Hi, Matt, Thank you for your attention. The information you provided is very helpful.
Best Regards > -----原始邮件----- > 发件人: "Matt Riedemann" <mriede...@gmail.com> > 发送时间: 2017-04-05 23:33:21 (星期三) > 收件人: email@example.com > 抄送: > 主题: Re: [openstack-dev] [nova] Risk prediction model for OpenStack > > On 4/5/2017 9:00 AM, Jeremy Stanley wrote: > > On 2017-04-05 14:00:59 +0800 (+0800), 林泽燕 wrote: > > [...] > >> I wonder if I could show you my study, including some metrics for > >> the prediction model and a visualization tool. > > [...] > > > > I want to start out thanking you for your research and interest in > > OpenStack's development practices. I love that our contribution > > model enables such scientific analysis, a sometimes less recognized > > benefit of our community's choice to work entirely in the open. This > > specific study is also very insightful and well-presented. > > > >> In this release, 36 developers left the development of this file > >> (they made contributions in last release but not this one). > >> Developers leaving a code file deprive the file of the knowledge > >> of the decisions they have made. > > [...] > > > > One potentially influential aspect of our development model is that > > we place a heavy importance on code review. For any patch to make it > > into a branch under official revision control, it must first be > > reviewed by multiple experienced, long-standing contributors to that > > repository. Our hope is that even though some developers may cease > > contributing new patches to a file, some of them would still be > > reviewing, guiding and refining changes proposed by newer > > contributors. It doesn't seem like this behavior was captured in > > your analysis, or alternatively the fact that your model yielded > > relatively accurate predictions could imply that our review process > > has little impact on defects introduced by new commits. > > > > If you do at some point wish to try integrating review metrics into > > your analysis, our code review system has a REST API you can > > leverage, and much of the data you'd likely be interested in can be > > queried via anonymous methods such that you wouldn't even need to > > create an account. Documentation for the interface is available at > > https://review.openstack.org/Documentation/rest-api.html and we also > > have documentation of our general developer workflow at > > https://docs.openstack.org/infra/manual/developers.html as well as > > some background on our development model at > > https://docs.openstack.org/project-team-guide/open-development.html > > if that helps. > > > > Jeremy pointed out what I was going to mention, which was the lack of > input on code reviews. Each major component of Nova, or virt drivers, > generally have subteams, or some sort of subject domain expert, that is > consulted or at least involved in reviewing code contributions. So while > they may not be making the changes themselves to a component, they > should be reviewing those changes. For example, with the > nova/virt/libvirt/driver.py, danpb was the main core reviewer and > maintainer for that code in the past, so while he didn't write > everything, he was reviewing a lot of the contributions. > > Some of the files are also skewed a bit, and you might want to take into > account logic paths in a module to exclude it. For example, exception.py > and the various opts.py modules are outliers. They are basically files > that contain constants but not logic code so the chance of those having > an actual owner is small, but so should be the risk for bugs. They will > also have a high diversity given how common they are. > > I'm not sure I understood the timeline graphs, or the point those are > making. We definitely have an ebb and flow of contributions based on the > release schedule where feature development and new code is loaded toward > the front of the release, and then that is supposed to be cut off toward > the 3rd milestone at the end of the release so we can stabilize and > focus on bugs. > > In general some of this is common sense. When one person "owns" most of > a module in a piece of software they are the expert and therefore bugs > due to lack of understanding the bigger picture of that module, or how > it fits into the bigger system, should be mitigated. When that person > leaves, if others on the team don't have the domain knowledge, there are > going to be mistakes. We definitely have parts of the nova codebase that > fall into areas that we know are just very touchy and error prone and we > avoid changing those if at all possible (block device mappings, quotas, > neutronv2.api, nova-network and cells v1 come to mind). This is hard in > a big open source project, but is also why we have high standards for > core reviewers (those that can approve code contributions) and a > ridiculous amount of continuous integration testing. > > -- > > Thanks, > > Matt > > __________________________________________________________________________ > OpenStack Development Mailing List (not for usage questions) > Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev Best regards! —————————— Zeyan Lin Department of Computer Science School of Electronics Engineering & Computer Science Peking University Beijing 100871, China E-mail：linze...@pku.edu.cn __________________________________________________________________________ OpenStack Development Mailing List (not for usage questions) Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev