MAPREDUCE-4105. Yarn RackResolver ignores rack configurations. Contributed by Ahmed Radwan.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1311520 13f79535-47bb-0310-9956-ffa450edef68

hadoop-mapreduce-project/CHANGES.txt

@@ -218,6 +218,9 @@ Release 2.0.0 - UNRELEASED
     org.apache.hadoop.mapred.TestMiniMRWithDFSWithDistinctUsers (Devaraj K via
     bobby)
 
+    MAPREDUCE-4105. Yarn RackResolver ignores rack configurations. 
+    (Ahmed Radwan via tomwhite)
+
 Release 0.23.3 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-mapreduce-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/util/RackResolver.java

@@ -31,6 +31,9 @@ import org.apache.hadoop.net.DNSToSwitchMapping;
 import org.apache.hadoop.net.Node;
 import org.apache.hadoop.net.NodeBase;
 import org.apache.hadoop.net.ScriptBasedMapping;
+import org.apache.hadoop.util.ReflectionUtils;
+
+import com.google.common.annotations.VisibleForTesting;
 
 public class RackResolver {
   private static DNSToSwitchMapping dnsToSwitchMapping;
@@ -49,10 +52,8 @@ public class RackResolver {
         ScriptBasedMapping.class,
         DNSToSwitchMapping.class);
     try {
-      Constructor<? extends DNSToSwitchMapping> dnsToSwitchMappingConstructor
-                             = dnsToSwitchMappingClass.getConstructor();
-      DNSToSwitchMapping newInstance =
-          dnsToSwitchMappingConstructor.newInstance();
+      DNSToSwitchMapping newInstance = ReflectionUtils.newInstance(
+          dnsToSwitchMappingClass, conf);
       // Wrap around the configured class with the Cached implementation so as
       // to save on repetitive lookups.
       // Check if the impl is already caching, to avoid double caching.
@@ -99,4 +100,12 @@ public class RackResolver {
     LOG.info("Resolved " + hostName + " to " + rName);
     return new NodeBase(hostName, rName);
   }
+
+  /**
+   * Only used by tests
+   */
+  @VisibleForTesting
+  static DNSToSwitchMapping getDnsToSwitchMapping(){
+    return dnsToSwitchMapping;
+  }
 }

hadoop-mapreduce-project/hadoop-yarn/hadoop-yarn-common/src/test/java/org/apache/hadoop/yarn/util/TestRackResolver.java

@@ -52,7 +52,7 @@ public class TestRackResolver {
       Assert.assertTrue(numHost1 <= 1);
       return returnList;
     }
-    
+
   }
 
   @Test

hadoop-mapreduce-project/hadoop-yarn/hadoop-yarn-common/src/test/java/org/apache/hadoop/yarn/util/TestRackResolverScriptBasedMapping.java

@@ -0,0 +1,44 @@
+/**
+* Licensed to the Apache Software Foundation (ASF) under one
+* or more contributor license agreements.  See the NOTICE file
+* distributed with this work for additional information
+* regarding copyright ownership.  The ASF licenses this file
+* to you under the Apache License, Version 2.0 (the
+* "License"); you may not use this file except in compliance
+* with the License.  You may obtain a copy of the License at
+*
+*     http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+
+package org.apache.hadoop.yarn.util;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.CommonConfigurationKeysPublic;
+import org.apache.hadoop.net.DNSToSwitchMapping;
+import org.apache.hadoop.net.ScriptBasedMapping;
+import org.junit.Assert;
+import org.junit.Test;
+
+public class TestRackResolverScriptBasedMapping {
+
+  @Test
+  public void testScriptName() {
+    Configuration conf = new Configuration();
+    conf
+        .setClass(
+            CommonConfigurationKeysPublic.
+                NET_TOPOLOGY_NODE_SWITCH_MAPPING_IMPL_KEY,
+            ScriptBasedMapping.class, DNSToSwitchMapping.class);
+    conf.set(CommonConfigurationKeysPublic.NET_TOPOLOGY_SCRIPT_FILE_NAME_KEY,
+        "testScript");
+    RackResolver.init(conf);
+    Assert.assertEquals(RackResolver.getDnsToSwitchMapping().toString(),
+        "script-based mapping with script testScript");
+  }
+}