2.1 KiB
Capacity-based QoS
Include the URL of your launchpad blueprint:
https://blueprints.launchpad.net/cinder/+spec/capacity-based-qos
QoS values in Cinder currently are able to be set to static values. This work proposes a way to derive QoS limit values based on volume capacities rather than static values.
Problem description
This proposes a mechanism to provision IOPS on a per-volume basis with the IOPS values adjusted based on the volume's size. (IOPS per GB)
Use Cases
A deployer wishes to cap "usage" of this system to limits based on space usage as well as throughput, in order to bill customers and not exceed limits of the backend.
Associating IOPS and size allows you to provide tiers such as
Gold: 1000 GB at 10000 IOPS per GB Silver: 1000 GB at 5000 IOPS per GB Bronze: 500 GB at 5000 IOPS per GB
Proposed change
- Allow creation of qos_keys:
-
read_iops_sec_per_gb write_iops_sec_per_gb total_iops_sec_per_gb
These function the same as our current <x>_iops_sec keys, except they are scaled by the volume size.
Alternatives
None
Data model impact
None
REST API impact
None
Security impact
None
Notifications impact
None
Other end user impact
None
Performance Impact
None
Other deployer impact
New optional qos spec values.
Off by default, opt-in.
Developer impact
None
Implementation
Assignee(s)
- Primary assignee:
-
eharney
Work Items
Dependencies
Testing
Documentation Impact
Document new fields available in qos types.