I like what you proposed in the blueprint. I totally agree that nova-scheduler needs finer granularity in its usage of filters and weighers. Our objective is thus very similar.
Our approach is little different. Since flavors are choices of clients, and aggregates are selected during host selection (which comes after filters), we choose to separate the policies from flavors and aggregates and put them into a Policy Repository (a database or a simple file). The Policy-based Scheduler then looks at the Repo first to know which policy applied to which target (aggregates, tenants, etc). It is an extensible architecture: It allows to customize policies and plug other solutions easily. The policy may be as simple as to apply, like in your proposal, a filter (policy -> (filter + aggregate)), a weigher, a combination of them or a completely new driver, say a new scheduling solution. Currently we're working on an implementation of the blueprint which allows only admin to set up policies, but I also like the idea of letting client say their preferences (e.g. preferred availability-zone, anti-affinity, choice between silver-class or gold-class service). It is a question of philosophy. Best regards, Toan Global archi: https://docs.google.com/document/d/1gr4Pb1ErXymxN9QXR4G_jVjLqNOg2ij9oA0JrLwMVRA ---------- Message original -------- Sujet: Re: [openstack-dev] [nova][scheduler] A new blueprint for Nova-scheduler: Policy-based Scheduler Date : Wed, 16 Oct 2013 14:38:38 +0300 De : Alex Glikson <glik...@il.ibm.com> Répondre à : OpenStack Development Mailing List <openstack-dev@lists.openstack.org> Pour : OpenStack Development Mailing List <openstack-dev@lists.openstack.org> This sounds very similar to https://blueprints.launchpad.net/nova/+spec/multiple-scheduler-drivers We worked on it in Havana, learned a lot from feedbacks during the review cycle, and hopefully will finalize the details at the summit and will be able to continue & finish the implementation in Icehouse. Would be great to collaborate. Regards, Alex From: Khanh-Toan Tran <khanh-toan.t...@cloudwatt.com> To: openstack-dev@lists.openstack.org, Date: 16/10/2013 01:42 PM Subject: [openstack-dev] [nova][scheduler] A new blueprint for Nova-scheduler: Policy-based Scheduler Dear all, I've registered a new blueprint for nova-scheduler. The purpose of the blueprint is to propose a new scheduler that is based on policy: https://blueprints.launchpad.net/nova/+spec/policy-based-scheduler With current Filter_Scheduler, admin cannot change his placement policy without restarting nova-scheduler. Neither can he define local policy for a group of resources (say, an aggregate), or a particular client. Thus we propose this scheduler to provide admin with the capability of defining/changing his placement policy in runtime. The placement policy can be global (concerning all resources), local (concerning a group of resources), or tenant-specific. Please don't hesitate to contact us for discussion, all your comments are welcomed! Best regards, Khanh-Toan TRAN Cloudwatt Email: khanh-toan.tran[at]cloudwatt.com 892 Rue Yves Kermen 92100 BOULOGNE-BILLANCOURT FRANCE _______________________________________________ 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
