[openstack-dev] [heat][ceilometer]: scale up/ down based on number of instances in a group

Daniel Comnea comnea.dani at gmail.com
Fri Apr 3 10:51:45 UTC 2015

Hi all,

Does anyone know if the above use case has made it into the convergence
project and in which release was/ is going to be merged?


On Tue, Oct 28, 2014 at 5:40 PM, Daniel Comnea <comnea.dani at gmail.com>

> Thanks all for reply.
> I have spoke with Qiming and @Shardy (IRC nickname) and they confirmed
> this is not possible as of today. Someone else - sorry i forgot his nicname
> on IRC suggested to write a Ceilometer query to count the number of
> instances but what @ZhiQiang said is true and this is what we have seen via
> the instance sample
> *@Clint - *that is the case indeed
> *@ZhiQiang* - what do you mean by "*count of resource should be queried
> from specific service's API*"? Is it related to Ceilometer's event types
> configuration?
> *@Mike - *my use case is very simple: i have a group of instances and in
> case the # of instances reach the minimum number i set, i would like a new
> instance to be spun up - think like a cluster where i want to maintain a
> minimum number of members
> With regards to the proposal you made -
> https://review.openstack.org/#/c/127884/ that works but only in a
> specific use case hence is not generic because the assumption is that my
> instances are hooked behind a LBaaS which is not always the case.
> Looking forward to see the 'convergence' in action.
> Cheers,
> Dani
> On Tue, Oct 28, 2014 at 3:06 AM, Mike Spreitzer <mspreitz at us.ibm.com>
> wrote:
>> Daniel Comnea <comnea.dani at gmail.com> wrote on 10/27/2014 07:16:32 AM:
>> > Yes i did but if you look at this example
>> >
>> >
>> https://github.com/openstack/heat-templates/blob/master/hot/autoscaling.yaml
>> >
>> > the flow is simple:
>> > CPU alarm in Ceilometer triggers the "type: OS::Heat::ScalingPolicy"
>> > which then triggers the "type: OS::Heat::AutoScalingGroup"
>> Actually the ScalingPolicy does not "trigger" the ASG.  BTW,
>> "ScalingPolicy" is mis-named; it is not a full policy, it is only an action
>> (the condition part is missing --- as you noted, that is in the Ceilometer
>> alarm).  The so-called ScalingPolicy does the action itself when
>> triggered.  But it respects your configured min and max size.
>> What are you concerned about making your scaling group smaller than your
>> configured minimum?  Just checking here that there is not a
>> misunderstanding.
>> As Clint noted, there is a large-scale effort underway to make Heat
>> maintain what it creates despite deletion of the underlying resources.
>> There is also a small-scale effort underway to make ASGs recover from
>> members stopping proper functioning for whatever reason.  See
>> https://review.openstack.org/#/c/127884/ for a proposed interface and
>> initial implementation.
>> Regards,
>> Mike
>> _______________________________________________
>> OpenStack-dev mailing list
>> OpenStack-dev at lists.openstack.org
>> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstack.org/pipermail/openstack-dev/attachments/20150403/4b51cec8/attachment.html>

More information about the OpenStack-dev mailing list