Exactly. Branch development is good, but I concerned about too many concurrent branches. In terms of code management, the good branch development candidate could be those like registry, shared cache and timeline service. Their most changes are the incremental code in some new sub-module, are less likely to conflict with trunk/branch-2, and are rarely depended by other parallel development.
Thanks, Zhijie ________________________________________ From: Bikas Saha <[email protected]> Sent: Thursday, April 30, 2015 12:52 PM To: [email protected] Subject: RE: [DISCUSS] Developing features in branches I think what Zhijie is talking about is a little different. Work happening in parallel across 2 branches have no clue about each other since they don’t get updates via master. If a bunch of these branches is tried to be merged close to a release then there are likely to be a lot of surprises. As an example, lets say support for speculation and node labels were happening in separate branches. It is very likely that >50% of the code would conflict - not just in code but also in semantics. Bikas -----Original Message----- From: Ray Chiang [mailto:[email protected]] Sent: Thursday, April 30, 2015 10:35 AM To: [email protected] Subject: Re: [DISCUSS] Developing features in branches Following up on Zhijie's comments, there's nothing to prevent periodically pulling updates from the "main" branch (e.g. branch-2 or trunk) into the feature branch, is there? Or cherry-picking some changes to alleviate conflict management during branch merging? I've seen other projects use one of the two techniques above. -Ray On Wed, Apr 29, 2015 at 9:43 PM, Zhijie Shen <[email protected]> wrote: > My 2 cents: > > Branch maintenance cost should be fine if we have few features to be > developed in branches. However, if there're too many, each other > branch may be blind to most of latest code change from others, and > trunk/branch-2 becomes stale. That said, with the increasing adopting > of branch development, it's likely to increase the cost of merging each > branch back. > > Some features may last more than one releases, such as RM restarting > before and timeline service now. Even if it's developed in a branch, > we may want to merge its milestones such as phase 1, phase 2 back to > trunk/branch-2 to align with some release before it's completely done. > Moreover, my experience is that the longer a feature stays in the > branch, the more conflicts we have to merge. Hence, it may not be a > good idea to hold a feature in the branch too long before merging it back. > > Thanks, > Zhijie > ________________________________________ > From: Subramaniam V K <[email protected]> > Sent: Wednesday, April 29, 2015 7:16 PM > To: [email protected] > Subject: Re: [DISCUSS] Developing features in branches > > Karthik, thanks for starting the thread. > > Here's my $0.02 based on the experience of working on a feature branch > while adding reservations (YARN-1051). > > Overall a +1 for the approach. > > The couple of pain points we faced were: > 1) Merge cost with trunk > 2) Lack of CI in the feature branch > > The migration to git & keeping the feature branch in continuous sync > with trunk mitigated (1) and with Allen's new test-patch.sh addressing > (2), branches for features especially if used for all major features > seems like an excellent choice. > > -Subru > > On Tue, Apr 28, 2015 at 5:47 PM, Sangjin Lee <[email protected]> wrote: > > > Ah, I missed that part (obviously). Fantastic! > > > > On Tue, Apr 28, 2015 at 5:31 PM, Sean Busbey <[email protected]> > wrote: > > > > > On Apr 28, 2015 5:59 PM, "Sangjin Lee" <[email protected]> wrote: > > > > > > > > > > > That said, in a way we're deferring the cost of cleaning things > > > > up > > > towards > > > > the end of the branch. For example, we don't get the same > > > > treatment > of > > > the > > > > hadoop jenkins in a branch development. It's left up to the > > > > group or > > the > > > > individuals to make sure to run test-patch.sh to ensure tech > > > > debt > does > > > not > > > > accumulate. > > > > > > As Allen previously mentioned, the QA bot will run test-patch > > > against feature branches so long as you name the patch file correctly. > > > > > >
