Hi Konst, thanks for taking a look. I think I essentially agree with your points.
On Mon, Mar 2, 2015 at 11:04 PM, Konstantin Shvachko <shv.had...@gmail.com> wrote: > Andrew, > > Hadoop 3 seems in general like a good idea to me. > 1. I did not understand if you propose to release 3.0 instead of 2.7 or in > addition? > I think 2.7 is needed at least as a stabilization step for the 2.x line. > > I agree with this, 2.7 is needed, and I think Vinod/Arun are working on it now. I expect branch-2 to be maintained for a while yet, separate from a branch-3. > 2. If Hadoop 3 and 2.x are meant to exist together, we run a risk to > manifest split-brain behavior again, as we had with hadoop-1, hadoop-2 and > other versions. If that somehow beneficial for commercial vendors, which I > don't see how, for the community it was proven to be very disruptive. Would > be really good to avoid it this time. > > My motivations here are purely what I've stated above. I remember the pain of the branch-1 days as well, and this would be a far, far smaller difference. JDK8 min version and classpath isolation are compelling, yet incompatible, which is why I'm proposing Hadoop 3. Besides those two features, it should be approximately the same "size" as our 2.x releases. > 3. Could we release Hadoop 3 directly from trunk? With a proper feature > freeze in advance. Current trunk is in the best working condition I've seen > in years - much better, than when hadoop-2 was coming to life. It could > make a good alpha. > I believe we can start planning 3.0 from trunk right after 2.7 is out. > I agree with this, and would be okay with this if our audit of trunk reveals no incompatible changes we're uncomfortable releasing. I'll note though that committing to multiple branches is way easier now with git and cherry-pick, so that overhead is reduced. Rolling out an alpha now is strictly a good thing for our downstreams, even if it means we need to do extra commits. Thanks, Andrew
