/**
* 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 org.apache.hadoop.hdfs.DFSTestUtil;
import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeDescriptor;
import org.junit.Before;
import org.junit.Test;
import java.util.HashMap;
import java.util.Map;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertTrue;
import static org.junit.Assert.fail;
public class TestNetworkTopology {
private final static NetworkTopology cluster = new NetworkTopology();
private DatanodeDescriptor dataNodes[];
@Before
public void setupDatanodes() {
dataNodes = new DatanodeDescriptor[]{
DFSTestUtil.getDatanodeDescriptor("1.1.1.1", "/d1/r1"),
DFSTestUtil.getDatanodeDescriptor("2.2.2.2", "/d1/r1"),
DFSTestUtil.getDatanodeDescriptor("3.3.3.3", "/d1/r2"),
DFSTestUtil.getDatanodeDescriptor("4.4.4.4", "/d1/r2"),
DFSTestUtil.getDatanodeDescriptor("5.5.5.5", "/d1/r2"),
DFSTestUtil.getDatanodeDescriptor("6.6.6.6", "/d2/r3"),
DFSTestUtil.getDatanodeDescriptor("7.7.7.7", "/d2/r3")};
for (int i = 0; i < dataNodes.length; i++) {
cluster.add(dataNodes[i]);
}
}
@Test
public void testContains() throws Exception {
DatanodeDescriptor nodeNotInMap =
DFSTestUtil.getDatanodeDescriptor("8.8.8.8", "/d2/r4");
for (int i = 0; i < dataNodes.length; i++) {
assertTrue(cluster.contains(dataNodes[i]));
}
assertFalse(cluster.contains(nodeNotInMap));
}
@Test
public void testNumOfChildren() throws Exception {
assertEquals(cluster.getNumOfLeaves(), dataNodes.length);
}
@Test
public void testCreateInvalidTopology() throws Exception {
NetworkTopology invalCluster = new NetworkTopology();
DatanodeDescriptor invalDataNodes[] = new DatanodeDescriptor[]{
DFSTestUtil.getDatanodeDescriptor("1.1.1.1", "/d1/r1"),
DFSTestUtil.getDatanodeDescriptor("2.2.2.2", "/d1/r1"),
DFSTestUtil.getDatanodeDescriptor("3.3.3.3", "/d1")};
invalCluster.add(invalDataNodes[0]);
invalCluster.add(invalDataNodes[1]);
try {
invalCluster.add(invalDataNodes[2]);
fail("expected InvalidTopologyException");
} catch (NetworkTopology.InvalidTopologyException e) {
assertTrue(e.getMessage().contains(
"You cannot have a rack and a non-rack node at the same level of the network topology."));
}
}
@Test
public void testRacks() throws Exception {
assertEquals(cluster.getNumOfRacks(), 3);
assertTrue(cluster.isOnSameRack(dataNodes[0], dataNodes[1]));
assertFalse(cluster.isOnSameRack(dataNodes[1], dataNodes[2]));
assertTrue(cluster.isOnSameRack(dataNodes[2], dataNodes[3]));
assertTrue(cluster.isOnSameRack(dataNodes[3], dataNodes[4]));
assertFalse(cluster.isOnSameRack(dataNodes[4], dataNodes[5]));
assertTrue(cluster.isOnSameRack(dataNodes[5], dataNodes[6]));
}
@Test
public void testGetDistance() throws Exception {
assertEquals(cluster.getDistance(dataNodes[0], dataNodes[0]), 0);
assertEquals(cluster.getDistance(dataNodes[0], dataNodes[1]), 2);
assertEquals(cluster.getDistance(dataNodes[0], dataNodes[3]), 4);
assertEquals(cluster.getDistance(dataNodes[0], dataNodes[6]), 6);
}
@Test
public void testPseudoSortByDistance() throws Exception {
DatanodeDescriptor[] testNodes = new DatanodeDescriptor[3];
// array contains both local node & local rack node
testNodes[0] = dataNodes[1];
testNodes[1] = dataNodes[2];
testNodes[2] = dataNodes[0];
cluster.pseudoSortByDistance(dataNodes[0], testNodes);
assertTrue(testNodes[0] == dataNodes[0]);
assertTrue(testNodes[1] == dataNodes[1]);
assertTrue(testNodes[2] == dataNodes[2]);
// array contains local node
testNodes[0] = dataNodes[1];
testNodes[1] = dataNodes[3];
testNodes[2] = dataNodes[0];
cluster.pseudoSortByDistance(dataNodes[0], testNodes);
assertTrue(testNodes[0] == dataNodes[0]);
assertTrue(testNodes[1] == dataNodes[1]);
assertTrue(testNodes[2] == dataNodes[3]);
// array contains local rack node
testNodes[0] = dataNodes[5];
testNodes[1] = dataNodes[3];
testNodes[2] = dataNodes[1];
cluster.pseudoSortByDistance(dataNodes[0], testNodes);
assertTrue(testNodes[0] == dataNodes[1]);
assertTrue(testNodes[1] == dataNodes[3]);
assertTrue(testNodes[2] == dataNodes[5]);
// array contains local rack node which happens to be in position 0
testNodes[0] = dataNodes[1];
testNodes[1] = dataNodes[5];
testNodes[2] = dataNodes[3];
cluster.pseudoSortByDistance(dataNodes[0], testNodes);
// peudoSortByDistance does not take the "data center" layer into consideration
// and it doesn't sort by getDistance, so 1, 5, 3 is also valid here
assertTrue(testNodes[0] == dataNodes[1]);
assertTrue(testNodes[1] == dataNodes[5]);
assertTrue(testNodes[2] == dataNodes[3]);
}
@Test
public void testRemove() throws Exception {
for (int i = 0; i < dataNodes.length; i++) {
cluster.remove(dataNodes[i]);
}
for (int i = 0; i < dataNodes.length; i++) {
assertFalse(cluster.contains(dataNodes[i]));
}
assertEquals(0, cluster.getNumOfLeaves());
for (int i = 0; i < dataNodes.length; i++) {
cluster.add(dataNodes[i]);
}
}
/**
* This picks a large number of nodes at random in order to ensure coverage
*
* @param numNodes
* the number of nodes
* @param excludedScope
* the excluded scope
* @return the frequency that nodes were chosen
*/
private Map<Node, Integer> pickNodesAtRandom(int numNodes,
String excludedScope) {
Map<Node, Integer> frequency = new HashMap<Node, Integer>();
for (DatanodeDescriptor dnd : dataNodes) {
frequency.put(dnd, 0);
}
for (int j = 0; j < numNodes; j++) {
Node random = cluster.chooseRandom(excludedScope);
frequency.put(random, frequency.get(random) + 1);
}
return frequency;
}
/**
* This test checks that chooseRandom works for an excluded node.
*/
@Test
public void testChooseRandomExcludedNode() {
String scope = "~" + NodeBase.getPath(dataNodes[0]);
Map<Node, Integer> frequency = pickNodesAtRandom(100, scope);
for (Node key : dataNodes) {
// all nodes except the first should be more than zero
assertTrue(frequency.get(key) > 0 || key == dataNodes[0]);
}
}
/**
* This test checks that chooseRandom works for an excluded rack.
*/
@Test
public void testChooseRandomExcludedRack() {
Map<Node, Integer> frequency = pickNodesAtRandom(100, "~" + "/d2");
// all the nodes on the second rack should be zero
for (int j = 0; j < dataNodes.length; j++) {
int freq = frequency.get(dataNodes[j]);
if (dataNodes[j].getNetworkLocation().startsWith("/d2")) {
assertEquals(0, freq);
} else {
assertTrue(freq > 0);
}
}
}
}