/**
* 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.nfs.nfs3;
import java.io.IOException;
import java.security.PrivilegedExceptionAction;
import java.util.ArrayList;
import java.util.List;
import java.util.Map.Entry;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import com.google.common.base.Preconditions;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.hdfs.DFSClient;
import org.apache.hadoop.hdfs.DFSInputStream;
import org.apache.hadoop.hdfs.server.namenode.NameNode;
import org.apache.hadoop.io.MultipleIOException;
import org.apache.hadoop.security.UserGroupInformation;
import org.apache.hadoop.util.ShutdownHookManager;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Objects;
import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;
import com.google.common.cache.RemovalListener;
import com.google.common.cache.RemovalNotification;
/**
* A cache saves DFSClient objects for different users
*/
class DFSClientCache {
private static final Log LOG = LogFactory.getLog(DFSClientCache.class);
/**
* Cache that maps User id to the corresponding DFSClient.
*/
@VisibleForTesting
final LoadingCache<String, DFSClient> clientCache;
final static int DEFAULT_DFS_CLIENT_CACHE_SIZE = 256;
/**
* Cache that maps <DFSClient, inode path> to the corresponding
* FSDataInputStream.
*/
final LoadingCache<DFSInputStreamCaheKey, FSDataInputStream> inputstreamCache;
/**
* Time to live for a DFSClient (in seconds)
*/
final static int DEFAULT_DFS_INPUTSTREAM_CACHE_SIZE = 1024;
final static int DEFAULT_DFS_INPUTSTREAM_CACHE_TTL = 10 * 60;
private final Configuration config;
private static class DFSInputStreamCaheKey {
final String userId;
final String inodePath;
private DFSInputStreamCaheKey(String userId, String inodePath) {
super();
this.userId = userId;
this.inodePath = inodePath;
}
@Override
public boolean equals(Object obj) {
if (obj instanceof DFSInputStreamCaheKey) {
DFSInputStreamCaheKey k = (DFSInputStreamCaheKey) obj;
return userId.equals(k.userId) && inodePath.equals(k.inodePath);
}
return false;
}
@Override
public int hashCode() {
return Objects.hashCode(userId, inodePath);
}
}
DFSClientCache(Configuration config) {
this(config, DEFAULT_DFS_CLIENT_CACHE_SIZE);
}
DFSClientCache(Configuration config, int clientCache) {
this.config = config;
this.clientCache = CacheBuilder.newBuilder()
.maximumSize(clientCache)
.removalListener(clientRemovalListener())
.build(clientLoader());
this.inputstreamCache = CacheBuilder.newBuilder()
.maximumSize(DEFAULT_DFS_INPUTSTREAM_CACHE_SIZE)
.expireAfterAccess(DEFAULT_DFS_INPUTSTREAM_CACHE_TTL, TimeUnit.SECONDS)
.removalListener(inputStreamRemovalListener())
.build(inputStreamLoader());
ShutdownHookManager.get().addShutdownHook(new CacheFinalizer(),
SHUTDOWN_HOOK_PRIORITY);
}
/**
* Priority of the FileSystem shutdown hook.
*/
public static final int SHUTDOWN_HOOK_PRIORITY = 10;
private class CacheFinalizer implements Runnable {
@Override
public synchronized void run() {
try {
closeAll(true);
} catch (IOException e) {
LOG.info("DFSClientCache.closeAll() threw an exception:\n", e);
}
}
}
/**
* Close all DFSClient instances in the Cache.
