[Openstack-operators] [Fuel][Nova][Cinder] Operations: adding new nodes in "disabled" state, allowed for test tenant only

Bogdan Dobrelya bdobrelia at mirantis.com
Mon Feb 23 14:13:38 UTC 2015

+ [Fuel] tag
+ openstack-operators ML

Joe Gordon joe.gordon0 at gmail.com
Thu Dec 4 13:26:59 UTC 2014

>On Wed, Dec 3, 2014 at 3:31 PM, Mike Scherbakov <mscherbakov at

>> Hi all,
>> enable_new_services in nova.conf seems to allow add new compute nodes in
>> disabled state:
>> so it would allow to check everything first, before allowing production
>> workloads host a VM on it. I've filed a bug to Fuel to use this by
>> when we scale up the env (add more computes) [1].
>> A few questions:
>>    1. can we somehow enable compute service for test tenant first? So
>>    cloud administrator would be able to run test VMs on the node, and
>>    ensuring that everything is fine - to enable service for all tenants

>Although there may be more then one way to set this up in nova, this can
>definitely be done via nova host aggregates. Put new compute services into
>an aggregate that only specific tenants can access (controlled via
scheduler filter).

Looks reasonable, +1 for Nova host aggregates [0].

There is still a question, though, about an enable_new_services
parameter, cinder and other OpenStack services. It is not clear how to
use this parameter from an operator perspective, for example:
1) While deploying or scaling the OpenStack environment, we should set
enable_new_services=false for all services which support it.
2) Once the deploy/scale is done, re-enable disabled services. But how
exactly that should be done?
* Set enable_new_services=True and restart the schedulers and conductor
services? Or API services as well?
* Keep enable_new_services=false in configs, but issue - for nova
exmaple - 'nova-manage service enable ...' commands for added compute
nodes? And what about cinder and other ones (there are no *-manage
service enable commands)?
* Some another way?

And regarding plans for implementing this improvement in Fuel, I believe
for nova computes it could be done as a workaround for the 6.1 release
with the help of enable_new_services configuration parameter and a
separate Fuel post-deploy granular task which should re-enable the
disabled compute services. But this should be re-implemented later with
separate host aggregate for deployment and health checks, see the
related blueprint [1].

[1] https://blueprints.launchpad.net/fuel/+spec/disable-new-computes

>    1.
>    2. What about Cinder? Is there a similar option / ability?
>    3. What about other OpenStack projects?
> What is your opinion, how we should approach the problem (if there is a
> problem)?
> [1] https://bugs.launchpad.net/fuel/+bug/1398817
> --
> Mike Scherbakov
> #mihgen

Best regards,
Bogdan Dobrelya,
Skype #bogdando_at_yahoo.com
Irc #bogdando

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