On 07/03/2014 10:13 PM, Mike Spreitzer wrote:
I do think the issue these address --- the need to get application logic involved in, e.g., shutdown --- is most of what an application needs; involvement in selection of which member(s) to delete is much less important (provided that clean shutdown mechanism prevents concurrent shutdowns).
I assume this is more of the whole "cattle" model, where an instance could disappear at any time so applications should design for that?
As an alternate viewpoint, if a particular instance in a group is working on something "expensive" (long-running, difficult to checkpoint, etc.), maybe it would make sense to allow the application to help make the decision on which instance to shut down (or possibly even veto/delay the scale down operation). If it takes a minute to finish the operation, and 15 minutes to redo it on another instance...
Chris _______________________________________________ OpenStack-dev mailing list OpenStackemail@example.com http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev