The default version of yarn is equal to the hadoop version

This is a part of [PR 590](https://github.com/apache/spark/pull/590)

Author: witgo <witgo@qq.com>

Closes #626 from witgo/yarn_version and squashes the following commits:

c390631 [witgo] restore  the yarn dependency declarations
f8a4ad8 [witgo] revert remove the dependency of avro in yarn-alpha
2df6cf5 [witgo] review commit
a1d876a [witgo] review commit
20e7e3e [witgo] review commit
c76763b [witgo] The default value of yarn.version is equal to hadoop.version

bin/compute-classpath.sh

@@ -44,6 +44,7 @@ if [ -f "$ASSEMBLY_DIR"/spark-assembly*hadoop*-deps.jar ]; then
   CLASSPATH="$CLASSPATH:$FWDIR/sql/catalyst/target/scala-$SCALA_VERSION/classes"
   CLASSPATH="$CLASSPATH:$FWDIR/sql/core/target/scala-$SCALA_VERSION/classes"
   CLASSPATH="$CLASSPATH:$FWDIR/sql/hive/target/scala-$SCALA_VERSION/classes"
+  CLASSPATH="$CLASSPATH:$FWDIR/yarn/stable/target/scala-$SCALA_VERSION/classes"
 
   DEPS_ASSEMBLY_JAR=`ls "$ASSEMBLY_DIR"/spark-assembly*hadoop*-deps.jar`
   CLASSPATH="$CLASSPATH:$DEPS_ASSEMBLY_JAR"

docs/building-with-maven.md

@@ -45,17 +45,20 @@ For Apache Hadoop versions 1.x, Cloudera CDH MRv1, and other Hadoop versions wit
 For Apache Hadoop 2.x, 0.23.x, Cloudera CDH MRv2, and other Hadoop versions with YARN, you can enable the "yarn-alpha" or "yarn" profile and set the "hadoop.version", "yarn.version" property. Note that Hadoop 0.23.X requires a special `-Phadoop-0.23` profile:
 
     # Apache Hadoop 2.0.5-alpha
-    $ mvn -Pyarn-alpha -Dhadoop.version=2.0.5-alpha -Dyarn.version=2.0.5-alpha -DskipTests clean package
+    $ mvn -Pyarn-alpha -Dhadoop.version=2.0.5-alpha -DskipTests clean package
 
     # Cloudera CDH 4.2.0 with MapReduce v2
-    $ mvn -Pyarn-alpha -Dhadoop.version=2.0.0-cdh4.2.0 -Dyarn.version=2.0.0-cdh4.2.0 -DskipTests clean package
+    $ mvn -Pyarn-alpha -Dhadoop.version=2.0.0-cdh4.2.0 -DskipTests clean package
 
     # Apache Hadoop 2.2.X (e.g. 2.2.0 as below) and newer
-    $ mvn -Pyarn -Dhadoop.version=2.2.0 -Dyarn.version=2.2.0 -DskipTests clean package
+    $ mvn -Pyarn -Dhadoop.version=2.2.0 -DskipTests clean package
 
     # Apache Hadoop 0.23.x
     $ mvn -Pyarn-alpha -Phadoop-0.23 -Dhadoop.version=0.23.7 -Dyarn.version=0.23.7 -DskipTests clean package
 
+    # Different versions of HDFS and YARN.
+    $ mvn -Pyarn-alpha -Dhadoop.version=2.3.0 -Dyarn.version=0.23.7 -DskipTests clean package
+
 ## Spark Tests in Maven ##
 
 Tests are run by default via the [ScalaTest Maven plugin](http://www.scalatest.org/user_guide/using_the_scalatest_maven_plugin). Some of the require Spark to be packaged first, so always run `mvn package` with `-DskipTests` the first time. You can then run the tests with `mvn -Dhadoop.version=... test`.

pom.xml

@@ -16,7 +16,8 @@
   ~ limitations under the License.
   -->
 
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
   <modelVersion>4.0.0</modelVersion>
   <parent>
     <groupId>org.apache</groupId>
@@ -119,7 +120,7 @@
     <log4j.version>1.2.17</log4j.version>
     <hadoop.version>1.0.4</hadoop.version>
     <protobuf.version>2.4.1</protobuf.version>
-    <yarn.version>0.23.7</yarn.version>
+    <yarn.version>${hadoop.version}</yarn.version>
     <hbase.version>0.94.6</hbase.version>
     <hive.version>0.12.0</hive.version>
     <parquet.version>1.3.2</parquet.version>
@@ -135,7 +136,8 @@
 
   <repositories>
     <repository>
-      <id>maven-repo</id> <!-- This should be at top, it makes maven try the central repo first and then others and hence faster dep resolution -->
+      <id>maven-repo</id>
+      <!-- This should be at top, it makes maven try the central repo first and then others and hence faster dep resolution -->
       <name>Maven Repository</name>
       <!-- HTTPS is unavailable for Maven Central -->
       <url>http://repo.maven.apache.org/maven2</url>
@@ -847,15 +849,16 @@
         <hadoop.version>0.23.7</hadoop.version>
         <!--<hadoop.version>2.0.5-alpha</hadoop.version> -->
       </properties>
-      <modules>
-        <module>yarn</module>
-      </modules>
       <dependencies>
         <dependency>
           <groupId>org.apache.avro</groupId>
           <artifactId>avro</artifactId>
         </dependency>
       </dependencies>
+      <modules>
+        <module>yarn</module>
+      </modules>
+
     </profile>
 
     <!-- Ganglia integration is not included by default due to LGPL-licensed code -->

yarn/pom.xml

@@ -28,7 +28,7 @@
   <artifactId>yarn-parent_2.10</artifactId>
   <packaging>pom</packaging>
   <name>Spark Project YARN Parent POM</name>
-  
+
   <dependencies>
     <dependency>
       <groupId>org.apache.spark</groupId>
@@ -50,7 +50,6 @@
     <dependency>
       <groupId>org.apache.hadoop</groupId>
       <artifactId>hadoop-client</artifactId>
-      <version>${yarn.version}</version>
     </dependency>
     <dependency>
       <groupId>org.scalatest</groupId>
@@ -128,7 +127,7 @@
               <target>
                 <property name="spark.classpath" refid="maven.test.classpath" />
                 <property environment="env" />
-                <fail message="Please set the SCALA_HOME (or SCALA_LIBRARY_PATH if scala is on the path) environment variables and retry.">  
+                <fail message="Please set the SCALA_HOME (or SCALA_LIBRARY_PATH if scala is on the path) environment variables and retry.">
                   <condition>
                     <not>
                       <or>