[
https://issues.apache.org/jira/browse/HBASE-20332?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16508456#comment-16508456
]
Sean Busbey commented on HBASE-20332:
-------------------------------------
{quote}
Since we're removing the exclusion in a bunch of places, we need to make sure
folks don't inadvertently rely on it as an unlisted dependency. We want to make
sure that when folks reference HTrace they're referencing HTrace v4 classes and
not earlier classes. so for now we tell checkstyle to flag org.htrace and
org.apache.htrace (I don't know of a way to flag that use of
org.apache.htrace.core specifically is fine).
{quote}
In a prior version of this patch I did this as an "hbase antipattern" check
that was able to use a regex to say importing {{org.apache.htrace.core}} and
subpackages is fine. I could switch back to that if y'all prefer.
> shaded mapreduce module shouldn't include hadoop
> ------------------------------------------------
>
> Key: HBASE-20332
> URL: https://issues.apache.org/jira/browse/HBASE-20332
> Project: HBase
> Issue Type: Sub-task
> Components: mapreduce, shading
> Affects Versions: 2.0.0
> Reporter: Sean Busbey
> Assignee: Sean Busbey
> Priority: Critical
> Fix For: 3.0.0, 2.1.0
>
> Attachments: HBASE-20332.0.patch, HBASE-20332.1.WIP.patch,
> HBASE-20332.2.WIP.patch, HBASE-20332.3.patch, HBASE-20332.4.patch
>
>
> AFAICT, we should just entirely skip including hadoop in our shaded mapreduce
> module
> 1) Folks expect to run yarn / mr apps via {{hadoop jar}} / {{yarn jar}}
> 2) those commands include all the needed Hadoop jars in your classpath by
> default (both client side and in the containers)
> 3) If you try to use "user classpath first" for your job as a workaround
> (e.g. for some library your application needs that hadoop provides) then our
> inclusion of *some but not all* hadoop classes then causes everything to fall
> over because of mixing rewritten and non-rewritten hadoop classes
> 4) if you don't use "user classpath first" then all of our
> non-relocated-but-still-shaded hadoop classes are ignored anyways so we're
> just wasting space
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
