/**
* 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.hdfs.server.blockmanagement;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertTrue;
import java.io.File;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.CommonConfigurationKeysPublic;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.hdfs.DFSConfigKeys;
import org.apache.hadoop.hdfs.DFSTestUtil;
import org.apache.hadoop.hdfs.HdfsConfiguration;
import org.apache.hadoop.hdfs.StorageType;
import org.apache.hadoop.hdfs.protocol.HdfsConstants;
import org.apache.hadoop.hdfs.server.namenode.NameNode;
import org.apache.hadoop.net.NetworkTopology;
import org.apache.hadoop.net.NetworkTopologyWithNodeGroup;
import org.apache.hadoop.net.Node;
import org.apache.hadoop.test.PathUtils;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
public class TestReplicationPolicyWithNodeGroup {
private static final int BLOCK_SIZE = 1024;
private static final int NUM_OF_DATANODES = 8;
private static final int NUM_OF_DATANODES_BOUNDARY = 6;
private static final int NUM_OF_DATANODES_MORE_TARGETS = 12;
private final Configuration CONF = new HdfsConfiguration();
private NetworkTopology cluster;
private NameNode namenode;
private BlockPlacementPolicy replicator;
private static final String filename = "/dummyfile.txt";
private static final DatanodeStorageInfo[] storages;
private static final DatanodeDescriptor[] dataNodes;
static {
final String[] racks = {
"/d1/r1/n1",
"/d1/r1/n1",
"/d1/r1/n2",
"/d1/r2/n3",
"/d1/r2/n3",
"/d1/r2/n4",
"/d2/r3/n5",
"/d2/r3/n6"
};
storages = DFSTestUtil.createDatanodeStorageInfos(racks);
dataNodes = DFSTestUtil.toDatanodeDescriptor(storages);
}
private static final DatanodeStorageInfo[] storagesInBoundaryCase;
private static final DatanodeDescriptor[] dataNodesInBoundaryCase;
static {
final String[] racksInBoundaryCase = {
"/d1/r1/n1",
"/d1/r1/n1",
"/d1/r1/n1",
"/d1/r1/n2",
"/d1/r2/n3",
"/d1/r2/n3"
};
storagesInBoundaryCase = DFSTestUtil.createDatanodeStorageInfos(racksInBoundaryCase);
dataNodesInBoundaryCase = DFSTestUtil.toDatanodeDescriptor(storagesInBoundaryCase);
}
private static final DatanodeStorageInfo[] storagesInMoreTargetsCase;
private final static DatanodeDescriptor[] dataNodesInMoreTargetsCase;
static {
final String[] racksInMoreTargetsCase = {
"/r1/n1",
"/r1/n1",
"/r1/n2",
"/r1/n2",
"/r1/n3",
"/r1/n3",
"/r2/n4",
"/r2/n4",
"/r2/n5",
"/r2/n5",
"/r2/n6",
"/r2/n6"
};
storagesInMoreTargetsCase = DFSTestUtil.createDatanodeStorageInfos(racksInMoreTargetsCase);
dataNodesInMoreTargetsCase = DFSTestUtil.toDatanodeDescriptor(storagesInMoreTargetsCase);
};
private final static DatanodeDescriptor NODE =
new DatanodeDescriptor(DFSTestUtil.getDatanodeDescriptor("9.9.9.9", "/d2/r4/n7"));
@Before
public void setUp() throws Exception {
FileSystem.setDefaultUri(CONF, "hdfs://localhost:0");
CONF.set(DFSConfigKeys.DFS_NAMENODE_HTTP_ADDRESS_KEY, "0.0.0.0:0");
// Set properties to make HDFS aware of NodeGroup.
