/**
* 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.namenode;
import java.io.File;
import java.io.IOException;
import java.net.URI;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.DF;
import org.apache.hadoop.hdfs.DFSConfigKeys;
import org.apache.hadoop.hdfs.server.common.Util;
import com.google.common.annotations.VisibleForTesting;
/**
*
* NameNodeResourceChecker provides a method -
* <code>hasAvailableDiskSpace</code> - which will return true if and only if
* the NameNode has disk space available on all volumes which are configured to
* be checked. Volumes containing file system name/edits dirs are added by
* default, and arbitrary extra volumes may be configured as well.
*/
public class NameNodeResourceChecker {
private static final Log LOG = LogFactory.getLog(NameNodeResourceChecker.class.getName());
// Space (in bytes) reserved per volume.
private long duReserved;
private final Configuration conf;
private Map<String, DF> volumes;
/**
* Create a NameNodeResourceChecker, which will check the name dirs and edits
* dirs set in <code>conf</code>.
*
* @param conf
* @throws IOException
*/
public NameNodeResourceChecker(Configuration conf) throws IOException {
this.conf = conf;
volumes = new HashMap<String, DF>();
duReserved = conf.getLong(DFSConfigKeys.DFS_NAMENODE_DU_RESERVED_KEY,
DFSConfigKeys.DFS_NAMENODE_DU_RESERVED_DEFAULT);
Collection<URI> extraCheckedVolumes = Util.stringCollectionAsURIs(conf
.getTrimmedStringCollection(DFSConfigKeys.DFS_NAMENODE_CHECKED_VOLUMES_KEY));
addDirsToCheck(FSNamesystem.getNamespaceDirs(conf));
addDirsToCheck(FSNamesystem.getNamespaceEditsDirs(conf));
addDirsToCheck(extraCheckedVolumes);
}
/**
* Add the passed-in directories to the list of volumes to check.
*
* @param directoriesToCheck
* The directories whose volumes will be checked for available space.
* @throws IOException
*/
private void addDirsToCheck(Collection<URI> directoriesToCheck)
throws IOException {
for (URI directoryUri : directoriesToCheck) {
File dir = new File(directoryUri.getPath());
if (!dir.exists()) {
throw new IOException("Missing directory "+dir.getAbsolutePath());
}
DF df = new DF(dir, conf);
volumes.put(df.getFilesystem(), df);
}
}
/**
* Return true if disk space is available on at least one of the configured
* volumes.
*
* @return True if the configured amount of disk space is available on at
* least one volume, false otherwise.
* @throws IOException
*/
boolean hasAvailableDiskSpace()
throws IOException {
return getVolumesLowOnSpace().size() < volumes.size();
}
/**
* Return the set of directories which are low on space.
* @return the set of directories whose free space is below the threshold.
* @throws IOException
*/
Collection<String> getVolumesLowOnSpace() throws IOException {
if (LOG.isDebugEnabled()) {
LOG.debug("Going to check the following volumes disk space: " + volumes);
}
Collection<String> lowVolumes = new ArrayList<String>();
for (DF volume : volumes.values()) {
long availableSpace = volume.getAvailable();
String fileSystem = volume.getFilesystem();
if (LOG.isDebugEnabled()) {
LOG.debug("Space available on volume '" + fileSystem + "' is " + availableSpace);
}
if (availableSpace < duReserved) {
LOG.warn("Space available on volume '" + fileSystem + "' is "
+ availableSpace +
", which is below the configured reserved amount " + duReserved);
lowVolumes.add(volume.getFilesystem());
}
}
return lowVolumes;
}
@VisibleForTesting
void setVolumes(Map<String, DF> volumes) {
this.volumes = volumes;
}
}