<div dir="ltr">Hi Nikolay and Patrick, thanks for your replies.<div><br></div><div>Virtual vs. Physical Resources</div><div>Ok, now I realize what you meant by "virtual resources," e.g. instances, volumes, networks...resources provided by existing OpenStack schedulers. In this case "physical resources" are actually more "removed" since there are no interfaces to them in the user-level OpenStack APIs. If you make a physical reservation on "this rack of machines right here", how do you supply this reservation information to nova-scheduler? Probably via scheduler hints + an availability zone or host-aggregates. At which point you're really defining a instance reservation that includes explicit scheduler hints. Am I missing something?</div>
<div><br></div><div>Eviction:<br></div><div>Nikolay, to your point that we might evict something that was already paid for: in the design I have in mind, this would only happen if the policies set up by the operator caused one reservation to be weighted higher than another reservation. Maybe because one client paid more? The point is that this would be configurable and the sensible default is to not evict anything.</div>
</div><div class="gmail_extra"><br><br><div class="gmail_quote">On Fri, Aug 9, 2013 at 8:05 AM, Nikolay Starodubtsev <span dir="ltr"><<a href="mailto:nstarodubtsev@mirantis.com" target="_blank">nstarodubtsev@mirantis.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Hello, Patrick!
<br> <br>We have several reasons to think that for the virtual resources this possibility is interesting. If we speak about physical resources, user may use them in the different ways, that's why it is impossible to include base actions with them to the reservation service. But speaking about virtual reservations, let's imagine user wants to reserve virtual machine. He knows everything about it - its parameters, flavor and time to be leased for. Really, in this case user wants to have already working (or at least starting to work) reserved virtual machine and it would be great to include this opportunity to the reservation service. We are thinking about base actions for the virtual reservations that will be supported by Climate, like boot/delete for instance, create/delete for volume and create/delete for the stacks. The same will be with volumes, IPs, etc. As for more complicated behaviour, it may be implemented in Heat. This will make reservations simpler to use for the end users.
<br> <br>Don't you think so?
<br> <br>P.S. Also we remember about the problem you mentioned some letters ago - how to guarantee that user will have already working and prepared host / VM / stack / etc. by the time lease actually starts, no just "lease begins and preparing process begins too". We are working on it now.<br>
</div><div class="HOEnZb"><div class="h5"><div class="gmail_extra"><br><br><div class="gmail_quote">On Thu, Aug 8, 2013 at 8:18 PM, Patrick Petit <span dir="ltr"><<a href="mailto:patrick.petit@bull.net" target="_blank">patrick.petit@bull.net</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000">
<div>Hi Nikolay,<br>
<br>
Relying on Heat for orchestration is obviously the right thing to
do. But there is still something in your design approach that I am
having difficulties to comprehend since the beginning. Why do you
keep thinking that orchestration and reservation should be treated
together? That's adding unnecessary complexity IMHO. I just don't
get it. Wouldn't it be much simpler and sufficient to say that
there are pools of reserved resources you create through the
reservation service. Those pools could be of different types i.e.
host, instance, volume, network,.., whatever if that's really
needed. Those pools are identified by a unique id that you pass
along when the resource is created. That's it. You know, the AWS
reservation service doesn't even care about referencing a
reservation when an instance is created. The association between
the two just happens behind the scene. That would work in all
scenarios, manual, automatic, whatever... So, why do you care so
much about this in a first place?<br>
Thanks, <br>
Patrick<div><div><br>
On 8/7/13 3:35 PM, Nikolay Starodubtsev wrote:<br>
</div></div></div><div><div>
<blockquote type="cite">
<div dir="ltr">
<div>Patrick, responding to your comments:</div>
<div><br>
</div>
<div>1) Dina mentioned "start automatically" and "start
manually" only as examples of how these politics may look
like. It doesn't seem to be a correct approach to put
orchestration functionality (that belongs to Heat) in Climate.
That's why now we can implement the basics like starting Heat
stack, and for more complex actions we may later utilize
something like Convection (Task-as-a-Service) project.</div>
</div>
</blockquote>
<blockquote type="cite">
<div dir="ltr">
<div><br>
</div>
<div>2) If we agree that Heat is the main consumer of
Reservation-as-a-Service, we can agree that lease may be
created according to one of the following scenarions (but not
multiple):</div>
<div>- a Heat stack (with requirements to stack's contents) as a
resource to be reserved</div>
<div>- some amount of physical hosts (random ones or filtered
based on certain characteristics). </div>
<div>- some amount of individual VMs OR Volumes OR IPs </div>
<div><br>
</div>
<div>3) Heat might be the main consumer of virtual reservations.
If not, Heat will require development efforts in order to
support:</div>
<div>- reservation of a stack </div>
<div>- waking up a reserved stack</div>
<div>- performing all the usual orchestration work</div>
<div><br>
</div>
<div>We will support reservation of individual instance/volume/
IP etc, but the use case with "giving user already working
group of connected VMs, volumes, networks" seems to be the
most interesting one. </div>
<div>As for Heat autoscaling, reservation of the maximum
instances set in the Heat template (not the minimum value) has
to be implemented in Heat. Some open questions remain though -
like updating of Heat stack when user changes the template to
support higher max number of running instances</div>
<div><br>
</div>
<div>4) As a user, I would of course want to have it already
working, running any configured hosts/stacks/etc by the time
lease starts. But in reality we can't predict how much time
the preparation process should take for every single use case.
So if you have an idea how this should be implemented, it
would be great you share your opinion.</div>
</div>
</blockquote>
</div></div><blockquote type="cite">
<div dir="ltr">
</div>
<br>
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