CONF.set(DFSConfigKeys.DFS_BLOCK_REPLICATOR_CLASSNAME_KEY,
BlockPlacementPolicyWithNodeGroup.class.getName());
CONF.set(CommonConfigurationKeysPublic.NET_TOPOLOGY_IMPL_KEY,
NetworkTopologyWithNodeGroup.class.getName());
CONF.setBoolean(DFSConfigKeys.DFS_NAMENODE_AVOID_STALE_DATANODE_FOR_WRITE_KEY, true);
File baseDir = PathUtils.getTestDir(TestReplicationPolicyWithNodeGroup.class);
CONF.set(DFSConfigKeys.DFS_NAMENODE_NAME_DIR_KEY,
new File(baseDir, "name").getPath());
DFSTestUtil.formatNameNode(CONF);
namenode = new NameNode(CONF);
final BlockManager bm = namenode.getNamesystem().getBlockManager();
replicator = bm.getBlockPlacementPolicy();
cluster = bm.getDatanodeManager().getNetworkTopology();
// construct network topology
for(int i=0; i<NUM_OF_DATANODES; i++) {
cluster.add(dataNodes[i]);
}
setupDataNodeCapacity();
}
@After
public void tearDown() throws Exception {
namenode.stop();
}
private static void updateHeartbeatWithUsage(DatanodeDescriptor dn,
long capacity, long dfsUsed, long remaining, long blockPoolUsed,
long dnCacheCapacity, long dnCacheUsed, int xceiverCount,
int volFailures) {
dn.getStorageInfos()[0].setUtilizationForTesting(
capacity, dfsUsed, remaining, blockPoolUsed);
dn.updateHeartbeat(
BlockManagerTestUtil.getStorageReportsForDatanode(dn),
dnCacheCapacity, dnCacheUsed, xceiverCount, volFailures);
}
private static void setupDataNodeCapacity() {
for(int i=0; i<NUM_OF_DATANODES; i++) {
updateHeartbeatWithUsage(dataNodes[i],
2*HdfsConstants.MIN_BLOCKS_FOR_WRITE*BLOCK_SIZE, 0L,
2*HdfsConstants.MIN_BLOCKS_FOR_WRITE*BLOCK_SIZE, 0L, 0L, 0L, 0, 0);
}
}
/**
* Scan the targets list: all targets should be on different NodeGroups.
* Return false if two targets are found on the same NodeGroup.
*/
private static boolean checkTargetsOnDifferentNodeGroup(
DatanodeStorageInfo[] targets) {
if(targets.length == 0)
return true;
Set<String> targetSet = new HashSet<String>();
for(DatanodeStorageInfo storage:targets) {
final DatanodeDescriptor node = storage.getDatanodeDescriptor();
String nodeGroup = NetworkTopology.getLastHalf(node.getNetworkLocation());
if(targetSet.contains(nodeGroup)) {
return false;
} else {
targetSet.add(nodeGroup);
}
}
return true;
}
private boolean isOnSameRack(DatanodeStorageInfo left, DatanodeStorageInfo right) {
return isOnSameRack(left.getDatanodeDescriptor(), right);
}
private boolean isOnSameRack(DatanodeDescriptor left, DatanodeStorageInfo right) {
return cluster.isOnSameRack(left, right.getDatanodeDescriptor());
}
private boolean isOnSameNodeGroup(DatanodeStorageInfo left, DatanodeStorageInfo right) {
return isOnSameNodeGroup(left.getDatanodeDescriptor(), right);
}
private boolean isOnSameNodeGroup(DatanodeDescriptor left, DatanodeStorageInfo right) {
return cluster.isOnSameNodeGroup(left, right.getDatanodeDescriptor());
}
private DatanodeStorageInfo[] chooseTarget(int numOfReplicas) {
return chooseTarget(numOfReplicas, dataNodes[0]);
}
private DatanodeStorageInfo[] chooseTarget(int numOfReplicas,
DatanodeDescriptor writer) {
return chooseTarget(numOfReplicas, writer,
new ArrayList<DatanodeStorageInfo>());
}
private DatanodeStorageInfo[] chooseTarget(int numOfReplicas,
List<DatanodeStorageInfo> chosenNodes) {
return chooseTarget(numOfReplicas, dataNodes[0], chosenNodes);
}
private DatanodeStorageInfo[] chooseTarget(int numOfReplicas,
DatanodeDescriptor writer, List<DatanodeStorageInfo> chosenNodes) {
return chooseTarget(numOfReplicas, writer, chosenNodes, null);
}
private DatanodeStorageInfo[] chooseTarget(
int numOfReplicas,
DatanodeDescriptor writer,
List<DatanodeStorageInfo> chosenNodes,
Set<Node> excludedNodes) {
return replicator.chooseTarget(filename, numOfReplicas, writer, chosenNodes,
false, excludedNodes, BLOCK_SIZE, StorageType.DEFAULT);
}
/**
* In this testcase, client is dataNodes[0]. So the 1st replica should be
* placed on dataNodes[0], the 2nd replica should be placed on
* different rack and third should be placed on different node (and node group)
* of rack chosen for 2nd node.
