Open Stack

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 <GLIKSON at il.ibm.com>
Répondre à : OpenStack Development Mailing List
<openstack-dev at lists.openstack.org>
Pour : OpenStack Development Mailing List
<openstack-dev at 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.tran at cloudwatt.com>
To:     openstack-dev at 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 at lists.openstack.org
http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev