hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/net/TestClusterTopology.java - hadoop - Git at Google

 /**
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
  * distributed with this work for additional information
  * regarding copyright ownership.  The ASF licenses this file
  * to you under the Apache License, Version 2.0 (the
  * "License"); you may not use this file except in compliance
  * with the License.  You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 package org.apache.hadoop.net;

 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Arrays;

 import org.apache.commons.lang3.tuple.Pair;
 import org.apache.commons.math3.stat.inference.ChiSquareTest;
 import org.apache.hadoop.conf.Configuration;
 import org.junit.Assert;
 import org.junit.Test;

 public class TestClusterTopology extends Assert {

   public static class NodeElement implements Node {
     private String location;
     private String name;
     private Node parent;
     private int level;

     public NodeElement(String name) {
       this.name = name;
     }

     @Override
     public String getNetworkLocation() {
       return location;
     }

     @Override
     public void setNetworkLocation(String location) {
       this.location = location;
     }

     @Override
     public String getName() {
       return name;
     }

     @Override
     public Node getParent() {
       return parent;
     }

     @Override
     public void setParent(Node parent) {
       this.parent = parent;
     }

     @Override
     public int getLevel() {
       return level;
     }

     @Override
     public void setLevel(int i) {
       this.level = i;
     }

   }

   /**
    * Test the count of nodes with exclude list
    */
   @Test
   public void testCountNumNodes() throws Exception {
     // create the topology
     NetworkTopology cluster = NetworkTopology.getInstance(new Configuration());
     NodeElement node1 = getNewNode("node1", "/d1/r1");
     cluster.add(node1);
     NodeElement node2 = getNewNode("node2", "/d1/r2");
     cluster.add(node2);
     NodeElement node3 = getNewNode("node3", "/d1/r3");
     cluster.add(node3);
     NodeElement node4 = getNewNode("node4", "/d1/r4");
     cluster.add(node4);
     // create exclude list
     List<Node> excludedNodes = new ArrayList<Node>();

     assertEquals("4 nodes should be available", 4,
         cluster.countNumOfAvailableNodes(NodeBase.ROOT, excludedNodes));
     NodeElement deadNode = getNewNode("node5", "/d1/r2");
     excludedNodes.add(deadNode);
     assertEquals("4 nodes should be available with extra excluded Node", 4,
         cluster.countNumOfAvailableNodes(NodeBase.ROOT, excludedNodes));
     // add one existing node to exclude list
     excludedNodes.add(node4);
     assertEquals("excluded nodes with ROOT scope should be considered", 3,
         cluster.countNumOfAvailableNodes(NodeBase.ROOT, excludedNodes));
     assertEquals("excluded nodes without ~ scope should be considered", 2,
         cluster.countNumOfAvailableNodes("~" + deadNode.getNetworkLocation(),
             excludedNodes));
     assertEquals("excluded nodes with rack scope should be considered", 1,
         cluster.countNumOfAvailableNodes(deadNode.getNetworkLocation(),
             excludedNodes));
     // adding the node in excluded scope to excluded list
     excludedNodes.add(node2);
     assertEquals("excluded nodes with ~ scope should be considered", 2,
         cluster.countNumOfAvailableNodes("~" + deadNode.getNetworkLocation(),
             excludedNodes));
     // getting count with non-exist scope.
     assertEquals("No nodes should be considered for non-exist scope", 0,
         cluster.countNumOfAvailableNodes("/non-exist", excludedNodes));
     // remove a node from the cluster
     cluster.remove(node1);
     assertEquals("1 node should be available", 1,
         cluster.countNumOfAvailableNodes(NodeBase.ROOT, excludedNodes));
   }

   /**
    * Test how well we pick random nodes.
    */
   @Test
   public void testChooseRandom() {
     // create the topology
     NetworkTopology cluster = NetworkTopology.getInstance(new Configuration());
     NodeElement node1 = getNewNode("node1", "/d1/r1");
     cluster.add(node1);
     NodeElement node2 = getNewNode("node2", "/d1/r2");
     cluster.add(node2);
     NodeElement node3 = getNewNode("node3", "/d1/r3");
     cluster.add(node3);
     NodeElement node4 = getNewNode("node4", "/d1/r3");
     cluster.add(node4);

     // Number of test runs
     int numTestRuns = 3;
     int chiSquareTestRejectedCounter = 0;

     // Number of iterations to do the test
     int numIterations = 100;

     for (int testRun = 0; testRun < numTestRuns; ++testRun) {

       // Pick random nodes
       HashMap<String, Integer> histogram = new HashMap<String, Integer>();
       for (int i = 0; i < numIterations; i++) {
         String randomNode = cluster.chooseRandom(NodeBase.ROOT).getName();
         if (!histogram.containsKey(randomNode)) {
           histogram.put(randomNode, 0);
         }
         histogram.put(randomNode, histogram.get(randomNode) + 1);
       }
       assertEquals("Random is not selecting all nodes", 4, histogram.size());

       // Check with 99% confidence alpha=0.01 as confidence = 100 * (1 - alpha)
       ChiSquareTest chiSquareTest = new ChiSquareTest();
       double[] expected = new double[histogram.size()];
       long[] observed = new long[histogram.size()];
       int j = 0;
       for (Integer occurrence : histogram.values()) {
         expected[j] = 1.0 * numIterations / histogram.size();
         observed[j] = occurrence;
         j++;
       }
       boolean chiSquareTestRejected =
             chiSquareTest.chiSquareTest(expected, observed, 0.01);

       if (chiSquareTestRejected) {
         ++chiSquareTestRejectedCounter;
       }
     }

     // Check that they have the proper distribution
     assertFalse("Random not choosing nodes with proper distribution",
             chiSquareTestRejectedCounter==3);

     // Pick random nodes excluding the 2 nodes in /d1/r3
     HashMap<String, Integer> histogram = new HashMap<String, Integer>();
     for (int i=0; i<numIterations; i++) {
       String randomNode = cluster.chooseRandom("~/d1/r3").getName();
       if (!histogram.containsKey(randomNode)) {
         histogram.put(randomNode, 0);
       }
       histogram.put(randomNode, histogram.get(randomNode) + 1);
     }
     assertEquals("Random is not selecting the nodes it should",
         2, histogram.size());

     Node val = cluster.chooseRandom("/d1", "/d", Collections.emptyList());
     assertNotNull(val);

   }

   @Test
   public void testChooseRandomExcluded() {
     // create the topology
     //                        a1
     //                b1------|--------b2
     //                 |                |
     //          c1-----|-----c2         c3
     //         /  \          |          |
     //        /    \         |          |
     //     node1    node2   node3      node4

     NetworkTopology cluster = NetworkTopology.getInstance(new Configuration());
     NodeElement node1 = getNewNode("node1", "/a1/b1/c1");
     cluster.add(node1);
     NodeElement node2 = getNewNode("node2", "/a1/b1/c1");
     cluster.add(node2);
     NodeElement node3 = getNewNode("node3", "/a1/b1/c2");
     cluster.add(node3);
     NodeElement node4 = getNewNode("node4", "/a1/b2/c3");
     cluster.add(node4);

     Node node = cluster.chooseRandom("/a1/b1", "/a1/b1/c1", null);
     assertSame("node3", node.getName());

     node = cluster.chooseRandom("/a1/b1", "/a1/b1/c1", Arrays.asList(node1));
     assertSame("node3", node.getName());

     node = cluster.chooseRandom("/a1/b1", "/a1/b1/c1", Arrays.asList(node3));
     assertNull(node);

     node = cluster.chooseRandom("/a1/b1", "/a1/b1/c1", Arrays.asList(node4));
     assertSame("node3", node.getName());
   }

   @Test
   public void testNodeBaseNormalizeRemoveLeadingSlash() {
     assertEquals("/d1", NodeBase.normalize("/d1///"));
     assertEquals("/d1", NodeBase.normalize("/d1/"));
     assertEquals("/d1", NodeBase.normalize("/d1"));
     assertEquals("", NodeBase.normalize("///"));
     assertEquals("", NodeBase.normalize("/"));
   }

   private NodeElement getNewNode(String name, String rackLocation) {
     NodeElement node = new NodeElement(name);
     node.setNetworkLocation(rackLocation);
     return node;
   }

   private NodeElement getNewNode(NetworkTopology cluster,
                                  String name, String rackLocation) {
     NodeElement node = getNewNode(name, rackLocation);
     cluster.add(node);
     return node;
   }

