Provide docs to describe running on CDH/HDP cluster.

This doc consolidates information relevant to CDH/HDP users in a single place.

docs/_layouts/global.html

@@ -98,6 +98,7 @@
                             <ul class="dropdown-menu">
                                 <li><a href="configuration.html">Configuration</a></li>
                                 <li><a href="tuning.html">Tuning Guide</a></li>
+                                <li><a href="cdh-hdp.html">Running with CDH/HDP</a></li>
                                 <li><a href="hardware-provisioning.html">Hardware Provisioning</a></li>
                                 <li><a href="building-with-maven.html">Building Spark with Maven</a></li>
                                 <li><a href="contributing-to-spark.html">Contributing to Spark</a></li>

docs/cdh-hdp.md

+---
+layout: global
+title: Running with Cloudera and HortonWorks Distributions
+---
+
+Spark is fully compatible with all versions of Cloudera's Distribution Including Hadoop (CDH) and
+the Hortonworks Data Platform (HDP). There are a few things to keep in mind when running against
+these distributions:
+
+# Compile-time Hadoop Version
+When compiling Spark, you'll need to 
+[set the HADOOP_VERSION flag](http://localhost:4000/index.html#a-note-about-hadoop-versions). 
+The table below lists the corresponding HADOOP_VERSION for each CDH/HDP release. _Note_ that
+some Hadoop releases are binary compatible across client versions. This means the pre-built Spark
+distribution may "just work" without you needing to compile. That said, we recommend compiling with 
+the _exact_ Hadoop version you are running to avoid any compatibility errors.
+
+<table>
+  <tr valign="top">
+    <td>
+      <h3>CDH Releases</h3>
+      <table class="table" style="width:350px;">
+        <tr><th>Version</th><th>HADOOP_VERSION</th></tr>
+        <tr><td>CDH 4.X.X (YARN mode)</td><td>2.0.0-chd4.X.X</td></tr>
+        <tr><td>CDH 4.X.X</td><td>2.0.0-mr1-chd4.X.X</td></tr>
+        <tr><td>CDH 3u6</td><td>0.20.2-cdh3u6</td></tr>
+        <tr><td>CDH 3u5</td><td>0.20.2-cdh3u5</td></tr>
+        <tr><td>CDH 3u4</td><td>0.20.2-cdh3u4</td></tr>
+      </table>
+    </td>
+    <td>
+      <h3>HDP Releases</h3>
+      <table class="table" style="width:350px;">
+        <tr><th>Version</th><th>HADOOP_VERSION</th></tr>
+        <tr><td>HDP 1.3</td><td>1.2.0</td></tr>
+        <tr><td>HDP 1.2</td><td>1.1.2</td></tr>
+        <tr><td>HDP 1.1</td><td>1.0.3</td></tr>
+        <tr><td>HDP 1.0</td><td>1.0.3</td></tr>
+      </table>
+    </td>
+  </tr>
+</table>
+
+# Where to Run Spark
+As described in the [Hardware Provisioning](hardware-provisioning.html#storage-systems) guide,
+Spark can run in a variety of deployment modes:
+
+* Using dedicated set of Spark nodes in your cluster. These nodes should be co-located with your
+  Hadoop installation.
+* Running on the same nodes as an existing Hadoop installation, with a fixed amount memory and 
+  cores dedicated to Spark on each node.
+* Run Spark alongside Hadoop using a cluster resource manager, such as YARN or Mesos.
+
+These options are identical for those using CDH and HDP. Note that if you are running a YARN 
+cluster, you may still choose to run Spark on dedicated nodes. In this case, you should use 
+the `mr1` versions of HADOOP_HOME when compiling, not the YARN versions.
+
+# Inheriting Cluster Configuration
+If you plan to read and write from HDFS using Spark, it is good to include copies of two relevant 
+Hadoop configuration files in your $SPARK_HOME/conf directory. These are `hdfs-site.xml`, which 
+provides default behaviors for the HDFS client, and `core-site.xml`, which sets the default 
+filesystem name. The location of these configuration files varies across CDH and HDP versions, but
+a common location is inside of `/etc/hadoop/conf`. Some tools, such as Cloudera Manager, create
+configurations on-the-fly, but offer a mechanisms to download copies of them.
+
+If you can locate these files, copy them into $SPARK_HOME/conf/.