* The only excpetion is when the <i>numOfReplicas</i> is 2,
* the 1st is on dataNodes[0] and the 2nd is on a different rack.
* @throws Exception
*/
@Test
public void testChooseTarget1() throws Exception {
updateHeartbeatWithUsage(dataNodes[0],
2*HdfsConstants.MIN_BLOCKS_FOR_WRITE*BLOCK_SIZE, 0L,
HdfsConstants.MIN_BLOCKS_FOR_WRITE*BLOCK_SIZE, 0L,
0L, 0L, 4, 0); // overloaded
DatanodeStorageInfo[] targets;
targets = chooseTarget(0);
assertEquals(targets.length, 0);
targets = chooseTarget(1);
assertEquals(targets.length, 1);
assertEquals(storages[0], targets[0]);
targets = chooseTarget(2);
assertEquals(targets.length, 2);
assertEquals(storages[0], targets[0]);
assertFalse(isOnSameRack(targets[0], targets[1]));
targets = chooseTarget(3);
assertEquals(targets.length, 3);
assertEquals(storages[0], targets[0]);
assertFalse(isOnSameRack(targets[0], targets[1]));
assertTrue(isOnSameRack(targets[1], targets[2]));
assertFalse(isOnSameNodeGroup(targets[1], targets[2]));
targets = chooseTarget(4);
assertEquals(targets.length, 4);
assertEquals(storages[0], targets[0]);
assertTrue(isOnSameRack(targets[1], targets[2]) ||
isOnSameRack(targets[2], targets[3]));
assertFalse(isOnSameRack(targets[0], targets[2]));
// Make sure no more than one replicas are on the same nodegroup
verifyNoTwoTargetsOnSameNodeGroup(targets);
updateHeartbeatWithUsage(dataNodes[0],
2*HdfsConstants.MIN_BLOCKS_FOR_WRITE*BLOCK_SIZE, 0L,
HdfsConstants.MIN_BLOCKS_FOR_WRITE*BLOCK_SIZE, 0L, 0L, 0L, 0, 0);
}
private void verifyNoTwoTargetsOnSameNodeGroup(DatanodeStorageInfo[] targets) {
Set<String> nodeGroupSet = new HashSet<String>();
for (DatanodeStorageInfo target: targets) {
nodeGroupSet.add(target.getDatanodeDescriptor().getNetworkLocation());
}
assertEquals(nodeGroupSet.size(), targets.length);
}
/**
* In this testcase, client is dataNodes[0], but the dataNodes[1] is
* not allowed to be chosen. So the 1st replica should be
* placed on dataNodes[0], the 2nd replica should be placed on a different
* rack, the 3rd should be on same rack as the 2nd replica but in different
* node group, and the rest should be placed on a third rack.
* @throws Exception
*/
@Test
public void testChooseTarget2() throws Exception {
DatanodeStorageInfo[] targets;
BlockPlacementPolicyDefault repl = (BlockPlacementPolicyDefault)replicator;
List<DatanodeStorageInfo> chosenNodes = new ArrayList<DatanodeStorageInfo>();
Set<Node> excludedNodes = new HashSet<Node>();
excludedNodes.add(dataNodes[1]);
targets = repl.chooseTarget(filename, 4, dataNodes[0], chosenNodes, false,
excludedNodes, BLOCK_SIZE, StorageType.DEFAULT);
assertEquals(targets.length, 4);
assertEquals(storages[0], targets[0]);
assertTrue(cluster.isNodeGroupAware());
// Make sure no replicas are on the same nodegroup
for (int i=1;i<4;i++) {
assertFalse(isOnSameNodeGroup(targets[0], targets[i]));
}
assertTrue(isOnSameRack(targets[1], targets[2]) ||
isOnSameRack(targets[2], targets[3]));
assertFalse(isOnSameRack(targets[1], targets[3]));
excludedNodes.clear();
chosenNodes.clear();
excludedNodes.add(dataNodes[1]);
chosenNodes.add(storages[2]);
targets = repl.chooseTarget(filename, 1, dataNodes[0], chosenNodes, true,
excludedNodes, BLOCK_SIZE, StorageType.DEFAULT);
System.out.println("targets=" + Arrays.asList(targets));
assertEquals(2, targets.length);
//make sure that the chosen node is in the target.
int i = 0;
for(; i < targets.length && !storages[2].equals(targets[i]); i++);
assertTrue(i < targets.length);
}
/**
* In this testcase, client is dataNodes[0], but dataNodes[0] is not qualified
* to be chosen. So the 1st replica should be placed on dataNodes[1],
* the 2nd replica should be placed on a different rack,
* the 3rd replica should be placed on the same rack as the 2nd replica but in different nodegroup,
* and the rest should be placed on the third rack.
* @throws Exception
*/
@Test
public void testChooseTarget3() throws Exception {
// make data node 0 to be not qualified to choose
updateHeartbeatWithUsage(dataNodes[0],
2*HdfsConstants.MIN_BLOCKS_FOR_WRITE*BLOCK_SIZE, 0L,
(HdfsConstants.MIN_BLOCKS_FOR_WRITE-1)*BLOCK_SIZE, 0L,
0L, 0L, 0, 0); // no space
DatanodeStorageInfo[] targets;
targets = chooseTarget(0);
assertEquals(targets.length, 0);
targets = chooseTarget(1);
assertEquals(targets.length, 1);
assertEquals(storages[1], targets[0]);
targets = chooseTarget(2);
assertEquals(targets.length, 2);
assertEquals(storages[1], targets[0]);
assertFalse(isOnSameRack(targets[0], targets[1]));
targets = chooseTarget(3);
assertEquals(targets.length, 3);
assertEquals(storages[1], targets[0]);
assertTrue(isOnSameRack(targets[1], targets[2]));
assertFalse(isOnSameRack(targets[0], targets[1]));
targets = chooseTarget(4);
assertEquals(targets.length, 4);
assertEquals(storages[1], targets[0]);
assertTrue(cluster.isNodeGroupAware());
verifyNoTwoTargetsOnSameNodeGroup(targets);
assertTrue(isOnSameRack(targets[1], targets[2]) ||
isOnSameRack(targets[2], targets[3]));
updateHeartbeatWithUsage(dataNodes[0],
2*HdfsConstants.MIN_BLOCKS_FOR_WRITE*BLOCK_SIZE, 0L,
HdfsConstants.MIN_BLOCKS_FOR_WRITE*BLOCK_SIZE, 0L, 0L, 0L, 0, 0);
}
/**
* In this testcase, client is dataNodes[0], but none of the nodes on rack 1
* is qualified to be chosen. So the 1st replica should be placed on either
* rack 2 or rack 3.
* the 2nd replica should be placed on a different rack,
* the 3rd replica should be placed on the same rack as the 1st replica, but
* in different node group.
* @throws Exception
*/
@Test
public void testChooseTarget4() throws Exception {
// make data node 0-2 to be not qualified to choose: not enough disk space
for(int i=0; i<3; i++) {
updateHeartbeatWithUsage(dataNodes[i],
2*HdfsConstants.MIN_BLOCKS_FOR_WRITE*BLOCK_SIZE, 0L,
(HdfsConstants.MIN_BLOCKS_FOR_WRITE-1)*BLOCK_SIZE, 0L, 0L, 0L, 0, 0);
}
DatanodeStorageInfo[] targets;
targets = chooseTarget(0);
assertEquals(targets.length, 0);
targets = chooseTarget(1);
assertEquals(targets.length, 1);
assertFalse(isOnSameRack(dataNodes[0], targets[0]));
targets = chooseTarget(2);
assertEquals(targets.length, 2);
assertFalse(isOnSameRack(dataNodes[0], targets[0]));
assertFalse(isOnSameRack(targets[0], targets[1]));
targets = chooseTarget(3);
assertEquals(targets.length, 3);
for(int i=0; i<3; i++) {
assertFalse(isOnSameRack(dataNodes[0], targets[i]));
}
verifyNoTwoTargetsOnSameNodeGroup(targets);
assertTrue(isOnSameRack(targets[0], targets[1]) ||
isOnSameRack(targets[1], targets[2]));
assertFalse(isOnSameRack(targets[0], targets[2]));
}
/**
* In this testcase, client is is a node outside of file system.
* So the 1st replica can be placed on any node.
* the 2nd replica should be placed on a different rack,
* the 3rd replica should be placed on the same rack as the 2nd replica,
* @throws Exception
*/
@Test
public void testChooseTarget5() throws Exception {
setupDataNodeCapacity();
DatanodeStorageInfo[] targets;
targets = chooseTarget(0, NODE);
assertEquals(targets.length, 0);
targets = chooseTarget(1, NODE);
assertEquals(targets.length, 1);
targets = chooseTarget(2, NODE);
assertEquals(targets.length, 2);
assertFalse(isOnSameRack(targets[0], targets[1]));
targets = chooseTarget(3, NODE);
assertEquals(targets.length, 3);
assertTrue(isOnSameRack(targets[1], targets[2]));
assertFalse(isOnSameRack(targets[0], targets[1]));
verifyNoTwoTargetsOnSameNodeGroup(targets);
}
/**
* This testcase tests re-replication, when dataNodes[0] is already chosen.
* So the 1st replica can be placed on random rack.
* the 2nd replica should be placed on different node and nodegroup by same rack as
* the 1st replica. The 3rd replica can be placed randomly.
* @throws Exception
*/
@Test
public void testRereplicate1() throws Exception {
setupDataNodeCapacity();
List<DatanodeStorageInfo> chosenNodes = new ArrayList<DatanodeStorageInfo>();
chosenNodes.add(storages[0]);
DatanodeStorageInfo[] targets;
targets = chooseTarget(0, chosenNodes);
assertEquals(targets.length, 0);
targets = chooseTarget(1, chosenNodes);
assertEquals(targets.length, 1);
assertFalse(isOnSameRack(dataNodes[0], targets[0]));
targets = chooseTarget(2, chosenNodes);
assertEquals(targets.length, 2);
assertTrue(isOnSameRack(dataNodes[0], targets[0]));
assertFalse(isOnSameRack(targets[0], targets[1]));
targets = chooseTarget(3, chosenNodes);
assertEquals(targets.length, 3);
assertTrue(isOnSameRack(dataNodes[0], targets[0]));
assertFalse(isOnSameNodeGroup(dataNodes[0], targets[0]));
assertFalse(isOnSameRack(targets[0], targets[2]));
}
/**
* This testcase tests re-replication,
* when dataNodes[0] and dataNodes[1] are already chosen.
* So the 1st replica should be placed on a different rack of rack 1.
* the rest replicas can be placed randomly,
* @throws Exception
*/
@Test
public void testRereplicate2() throws Exception {
setupDataNodeCapacity();
List<DatanodeStorageInfo> chosenNodes = new ArrayList<DatanodeStorageInfo>();
chosenNodes.add(storages[0]);
chosenNodes.add(storages[1]);
DatanodeStorageInfo[] targets;
targets = chooseTarget(0, chosenNodes);
assertEquals(targets.length, 0);
targets = chooseTarget(1, chosenNodes);
assertEquals(targets.length, 1);
assertFalse(isOnSameRack(dataNodes[0], targets[0]));
targets = chooseTarget(2, chosenNodes);
assertEquals(targets.length, 2);
assertFalse(isOnSameRack(dataNodes[0], targets[0]) &&
isOnSameRack(dataNodes[0], targets[1]));
}
/**
* This testcase tests re-replication,
* when dataNodes[0] and dataNodes[3] are already chosen.
* So the 1st replica should be placed on the rack that the writer resides.
* the rest replicas can be placed randomly,
* @throws Exception
*/
@Test
public void testRereplicate3() throws Exception {
setupDataNodeCapacity();
List<DatanodeStorageInfo> chosenNodes = new ArrayList<DatanodeStorageInfo>();
chosenNodes.add(storages[0]);
chosenNodes.add(storages[3]);
DatanodeStorageInfo[] targets;
targets = chooseTarget(0, chosenNodes);
assertEquals(targets.length, 0);
targets = chooseTarget(1, chosenNodes);
assertEquals(targets.length, 1);
assertTrue(isOnSameRack(dataNodes[0], targets[0]));
assertFalse(isOnSameRack(dataNodes[3], targets[0]));
targets = chooseTarget(1, dataNodes[3], chosenNodes);
assertEquals(targets.length, 1);
assertTrue(isOnSameRack(dataNodes[3], targets[0]));
assertFalse(isOnSameNodeGroup(dataNodes[3], targets[0]));
assertFalse(isOnSameRack(dataNodes[0], targets[0]));
targets = chooseTarget(2, chosenNodes);
assertEquals(targets.length, 2);
assertTrue(isOnSameRack(dataNodes[0], targets[0]));
assertFalse(isOnSameNodeGroup(dataNodes[0], targets[0]));
targets = chooseTarget(2, dataNodes[3], chosenNodes);
assertEquals(targets.length, 2);
assertTrue(isOnSameRack(dataNodes[3], targets[0]));
}
/**
* Test for the chooseReplicaToDelete are processed based on
* block locality and free space
*/
@Test
public void testChooseReplicaToDelete() throws Exception {
List<DatanodeDescriptor> replicaNodeList =
new ArrayList<DatanodeDescriptor>();
final Map<String, List<DatanodeDescriptor>> rackMap =
new HashMap<String, List<DatanodeDescriptor>>();
dataNodes[0].setRemaining(4*1024*1024);
replicaNodeList.add(dataNodes[0]);
dataNodes[1].setRemaining(3*1024*1024);
replicaNodeList.add(dataNodes[1]);
dataNodes[2].setRemaining(2*1024*1024);
replicaNodeList.add(dataNodes[2]);
dataNodes[5].setRemaining(1*1024*1024);
replicaNodeList.add(dataNodes[5]);
List<DatanodeDescriptor> first = new ArrayList<DatanodeDescriptor>();
List<DatanodeDescriptor> second = new ArrayList<DatanodeDescriptor>();
replicator.splitNodesWithRack(
replicaNodeList, rackMap, first, second);
assertEquals(3, first.size());
assertEquals(1, second.size());
DatanodeDescriptor chosenNode = replicator.chooseReplicaToDelete(
null, null, (short)3, first, second);
// Within first set {dataNodes[0], dataNodes[1], dataNodes[2]},
// dataNodes[0] and dataNodes[1] are in the same nodegroup,
// but dataNodes[1] is chosen as less free space
assertEquals(chosenNode, dataNodes[1]);
replicator.adjustSetsWithChosenReplica(rackMap, first, second, chosenNode);
assertEquals(2, first.size());
assertEquals(1, second.size());
// Within first set {dataNodes[0], dataNodes[2]}, dataNodes[2] is chosen
// as less free space
chosenNode = replicator.chooseReplicaToDelete(
null, null, (short)2, first, second);
assertEquals(chosenNode, dataNodes[2]);
replicator.adjustSetsWithChosenReplica(rackMap, first, second, chosenNode);
assertEquals(0, first.size());
assertEquals(2, second.size());
// Within second set, dataNodes[5] with less free space
chosenNode = replicator.chooseReplicaToDelete(
null, null, (short)1, first, second);
assertEquals(chosenNode, dataNodes[5]);
}
/**
* Test replica placement policy in case of boundary topology.
* Rack 2 has only 1 node group & can't be placed with two replicas
* The 1st replica will be placed on writer.
* The 2nd replica should be placed on a different rack
* The 3rd replica should be placed on the same rack with writer, but on a
* different node group.
*/
@Test
public void testChooseTargetsOnBoundaryTopology() throws Exception {
for(int i=0; i<NUM_OF_DATANODES; i++) {
cluster.remove(dataNodes[i]);
}
for(int i=0; i<NUM_OF_DATANODES_BOUNDARY; i++) {
cluster.add(dataNodesInBoundaryCase[i]);
}
for(int i=0; i<NUM_OF_DATANODES_BOUNDARY; i++) {
updateHeartbeatWithUsage(dataNodes[0],
2*HdfsConstants.MIN_BLOCKS_FOR_WRITE*BLOCK_SIZE, 0L,
(HdfsConstants.MIN_BLOCKS_FOR_WRITE-1)*BLOCK_SIZE,
0L, 0L, 0L, 0, 0);
updateHeartbeatWithUsage(dataNodesInBoundaryCase[i],
2*HdfsConstants.MIN_BLOCKS_FOR_WRITE*BLOCK_SIZE, 0L,
2*HdfsConstants.MIN_BLOCKS_FOR_WRITE*BLOCK_SIZE, 0L, 0L, 0L, 0, 0);
}
DatanodeStorageInfo[] targets;
targets = chooseTarget(0, dataNodesInBoundaryCase[0]);
assertEquals(targets.length, 0);
targets = chooseTarget(1, dataNodesInBoundaryCase[0]);
assertEquals(targets.length, 1);
targets = chooseTarget(2, dataNodesInBoundaryCase[0]);
assertEquals(targets.length, 2);
assertFalse(isOnSameRack(targets[0], targets[1]));
targets = chooseTarget(3, dataNodesInBoundaryCase[0]);
assertEquals(targets.length, 3);
assertTrue(checkTargetsOnDifferentNodeGroup(targets));
}
/**
* Test re-replication policy in boundary case.
* Rack 2 has only one node group & the node in this node group is chosen
* Rack 1 has two nodegroups & one of them is chosen.
* Replica policy should choose the node from node group of Rack1 but not the
* same nodegroup with chosen nodes.
*/
@Test
public void testRereplicateOnBoundaryTopology() throws Exception {
for(int i=0; i<NUM_OF_DATANODES_BOUNDARY; i++) {
updateHeartbeatWithUsage(dataNodesInBoundaryCase[i],
2*HdfsConstants.MIN_BLOCKS_FOR_WRITE*BLOCK_SIZE, 0L,
2*HdfsConstants.MIN_BLOCKS_FOR_WRITE*BLOCK_SIZE, 0L, 0L, 0L, 0, 0);
}
List<DatanodeStorageInfo> chosenNodes = new ArrayList<DatanodeStorageInfo>();
chosenNodes.add(storagesInBoundaryCase[0]);
chosenNodes.add(storagesInBoundaryCase[5]);
DatanodeStorageInfo[] targets;
targets = chooseTarget(1, dataNodesInBoundaryCase[0], chosenNodes);
assertFalse(isOnSameNodeGroup(dataNodesInBoundaryCase[0], targets[0]));
assertFalse(isOnSameNodeGroup(dataNodesInBoundaryCase[5], targets[0]));
assertTrue(checkTargetsOnDifferentNodeGroup(targets));
}
/**
* Test replica placement policy in case of targets more than number of
* NodeGroups.
* The 12-nodes cluster only has 6 NodeGroups, but in some cases, like:
* placing submitted job file, there is requirement to choose more (10)
* targets for placing replica. We should test it can return 6 targets.
*/
@Test
public void testChooseMoreTargetsThanNodeGroups() throws Exception {
for(int i=0; i<NUM_OF_DATANODES; i++) {
cluster.remove(dataNodes[i]);
}
for(int i=0; i<NUM_OF_DATANODES_BOUNDARY; i++) {
DatanodeDescriptor node = dataNodesInBoundaryCase[i];
if (cluster.contains(node)) {
cluster.remove(node);
}
}
for(int i=0; i<NUM_OF_DATANODES_MORE_TARGETS; i++) {
cluster.add(dataNodesInMoreTargetsCase[i]);
}
for(int i=0; i<NUM_OF_DATANODES_MORE_TARGETS; i++) {
updateHeartbeatWithUsage(dataNodesInMoreTargetsCase[i],
2*HdfsConstants.MIN_BLOCKS_FOR_WRITE*BLOCK_SIZE, 0L,
2*HdfsConstants.MIN_BLOCKS_FOR_WRITE*BLOCK_SIZE, 0L, 0L, 0L, 0, 0);
}
DatanodeStorageInfo[] targets;
// Test normal case -- 3 replicas
targets = chooseTarget(3, dataNodesInMoreTargetsCase[0]);
assertEquals(targets.length, 3);
assertTrue(checkTargetsOnDifferentNodeGroup(targets));
// Test special case -- replica number over node groups.
targets = chooseTarget(10, dataNodesInMoreTargetsCase[0]);
assertTrue(checkTargetsOnDifferentNodeGroup(targets));
// Verify it only can find 6 targets for placing replicas.
assertEquals(targets.length, 6);
}
}