/**
* 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.balancer;
import java.io.Closeable;
import java.io.IOException;
import java.io.OutputStream;
import java.net.InetAddress;
import java.net.URI;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicLong;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.FsServerDefaults;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hdfs.DistributedFileSystem;
import org.apache.hadoop.hdfs.NameNodeProxies;
import org.apache.hadoop.hdfs.protocol.AlreadyBeingCreatedException;
import org.apache.hadoop.hdfs.protocol.ClientProtocol;
import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
import org.apache.hadoop.hdfs.protocol.HdfsConstants;
import org.apache.hadoop.hdfs.protocol.HdfsConstants.DatanodeReportType;
import org.apache.hadoop.hdfs.protocol.RollingUpgradeInfo;
import org.apache.hadoop.hdfs.server.protocol.BlocksWithLocations;
import org.apache.hadoop.hdfs.server.protocol.DatanodeStorageReport;
import org.apache.hadoop.hdfs.server.protocol.NamenodeProtocol;
import org.apache.hadoop.hdfs.server.protocol.NamespaceInfo;
import org.apache.hadoop.io.IOUtils;
import org.apache.hadoop.ipc.RemoteException;
import com.google.common.annotations.VisibleForTesting;
/**
* The class provides utilities for accessing a NameNode.
*/
@InterfaceAudience.Private
public class NameNodeConnector implements Closeable {
private static final Log LOG = LogFactory.getLog(NameNodeConnector.class);
public static final int DEFAULT_MAX_IDLE_ITERATIONS = 5;
private static boolean write2IdFile = true;
/** Create {@link NameNodeConnector} for the given namenodes. */
public static List<NameNodeConnector> newNameNodeConnectors(
Collection<URI> namenodes, String name, Path idPath, Configuration conf,
int maxIdleIterations) throws IOException {
final List<NameNodeConnector> connectors = new ArrayList<NameNodeConnector>(
namenodes.size());
for (URI uri : namenodes) {
NameNodeConnector nnc = new NameNodeConnector(name, uri, idPath,
null, conf, maxIdleIterations);
nnc.getKeyManager().startBlockKeyUpdater();
connectors.add(nnc);
}
return connectors;
}
public static List<NameNodeConnector> newNameNodeConnectors(
Map<URI, List<Path>> namenodes, String name, Path idPath,
Configuration conf, int maxIdleIterations) throws IOException {
final List<NameNodeConnector> connectors = new ArrayList<NameNodeConnector>(
namenodes.size());
for (Map.Entry<URI, List<Path>> entry : namenodes.entrySet()) {
NameNodeConnector nnc = new NameNodeConnector(name, entry.getKey(),
idPath, entry.getValue(), conf, maxIdleIterations);
nnc.getKeyManager().startBlockKeyUpdater();
connectors.add(nnc);
}
return connectors;
}
@VisibleForTesting
public static void setWrite2IdFile(boolean write2IdFile) {
NameNodeConnector.write2IdFile = write2IdFile;
}
private final URI nameNodeUri;
private final String blockpoolID;
private final NamenodeProtocol namenode;
private final ClientProtocol client;
private final KeyManager keyManager;
final AtomicBoolean fallbackToSimpleAuth = new AtomicBoolean(false);
private final DistributedFileSystem fs;
private final Path idPath;
private final OutputStream out;
private final List<Path> targetPaths;
private final AtomicLong bytesMoved = new AtomicLong();
private final int maxNotChangedIterations;
private int notChangedIterations = 0;
public NameNodeConnector(String name, URI nameNodeUri, Path idPath,
List<Path> targetPaths, Configuration conf,
int maxNotChangedIterations)
throws IOException {
this.nameNodeUri = nameNodeUri;
this.idPath = idPath;
this.targetPaths = targetPaths == null || targetPaths.isEmpty() ? Arrays
.asList(new Path("/")) : targetPaths;
this.maxNotChangedIterations = maxNotChangedIterations;
this.namenode = NameNodeProxies.createProxy(conf, nameNodeUri,
NamenodeProtocol.class).getProxy();
this.client = NameNodeProxies.createProxy(conf, nameNodeUri,
ClientProtocol.class, fallbackToSimpleAuth).getProxy();
this.fs = (DistributedFileSystem)FileSystem.get(nameNodeUri, conf);
final NamespaceInfo namespaceinfo = namenode.versionRequest();
this.blockpoolID = namespaceinfo.getBlockPoolID();
final FsServerDefaults defaults = fs.getServerDefaults(new Path("/"));
this.keyManager = new KeyManager(blockpoolID, namenode,
defaults.getEncryptDataTransfer(), conf);
// if it is for test, we do not create the id file
out = checkAndMarkRunning();
if (out == null) {
// Exit if there is another one running.
