From c44d8b8bdf98d7e39e49344db5f1127cf4829967 Mon Sep 17 00:00:00 2001
From: Takanobu Asanuma <tasanuma@apache.org>
Date: Sat, 23 May 2020 17:28:38 +0900
Subject: [PATCH] HDFS-15363. BlockPlacementPolicyWithNodeGroup should validate
 if it is initialized by NetworkTopologyWithNodeGroup. Contributed by
 hemanthboyina.

(cherry picked from commit 4d22d1c58f0eb093775f0fe4f39ef4be639ad752)
---
 .../BlockPlacementPolicyWithNodeGroup.java    |  5 ++++
 .../balancer/TestBalancerWithNodeGroup.java   | 27 +++++++++++++++++++
 2 files changed, 32 insertions(+)

diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockPlacementPolicyWithNodeGroup.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockPlacementPolicyWithNodeGroup.java
index 194f6ba9c87..39f15191534 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockPlacementPolicyWithNodeGroup.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockPlacementPolicyWithNodeGroup.java
@@ -46,6 +46,11 @@ public class BlockPlacementPolicyWithNodeGroup extends BlockPlacementPolicyDefau
   public void initialize(Configuration conf,  FSClusterStats stats,
           NetworkTopology clusterMap, 
           Host2NodesMap host2datanodeMap) {
+    if (!(clusterMap instanceof NetworkTopologyWithNodeGroup)) {
+      throw new IllegalArgumentException(
+          "Configured cluster topology should be "
+              + NetworkTopologyWithNodeGroup.class.getName());
+    }
     super.initialize(conf, stats, clusterMap, host2datanodeMap);
   }
 
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/balancer/TestBalancerWithNodeGroup.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/balancer/TestBalancerWithNodeGroup.java
index caac02c1bf9..6088722ef26 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/balancer/TestBalancerWithNodeGroup.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/balancer/TestBalancerWithNodeGroup.java
@@ -47,6 +47,7 @@ import org.apache.hadoop.hdfs.protocol.HdfsConstants.DatanodeReportType;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockPlacementPolicyWithNodeGroup;
 import org.apache.hadoop.net.NetworkTopology;
 import org.apache.hadoop.net.NetworkTopologyWithNodeGroup;
+import org.apache.hadoop.test.LambdaTestUtils;
 import org.junit.Assert;
 import org.junit.Test;
 
@@ -361,4 +362,30 @@ public class TestBalancerWithNodeGroup {
       cluster.shutdown();
     }
   }
+
+  /**
+   * verify BlockPlacementPolicyNodeGroup uses NetworkTopologyWithNodeGroup.
+   */
+
+  @Test
+  public void testBPPNodeGroup() throws Exception {
+    Configuration conf = createConf();
+    conf.setBoolean(DFSConfigKeys.DFS_USE_DFS_NETWORK_TOPOLOGY_KEY, true);
+    long[] capacities = new long[] {CAPACITY, CAPACITY, CAPACITY, CAPACITY};
+    String[] racks = new String[] {RACK0, RACK0, RACK1, RACK1};
+    String[] nodeGroups =
+        new String[] {NODEGROUP0, NODEGROUP0, NODEGROUP1, NODEGROUP2};
+
+    int numOfDatanodes = capacities.length;
+    assertEquals(numOfDatanodes, racks.length);
+    assertEquals(numOfDatanodes, nodeGroups.length);
+    MiniDFSCluster.Builder builder =
+        new MiniDFSCluster.Builder(conf).numDataNodes(capacities.length)
+            .racks(racks).simulatedCapacities(capacities);
+    MiniDFSClusterWithNodeGroup.setNodeGroups(nodeGroups);
+    LambdaTestUtils.intercept(IllegalArgumentException.class,
+        "Configured cluster topology should be "
+            + "org.apache.hadoop.net.NetworkTopologyWithNodeGroup",
+        () -> new MiniDFSClusterWithNodeGroup(builder));
+  }
 }