Open Stack

On 07/28/2016 09:02 PM, Devananda van der Veen wrote:
> On 07/28/2016 05:40 PM, Brad Morgan wrote:
>> I'd like to solicit some advice about potentially implementing
>> get_all_bw_counters() in the Ironic virt driver.
>>
>> https://github.com/openstack/nova/blob/master/nova/virt/driver.py#L438
>> Example Implementation:
>> https://github.com/openstack/nova/blob/master/nova/virt/xenapi/driver.py#L320
>>
>> I'm ignoring the obvious question about how this data will actually be
>> collected/fetched as that's probably it's own topic (involving neutron), but I
>> have a few questions about the Nova -> Ironic interaction:
>>
>> Nova
>> * Is get_all_bw_counters() going to stick around for the foreseeable future? If
>> not, what (if anything) is the replacement?

I don't think Nova should be in the business of monitoring *any* 
transient metrics at all.

There are many tools out there -- Nagios, collectd, HEKA, Snap, gnocchi, 
monasca just to name a few -- that can do this work.

What action is taken if some threshold is reached is entirely 
deployment-dependent and not something that Nova should care about. Nova 
should just expose an API for other services to use to control the guest 
instances under its management, nothing more.

Best,
-jay

p.s. Related: I don't think Nova should be in the business of 
implementing service group membership functionality either. We should be 
using Zookeeper or another system that was built for that purpose 
instead of continuing to maintain a wonky RDBMS-based home-grown service 
group system.