4.3.3.
Capacity Management
Up one level
The service provider may optionally define the size/quantity of the resources they wish to provide: their "capacity". New SLAs will then be agreed up to the point where the entire capacity has been allocated. This is most obviously necessary for disc space, where a service provider has a finite amount of disc space and will probably want to guarantee each of its customers a certain amount. If the service provider does not define the capacity then there will be no limit on the number of SLAs allocated to customers. This will in turn have an impact on the service provider's ability to fulfill resource commitments defined in their SLAs.
There are two ways to define the capacity:
- Upload an XML file defining the capacity.
- Use the capacity editor in the web page.
Uploading a Capacity Definition
A sample XML capacity definition is provided with the application. It can be downloaded from here or from the administration web page. The sample file defines the capacity to be 10 CPUs and 2GiB of disc space. This may be changed and extended according to the specific requirements of the service provider. The <constraint> elements in the file follow the same schema as those in the SLA template (described here), but must all be instantaneous indefinite constraints.
It is important to note that uploading a capacity definition will completely overwrite any existing definition.
Using the Capacity Editor
The capacity definition may be defined from scratch or edited using the built in capacity editor. Each constraint can be edited or deleted. When the service is first installed, no metrics are defined and so no capacity constraints can be defined either.