   @Test
   @SuppressWarnings("unchecked")
   public void testWeights() {
     // create the topology
     NetworkTopology cluster = NetworkTopology.getInstance(new Configuration());
     NodeElement node1 = getNewNode(cluster, "node1", "/r1");
     NodeElement node2 = getNewNode(cluster, "node2", "/r1");
     NodeElement node3 = getNewNode(cluster, "node3", "/r2");
     for (Pair<Integer, NodeElement> test: new Pair[]{Pair.of(0, node1),
         Pair.of(2, node2), Pair.of(4, node3)}) {
       int expect = test.getLeft();
       assertEquals(test.toString(), expect, cluster.getWeight(node1, test.getRight()));
       assertEquals(test.toString(), expect,
           cluster.getWeightUsingNetworkLocation(node1, test.getRight()));
     }
     // Reset so that we can have 2 levels
     cluster = NetworkTopology.getInstance(new Configuration());
     NodeElement node5 = getNewNode(cluster, "node5", "/pod1/r1");
     NodeElement node6 = getNewNode(cluster, "node6", "/pod1/r1");
     NodeElement node7 = getNewNode(cluster, "node7", "/pod1/r2");
     NodeElement node8 = getNewNode(cluster, "node8", "/pod2/r3");
     for (Pair<Integer, NodeElement> test: new Pair[]{Pair.of(0, node5),
         Pair.of(2, node6), Pair.of(4, node7), Pair.of(6, node8)}) {
       int expect = test.getLeft();
       assertEquals(test.toString(), expect, cluster.getWeight(node5, test.getRight()));
       assertEquals(test.toString(), expect,
           cluster.getWeightUsingNetworkLocation(node5, test.getRight()));
     }
   }
 }
	/**
	* Licensed to the Apache Software Foundation (ASF) under one
	* or more contributor license agreements. See the NOTICE file
	* distributed with this work for additional information
	* regarding copyright ownership. The ASF licenses this file
	* to you under the Apache License, Version 2.0 (the
	* "License"); you may not use this file except in compliance
	* with the License. You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/
	package org.apache.hadoop.net;

	import java.util.ArrayList;
	import java.util.Collections;
	import java.util.HashMap;
	import java.util.List;
	import java.util.Arrays;

	import org.apache.commons.lang3.tuple.Pair;
	import org.apache.commons.math3.stat.inference.ChiSquareTest;
	import org.apache.hadoop.conf.Configuration;
	import org.junit.Assert;
	import org.junit.Test;

	public class TestClusterTopology extends Assert {

	public static class NodeElement implements Node {
	private String location;
	private String name;
	private Node parent;
	private int level;

	public NodeElement(String name) {
	this.name = name;
	}

	@Override
	public String getNetworkLocation() {
	return location;
	}

	@Override
	public void setNetworkLocation(String location) {
	this.location = location;
	}

	@Override
	public String getName() {
	return name;
	}

	@Override
	public Node getParent() {
	return parent;
	}

	@Override
	public void setParent(Node parent) {
	this.parent = parent;
	}

	@Override
	public int getLevel() {
	return level;
	}

	@Override
	public void setLevel(int i) {
	this.level = i;
	}

	}

	/**
	* Test the count of nodes with exclude list
	*/
	@Test
	public void testCountNumNodes() throws Exception {
	// create the topology
	NetworkTopology cluster = NetworkTopology.getInstance(new Configuration());
	NodeElement node1 = getNewNode("node1", "/d1/r1");
	cluster.add(node1);
	NodeElement node2 = getNewNode("node2", "/d1/r2");
	cluster.add(node2);
	NodeElement node3 = getNewNode("node3", "/d1/r3");
	cluster.add(node3);
	NodeElement node4 = getNewNode("node4", "/d1/r4");
	cluster.add(node4);
	// create exclude list
	List<Node> excludedNodes = new ArrayList<Node>();

	assertEquals("4 nodes should be available", 4,
	cluster.countNumOfAvailableNodes(NodeBase.ROOT, excludedNodes));
	NodeElement deadNode = getNewNode("node5", "/d1/r2");
	excludedNodes.add(deadNode);
	assertEquals("4 nodes should be available with extra excluded Node", 4,
	cluster.countNumOfAvailableNodes(NodeBase.ROOT, excludedNodes));
	// add one existing node to exclude list
	excludedNodes.add(node4);
	assertEquals("excluded nodes with ROOT scope should be considered", 3,
	cluster.countNumOfAvailableNodes(NodeBase.ROOT, excludedNodes));
	assertEquals("excluded nodes without ~ scope should be considered", 2,
	cluster.countNumOfAvailableNodes("~" + deadNode.getNetworkLocation(),
	excludedNodes));
	assertEquals("excluded nodes with rack scope should be considered", 1,
	cluster.countNumOfAvailableNodes(deadNode.getNetworkLocation(),
	excludedNodes));
	// adding the node in excluded scope to excluded list
	excludedNodes.add(node2);
	assertEquals("excluded nodes with ~ scope should be considered", 2,
	cluster.countNumOfAvailableNodes("~" + deadNode.getNetworkLocation(),
	excludedNodes));
	// getting count with non-exist scope.
	assertEquals("No nodes should be considered for non-exist scope", 0,
	cluster.countNumOfAvailableNodes("/non-exist", excludedNodes));
	// remove a node from the cluster
	cluster.remove(node1);
	assertEquals("1 node should be available", 1,
	cluster.countNumOfAvailableNodes(NodeBase.ROOT, excludedNodes));
	}

	/**
	* Test how well we pick random nodes.
	*/
	@Test
	public void testChooseRandom() {
	// create the topology
	NetworkTopology cluster = NetworkTopology.getInstance(new Configuration());
	NodeElement node1 = getNewNode("node1", "/d1/r1");
	cluster.add(node1);
	NodeElement node2 = getNewNode("node2", "/d1/r2");
	cluster.add(node2);
	NodeElement node3 = getNewNode("node3", "/d1/r3");
	cluster.add(node3);
	NodeElement node4 = getNewNode("node4", "/d1/r3");
	cluster.add(node4);

	// Number of test runs
	int numTestRuns = 3;
	int chiSquareTestRejectedCounter = 0;

	// Number of iterations to do the test
	int numIterations = 100;

	for (int testRun = 0; testRun < numTestRuns; ++testRun) {

	// Pick random nodes
	HashMap<String, Integer> histogram = new HashMap<String, Integer>();
	for (int i = 0; i < numIterations; i++) {
	String randomNode = cluster.chooseRandom(NodeBase.ROOT).getName();
	if (!histogram.containsKey(randomNode)) {
	histogram.put(randomNode, 0);
	}
	histogram.put(randomNode, histogram.get(randomNode) + 1);
	}
	assertEquals("Random is not selecting all nodes", 4, histogram.size());

	// Check with 99% confidence alpha=0.01 as confidence = 100 * (1 - alpha)
	ChiSquareTest chiSquareTest = new ChiSquareTest();
	double[] expected = new double[histogram.size()];
	long[] observed = new long[histogram.size()];
	int j = 0;
	for (Integer occurrence : histogram.values()) {
	expected[j] = 1.0 * numIterations / histogram.size();
	observed[j] = occurrence;
	j++;
	}
	boolean chiSquareTestRejected =
	chiSquareTest.chiSquareTest(expected, observed, 0.01);

	if (chiSquareTestRejected) {
	++chiSquareTestRejectedCounter;
	}
	}

	// Check that they have the proper distribution
	assertFalse("Random not choosing nodes with proper distribution",
	chiSquareTestRejectedCounter==3);

	// Pick random nodes excluding the 2 nodes in /d1/r3
	HashMap<String, Integer> histogram = new HashMap<String, Integer>();
	for (int i=0; i<numIterations; i++) {
	String randomNode = cluster.chooseRandom("~/d1/r3").getName();
	if (!histogram.containsKey(randomNode)) {
	histogram.put(randomNode, 0);
	}
	histogram.put(randomNode, histogram.get(randomNode) + 1);
	}
	assertEquals("Random is not selecting the nodes it should",
	2, histogram.size());

	Node val = cluster.chooseRandom("/d1", "/d", Collections.emptyList());
	assertNotNull(val);

	}

	@Test
	public void testChooseRandomExcluded() {
	// create the topology
	// a1
	// b1------\|--------b2
	// \| \|
	// c1-----\|-----c2 c3
	// / \ \| \|
	// / \ \| \|
	// node1 node2 node3 node4

	NetworkTopology cluster = NetworkTopology.getInstance(new Configuration());
	NodeElement node1 = getNewNode("node1", "/a1/b1/c1");
	cluster.add(node1);
	NodeElement node2 = getNewNode("node2", "/a1/b1/c1");
	cluster.add(node2);
	NodeElement node3 = getNewNode("node3", "/a1/b1/c2");
	cluster.add(node3);
	NodeElement node4 = getNewNode("node4", "/a1/b2/c3");
	cluster.add(node4);

	Node node = cluster.chooseRandom("/a1/b1", "/a1/b1/c1", null);
	assertSame("node3", node.getName());

	node = cluster.chooseRandom("/a1/b1", "/a1/b1/c1", Arrays.asList(node1));
	assertSame("node3", node.getName());

	node = cluster.chooseRandom("/a1/b1", "/a1/b1/c1", Arrays.asList(node3));
	assertNull(node);

	node = cluster.chooseRandom("/a1/b1", "/a1/b1/c1", Arrays.asList(node4));
	assertSame("node3", node.getName());
	}

	@Test
	public void testNodeBaseNormalizeRemoveLeadingSlash() {
	assertEquals("/d1", NodeBase.normalize("/d1///"));
	assertEquals("/d1", NodeBase.normalize("/d1/"));
	assertEquals("/d1", NodeBase.normalize("/d1"));
	assertEquals("", NodeBase.normalize("///"));
	assertEquals("", NodeBase.normalize("/"));
	}

	private NodeElement getNewNode(String name, String rackLocation) {
	NodeElement node = new NodeElement(name);
	node.setNetworkLocation(rackLocation);
	return node;
	}

	private NodeElement getNewNode(NetworkTopology cluster,
	String name, String rackLocation) {
	NodeElement node = getNewNode(name, rackLocation);
	cluster.add(node);
	return node;
	}

	@Test
	@SuppressWarnings("unchecked")
	public void testWeights() {
	// create the topology
	NetworkTopology cluster = NetworkTopology.getInstance(new Configuration());
	NodeElement node1 = getNewNode(cluster, "node1", "/r1");
	NodeElement node2 = getNewNode(cluster, "node2", "/r1");
	NodeElement node3 = getNewNode(cluster, "node3", "/r2");
	for (Pair<Integer, NodeElement> test: new Pair[]{Pair.of(0, node1),
	Pair.of(2, node2), Pair.of(4, node3)}) {
	int expect = test.getLeft();
	assertEquals(test.toString(), expect, cluster.getWeight(node1, test.getRight()));
	assertEquals(test.toString(), expect,
	cluster.getWeightUsingNetworkLocation(node1, test.getRight()));
	}
	// Reset so that we can have 2 levels
	cluster = NetworkTopology.getInstance(new Configuration());
	NodeElement node5 = getNewNode(cluster, "node5", "/pod1/r1");
	NodeElement node6 = getNewNode(cluster, "node6", "/pod1/r1");
	NodeElement node7 = getNewNode(cluster, "node7", "/pod1/r2");
	NodeElement node8 = getNewNode(cluster, "node8", "/pod2/r3");
	for (Pair<Integer, NodeElement> test: new Pair[]{Pair.of(0, node5),
	Pair.of(2, node6), Pair.of(4, node7), Pair.of(6, node8)}) {
	int expect = test.getLeft();
	assertEquals(test.toString(), expect, cluster.getWeight(node5, test.getRight()));
	assertEquals(test.toString(), expect,
	cluster.getWeightUsingNetworkLocation(node5, test.getRight()));
	}
	}
	}