[openstack-dev] [Heat] Instance naming in IG/ASG and problems related to UpdatePolicy

Clint Byrum clint at fewbar.com
Fri Aug 30 16:39:39 UTC 2013

Excerpts from Chan, Winson C's message of 2013-08-30 07:23:18 -0700:
> The ideal I think is to just use some random short id for the name of the instances and then store a creation timestamp somewhere with the resource and use the timestamp to determine the age of the instances for removal.  Thoughts?

+1 for this approach. Simple and straight forward answer to all of the
problems spelled out above.

However, I do not see this timestamp in the resource table, but in the
resource_data table. I would suggest adding a created_at column to the
resource table, as the data table may be misleading.

As an arbitrary but predictable algorithm, because timestamps can be equal
for many many resources, I would also suggest sorting on the resource
id. This just makes it so that one can predict which instances _should_
be removed before a downsize.

So, I'd recommend a fully covering index for that query.. created_at, id.

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