Autoconfiguring templates
=========================

During the Liberty development cycle sahara implemented a tool that recommends and
applies configuration values for cluster templates and node group templates.
These recommendations are based on the number of specific instances and on
flavors of the cluster node groups. Currently the following plugins support
this feature:

  * Cloudera;
  * Spark;
  * the Vanilla Apache Hadoop plugin.

By default this feature is enabled for all cluster templates and node group templates.
If you want to disable this feature for a particular cluster or node group template
you should set the ``use_autoconfig`` field to ``false``.

.. NOTE
  Also, if you manually set configs from the list below, the recommended configs
  will not be applied.

The following describes the settings for which sahara can recommend autoconfiguration:

The Cloudera, Spark and Vanilla Apache Hadoop plugin support configuring
``dfs.replication`` (``dfs_replication`` for Cloudera plugin) which is calculated as
a minimun from the amount of ``datanode`` (``HDFS_DATANODE`` for Cloudera plugin) instances in
the cluster and the default value for ``dfs.replication``.

The Vanilla Apache Hadoop plugin and Cloudera plugin support autoconfiguration
of basic YARN and MapReduce configs. These autoconfigurations are based on the following
documentation: http://docs.hortonworks.com/HDPDocuments/HDP2/HDP-2.0.9.1/bk_installing_manually_book/content/rpm-chap1-11.html
