nova/releasenotes/notes/bp-num_instances_weigher-bba342c82aac5509.yaml
Sylvain Bauza ca3fbb4d15 Add a new NumInstancesWeigher
Despite having a NumInstancesFilter, we miss a weigher that would classify hosts
based on their instance usage.

Change-Id: Id232c2caf29d3443c61c0329d573a34a7481fd57
Implements-Blueprint: bp/num-instances-weigher
2023-07-21 15:50:57 +02:00

14 lines
741 B
YAML

---
features:
- |
A new `num_instances_weigher` weigher has been added. This weigher will
compare the number of instances between each node and order the list of
filtered results by its number, By default, this weigher is enabled but with
a default of 0.0 which doesn't change the current behavior.
In order to use it, please change the value of
``[filter_scheduler]/num_instances_weight_multiplier`` config option where
a positive value will favor the host with the higher number of instances
(ie. packing strategy) vs. a negative value that will spread instances
between hosts. As a side note, this weigher will count *all* of the existing
instances on the host, even the stopped or shelved ones.