Hadoop devs, Eli and I have been working on a writeup on compatibility for developers, downstream projects and end users. The wiki page - http://wiki.apache.org/hadoop/Compatibility - is a strawman effort towards consolidating prior discussions and decisions; including the API classification effort on HADOOP-5073, Sanjay’s work on Hadoop 1.0 compatibility (HADOOP-5071), and the roadmap page on the Hadoop wiki. The goal is to identify the the relevant interfaces and concerns for downstream projects and users. In cases where the community has explicitly agreed upon a policy (e.g. HADOOP-5073: API classification), call out that policy.
This doc does not intend to propose new policies. The idea is to have one document that outlines the various compatibility concerns (lots of areas beyond API compatibility), captures the respective policies that exist, and if we want to define policies for the items where it’s not clear we have something to iterate on. The first draft just lists the types of compatibility. In the next step, we can add existing policies and subsequently work towards policies for others. Would love to incorporate your feedback on the first draft. Thanks Karthik
