/**
* 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.classification.InterfaceAudience;
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;
import com.google.common.collect.Collections2;
import com.google.common.base.Predicate;
/**
*
* NameNodeResourceChecker provides a method -
* <code>hasAvailableDiskSpace</code> - which will return true if and only if
* the NameNode has disk space available on all required volumes, and any volume
* which is configured to be redundant. Volumes containing file system edits dirs
* are added by default, and arbitrary extra volumes may be configured as well.
*/
@InterfaceAudience.Private
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, CheckedVolume> volumes;
private int minimumRedundantVolumes;
@VisibleForTesting
class CheckedVolume implements CheckableNameNodeResource {
private DF df;
private boolean required;
private String volume;
public CheckedVolume(File dirToCheck, boolean required)
throws IOException {
df = new DF(dirToCheck, conf);
this.required = required;
volume = df.getFilesystem();
}
public String getVolume() {
return volume;
}
@Override
public boolean isRequired() {
return required;
}
@Override
public boolean isResourceAvailable() {
long availableSpace = df.getAvailable();
if (LOG.isDebugEnabled()) {
LOG.debug("Space available on volume '" + volume + "' is "
+ availableSpace);
}
if (availableSpace < duReserved) {
LOG.warn("Space available on volume '" + volume + "' is "
+ availableSpace +
", which is below the configured reserved amount " + duReserved);
return false;
} else {
return true;
}
}
@Override
public String toString() {
return "volume: " + volume + " required: " + required +
" resource available: " + isResourceAvailable();
}
}
/**
* Create a NameNodeResourceChecker, which will check the edits dirs and any
* additional dirs to check set in <code>conf</code>.
*/
public NameNodeResourceChecker(Configuration conf) throws IOException {
this.conf = conf;
volumes = new HashMap<String, CheckedVolume>();
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));
Collection<URI> localEditDirs = Collections2.filter(
FSNamesystem.getNamespaceEditsDirs(conf),
new Predicate<URI>() {
@Override
public boolean apply(URI input) {
if (input.getScheme().equals(NNStorage.LOCAL_URI_SCHEME)) {
return true;
}
return false;
}
});
// Add all the local edits dirs, marking some as required if they are
// configured as such.
for (URI editsDirToCheck : localEditDirs) {
addDirToCheck(editsDirToCheck,
FSNamesystem.getRequiredNamespaceEditsDirs(conf).contains(
editsDirToCheck));
}
// All extra checked volumes are marked "required"
for (URI extraDirToCheck : extraCheckedVolumes) {
addDirToCheck(extraDirToCheck, true);
}
minimumRedundantVolumes = conf.getInt(
DFSConfigKeys.DFS_NAMENODE_CHECKED_VOLUMES_MINIMUM_KEY,
DFSConfigKeys.DFS_NAMENODE_CHECKED_VOLUMES_MINIMUM_DEFAULT);
}
/**
* Add the volume of the passed-in directory to the list of volumes to check.
* If <code>required</code> is true, and this volume is already present, but
* is marked redundant, it will be marked required. If the volume is already
* present but marked required then this method is a no-op.
*
* @param directoryToCheck
* The directory whose volume will be checked for available space.
*/
private void addDirToCheck(URI directoryToCheck, boolean required)
throws IOException {
File dir = new File(directoryToCheck.getPath());
if (!dir.exists()) {
throw new IOException("Missing directory "+dir.getAbsolutePath());
}
CheckedVolume newVolume = new CheckedVolume(dir, required);
CheckedVolume volume = volumes.get(newVolume.getVolume());
if (volume == null || !volume.isRequired()) {
volumes.put(newVolume.getVolume(), newVolume);
}
}
/**
* Return true if disk space is available on at least one of the configured
* redundant volumes, and all of the configured required volumes.
*
* @return True if the configured amount of disk space is available on at
* least one redundant volume and all of the required volumes, false
* otherwise.
*/
public boolean hasAvailableDiskSpace() {
return NameNodeResourcePolicy.areResourcesAvailable(volumes.values(),
minimumRedundantVolumes);
}
/**
* Return the set of directories which are low on space.
*
* @return the set of directories whose free space is below the threshold.
*/
@VisibleForTesting
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 (CheckedVolume volume : volumes.values()) {
lowVolumes.add(volume.getVolume());
}
return lowVolumes;
}
@VisibleForTesting
void setVolumes(Map<String, CheckedVolume> volumes) {
this.volumes = volumes;
}
@VisibleForTesting
void setMinimumReduntdantVolumes(int minimumRedundantVolumes) {
this.minimumRedundantVolumes = minimumRedundantVolumes;
}
}