HADOOP-8159. svn merge -c 1304118 from trunk

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.23@1304119 13f79535-47bb-0310-9956-ffa450edef68

hadoop-common-project/hadoop-common/CHANGES.txt

@@ -156,6 +156,9 @@ Release 0.23.3 - UNRELEASED
 
     HADOOP-8197. Configuration logs WARNs on every use of a deprecated key (tucu)
 
+    HADOOP-8159. NetworkTopology: getLeaf should check for invalid topologies.
+    (Colin Patrick McCabe via eli)
+
   BREAKDOWN OF HADOOP-7454 SUBTASKS
 
     HADOOP-7455. HA: Introduce HA Service Protocol Interface. (suresh)

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/net/NetworkTopology.java

@@ -45,6 +45,13 @@ public class NetworkTopology {
   public static final Log LOG = 
     LogFactory.getLog(NetworkTopology.class);
     
+  public static class InvalidTopologyException extends RuntimeException {
+    private static final long serialVersionUID = 1L;
+    public InvalidTopologyException(String msg) {
+      super(msg);
+    }
+  }
+
   /** InnerNode represents a switch/router of a data center or rack.
    * Different from a leaf node, it has non-null children.
    */
@@ -311,6 +318,8 @@ public class NetworkTopology {
    * the root cluster map
    */
   InnerNode clusterMap = new InnerNode(InnerNode.ROOT);
+  /** Depth of all leaf nodes */
+  private int depthOfAllLeaves = -1;
   /** rack counter */
   private int numOfRacks = 0;
   /** the lock used to manage access */
@@ -328,6 +337,7 @@ public class NetworkTopology {
    */
   public void add(Node node) {
     if (node==null) return;
+    String oldTopoStr = this.toString();
     if( node instanceof InnerNode ) {
       throw new IllegalArgumentException(
         "Not allow to add an inner node: "+NodeBase.getPath(node));
@@ -345,6 +355,19 @@ public class NetworkTopology {
         if (rack == null) {
           numOfRacks++;
         }
+        if (!(node instanceof InnerNode)) {
+          if (depthOfAllLeaves == -1) {
+            depthOfAllLeaves = node.getLevel();
+          } else {
+            if (depthOfAllLeaves != node.getLevel()) {
+              LOG.error("Error: can't add leaf node at depth " +
+                  node.getLevel() + " to topology:\n" + oldTopoStr);
+              throw new InvalidTopologyException("Invalid network topology. " +
+                  "You cannot have a rack and a non-rack node at the same " +
+                  "level of the network topology.");
+            }
+          }
+        }
       }
       if(LOG.isDebugEnabled()) {
         LOG.debug("NetworkTopology became:\n" + this.toString());