Hi Sylvain,
1) Some Filters such as AggregateCoreFilter, AggregateRAMFilter can change its parameters for aggregates. But what if admin wants to change for all hosts in an availability-zone? Does he have to rewrite all the parameters in all aggregates? Or should we create a new AvailabilityZoneCoreFilter? The Policy Based Scheduler (PBS) blueprint separates the effect (filter according to Core) from its target (all hosts in an aggregate, or in an availability-zone). It will benefit all filters, not just CoreFilter or RAMFilter, so that we can avoid creating for each filter XFilter the AggregateXFilter and AvailabilityZoneWFilter from now on. Beside, if admin wants to apply the a filter to some aggregates (or availability-zone) and not the other (dont call filters at all, not just modify parameters), he can do it. It help us avoid running all filters on all hosts. 2) In fact, we also prepare for a separated scheduler in which PBS is a very first step of it, thats why we purposely separate the Policy Based Scheduler from Policy Based Scheduling Module (PBSM) [1] which is the core of our architecture. If you look at our code, you will see that Policy_Based_Scheduler.py is only slightly different from Filter Scheduler. That is because we just want a link from Nova-scheduler to PBSM. Were trying to push some more management into scheduler without causing too much modification, as you can see in the patch . Thus Im very happy when Gantt is proposed. As I see it, Gantt is based on Nova-scheduler code, with the planning on replacing nova-scheduler in J. The separation from Nova will be complicated, but not on scheduling part. Thus integrating PBS and PBSM into Gantt would not be a problem. Best regards, [1] https://docs.google.com/document/d/1gr4Pb1ErXymxN9QXR4G_jVjLqNOg2ij9oA0JrL wMVRA Toan De : Sylvain Bauza [mailto:sylvain.ba...@gmail.com] Envoyé : jeudi 30 janvier 2014 11:16 À : OpenStack Development Mailing List (not for usage questions) Objet : Re: [openstack-dev] [Nova][Scheduler] Policy Based Scheduler and Solver Scheduler Hi Khanh-Toan, I only have one comment on your proposal : why are you proposing something new for overcommitments with aggregates while the AggregateCoreFilter [1] and AggregateRAMFilter [2]already exist, which AIUI provide same feature ? I'm also concerned about the scope of changes for scheduler, as Gantt is currently trying to replace it. Can we imagine such big changes to be committed on the Nova side, while it's planned to have a Scheduler service in the next future ? -Sylvain [1] https://github.com/openstack/nova/blob/master/nova/scheduler/filters/core_ filter.py#L74 [2] https://github.com/openstack/nova/blob/master/nova/scheduler/filters/ram_f ilter.py#L75 2014-01-30 Khanh-Toan Tran <khanh-toan.t...@cloudwatt.com> There is an unexpected line break in the middle of the link, so I post it again: https://docs.google.com/document/d/1RfP7jRsw1mXMjd7in72ARjK0fTrsQv1bqolOri <https://docs.google.com/document/d/1RfP7jRsw1mXMjd7in72ARjK0fTrsQv1bqolOr iIQB2Y> IQB2Y > -----Message d'origine----- > De : Khanh-Toan Tran [mailto:khanh-toan.t...@cloudwatt.com] > Envoyé : mercredi 29 janvier 2014 13:25 > À : 'OpenStack Development Mailing List (not for usage questions)' > Objet : [openstack-dev] [Nova][Scheduler] Policy Based Scheduler and Solver > Scheduler > > Dear all, > > As promised in the Scheduler/Gantt meeting, here is our analysis on the > connection between Policy Based Scheduler and Solver Scheduler: > > https://docs.google.com/document/d/1RfP7jRsw1mXMjd7in72ARjK0fTrsQv1bq > olOri > IQB2Y > > This document briefs the mechanism of the two schedulers and the possibility of > cooperation. It is my personal point of view only. > > In a nutshell, Policy Based Scheduler allows admin to define policies for different > physical resources (an aggregate, an availability-zone, or all > infrastructure) or different (classes of) users. Admin can modify > (add/remove/modify) any policy in runtime, and the modification effect is only > in the target (e.g. the aggregate, the users) that the policy is defined to. Solver > Scheduler solves the placement of groups of instances simultaneously by putting > all the known information into a integer linear system and uses Integer Program > solver to solve the latter. Thus relation between VMs and between VMs- > computes are all accounted for. > > If working together, Policy Based Scheduler can supply the filters and weighers > following the policies rules defined for different computes. > These filters and weighers can be converted into constraints & cost function for > Solver Scheduler to solve. More detailed will be found in the doc. > > I look forward for comments and hope that we can work it out. > > Best regards, > > Khanh-Toan TRAN > > > _______________________________________________ > OpenStack-dev mailing list > OpenStack-dev@lists.openstack.org > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev _______________________________________________ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
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