Open Stack

I have one quick question regarding the 3rd point you have mentioned (Multiple scheduler configurations
within a single (potentially heterogeneous) Nova deployment)

In this case ultimately when a VM is created - would it have gone through all the schedulers or just one scheduler which was dynamically selected?
Is there any chance of having 2 schedulers  impacting creation of one VM?


Thanks,
Sudheesh

________________________________
 From: Alex Glikson <GLIKSON at il.ibm.com>
To: sudheesh sk <sudh03 at yahoo.com>; OpenStack Development Mailing List <openstack-dev at lists.openstack.org> 
Sent: Tuesday, 13 August 2013 1:45 PM
Subject: Re: [openstack-dev] Can we use two nova schedulers at the same time?
 


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 <sudh03 at yahoo.com> 
To:      
 "openstack-dev at lists.openstack.org"
<openstack-dev at 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 at lists.openstack.org
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