I want to understand a lot more about the classpath isolation (HADOOP-11656) proposal, specifically, what is proposed and does it have to be tagged as incompatible? That's a bigger change than must setting javac.version=8 in the POM —though given what a fundamental problem it addresses, I'm in favour of doing something there.

On 3 March 2015 at 08:05:46, Andrew Wang (andrew.wang@cloudera.com) wrote:

I view branch-3 as essentially the same size as our recent 2.x releases, 
with the exception of incompatible changes like classpath isolation and 
JDK8 target version. These, while perhaps not revolutionary, are still 
incompatible, and require a major version bump.