Hi,

I noticed that that yarn-default.xml
(mapreduce/yarn/yarn-server/yarn-server-common/src/main/resources/yarn-default.xml)
has the configurable parameters for yarn.

The installation instructions (1) requires to add the
nodemanager.auxiluary.services and
nodemanager.aux.service.mapreduce.shuffle.class properties to the
yarn-site.xml. What is the purpose of these parameters? Are all the
properties for MRv2 with the descriptions and default values mentioned some
where in the documentation?

It would be nice to update the build process something like what Cloudera
has done (2) to figure out the what configuration parameters have been added
in a particular release and prepare documentation for the same. Also, the
patch owner can be sent a mail to add description for the configuration
parameter.

Thanks,
Praveen

(1) -
http://svn.apache.org/repos/asf/hadoop/common/branches/MR-279/mapreduce/INSTALL

(2) -
http://www.cloudera.com/blog/2011/08/automatically-documenting-apache-hadoop-configuration/