<div dir="ltr"><div style="font-family:arial,sans-serif;font-size:12.727272033691406px">Some thoughts:</div><div style="font-family:arial,sans-serif;font-size:12.727272033691406px"><br></div><div style="font-family:arial,sans-serif;font-size:12.727272033691406px">
0. Should Climate also address the need for an eviction service? That is, a service that can weight incoming requests and existing resource allocations using some set of policies and evict an existing resource allocations to make room for the higher weighted request. Eviction is necessary if you want to implement a Spot-like service. And if you want Climate reservations that do not tie physical resources to the reservation, this is also required to ensure that requests against the reservation succeed. (Note that even if you do tie physical resources as in whole-host reservations, an eviction service can help when physical resources fail.)</div>
<div style="font-family:arial,sans-serif;font-size:12.727272033691406px"><br></div><span style="font-family:arial,sans-serif;font-size:12.727272033691406px">1. +1 Let end users continue to use existing APIs for resources and extend those interfaces with reservation attributes. Climate should only handle reservation crud and tracking.</span><div style="font-family:arial,sans-serif;font-size:12.727272033691406px">
<br></div><div style="font-family:arial,sans-serif;font-size:12.727272033691406px">2a. As an operator, I want the power to define reservations in terms of host capacity / flavor, min duration, max duration... and limit what kind of reservation requests can come in. Basically define "reservation flavors" and let users submit requests as instances of one "reservation flavor". If you let the end user define all of these parameters I will be rejecting a lot of reservation requests.</div>
<div style="font-family:arial,sans-serif;font-size:12.727272033691406px"><br></div><div style="font-family:arial,sans-serif;font-size:12.727272033691406px">2b. What's the point of an "immediate lease"? This should be equivalent to making the request against Nova directly right? Perhaps there's a rational for this w.r.t. billing? Otherwise I'm not sure what utility this kind of reservation provides?</div>
<div class="im" style="font-family:arial,sans-serif;font-size:12.727272033691406px"><div><br></div><div>2c. Automatic vs. manual reservation approval:</div><div><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
What a user wants to know is whether a reservation can be granted in a all-or-nothing manner at the time he is asking the lease.</blockquote><div><br></div></div><div style="font-family:arial,sans-serif;font-size:12.727272033691406px">
This is a very hard problem to solve: you have to model resource availability (MTTF, MTBF), resource demand (how full are we going to be), and bake in explicit policies (this tenant gets priority) to automatically grant / deny such reservations. Having reservations go through a manual request -> operator approval system is extremely simple and allows operators to tackle the automated case as they need to.</div>
<div style="font-family:arial,sans-serif;font-size:12.727272033691406px"><br></div><div style="font-family:arial,sans-serif;font-size:12.727272033691406px">All I need is a tool that lets a tenant spawn a single critical instance even when another tenant is running an application that's constantly trying to grab as many instances as it can get.</div>
<div style="font-family:arial,sans-serif;font-size:12.727272033691406px"> </div><div style="font-family:arial,sans-serif;font-size:12.727272033691406px">3. This will add a lot of complexity, particularly if you want to tackle #0.</div>
<div style="font-family:arial,sans-serif;font-size:12.727272033691406px"><br></div><div style="font-family:arial,sans-serif;font-size:12.727272033691406px">5. (NEW) Note that Amazon's reserved instances feature doesn't tie reservations against specific instances. Effectively you purchase discount coupons to be applied at the end of the billing cycle. I am not sure how Amazon handles tenants with multiple reservations at different utilization levels (prioritize heavy -> light?).</div>
<div style="font-family:arial,sans-serif;font-size:12.727272033691406px"><br></div><div style="font-family:arial,sans-serif;font-size:12.727272033691406px">~ Scott</div></div><div class="gmail_extra"><br><br><div class="gmail_quote">
On Tue, Aug 6, 2013 at 6:12 AM, 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 Dina and All,<br>
Please see comments inline. We can drill down on the specifics
off-line if that's more practical. <br>
Thanks in advance,<br>
Patrick<div class="im"><br>
On 8/5/13 3:19 PM, Dina Belova wrote:<br>
</div></div><div class="im">
<blockquote type="cite">
<div dir="ltr">
<p style="margin:0px;font-size:12px;font-family:Helvetica">Hello,
everyone!</p>
<p style="margin:0px;font-size:12px;font-family:Helvetica;min-height:14px"><br>
</p>
<p style="margin:0px;font-size:12px;font-family:Helvetica">Patrick,
Julien, thank you so much for your comments. As for the
moments Patrick mentioned in his letter, I'll describe our
vision for them below.</p>
<p style="margin:0px;font-size:12px;font-family:Helvetica;min-height:14px"><br>
</p>
<p style="margin:0px;font-size:12px;font-family:Helvetica">1)
Patrick, thank you for the idea! I think it would be great to
add not only 'post-lease actions policy', but also
'start-lease actions policy'. I mean like having two types of
what can be done with resource (virtual one) on lease starting
- 'start VM automatically' or 'start VM manually'. This means
user may not use reserved resources at all, if he needs such a
behaviour.</p>
</div>
</blockquote></div>
Something along those lines would work but I think the 'start VM
