| /** |
| * 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; |
| |
| import static org.apache.hadoop.fs.CommonConfigurationKeys.FS_CLIENT_TOPOLOGY_RESOLUTION_ENABLED; |
| import static org.apache.hadoop.fs.CommonConfigurationKeys.FS_CLIENT_TOPOLOGY_RESOLUTION_ENABLED_DEFAULT; |
| |
| import java.util.ArrayList; |
| import java.util.HashMap; |
| import java.util.List; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.fs.CommonConfigurationKeys; |
| import org.apache.hadoop.hdfs.client.HdfsClientConfigKeys; |
| import org.apache.hadoop.hdfs.client.impl.DfsClientConf; |
| import org.apache.hadoop.hdfs.client.impl.DfsClientConf.ShortCircuitConf; |
| import org.apache.hadoop.hdfs.protocol.DatanodeInfo; |
| import org.apache.hadoop.hdfs.shortcircuit.DomainSocketFactory; |
| import org.apache.hadoop.hdfs.shortcircuit.ShortCircuitCache; |
| import org.apache.hadoop.hdfs.util.ByteArrayManager; |
| import org.apache.hadoop.net.DNSToSwitchMapping; |
| import org.apache.hadoop.net.NetUtils; |
| import org.apache.hadoop.net.NetworkTopology; |
| import org.apache.hadoop.net.NodeBase; |
| import org.apache.hadoop.net.ScriptBasedMapping; |
| import org.apache.hadoop.util.ReflectionUtils; |
| |
| import com.google.common.annotations.VisibleForTesting; |
| |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * ClientContext contains context information for a client. |
| * |
| * This allows us to share caches such as the socket cache across |
| * DFSClient instances. |
| */ |
| @InterfaceAudience.Private |
| public class ClientContext { |
| private static final Logger LOG = LoggerFactory.getLogger( |
| ClientContext.class); |
| |
| /** |
| * Global map of context names to caches contexts. |
| */ |
| private final static HashMap<String, ClientContext> CACHES = new HashMap<>(); |
| |
| /** |
| * Name of context. |
| */ |
| private final String name; |
| |
| /** |
| * String representation of the configuration. |
| */ |
| private final String confString; |
| |
| /** |
| * Caches short-circuit file descriptors, mmap regions. |
| */ |
| private final ShortCircuitCache shortCircuitCache; |
| |
| /** |
| * Caches TCP and UNIX domain sockets for reuse. |
| */ |
| private final PeerCache peerCache; |
| |
| /** |
| * Stores information about socket paths. |
| */ |
| private final DomainSocketFactory domainSocketFactory; |
| |
| /** |
| * Caches key Providers for the DFSClient |
| */ |
| private final KeyProviderCache keyProviderCache; |
| /** |
| * True if we should use the legacy BlockReaderLocal. |
| */ |
| private final boolean useLegacyBlockReaderLocal; |
| |
| /** |
| * True if the legacy BlockReaderLocal is disabled. |
| * |
| * The legacy block reader local gets disabled completely whenever there is an |
| * error or miscommunication. The new block reader local code handles this |
| * case more gracefully inside DomainSocketFactory. |
| */ |
| private volatile boolean disableLegacyBlockReaderLocal = false; |
| |
| /** Creating byte[] for {@link DFSOutputStream}. */ |
| private final ByteArrayManager byteArrayManager; |
| |
| /** |
| * Whether or not we complained about a DFSClient fetching a CacheContext that |
| * didn't match its config values yet. |
| */ |
| private boolean printedConfWarning = false; |
| |
| private NodeBase clientNode; |
| private boolean topologyResolutionEnabled; |
| |
| private ClientContext(String name, DfsClientConf conf, |
| Configuration config) { |
| final ShortCircuitConf scConf = conf.getShortCircuitConf(); |
| |
| this.name = name; |
| this.confString = scConf.confAsString(); |
| this.shortCircuitCache = ShortCircuitCache.fromConf(scConf); |
| this.peerCache = new PeerCache(scConf.getSocketCacheCapacity(), |
| scConf.getSocketCacheExpiry()); |
| this.keyProviderCache = new KeyProviderCache( |
| scConf.getKeyProviderCacheExpiryMs()); |
| this.useLegacyBlockReaderLocal = scConf.isUseLegacyBlockReaderLocal(); |
| this.domainSocketFactory = new DomainSocketFactory(scConf); |
