Eli, I will post a more detailed reply soon. But one small correction:
I'm also not sure there's currently consensus on what an incompatible > change is. For example, I think HADOOP-9151 is incompatible because it > broke client/server wire compatibility with previous releases and any > change that breaks wire compatibility is incompatible. Suresh felt it > was not an incompatible change because it did not affect API > compatibility (ie PB is not considered part of the API) and the change > occurred while v2 is in alpha. > This is not correct. I did not say it was not an incompatible change. It was indeed an incompatible wire protocol change. My argument was, the phase of development we were in, we could not mark wire protocol as stable and not make any incompatible change. But once 2.0.5-beta is out, as had discussed earlier, we should not make further incompatible changes to wire protocol. -- http://hortonworks.com/download/
