Update a capacity of reserved resource¶

Problem description¶

The start date and the end date of a lease can be updated through the update lease request. However, the capacity of reserved resource cannot be changed once the reservation is created for now. The capacity should be able to be changed for improving the flexibility of resource usage requests.

Proposed change¶

The update_reservation() method of a resource plugin currently checks only the start_date and end_date of the request body. Change it to check other parameters, e.g., min, max, hypervisor_properties and resource_properties for the host plugin. And enable the update_reservation() method to update allocations.

The update_reservation() succeeds if all of the request parameters can be satisfied. Otherwise, it raises exceptions.

First target is the host plugin. For the host plugin, min, max, hypervisor_properties and resource_properties can be updated if an update request satisfies all of following conditions:

• Enough resources are available for the new request.
• Any host does not removed from the aggregate associated with the lease if the lease has already started. This condition is needed for preventing unexpected deletion and error of instances on the reserved host.

Otherwise, Blazar returns an error and nothing is updated.

Implementation¶

Dependencies¶

None

Testing¶

• Adds unit tests of update capacity request for the the update_reservation() method
• Adds scenario test of update capacity request

Documentation Impact¶

Write a release note.

References¶

1. Capacity management development proposal: http://git.openstack.org/cgit/openstack/development-proposals/tree/development-proposals/proposed/capacity-management.rst

History¶