| |
| this.byteArrayManager = ByteArrayManager.newInstance( |
| conf.getWriteByteArrayManagerConf()); |
| initTopologyResolution(config); |
| } |
| |
| private void initTopologyResolution(Configuration config) { |
| topologyResolutionEnabled = config.getBoolean( |
| FS_CLIENT_TOPOLOGY_RESOLUTION_ENABLED, |
| FS_CLIENT_TOPOLOGY_RESOLUTION_ENABLED_DEFAULT); |
| if (!topologyResolutionEnabled) { |
| return; |
| } |
| DNSToSwitchMapping dnsToSwitchMapping = ReflectionUtils.newInstance( |
| config.getClass( |
| CommonConfigurationKeys.NET_TOPOLOGY_NODE_SWITCH_MAPPING_IMPL_KEY, |
| ScriptBasedMapping.class, DNSToSwitchMapping.class), config); |
| String clientHostName = NetUtils.getLocalHostname(); |
| List<String> nodes = new ArrayList<>(); |
| nodes.add(clientHostName); |
| List<String> resolvedHosts = dnsToSwitchMapping.resolve(nodes); |
| if (resolvedHosts != null && !resolvedHosts.isEmpty() && |
| !resolvedHosts.get(0).equals(NetworkTopology.DEFAULT_RACK)) { |
| // The client machine is able to resolve its own network location. |
| this.clientNode = new NodeBase(clientHostName, resolvedHosts.get(0)); |
| } |
| } |
| |
| public static ClientContext get(String name, DfsClientConf conf, |
| Configuration config) { |
| ClientContext context; |
| synchronized(ClientContext.class) { |
| context = CACHES.get(name); |
| if (context == null) { |
| context = new ClientContext(name, conf, config); |
| CACHES.put(name, context); |
| } else { |
| context.printConfWarningIfNeeded(conf); |
| } |
| } |
| return context; |
| } |
| |
| public static ClientContext get(String name, Configuration config) { |
| return get(name, new DfsClientConf(config), config); |
| } |
| |
| /** |
| * Get a client context, from a Configuration object. |
| * |
| * This method is less efficient than the version which takes a DFSClient#Conf |
| * object, and should be mostly used by tests. |
| */ |
| @VisibleForTesting |
| public static ClientContext getFromConf(Configuration conf) { |
| return get(conf.get(HdfsClientConfigKeys.DFS_CLIENT_CONTEXT, |
| HdfsClientConfigKeys.DFS_CLIENT_CONTEXT_DEFAULT), conf); |
| } |
| |
| private void printConfWarningIfNeeded(DfsClientConf conf) { |
| String existing = this.getConfString(); |
| String requested = conf.getShortCircuitConf().confAsString(); |
| if (!existing.equals(requested)) { |
| if (!printedConfWarning) { |
| printedConfWarning = true; |
| LOG.warn("Existing client context '" + name + "' does not match " + |
| "requested configuration. Existing: " + existing + |
| ", Requested: " + requested); |
| } |
| } |
| } |
| |
| public String getConfString() { |
| return confString; |
| } |
| |
| public ShortCircuitCache getShortCircuitCache() { |
| return shortCircuitCache; |
| } |
| |
| public PeerCache getPeerCache() { |
| return peerCache; |
| } |
| |
| public KeyProviderCache getKeyProviderCache() { |
| return keyProviderCache; |
| } |
| |
| public boolean getUseLegacyBlockReaderLocal() { |
| return useLegacyBlockReaderLocal; |
| } |
| |
| public boolean getDisableLegacyBlockReaderLocal() { |
| return disableLegacyBlockReaderLocal; |
| } |
| |
| public void setDisableLegacyBlockReaderLocal() { |
| disableLegacyBlockReaderLocal = true; |
| } |
| |
| public DomainSocketFactory getDomainSocketFactory() { |
| return domainSocketFactory; |
| } |
| |
| public ByteArrayManager getByteArrayManager() { |
| return byteArrayManager; |
| } |
| |
| public int getNetworkDistance(DatanodeInfo datanodeInfo) { |
| // If applications disable the feature or the client machine can't |
| // resolve its network location, clientNode will be set to null. |
| if (clientNode == null) { |
| return DFSUtilClient.isLocalAddress(NetUtils. |
| createSocketAddr(datanodeInfo.getXferAddr())) ? 0 : |
| Integer.MAX_VALUE; |
| } |
| NodeBase node = new NodeBase(datanodeInfo.getHostName(), |
| datanodeInfo.getNetworkLocation()); |
| return NetworkTopology.getDistanceByPath(clientNode, node); |
| } |
| } |