[openstack-dev] Hyper-V meeting Minutes
Sean Dague
sean at dague.net
Tue Oct 15 23:36:03 UTC 2013
On 10/15/2013 04:54 PM, Vishvananda Ishaya wrote:
> Hi Everyone,
>
> I've been following this conversation and weighing the different sides. This is a tricky issue but I think it is important to decouple further and extend our circle of trust.
>
> When nova started it was very easy to do feature development. As it has matured the pace has slowed. This is expected and necessary, but we periodically must make decoupling decisions or we will become mired in overhead. We did this already with cinder and neutron, and we have discussed doing this with virt drivers in the past.
>
> We have a large number of people attempting to contribute to small sections of nova and getting frustrated with the process. The perception of developers is much more important than the actual numbers here. If people are frustrated they are disincentivized to help and it hurts everyone. Suggesting that these contributors need to learn all of nova and help with the review queue is silly and makes us seem elitist. We should make it as easy as possible for new contributors to help.
>
> I think our current model is breaking down at our current size and we need to adopt something more similar to the linux model when dealing with subsystems. The hyper-v team is the only one suggesting changes, but there have been similar concerns from the vmware team. I have no doubt that there are similar issues with the PowerVM, Xen, Docker, lxc and even kvm driver contributors.
The Linux kernel process works for a couple of reasons...
1) the subsystem maintainers have known each other for a solid decade
(i.e. 3x the lifespan of the OpenStack project), over a history of 10
years, of people doing the right things, you build trust in their judgment.
*no one* in the Linux tree was given trust first, under the hope that it
would work out. They had to earn it, hard, by doing community work, and
not just playing in their corner of the world.
2) This
http://www.wired.com/wiredenterprise/2012/06/torvalds-nvidia-linux/ is
completely acceptable behavior. So when someone has bad code, they are
flamed to within an inch of their life, repeatedly, until they never
ever do that again. This is actually a time saving measure in code
review. It's a lot faster to just call people idiots then to help them
with line by line improvements in their code, 10, 20, 30, or 40
iterations in gerrit.
We, as a community have decided, I think rightly, that #2 really isn't
in our culture. But you can't start cherry picking parts of the Linux
kernel community without considering how all the parts work together.
The good and the bad are part of why the whole system works.
> In my opinion, nova-core needs to be willing to trust the subsystem developers and let go of a little bit of control. I frankly don't see the drawbacks.
I actually see huge draw backs. Culture matters. Having people active
and willing to work on real core issues matter. The long term health of
Nova matters.
As the QA PTL I can tell you that when you look at Nova vs. Cinder vs.
Neutron, you'll see some very clear lines about how long it takes to get
to the bottom of a race condition, and how many deep races are in each
of them. I find this directly related to the stance each project has
taken on whether it's socially acceptable to only work on your own
vendor code. Nova's insistence up until this point that if you only play
in your corner, you don't get the same attention is important incentive
for people to integrate and work beyond just their boundaries. I think
diluting this part of the culture would be hugely detrimental to Nova.
Let's take an example that came up today, the compute_diagnostics API.
This is an area where we've left it completely to the virt drivers to
vomit up a random dictionary of the day for debugging reasons, and
stamped it as an API. With a model where we let virt driver authors go
hide in a corner, that's never going to become an API with any kind of
contract, and given how much effort we've spent on ensuring RPC
versioning and message formats, the idea that we are exposing a public
rest endpoint that's randomly fluctuating data based on date and
underlying implementation, is a bit saddening.
> I'm leaning towards giving control of the subtree to the team as the best option because it is simple and works with our current QA system. Alternatively, we could split out the driver into a nova subproject (2 below) or we could allow them to have a separate branch and do a trusted merge of all changes at the end of the cycle (similar to the linux model).
>
> I hope we can come to a solution to the summit that makes all of our contributors want to participate more. I believe that giving people more responsibility inspires them to participate more fully.
I would like nothing more than all our contributors to participate more.
But more has to mean caring about not only your stuff.
I was called out today in the hyper-v meeting because I had the audacity
to -1 a hyper-v patch because I wanted some reference in the code
somewhere to format references so why we had some new random seek call
would be understood by people down the road -
http://eavesdrop.openstack.org/meetings/hyper_v/2013/hyper_v.2013-10-15-16.03.log.html
As OpenStack grows, the single biggest factor in it's success isn't
going to be a feature in a driver, it's going to be if this crazy
complicated system holds together. Whether or not we've got a handle on
the emergent behavior that happens in an asynchronous message based
system, with 10s of integrated projects, and many dozens of daemons
cross talking with each other.
I mean seriously, one of the only reasons we made it through to Havana
RC phase is because we built a search engine based system to build
statistical frequency analysis of unique failures on our gate resets to
fully expose the top race conditions that had gotten so bad the gate
basically locked up. And a bunch of people went all hands on deck to
drive these out. People jumped across normal project lines to help on
some of these top bugs, because that's what makes OpenStack a whole system.
Things actually looked *really* bleak for release for a while. All the
people that helped out and got us through this deserve a huge pat on the
back. That's what OpenStack is about.
So I feel pretty strongly that optimizing the contribution process for
people that aren't helping with that larger problem, is the tragedy of
the commons, and I think entirely the wrong optimization to be made.
-Sean
--
Sean Dague
http://dague.net
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