There are roughly three cases. 1. Multiple identical instances of the scheduler service. This is typically done to increase scalability, and is already supported (although sometimes may result in provisioning failures due to race conditions between scheduler instances). There is a single queue of provisioning requests, all the scheduler instances are subscribed, and each request will be processed by one of the instances (randomly, more or less). I think this is not the option that you referred to, though. 2. Multiple cells, each having its own scheduler. This is also supported, but is applicable only if you decide to use cells (e.g., in large-scale geo-distributed deployments). 3. Multiple scheduler configurations within a single (potentially heterogeneous) Nova deployment, with dynamic selection of configuration/policy at run time (for simplicity let's assume just one scheduler service/runtime). This capability is under development ( https://review.openstack.org/#/c/37407/) , targeting Havana. The current design is that the admin will be able to override scheduler properties (such as driver, filters, etc) using flavor extra specs. In some cases you would want to combine this capability with a mechanism that would ensure disjoint partitioning of the managed compute nodes between the drivers. This can be currently achieved by using host aggregates and AggregateInstanceExtraSpec filter of FilterScheduler. For example, if you want to apply driver_A on hosts in aggregate_X, and dirver_B on hosts in aggregate_Y, you would have flavor AX specifying driver_A and properties that would map to aggregate_X, and similarly for BY.
Hope this helps. Regards, Alex From: sudheesh sk <sud...@yahoo.com> To: "openstack-dev@lists.openstack.org" <openstack-dev@lists.openstack.org>, Date: 13/08/2013 10:30 AM Subject: [openstack-dev] Can we use two nova schedulers at the same time? Hi, 1) Can nova have more than one scheduler at a time? Standard Scheduler + one custom scheduler? 2) If its possible to add multiple schedulers - how we should configure it. lets say I have a scheduler called 'Scheduler' . So nova conf may look like below scheduler_manager = nova.scheduler.filters.SchedulerManager scheduler_driver = nova.scheduler.filter.Scheduler Then how can I add a second scheduler 3) If there are 2 schedulers - will both of these called when creating a VM? I am asking these questions based on a response I got from ask openstack forum Thanks, Sudheesh_______________________________________________ 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
