[HIVEMALL-85] Upgrade hivemall-xgboost's hadoop version to 2.6.5

[wangyum]

What changes were proposed in this pull request?

Upgrade hivemall-xgboost's hadoop version to 2.6.5

What type of PR is it?

Improvement

What is the Jira issue?

HIVEMALL-85

How was this patch tested?

manual tests

[maropu]

@wangyum Thanks for your continuous contributions!
@myui Do we have any reason to have a dependency with hadoop-core 0.20.2-cdh3u6? I just used this dependency along with the other modules.

$find . -type f | grep pom.xml | xargs grep cdh
./core/pom.xml:                 <version>0.20.2-cdh3u6</version>
./mixserv/pom.xml:                      <version>0.20.2-cdh3u6</version>
./nlp/pom.xml:                  <version>0.20.2-cdh3u6</version>
./spark/spark-common/pom.xml:                   <version>0.20.2-cdh3u6</version>

[myui]

@wangyum @maropu I think it's provided maven space and thus no need to change.
provided scope libraries are used just for compiling and not bundled in jars.

[maropu]

Yea, I know, but I know the reason why we use cdh instead of hadoop community version?

[myui]

Mostly for historical reasons. Better to change the version dependencies to Hadoop v2.4.0 (not v2.6.x) but dependencies packages change and careful verification is required.

This branch changed the dependencies to v2.4.0
https://github.com/myui/hivemall/tree/dev/yarnkit

[coveralls]

Coverage increased (+0.3%) to 37.03% when pulling 66b6be5 on wangyum:HIVEMALL-85 into 1cccf66 on apache:master.

[coveralls]

Coverage remained the same at 36.739% when pulling 66b6be5 on wangyum:HIVEMALL-85 into 1cccf66 on apache:master.

[maropu]

@wangyum Why you select 2.6.5 in this pr? Any reason?

[wangyum]

Be consistent with the Spark.
https://github.com/apache/spark/blob/d76c18746bdd0908bae89e62da9667001be75624/pom.xml#L125

[myui]

We need to change whole dependencies to v2.4.0 following the way in https://github.com/myui/hivemall/tree/dev/yarnkit

Filed a ticket https://issues.apache.org/jira/browse/HIVEMALL-86

I would like to move the discussions to Hivemall-86.

@wangyum Could you close this pull request?

[wangyum]

OK

[myui]

Thanks!