HDFS-9354. Fix TestBalancer#testBalancerWithZeroThreadsForMove on Windows. Contributed by Xiaoyu Yao.

(cherry picked from commit 095ac83402)

Conflicts:
	hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/balancer/TestBalancer.java

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -1376,6 +1376,9 @@ Release 2.8.0 - UNRELEASED
     HDFS-9313. Possible NullPointerException in BlockManager if no excess
     replica can be chosen. (mingma)
 
+    HDFS-9354. Fix TestBalancer#testBalancerWithZeroThreadsForMove on Windows.
+    (Xiaoyu Yao via cnauroth)
+
 Release 2.7.2 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/balancer/TestBalancer.java

@@ -84,6 +84,7 @@ import org.apache.hadoop.test.GenericTestUtils;
 import org.apache.hadoop.util.Time;
 import org.apache.hadoop.util.Tool;
 import org.apache.log4j.Level;
+import org.junit.After;
 import org.junit.Test;
 
 /**
@@ -104,6 +105,14 @@ public class TestBalancer {
   final static Path filePath = new Path(fileName);
   private MiniDFSCluster cluster;
 
+  @After
+  public void shutdown() throws Exception {
+    if (cluster != null) {
+      cluster.shutdown();
+      cluster = null;
+    }
+  }
+
   ClientProtocol client;
 
   static final long TIMEOUT = 40000L; //msec
@@ -348,7 +357,6 @@ public class TestBalancer {
     cluster = new MiniDFSCluster.Builder(conf).numDataNodes(capacities.length)
         .hosts(hosts).racks(racks).simulatedCapacities(capacities).build();
 
-    try {
     cluster.waitActive();
     client = NameNodeProxies.createProxy(conf,
         cluster.getFileSystem(0).getUri(), ClientProtocol.class).getProxy();
@@ -381,11 +389,6 @@ public class TestBalancer {
     Collection<URI> namenodes = DFSUtil.getNsServiceRpcUris(conf);
     int r = Balancer.run(namenodes, BalancerParameters.DEFAULT, conf);
     assertEquals(ExitStatus.NO_MOVE_PROGRESS.getExitCode(), r);
-      
-    } finally {
-      cluster.shutdown();
-    }
-    
   }
   
   /**
@@ -865,7 +868,6 @@ public class TestBalancer {
         .racks(racks)
         .simulatedCapacities(capacities)
         .build();
-    try {
     cluster.waitActive();
     client = NameNodeProxies.createProxy(conf, cluster.getFileSystem(0).getUri(),
         ClientProtocol.class).getProxy();
@@ -887,9 +889,6 @@ public class TestBalancer {
     pBuilder.setRunDuringUpgrade(false);
     final int r = Balancer.run(namenodes, pBuilder.build(), conf);
     assertEquals(ExitStatus.SUCCESS.getExitCode(), r);
-    } finally {
-      cluster.shutdown();
-    }
   }
 
   /**
@@ -1322,7 +1321,6 @@ public class TestBalancer {
       .storageTypes(new StorageType[] { RAM_DISK, DEFAULT })
       .build();
 
-    try {
     cluster.waitActive();
     // Create few files on RAM_DISK
     final String METHOD_NAME = GenericTestUtils.getMethodName();
@@ -1343,7 +1341,8 @@ public class TestBalancer {
 
     // Add another fresh DN with the same type/capacity without files on RAM_DISK
     StorageType[][] storageTypes = new StorageType[][] {{RAM_DISK, DEFAULT}};
-      long[][] storageCapacities = new long[][]{{ramDiskStorageLimit, diskStorageLimit}};
+    long[][] storageCapacities = new long[][]{{ramDiskStorageLimit,
+        diskStorageLimit}};
     cluster.startDataNodes(conf, REPL_FACT, storageTypes, true, null,
       null, null, storageCapacities, null, false, false, false, null);
 
@@ -1360,9 +1359,6 @@ public class TestBalancer {
     // Verify files are still on RAM_DISK
     DFSTestUtil.verifyFileReplicasOnStorageType(fs, client, path1, RAM_DISK);
     DFSTestUtil.verifyFileReplicasOnStorageType(fs, client, path2, RAM_DISK);
-    } finally {
-      cluster.shutdown();
-    }
   }
 
   /**
@@ -1386,8 +1382,6 @@ public class TestBalancer {
         .storageTypes(new StorageType[] { DEFAULT })
         .storagesPerDatanode(1)
         .build();
-
-    try {
     cluster.waitActive();
     // Create a file on the single DN
     final String METHOD_NAME = GenericTestUtils.getMethodName();
@@ -1427,10 +1421,6 @@ public class TestBalancer {
     // Should also work after finalization.
     assertEquals(ExitStatus.SUCCESS.getExitCode(),
         Balancer.run(namenodes, p, conf));
-
-    } finally {
-      cluster.shutdown();
-    }
   }
 
   /**
@@ -1452,7 +1442,7 @@ public class TestBalancer {
     conf.setLong(DFSConfigKeys.DFS_BALANCER_GETBLOCKS_MIN_BLOCK_SIZE_KEY, 1L);
 
     int numOfDatanodes =2;
-    final MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf)
+    cluster = new MiniDFSCluster.Builder(conf)
         .numDataNodes(2)
         .racks(new String[]{"/default/rack0", "/default/rack0"})
         .storagesPerDatanode(2)
@@ -1463,8 +1453,6 @@ public class TestBalancer {
             {100 * blockSize, 20 * blockSize},
             {20 * blockSize, 100 * blockSize}})
         .build();
-
-    try {
     cluster.waitActive();
 
     //set "/bar" directory with ONE_SSD storage policy.
@@ -1492,10 +1480,6 @@ public class TestBalancer {
     // already has one. Otherwise DN1 will have 2 replicas.
     // For same reason, no replicas were moved.
     assertEquals(ExitStatus.NO_MOVE_PROGRESS.getExitCode(), r);
-
-    } finally {
-      cluster.shutdown();
-    }
   }
 
   /**
@@ -1526,7 +1510,6 @@ public class TestBalancer {
     int numOfDatanodes = capacities.length;
     cluster = new MiniDFSCluster.Builder(conf).numDataNodes(capacities.length)
         .racks(racks).simulatedCapacities(capacities).build();
-    try {
     cluster.waitActive();
     client = NameNodeProxies.createProxy(conf,
         cluster.getFileSystem(0).getUri(), ClientProtocol.class).getProxy();
@@ -1567,9 +1550,6 @@ public class TestBalancer {
     exitCode = tool.run(args); // start balancing
     assertEquals("Exit status code mismatches",
         ExitStatus.SUCCESS.getExitCode(), exitCode);
-    } finally {
-      cluster.shutdown();
-    }
   }
 
   /** Balancer should not move blocks with size < minBlockSize. */
@@ -1589,8 +1569,6 @@ public class TestBalancer {
         .simulatedCapacities(capacities)
         .build();
     final DistributedFileSystem dfs = cluster.getFileSystem();
-
-    try {
     cluster.waitActive();
     client = NameNodeProxies.createProxy(conf, dfs.getUri(),
         ClientProtocol.class).getProxy();
@@ -1680,9 +1658,6 @@ public class TestBalancer {
       final int r = Balancer.run(namenodes, p, conf);
       assertEquals(ExitStatus.SUCCESS.getExitCode(), r);
     }
-    } finally {
-      cluster.shutdown();
-    }
   }
 
   /**