From de30d66b2673d0344346fb985e786247ca682317 Mon Sep 17 00:00:00 2001 From: Kihwal Lee Date: Tue, 19 May 2015 08:04:38 -0500 Subject: [PATCH] HDFS-8131. Implement a space balanced block placement policy. Contributed by Liu Shaohui. --- hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt | 3 + .../org/apache/hadoop/hdfs/DFSConfigKeys.java | 6 +- .../AvailableSpaceBlockPlacementPolicy.java | 95 ++++++++++ .../BlockPlacementPolicyDefault.java | 11 +- ...estAvailableSpaceBlockPlacementPolicy.java | 167 ++++++++++++++++++ 5 files changed, 279 insertions(+), 3 deletions(-) create mode 100644 hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/AvailableSpaceBlockPlacementPolicy.java create mode 100644 hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/blockmanagement/TestAvailableSpaceBlockPlacementPolicy.java diff --git a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt index e5fcba291f..76888a959c 100644 --- a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt +++ b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt @@ -345,6 +345,9 @@ Release 2.8.0 - UNRELEASED HDFS-7891. A block placement policy with best rack failure tolerance. (Walter Su via szetszwo) + HDFS-8131. Implement a space balanced block placement policy (Liu Shaohui + via kihwal) + IMPROVEMENTS HDFS-3918. EditLogTailer shouldn't log WARN when other node diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSConfigKeys.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSConfigKeys.java index c903e76ada..9c19f91908 100644 --- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSConfigKeys.java +++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSConfigKeys.java @@ -519,7 +519,11 @@ public class DFSConfigKeys extends CommonConfigurationKeys { public static final String DFS_WEB_AUTHENTICATION_KERBEROS_KEYTAB_KEY = "dfs.web.authentication.kerberos.keytab"; public static final String DFS_NAMENODE_MAX_OP_SIZE_KEY = "dfs.namenode.max.op.size"; public static final int DFS_NAMENODE_MAX_OP_SIZE_DEFAULT = 50 * 1024 * 1024; - + public static final String DFS_NAMENODE_AVAILABLE_SPACE_BLOCK_PLACEMENT_POLICY_BALANCED_SPACE_PREFERENCE_FRACTION_KEY = + "dfs.namenode.available-space-block-placement-policy.balanced-space-preference-fraction"; + public static final float DFS_NAMENODE_AVAILABLE_SPACE_BLOCK_PLACEMENT_POLICY_BALANCED_SPACE_PREFERENCE_FRACTION_DEFAULT = + 0.6f; + public static final String DFS_BLOCK_LOCAL_PATH_ACCESS_USER_KEY = "dfs.block.local-path-access.user"; public static final String DFS_DOMAIN_SOCKET_PATH_KEY = "dfs.domain.socket.path"; public static final String DFS_DOMAIN_SOCKET_PATH_DEFAULT = ""; diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/AvailableSpaceBlockPlacementPolicy.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/AvailableSpaceBlockPlacementPolicy.java new file mode 100644 index 0000000000..74c1c786e8 --- /dev/null +++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/AvailableSpaceBlockPlacementPolicy.java @@ -0,0 +1,95 @@ +/** + * 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.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMENODE_AVAILABLE_SPACE_BLOCK_PLACEMENT_POLICY_BALANCED_SPACE_PREFERENCE_FRACTION_KEY; +import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMENODE_AVAILABLE_SPACE_BLOCK_PLACEMENT_POLICY_BALANCED_SPACE_PREFERENCE_FRACTION_DEFAULT; + +import java.util.Random; + +import org.apache.commons.logging.Log; +import org.apache.commons.logging.LogFactory; +import org.apache.hadoop.conf.Configuration; +import org.apache.hadoop.hdfs.DFSConfigKeys; +import org.apache.hadoop.net.NetworkTopology; + +/** + * Space balanced block placement policy. + */ +public class AvailableSpaceBlockPlacementPolicy extends + BlockPlacementPolicyDefault { + private static final Log LOG = LogFactory + .getLog(AvailableSpaceBlockPlacementPolicy.class); + private static final Random RAND = new Random(); + private int balancedPreference = + (int) (100 * DFS_NAMENODE_AVAILABLE_SPACE_BLOCK_PLACEMENT_POLICY_BALANCED_SPACE_PREFERENCE_FRACTION_DEFAULT); + + @Override + public void initialize(Configuration conf, FSClusterStats stats, + NetworkTopology