Allow having placement inventories with reserved value equal to total¶
https://blueprints.launchpad.net/nova/+spec/allow-reserved-equal-total-inventory
Currently, we delete ironic node resource provider inventory from placement to indicate that the node is not available for deployment during the cleaning process or when in maintenance. This causes placement to report the incorrect inventory and capacity information, as the node is actually still present, and its inventory remains the same. Reserving all the inventory describes more accurately what is going on. Also doing the resource reservation will allow us to fix bugs like [1] properly, as it is possible to set reservation for inventory before deleting the allocation, even if inventory gets exceeded because of that. But placement API does not allow to set reserved value to be equal to total in the inventory record.
Problem description¶
Placement API does not allow to set reserved value to be equal to total in the inventory record. This makes ironic virt driver to delete inventory records from placement e.g. during node cleaning instead of reserving them.
Deleting resource provider inventory should mean that it is actually gone.
For purposes of indicating that resources are temporarily unavailable
placement provides the reserved field in the inventory object. This will
enable placement to report the correct inventory and capacity information.
It will also enable us to fix ironic virt driver issue [1].
Use Cases¶
Reserve ironic node inventory during node cleaning or maintenance.
Reserve FPGA inventory during its programming by cyborg.
Proposed change¶
Add a new microversion to placement API that will allow to set reserved value of the inventory record to be equal to total value. It will become the placement behaviour for all subsequent microversion.
This new microversion will be used by nova scheduler report client when
doing the inventory update calls. This will enable virt drivers in nova
to decide whether they need to report all the inventory resources as reserved
in the get_inventory() call.
Alternatives¶
None
Data model impact¶
None
REST API impact¶
POST /resource_providers/<UUID>/inventories,
PUT /resource_providers/<UUID>/inventories and
PUT /resource_providers/<UUID>/inventories/<RC> API endpoints will return
response code 200 instead of 400 when called with
new microversion and body containing inventory records that have reserved
value equal to total.
Example request:
path – PUT /resource_providers/UUID/inventories
- headers –
Content-type: application/json, Openstack-API-Version: placement 1.NEW_MV
body:
{
"inventories": {
"CUSTOM_GOLD": {
"total": 1,
"reserved": 1
}
},
"resource_provider_generation": 5
}
Example response:
200 OK
Security impact¶
None
Notifications impact¶
None
Other end user impact¶
None
Performance Impact¶
None
Other deployer impact¶
None
Developer impact¶
Virt drivers now are able to set the reserved key in the
get_inventory() returned dictionary to a total inventory value when needed.
Upgrade impact¶
None
Implementation¶
Assignee(s)¶
- Primary assignee:
vdrok
Work Items¶
change to placement API adding the logic and new microversion
change scheduler report client to use the new microversion during inventory update calls
change ironic virt driver to report resources as reserved during cleaning and maintenance
Dependencies¶
None
Testing¶
Unit and functional testing will be added.
Documentation Impact¶
API reference will be updated.
References¶
History¶
Release Name |
Description |
|---|---|
Rocky |
Introduced |
