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From Allen Wittenauer ...@altiscale.com>
Subject Re: [DISCUSS] Looking to a 2.8.0 release
Date Wed, 11 Nov 2015 20:43:31 GMT

> On Nov 11, 2015, at 12:13 PM, Vinod Vavilapalli <vinodkv@hortonworks.com> wrote:
> 
>    — HDFS-6200 Create a separate jar for hdfs-client: Compatible improvement - no dimension
of alpha/betaness here.

	IMO: this feels like a massive break in backwards compatibility. Anyone who is looking for
specific methods in specific jars are going to have a bad time. Also, it seems as though every
week a new issue crops up that is related to this change.  Is Slider still having problems
with it?  The reasoning “well, the pom sets the dependencies so it’s ok” feels like
an *extremely weak* reason this wasn’t marked incompatible— it basically makes the assumption
that everyone recompiles for every minor release.

>    — Compatibility tools to catch backwards, forwards compatibility issues at patch
submission, release times. Some of it is captured at YARN-3292. This also involves resurrecting
jdiff (HADOOP-11776/YARN-3426/MAPREDUCE-6310) and/or investing in new tools.

	There has been talk in the past about adding Java ACC support to Yetus.

> Thoughts?

	I’d rather see efforts on 3.x than another disastrous 2.x release.  The track record is
not good.  At least a new major will signify that danger looms ahead.  We’re already treating
2.x minor releases as effectively major (see the list of incompatible JIRAs) so what different
does it make if we do 2.x vs. 3.x anyway?

> 
> Thanks
> +Vinod
> PS:As you may have noted above, this time around, I want to do something that we’ve
always wanted to do, but never explicitly did. I’m calling out readiness of each feature
as they stand today so we can inform our users better of what they can start relying on in
production clusters.

	… except some of these changes are so deep reaching that even if you don’t use the feature,
you’re still impacted by it ...



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