clusterMap, Host2NodesMap host2datanodeMap) { + super.initialize(conf, stats, clusterMap, host2datanodeMap); + float balancedPreferencePercent = + conf.getFloat( + DFS_NAMENODE_AVAILABLE_SPACE_BLOCK_PLACEMENT_POLICY_BALANCED_SPACE_PREFERENCE_FRACTION_KEY, + DFS_NAMENODE_AVAILABLE_SPACE_BLOCK_PLACEMENT_POLICY_BALANCED_SPACE_PREFERENCE_FRACTION_DEFAULT); + + LOG.info("Available space block placement policy initialized: " + + DFSConfigKeys.DFS_NAMENODE_AVAILABLE_SPACE_BLOCK_PLACEMENT_POLICY_BALANCED_SPACE_PREFERENCE_FRACTION_KEY + + " = " + balancedPreferencePercent); + + if (balancedPreferencePercent > 1.0) { + LOG.warn("The value of " + + DFS_NAMENODE_AVAILABLE_SPACE_BLOCK_PLACEMENT_POLICY_BALANCED_SPACE_PREFERENCE_FRACTION_KEY + + " is greater than 1.0 but should be in the range 0.0 - 1.0"); + } + if (balancedPreferencePercent < 0.5) { + LOG.warn("The value of " + + DFS_NAMENODE_AVAILABLE_SPACE_BLOCK_PLACEMENT_POLICY_BALANCED_SPACE_PREFERENCE_FRACTION_KEY + + " is less than 0.5 so datanodes with more used percent will" + + " receive more block allocations."); + } + balancedPreference = (int) (100 * balancedPreferencePercent); + } + + @Override + protected DatanodeDescriptor chooseDataNode(String scope) { + DatanodeDescriptor a = (DatanodeDescriptor) clusterMap.chooseRandom(scope); + DatanodeDescriptor b = (DatanodeDescriptor) clusterMap.chooseRandom(scope); + int ret = compareDataNode(a, b); + if (ret == 0) { + return a; + } else if (ret < 0) { + return (RAND.nextInt(100) < balancedPreference) ? a : b; + } else { + return (RAND.nextInt(100) < balancedPreference) ? b : a; + } + } + + /** + * Compare the two data nodes. + */ + protected int compareDataNode(final DatanodeDescriptor a, + final DatanodeDescriptor b) { + if (a.equals(b) + || Math.abs(a.getDfsUsedPercent() - b.getDfsUsedPercent()) < 5) { + return 0; + } + return a.getDfsUsedPercent() < b.getDfsUsedPercent() ? -1 : 1; + } +} diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockPlacementPolicyDefault.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockPlacementPolicyDefault.java index 620d2a6504..21ad01d162 100644 --- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockPlacementPolicyDefault.java +++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockPlacementPolicyDefault.java @@ -646,8 +646,7 @@ protected DatanodeStorageInfo chooseRandom(int numOfReplicas, boolean badTarget = false; DatanodeStorageInfo firstChosen = null; while(numOfReplicas > 0 && numOfAvailableNodes > 0) { - DatanodeDescriptor chosenNode = - (DatanodeDescriptor)clusterMap.chooseRandom(scope); + DatanodeDescriptor chosenNode = chooseDataNode(scope); if (excludedNodes.add(chosenNode)) { //was not in the excluded list if (LOG.isDebugEnabled()) { builder.append("\nNode ").append(NodeBase.getPath(chosenNode)).append(" ["); @@ -708,6 +707,14 @@ protected DatanodeStorageInfo chooseRandom(int numOfReplicas, return firstChosen; } + /** + * Choose a datanode from the given scope. + * @return the chosen node, if there is any. + */ + protected DatanodeDescriptor chooseDataNode(final String scope) { + return (DatanodeDescriptor) clusterMap.chooseRandom(scope); + } + /** * If the given storage is a good target, add it to the result list and * update the set of excluded nodes. diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/blockmanagement/TestAvailableSpaceBlockPlacementPolicy.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/blockmanagement/TestAvailableSpaceBlockPlacementPolicy.java new file mode 100644 index 0000000000..f1e4e1cc61 --- /dev/null +++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/blockmanagement/TestAvailableSpaceBlockPlacementPolicy.java @@ -0,0 +1,167 @@ +/** + * 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 java.io.File; +import java.util.ArrayList; + +import org.apache.hadoop.conf.Configuration; +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.TestBlockStoragePolicy; +import org.apache.hadoop.hdfs.server.common.HdfsServerConstants; +import org.apache.hadoop.hdfs.server.namenode.NameNode; +import org.apache.hadoop.net.NetworkTopology; +import org.apache.hadoop.test.PathUtils; +import