* @param onlyAutomatic only close those that are marked for automatic closing
*/
synchronized void closeAll(boolean onlyAutomatic) throws IOException {
List<IOException> exceptions = new ArrayList<IOException>();
ConcurrentMap<String, DFSClient> map = clientCache.asMap();
for (Entry<String, DFSClient> item : map.entrySet()) {
final DFSClient client = item.getValue();
if (client != null) {
try {
client.close();
} catch (IOException ioe) {
exceptions.add(ioe);
}
}
}
if (!exceptions.isEmpty()) {
throw MultipleIOException.createIOException(exceptions);
}
}
private CacheLoader<String, DFSClient> clientLoader() {
return new CacheLoader<String, DFSClient>() {
@Override
public DFSClient load(String userName) throws Exception {
UserGroupInformation ugi = getUserGroupInformation(
userName,
UserGroupInformation.getCurrentUser());
// Guava requires CacheLoader never returns null.
return ugi.doAs(new PrivilegedExceptionAction<DFSClient>() {
@Override
public DFSClient run() throws IOException {
return new DFSClient(NameNode.getAddress(config), config);
}
});
}
};
}
/**
* This method uses the currentUser, and real user to create a proxy
* @param effectiveUser The user who is being proxied by the real user
* @param realUser The actual user who does the command
* @return Proxy UserGroupInformation
* @throws IOException If proxying fails
*/
UserGroupInformation getUserGroupInformation(
String effectiveUser,
UserGroupInformation realUser)
throws IOException {
Preconditions.checkNotNull(effectiveUser);
Preconditions.checkNotNull(realUser);
UserGroupInformation ugi =
UserGroupInformation.createProxyUser(effectiveUser, realUser);
if (LOG.isDebugEnabled()){
LOG.debug(String.format("Created ugi:" +
" %s for username: %s", ugi, effectiveUser));
}
return ugi;
}
private RemovalListener<String, DFSClient> clientRemovalListener() {
return new RemovalListener<String, DFSClient>() {
@Override
public void onRemoval(RemovalNotification<String, DFSClient> notification) {
DFSClient client = notification.getValue();
try {
client.close();
} catch (IOException e) {
LOG.warn(String.format(
"IOException when closing the DFSClient(%s), cause: %s", client,
e));
}
}
};
}
private RemovalListener<DFSInputStreamCaheKey, FSDataInputStream> inputStreamRemovalListener() {
return new RemovalListener<DFSClientCache.DFSInputStreamCaheKey, FSDataInputStream>() {
@Override
public void onRemoval(
RemovalNotification<DFSInputStreamCaheKey, FSDataInputStream> notification) {
try {
notification.getValue().close();
} catch (IOException e) {
}
}
};
}
private CacheLoader<DFSInputStreamCaheKey, FSDataInputStream> inputStreamLoader() {
return new CacheLoader<DFSInputStreamCaheKey, FSDataInputStream>() {
@Override
public FSDataInputStream load(DFSInputStreamCaheKey key) throws Exception {
DFSClient client = getDfsClient(key.userId);
DFSInputStream dis = client.open(key.inodePath);
return new FSDataInputStream(dis);
}
};
}
DFSClient getDfsClient(String userName) {
DFSClient client = null;
try {
client = clientCache.get(userName);
} catch (ExecutionException e) {
LOG.error("Failed to create DFSClient for user:" + userName + " Cause:"
+ e);
}
return client;
}
FSDataInputStream getDfsInputStream(String userName, String inodePath) {
DFSInputStreamCaheKey k = new DFSInputStreamCaheKey(userName, inodePath);
FSDataInputStream s = null;
try {
s = inputstreamCache.get(k);
} catch (ExecutionException e) {
LOG.warn("Failed to create DFSInputStream for user:" + userName
+ " Cause:" + e);
}
return s;
}
public void invalidateDfsInputStream(String userName, String inodePath) {
DFSInputStreamCaheKey k = new DFSInputStreamCaheKey(userName, inodePath);
inputstreamCache.invalidate(k);
}
DFSClient get(String userName) {
DFSClient client = null;
try {
client = clientCache.get(userName);
} catch (ExecutionException e) {
LOG.error("Failed to create DFSClient for user:" + userName + " Cause:"
+ e);
}
return client;
}
}