Current Series Release Notes

14.0.0-5

Bug Fixes

• Added a new config option [workarounds]optimize_for_wide_provider_trees. It is disable by default.

  As reported in bug #2126751 in the situation where many similar child provider is defined under the same root provider, placement’s allocation candidate generation algorithm scales poorly. This config option enables certain optimizations that help decrease the time it takes to generate the GET /allocation_candidates response for queries requesting multiple resources from those child providers.

  It should be enabled if you have at least 8 child resource providers within a tree providing inventory of the same resource class. And you are trying to support VMs with more than 4 such resources. E.g.:

  • Nova’s PCI in Placement feature is enabled and you have at least 8 PCI devices with the same product_id in a single compute and you are using flavors requesting more than 4 such devices.

  • Nova’s GPU support is enabled and you have at least 8 GPUs per compute node while requesting more than 4 per VM.

  You can keep it disabled if you have a flat resource provider tree, i.e. all resources reported on the root provider. Or if your flavors are not requesting more than 4 PCI or GPU resources of the same type.