I think Soren suggested this way back in Cactus to use MQ for compute node state rather than database and it was a good idea then. On Jul 19, 2013, at 10:52 AM, Boris Pavlovic <boris at pavlovic.me> wrote: > 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. > > _______________________________________________ > OpenStack-dev mailing list > OpenStack-dev at lists.openstack.org > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.openstack.org/pipermail/openstack-dev/attachments/20130719/cdc42869/attachment.html>