throw new IOException("Another " + name + " is running.");
}
}
public DistributedFileSystem getDistributedFileSystem() {
return fs;
}
/** @return the block pool ID */
public String getBlockpoolID() {
return blockpoolID;
}
AtomicLong getBytesMoved() {
return bytesMoved;
}
/** @return blocks with locations. */
public BlocksWithLocations getBlocks(DatanodeInfo datanode, long size)
throws IOException {
return namenode.getBlocks(datanode, size);
}
/**
* @return true if an upgrade is in progress, false if not.
* @throws IOException
*/
public boolean isUpgrading() throws IOException {
// fsimage upgrade
final boolean isUpgrade = !namenode.isUpgradeFinalized();
// rolling upgrade
RollingUpgradeInfo info = fs.rollingUpgrade(
HdfsConstants.RollingUpgradeAction.QUERY);
final boolean isRollingUpgrade = (info != null && !info.isFinalized());
return (isUpgrade || isRollingUpgrade);
}
/** @return live datanode storage reports. */
public DatanodeStorageReport[] getLiveDatanodeStorageReport()
throws IOException {
return client.getDatanodeStorageReport(DatanodeReportType.LIVE);
}
/** @return the key manager */
public KeyManager getKeyManager() {
return keyManager;
}
/** @return the list of paths to scan/migrate */
public List<Path> getTargetPaths() {
return targetPaths;
}
/** Should the instance continue running? */
public boolean shouldContinue(long dispatchBlockMoveBytes) {
if (dispatchBlockMoveBytes > 0) {
notChangedIterations = 0;
} else {
notChangedIterations++;
if (LOG.isDebugEnabled()) {
LOG.debug("No block has been moved for " +
notChangedIterations + " iterations, " +
"maximum notChangedIterations before exit is: " +
((maxNotChangedIterations >= 0) ? maxNotChangedIterations : "Infinite"));
}
if ((maxNotChangedIterations >= 0) &&
(notChangedIterations >= maxNotChangedIterations)) {
System.out.println("No block has been moved for "
+ notChangedIterations + " iterations. Exiting...");
return false;
}
}
return true;
}
/**
* The idea for making sure that there is no more than one instance
* running in an HDFS is to create a file in the HDFS, writes the hostname
* of the machine on which the instance is running to the file, but did not
* close the file until it exits.
*
* This prevents the second instance from running because it can not
* creates the file while the first one is running.
*
* This method checks if there is any running instance. If no, mark yes.
* Note that this is an atomic operation.
*
* @return null if there is a running instance;
* otherwise, the output stream to the newly created file.
*/
private OutputStream checkAndMarkRunning() throws IOException {
try {
if (fs.exists(idPath)) {
// try appending to it so that it will fail fast if another balancer is
// running.
IOUtils.closeStream(fs.append(idPath));
fs.delete(idPath, true);
}
final FSDataOutputStream fsout = fs.create(idPath, false);
// mark balancer idPath to be deleted during filesystem closure
fs.deleteOnExit(idPath);
if (write2IdFile) {
fsout.writeBytes(InetAddress.getLocalHost().getHostName());
fsout.hflush();
}
return fsout;
} catch(RemoteException e) {
if(AlreadyBeingCreatedException.class.getName().equals(e.getClassName())){
return null;
} else {
throw e;
}
}
}
@Override
public void close() {
keyManager.close();
// close the output file
IOUtils.closeStream(out);
if (fs != null) {
try {
fs.delete(idPath, true);
} catch(IOException ioe) {
LOG.warn("Failed to delete " + idPath, ioe);
}
}
}
@Override
public String toString() {
return getClass().getSimpleName() + "[namenodeUri=" + nameNodeUri
+ ", bpid=" + blockpoolID + "]";
}
}