manually' keeps over specifying the behavior IMO since you still
make the assumption that reserved resources are always started using
a term 'manually' that is misleading because if not automatically
started by the reservation service they can still be automatically
started elsewhere like in Heat. I general I agree that users can
take advantage of being able to specify pre and post lease actions /
conditions although it shouldn't be prescriptive of something binary
like start automatically or manually. Another beneficial usage could
be to send parametrized notifications. I would also make the pre and
post action optional so that if the user choose not to associate an
action with the realization of a lease, he doesn't have to specify
anything. Finally, I would also that the specification of a pre and
post action is assorted of a time offset to take into account the
lead time to provision certain types of resources like physical
hosts. That's a possible solution to point 4.<div class="im"><br>
<blockquote type="cite">
<div dir="ltr">
<p style="margin:0px;font-size:12px;font-family:Helvetica"><br>
</p>
<p style="margin:0px;font-size:12px;font-family:Helvetica">2) We
really believe that creating lease first, and going with its
id to all the OpenStack projects to use is a better idea than
'filling' the lease with resources just at the moment of its
creation. I'll try to explain why. First of all, as for
virtual reservations, we'll need to proxy Nova, Cinder, etc.
APIs through Reservation API to reserve VM or volume or
something else. Workflow for VM/volume/etc. creation is really
complicated and only services written to do this have to do
it, in our opinion. Second, this makes adding new reservations
to the created lease simple and user friendly. And the last
moment, we should not copy all these dashboard pages for
instance/volume/... creation to the reservation Dashboard tab
in this case. As for the physical reservations, as you
mentioned, there is no way to 'create' them like virtual
resources in the Nova's, for example, API now. That's why
there are two ways to solve this problem and reserve them.
First way is to reserve them from Reservation Service as it is
implemented now and described also in our document (WF-2b part
of it). The second variant (that seems to be more elegant, but
more complicated as well) is to implement needed parts as Nova
API extension to let Nova do the things it does the best way -
managing hosts, VMs, etc. Our concern in this question is not
doing things Nova (or any other service) can do much better.</p>
</div>
</blockquote></div>
Well, I am under the impression that you put forward an
argumentation that is mostly based on an implementation artifact
which takes advantage of the actual resource provisioning workflow
and dashboard rather than taking into account the most common use
cases and practices. There maybe use cases that mandate for an
iterative workflow that is similar to what you describe. I may be
wrong, but I am doubtful it is going to be a common use case. We
tend to think of AWS as being a reference and you've probably
noticed that reservations in AWS are performed by chunk (the more I
reserve for the longer period of time, the cheaper). The problem
with adding reservations into a lease on a continuous basis is that
as a user I may end up undo what I have done (e.g. I got only 900
out of the 1000 VMs I want) and keep trying forever. That's
potentially a lot of overhead. Also, as a cloud operator, I'd like
to know what my reservation pipeline looks like ahead of time so
that I can provision new hardware in due time. That's capacity
planning. As an operator, I also want to be able grant reservations
and charge for it even if I don't have the capacity right now
provided the lead time to provisioning new hardware doesn't conflict
with the terms of the pending leases. If a user can add reservations
to a lease at the last moment, that flexibility may be compromised.
In any events, this is how we envision the behavior of the
reservation service for the reservation of physical capacity and so,
it is important the service API can support that interaction model.
I think it's probably okay to do it in two separate steps 1) create
the lease, 2) add reservation (although it seems problematic in the
case of immediate lease) but the actual hosts reservation request
should include a cardinality factor so that if the user wants to
reserve x number of hosts in one chunk he can do it. The reservation
service would respond yes or no depending on the three possible
lease terms (immediate, best effort and schedule) along with the
operator's specific reservation policies that yet has to be
configurable one way or another. To be discussed...<div class="im"><br>
<blockquote type="cite">
<div dir="ltr">
<p style="margin:0px;font-size:12px;font-family:Helvetica"><br>
</p>
<p style="margin:0px;font-size:12px;font-family:Helvetica">3) We
completely agree with you! Our 'nested reservation' vision was
created only to let user the opportunity of checking
reservation status of complex virtual resources (stacks) by
having an opportunity to check status of all its 'nested'
components, like VMs, networks, etc. This can be done as well
by using just Heat without reservation service. Now we are
thinking about reservation as the reservation of the OpenStack
resource that has ID in the OpenStack service DB, no matter
how complex it is (VM, network, floating IP, stack, etc.)</p>
</div>
</blockquote></div>
I am not sure I am getting this...? All I wanted to say is that
orchestration is a pretty big deal and my recommendation is not to
do any of this at all in the reservation service but rely on Heat
instead when possible. I understand you seem to agree with this...
