Scheduler: Normalize Weights (initial work only)
See description on https:/
Blueprint information
- Status:
- Complete
- Approver:
- Andrew Laski
- Priority:
- Low
- Drafter:
- Alvaro Lopez
- Direction:
- Approved
- Assignee:
- Alvaro Lopez
- Definition:
- Approved
- Series goal:
- Accepted for icehouse
- Implementation:
- Implemented
- Milestone target:
- 2014.1
- Started by
- Alvaro Lopez
- Completed by
- John Garbutt
Related branches
Related bugs
Sprints
Whiteboard
Gerrit topic: https:/
Addressed by: https:/
Normalize the scheduler weights instead of using raw values.
Addressed by: https:/
Modify RAM weigher so that it can be percentage based
Addressed by: https:/
Use stacking flags instead of negative multipliers in weighers
Addressed by: https:/
Remove mute_weight_value option on mute child weigher
I had marked this approved last cycle, but it has been long enough since I looked over it that I'd like someone (me or someone else) to go back through this before approving for Icehouse. --russellb
The feature makes sense, and should help simplify some things for deployers. Because it does change the meanings of multipliers that could be configured already I think there needs to be some documentation on what this means for upgrades. --alaski
@alaski: Yes, I do agree. The impact in the scheduler is low, since there is only one weigher, but things change in the cells scheduler. Where should I put that documentation? In the commit itself? In the BP wiki page?
I think you should add it to the BP wiki page, but then also on each commit as it makes sense. An overall plan on the BP would be helpful, and I'm happy to approve this when that's done. And then by adding a DocImpact tag on commit messages with targeted information it will help the docs contributors know what to update. --alaski
@alaski: Each commit has its own DocImpact tag with the possible impact in existing deployments. I will add them to the wiki page.
changes punted to Juno:
==============
44255
Modify RAM weigher so that it can be percentage based
36417
Use stacking flags instead of negative multipliers in weighers
55873
Remove mute_weight_value option on mute child weigher
Apologies, this missed the deadline for Feature Freeze. Marking this one as Implemented, due to the upgrade impact, so please open a new blueprint for the remaining patches. Please rebase patches as soon as Juno opens, and we will try to get this in during that period. --johnthetubaguy (5th March 2014)
Done in https:/
Upgrade impact of merged changes:
=============
Addressed by: https:/
Normalize the scheduler weights instead of using raw values.
This has an upgrade impact:
* Weights are normalized, so there is no need to inflate multipliers
artificially. The maximum weight that a weigher will put for a node is 1.0
and the minimum is 0.0.
* nova.cells.
configuration option 'offset_
Addressed by: https:/
Propose: Normalize Weights (adapt weighers)
Addressed by: https:/
Propose: Implement percentage-based RAM Weigher
Work Items
Work items:
[aloga] Refactor weights.BaseWeigher so that it is an ABC: DONE
[aloga] Adapt weighers to use the new weights.
[aloga] Implement weight normalization: DONE
[aloga] Introduce stacking flags for the weighers that neede them: POSTPONED
[aloga] Remove unecessary options from weighers: POSTPONED
[aloga] Add RamWeigher so that percentages can be used instad of absolute values: POSTPONED
Dependency tree
* Blueprints in grey have been implemented.