SPARK-1952 removed slf4j Pig conflicts

[rcompton]

Removed jul-to-slf4j and jcl-over-slf4j to allow Pig scripts to register jars containing the Spark-1.0 assembly, cf https://issues.apache.org/jira/browse/SPARK-1952

[AmplabJenkins]

Can one of the admins verify this patch?

[srowen]

As Patrick alluded to, those imports are on purpose, to direct logging from this like Pig that use JCL to the logging that the rest of the app uses. Because things like JCL have been excluded, also excluding these would cause libraries that use JCL to fail, so I don't think this can be included like this. The intended action would be to exclude JCL in your downstream app and keep this import. Of course you can get other effects, like rejiggering the whole setup to direct to JCL and not log4j. It's more, different work, but possible.

[mateiz]

@rcompton I believe this has been addressed by Sigmoid's recent work for Pig on Spark: https://issues.apache.org/jira/browse/PIG-4059. Given that, do we still need this patch?

[rcompton]

@mateiz no, for the reasons mentioned by Sean as well as the new work by Sigmoid, you don't need this patch.

[mateiz]

Alright, thanks for taking a look at this.