org.junit.AfterClass; +import org.junit.Assert; +import org.junit.BeforeClass; +import org.junit.Test; + +public class TestAvailableSpaceBlockPlacementPolicy { + private final static int numRacks = 4; + private final static int nodesPerRack = 5; + private final static int blockSize = 1024; + private final static int chooseTimes = 10000; + private final static String file = "/tobers/test"; + private final static int replica = 3; + + private static DatanodeStorageInfo[] storages; + private static DatanodeDescriptor[] dataNodes; + private static Configuration conf; + private static NameNode namenode; + private static BlockPlacementPolicy placementPolicy; + private static NetworkTopology cluster; + + @BeforeClass + public static void setupCluster() throws Exception { + conf = new HdfsConfiguration(); + conf.setFloat( + DFSConfigKeys.DFS_NAMENODE_AVAILABLE_SPACE_BLOCK_PLACEMENT_POLICY_BALANCED_SPACE_PREFERENCE_FRACTION_KEY, + 0.6f); + String[] racks = new String[numRacks]; + for (int i = 0; i < numRacks; i++) { + racks[i] = "/rack" + i; + } + + String[] owerRackOfNodes = new String[numRacks * nodesPerRack]; + for (int i = 0; i < nodesPerRack; i++) { + for (int j = 0; j < numRacks; j++) { + owerRackOfNodes[i * numRacks + j] = racks[j]; + } + } + + storages = DFSTestUtil.createDatanodeStorageInfos(owerRackOfNodes); + dataNodes = DFSTestUtil.toDatanodeDescriptor(storages); + + FileSystem.setDefaultUri(conf, "hdfs://localhost:0"); + conf.set(DFSConfigKeys.DFS_NAMENODE_HTTP_ADDRESS_KEY, "0.0.0.0:0"); + File baseDir = PathUtils.getTestDir(AvailableSpaceBlockPlacementPolicy.class); + conf.set(DFSConfigKeys.DFS_NAMENODE_NAME_DIR_KEY, new File(baseDir, "name").getPath()); + conf.set(DFSConfigKeys.DFS_BLOCK_REPLICATOR_CLASSNAME_KEY, + AvailableSpaceBlockPlacementPolicy.class.getName()); + + DFSTestUtil.formatNameNode(conf); + namenode = new NameNode(conf); + + final BlockManager bm = namenode.getNamesystem().getBlockManager(); + placementPolicy = bm.getBlockPlacementPolicy(); + cluster = bm.getDatanodeManager().getNetworkTopology(); + for (int i = 0; i < nodesPerRack * numRacks; i++) { + cluster.add(dataNodes[i]); + } + + setupDataNodeCapacity(); + } + + 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, null); + } + + private static void setupDataNodeCapacity() { + for (int i = 0; i < nodesPerRack * numRacks; i++) { + if ((i % 2) == 0) { + // remaining 100% + updateHeartbeatWithUsage(dataNodes[i], 2 * HdfsServerConstants.MIN_BLOCKS_FOR_WRITE * blockSize, + 0L, 2 * HdfsServerConstants.MIN_BLOCKS_FOR_WRITE * blockSize, 0L, 0L, 0L, 0, 0); + } else { + // remaining 50% + updateHeartbeatWithUsage(dataNodes[i], 2 * HdfsServerConstants.MIN_BLOCKS_FOR_WRITE * blockSize, + HdfsServerConstants.MIN_BLOCKS_FOR_WRITE * blockSize, HdfsServerConstants.MIN_BLOCKS_FOR_WRITE + * blockSize, 0L, 0L, 0L, 0, 0); + } + } + } + + /* + * To verify that the BlockPlacementPolicy can be replaced by AvailableSpaceBlockPlacementPolicy via + * changing the configuration. + */ + @Test + public void testPolicyReplacement() { + Assert.assertTrue((placementPolicy instanceof AvailableSpaceBlockPlacementPolicy)); + } + + /* + * Call choose target many times and verify that nodes with more remaining percent will be chosen + * with high possibility. + */ + @Test + public void testChooseTarget() { + int total = 0; + int moreRemainingNode = 0; + for (int i = 0; i < chooseTimes; i++) { + DatanodeStorageInfo[] targets = + namenode + .getNamesystem() + .getBlockManager() + .getBlockPlacementPolicy() + .chooseTarget(file, replica, null, new ArrayList(), false, null, + blockSize, TestBlockStoragePolicy.DEFAULT_STORAGE_POLICY); + + Assert.assertTrue(targets.length == replica); + for (int j = 0; j < replica; j++) { + total++; + if (targets[j].getDatanodeDescriptor().getRemainingPercent() > 60) { + moreRemainingNode++; + } + } + } + Assert.assertTrue(total == replica * chooseTimes); + double possibility = 1.0 * moreRemainingNode / total; + Assert.assertTrue(possibility > 0.52); + Assert.assertTrue(possibility < 0.55); + } + + @AfterClass + public static void teardownCluster() { + if (namenode != null) { + namenode.stop(); + } + } +}