MAPREDUCE-5083. MiniMRCluster should use a random component when creating an actual cluster. Contributed by Siddharth Seth.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2.0.4-alpha@1464637 13f79535-47bb-0310-9956-ffa450edef68

hadoop-mapreduce-project/CHANGES.txt

@@ -19,6 +19,9 @@ Release 2.0.4-beta - UNRELEASED
     fix failures in renewal of HistoryServer's delegations tokens. (Siddharth
     Seth via vinodkv)
 
+    MAPREDUCE-5083. MiniMRCluster should use a random component when creating an
+    actual cluster (Siddharth Seth via hitesh)
+
 Release 2.0.3-alpha - 2013-02-06 
 
   INCOMPATIBLE CHANGES

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-jobclient/src/test/java/org/apache/hadoop/mapred/MiniMRClientClusterFactory.java

@@ -38,6 +38,12 @@ public class MiniMRClientClusterFactory {
 
   public static MiniMRClientCluster create(Class<?> caller, int noOfNMs,
       Configuration conf) throws IOException {
+    return create(caller, caller.getName(), noOfNMs, conf);
+  }
+  
+  public static MiniMRClientCluster create(Class<?> caller, String identifier,
+      int noOfNMs,
+      Configuration conf) throws IOException {
 
     if (conf == null) {
       conf = new Configuration();
@@ -45,7 +51,7 @@ public class MiniMRClientClusterFactory {
 
     FileSystem fs = FileSystem.get(conf);
 
-    Path testRootDir = new Path("target", caller.getName() + "-tmpDir")
+    Path testRootDir = new Path("target", identifier + "-tmpDir")
         .makeQualified(fs);
     Path appJar = new Path(testRootDir, "MRAppJar.jar");
 
@@ -65,10 +71,10 @@ public class MiniMRClientClusterFactory {
     fs.setPermission(remoteCallerJar, new FsPermission("744"));
     job.addFileToClassPath(remoteCallerJar);
 
-    MiniMRYarnCluster miniMRYarnCluster = new MiniMRYarnCluster(caller
-        .getName(), noOfNMs);
+    MiniMRYarnCluster miniMRYarnCluster =
+        new MiniMRYarnCluster(identifier, noOfNMs);
     job.getConfiguration().set("minimrclientcluster.caller.name",
-        caller.getName());
+        identifier);
     job.getConfiguration().setInt("minimrclientcluster.nodemanagers.number",
         noOfNMs);
     miniMRYarnCluster.init(job.getConfiguration());

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-jobclient/src/test/java/org/apache/hadoop/mapred/MiniMRCluster.java

@@ -18,6 +18,7 @@
 package org.apache.hadoop.mapred;
 
 import java.io.IOException;
+import java.util.Random;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -177,8 +178,10 @@ public class MiniMRCluster {
       int numTrackerToExclude, Clock clock) throws IOException {
     if (conf == null) conf = new JobConf();
     FileSystem.setDefaultUri(conf, namenode);
+    String identifier = this.getClass().getName() + "_"
+        + Integer.toString(new Random().nextInt(Integer.MAX_VALUE));
     mrClientCluster = MiniMRClientClusterFactory.create(this.getClass(),
-        numTaskTrackers, conf);
+        identifier, numTaskTrackers, conf);
   }
 
   public UserGroupInformation getUgi() {