Add a test for single node rack case.

apache · Mar 27, 2020 · 8857bca · 8857bca
1 parent 1fe913f
commit 8857bca
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Showing 2 changed files with 36 additions and 1 deletion.
diff --git a/...server-scm/src/main/java/org/apache/hadoop/hdds/scm/pipeline/PipelinePlacementPolicy.java b/...server-scm/src/main/java/org/apache/hadoop/hdds/scm/pipeline/PipelinePlacementPolicy.java
@@ -408,7 +408,7 @@ private boolean checkAllNodesAreEqual(NetworkTopology topology) {
   @VisibleForTesting
   protected DatanodeDetails chooseNodeFromNetworkTopology(
       NetworkTopology networkTopology, DatanodeDetails anchor,
-      List<DatanodeDetails> excludedNodes) throws SCMException {
+      List<DatanodeDetails> excludedNodes) {
     Preconditions.checkArgument(networkTopology != null);
 
     Collection<Node> excluded = new ArrayList<>();

diff --git a/...er-scm/src/test/java/org/apache/hadoop/hdds/scm/pipeline/TestPipelinePlacementPolicy.java b/...er-scm/src/test/java/org/apache/hadoop/hdds/scm/pipeline/TestPipelinePlacementPolicy.java
@@ -110,6 +110,35 @@ public void testChooseNodeBasedOnNetworkTopology() throws SCMException {
         nextNode.getNetworkLocation());
   }
 
+  @Test
+  public void testChooseNodeWithSingleNodeRack() throws SCMException {
+    // There is only one node on 3 racks altogether.
+    List<DatanodeDetails> datanodes = new ArrayList<>();
+    for (Node node : SINGLE_NODE_RACK) {
+      DatanodeDetails datanode = overwriteLocationInNode(
+          MockDatanodeDetails.randomDatanodeDetails(), node);
+      datanodes.add(datanode);
+    }
+    MockNodeManager localNodeManager = new MockNodeManager(initTopology(),
+        datanodes, false, datanodes.size());
+    PipelinePlacementPolicy localPlacementPolicy = new PipelinePlacementPolicy(
+        localNodeManager, new PipelineStateManager(), conf);
+    int nodesRequired = HddsProtos.ReplicationFactor.THREE.getNumber();
+    List<DatanodeDetails> results = localPlacementPolicy.chooseDatanodes(
+        new ArrayList<>(datanodes.size()),
+        new ArrayList<>(datanodes.size()),
+        nodesRequired, 0);
+
+    Assert.assertEquals(nodesRequired, results.size());
+    // 3 nodes should be on different racks.
+    Assert.assertNotEquals(results.get(0).getNetworkLocation(),
+        results.get(1).getNetworkLocation());
+    Assert.assertNotEquals(results.get(0).getNetworkLocation(),
+        results.get(2).getNetworkLocation());
+    Assert.assertNotEquals(results.get(1).getNetworkLocation(),
+        results.get(2).getNetworkLocation());
+  }
+
   @Test
   public void testChooseNodeBasedOnRackAwareness() {
     List<DatanodeDetails> healthyNodes = overWriteLocationInNodes(
@@ -192,6 +221,12 @@ public void testRackAwarenessNotEnabledWithFallBack() throws SCMException{
       new NodeImpl("h8", "/r4", NetConstants.NODE_COST_DEFAULT),
   };
 
+  // 3 racks with single node.
+  private final static Node[] SINGLE_NODE_RACK = new NodeImpl[] {
+      new NodeImpl("h1", "/r1", NetConstants.NODE_COST_DEFAULT),
+      new NodeImpl("h2", "/r2", NetConstants.NODE_COST_DEFAULT),
+      new NodeImpl("h3", "/r3", NetConstants.NODE_COST_DEFAULT)
+  };
 
   private NetworkTopology createNetworkTopologyOnDifRacks() {
     NetworkTopology topology = new NetworkTopologyImpl(new Configuration());