling, the platform will search for a rule that is valid for the specific time range, or for a default rule. It will create or delete/undeploy the number of VMs in the rule, then wait for the cooldown period before accepting another scaling request.
To scale out, the platform does not deploy VMs that are undeployed in the scaling group. To clone the base VM, the platform will do the following:
To scale in, Abiquo currently selects the VMs to delete or undeploy using first in, first out (FIFO). The platform deletes and undeploys VMs without requesting user confirmation when there are disks that are not stored in the Apps library (ISO configuration drive or additional hard disk).
Maintenance mode temporarily disables autoscaling and enables you to make changes to your VMs (deploy, undeploy, delete etc.) and edit the scaling group. Note that you cannot delete the base VM without deleting the scaling group. Also you cannot create alarms for cloned VMs that are part of a scaling group, because the scaling group alarms are in the base VM. When you leave maintenance mode, Abiquo will apply your modifications to the scaling group, e.g. adding new rules. Then Abiquo will adjust the number of VMs in the group to within the minimum and maximum size range.
To restrict a scaling group, move the scaling group to a restricted virtual appliance, by selecting the Restrict scaling group checkbox, or by selecting a restricted virtual appliance.
When you delete a scaling group, Abiquo will place all the VMs in the virtual appliance as regular VMs and the scaling group constraints will no longer exist. To delete a scaling group, first put it into maintenance mode, then click the delete button.