Hi all, In Mirantis Alexey Ovtchinnikov and me are working on nova scheduler improvements. As far as we can see the problem, now scheduler has two major issues: 1) Scalability. Factors that contribute to bad scalability are these: *) Each compute node every periodic task interval (60 sec by default) updates resources state in DB. *) On every boot request scheduler has to fetch information about all compute nodes from DB. 2) Flexibility. Flexibility perishes due to problems with: *) Addiing new complex resources (such as big lists of complex objects e.g. required by PCI Passthrough https://review.openstack.org/#/c/34644/5/nova/db/sqlalchemy/models.py) *) Using different sources of data in Scheduler for example from cinder or ceilometer. (as required by Volume Affinity Filter https://review.openstack.org/#/c/29343/) We found a simple way to mitigate this issues by avoiding of DB usage for host state storage. A more detailed discussion of the problem state and one of a possible solution can be found here: https://docs.google.com/document/d/1_DRv7it_mwalEZzLy5WO92TJcummpmWL4NWsWf0UWiQ/edit# Best regards, Boris Pavlovic Mirantis Inc. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.openstack.org/pipermail/openstack-dev/attachments/20130719/319a3fa8/attachment.html>