[Openstack] [Heat] Autoscaling, scale VMs on different hosts
deepthi at linux.vnet.ibm.com
Mon Dec 8 15:07:25 UTC 2014
On 12/08/2014 08:13 AM, Qiming Teng wrote:
> On Fri, Dec 05, 2014 at 04:13:49PM +0530, Deepthi Dharwar wrote:
>> Hi all,
>> I have been using the autoscaling HOT template and have been successful
>> in running it. I do see number of VMs increasing and decreasing based on
>> my scaling metrics. However, I do have one extra requirement, i.e deploy
>> the VM on a different host.
>> The scenario being, if I have a VM1 running on a particular host1 and
>> when comes a need to scale up based on the metrics, I want the new VM2
>> to be deployed on a different host i.e host2.
>> Scheduler does provide a filter i.e DifferentHostFilter, where one can
>> deploy an instance on a different host from a set of instances. However
>> to provide this as a part of scheduler hint in the HOT template, one
>> would need the UUID of previous spawned VM. Is there a way to get this
>> data via the HOT template and also pass it as different_host hint for
>> the new VM ?
> If Nova forces you to specify a UUID of an existing VM when providing a
> scheduler hint, that means it is not a good interface IMO. Personally,
> I would prefer the Nova server-group APIs on which have been quite some
> disbutes whether they belong to Nova.
>> So, if I have 2 hosts and have my webserver VM1 running on the host1,
>> ideally i would want VM2 webserver to be running on host2.
>> Is there an elegant way to achieve this ?
> I don't know an easy way to do this today though I can feel the need to
> support this in future. Basically, there are discrete policies that can
> be associated with a group of resources, i.e. creation-policy,
> scheduling-policy, termination-policy, availability-policy, ... to name
> a few. There is a work thread on improving this , but users have to
> be patient at the moment.
Thank you for the pointers.
>> Please help!
> Mailing list: http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack
> Post to : openstack at lists.openstack.org
> Unsubscribe : http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack
More information about the Openstack