OK I'm not exactly asking for a vote here :) I don't think we should look at it from only maintenance point of view -- because in that case the answer is clearly supporting as few versions as possible (or just rm -rf spark source code and call it a day). It is a tradeoff between the number of users impacted and the maintenance burden.
So a few questions for those more familiar with Hadoop: 1. Can Hadoop 2.6 client read Hadoop 2.4 / 2.3? 2. If the answer to 1 is yes, are there known, major issues with backward compatibility? 3. Can Hadoop 2.6+ YARN work on older versions of YARN clusters? 4. (for Hadoop vendors) When did/will support for Hadoop 2.4 and below stop? To what extent do you care about running Spark on older Hadoop clusters. On Fri, Nov 20, 2015 at 7:52 AM, Steve Loughran <ste...@hortonworks.com> wrote: > > On 20 Nov 2015, at 14:28, ches...@alpinenow.com wrote: > > Assuming we have 1.6 and 1.7 releases, then spark 2.0 is about 9 months > away. > > customer will need to upgrade the new Hadoop clusters to Apache 2.6 or > later to leverage new spark 2.0 in one year. I think this possible as > latest release on cdh5.x, HDP 2.x are both on Apache 2.6.0 already. > Company will have enough time to upgrade cluster. > > +1 for me as well > > Chester > > > now, if you are looking that far ahead, the other big issue is "when to > retire Java 7 support".? > > That's a tough decision for all projects. Hadoop 3.x will be Java 8 only, > but nobody has committed the patch to the trunk codebase to force a java 8 > build; + most of *todays* hadoop clusters are Java 7. But as you can't even > download a Java 7 JDK for the desktop from oracle any more today, 2016 is a > time to look at the language support and decide what is the baseline > version > > Commentary from Twitter here -as they point out, it's not just the server > farm that matters, it's all the apps that talk to it > > > > http://mail-archives.apache.org/mod_mbox/hadoop-common-dev/201503.mbox/%3ccab7mwte+kefcxsr6n46-ztcs19ed7cwc9vobtr1jqewdkye...@mail.gmail.com%3E > > -Steve >