Also, I am not sure how you can do stack reservations on the basis
of a Heat template when it has auto-scaling groups. <br><div class="im">
<blockquote type="cite">
<div dir="ltr">
<p style="margin:0px;font-size:12px;font-family:Helvetica"><br>
</p>
<p style="margin:0px;font-size:12px;font-family:Helvetica">4) We
were thinking about Reservation Scheduler as a service that
controls lease life cycle (starting, ending, making user
notifications, etc.) and communicates with Reservation Manager
via RPC. Reservation Manager can send user notifications about
close lease ending using Ceilometer (this question has to be
researched). As for the time needed to run physical
reservation or complex virtual one, that is used to make
preparations and settings, I think it would be better for user
to amortise it in lease using period, because for physical
resources it much depends on hardware resources and for
virtual ones - on hardware, network and geo location of DCs.</p>
</div>
</blockquote></div>
Do you mean make the user aware of the provisioning lead time in the
lease schedule? How do suggest they know how to account for that? In
practice, a lease is a contract and so the reservations must be
available at the exact time the lease becomes effective.<div><div class="h5"><br>
<blockquote type="cite">
<div dir="ltr">
<p style="margin:0px;font-size:12px;font-family:Helvetica;min-height:14px"><br>
</p>
<p style="margin:0px;font-size:12px;font-family:Helvetica">Thank
you,</p>
<p style="margin:0px;font-size:12px;font-family:Helvetica">DIna. </p>
</div>
<div class="gmail_extra"><br>
<br>
<div class="gmail_quote">On Mon, Aug 5, 2013 at 1:22 PM, Julien
Danjou <span dir="ltr"><<a href="mailto:julien@danjou.info" target="_blank">julien@danjou.info</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">On Fri,
Aug 02 2013, Patrick Petit wrote:<br>
<br>
> 3. The proposal specifies that a lease can contain a
combo of different<br>
<div>> resources types reservations
(instances, volumes, hosts, Heat<br>
> stacks, ...) that can even be nested and that the
reservation<br>
> service will somehow orchestrate their deployment
when the lease<br>
> kicks in. In my opinion, many use cases (at least
ours) do not<br>
> warrant for that level of complexity and so, if
that's something<br>
> that is need to support your use cases, then it
should be delivered<br>
> as module that can be loaded optionally in the
system. Our preferred<br>
> approach is to use Heat for deployment
orchestration.<br>
<br>
</div>
I agree that this is not something Climate should be in
charge. If the<br>
user wants to reserve a set of services and deploys them
automatically,<br>
Climate should provide the lease and Heat the deployment
orchestration.<br>
Also, for example, it may be good to be able to reserve
automatically<br>
the right amount of resources needed to deploy a Heat stack
via Climate.<br>
<span><font color="#888888"><br>
--<br>
Julien Danjou<br>
// Free Software hacker / freelance consultant<br>
// <a href="http://julien.danjou.info" target="_blank">http://julien.danjou.info</a><br>
</font></span><br>
_______________________________________________<br>
OpenStack-dev mailing list<br>
<a href="mailto:OpenStack-dev@lists.openstack.org" target="_blank">OpenStack-dev@lists.openstack.org</a><br>
<a href="http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev" target="_blank">http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev</a><br>
<br>
</blockquote>
</div>
<br>
<br clear="all">
<div><br>
</div>
-- <br>
<div dir="ltr">
<div style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">
<p style="font-size:small;margin:0px;font-family:Helvetica">
Best regards,</p>
<p style="font-size:small;margin:0px;font-family:Helvetica">Dina
Belova</p>
<p style="font-size:small;margin:0px;font-family:Helvetica">Software
Engineer</p>
<p style="font-size:small;margin:0px;font-family:Helvetica">
Mirantis Inc.</p>
</div>
</div>
</div>
</blockquote>
<br>
<br>
</div></div><div class="im"><pre cols="72">--
Patrick Petit
Cloud Computing Principal Architect, Innovative Products
Bull, Architect of an Open World TM
Tél : <a href="tel:%2B33%20%280%294%2076%2029%2070%2031" value="+33476297031" target="_blank">+33 (0)4 76 29 70 31</a>
Mobile : <a href="tel:%2B33%20%280%296%2085%2022%2006%2039" value="+33685220639" target="_blank">+33 (0)6 85 22 06 39</a>
<a href="http://www.bull.com" target="_blank">http://www.bull.com</a></pre>
</div></div>
<br>_______________________________________________<br>
OpenStack-dev mailing list<br>
<a href="mailto:OpenStack-dev@lists.openstack.org">OpenStack-dev@lists.openstack.org</a><br>
<a href="http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev" target="_blank">http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev</a><br>
<br></blockquote></div><br></div>