/*
* 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.cassandra.db;
import static com.google.common.collect.Sets.newHashSet;
import java.io.File;
import java.io.FileFilter;
import java.io.IOError;
import java.io.IOException;
import java.nio.file.FileVisitResult;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.SimpleFileVisitor;
import java.nio.file.attribute.BasicFileAttributes;
import java.util.*;
import java.util.concurrent.ThreadLocalRandom;
import java.util.concurrent.atomic.AtomicLong;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Predicate;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.ImmutableSet.Builder;
import com.google.common.collect.Iterables;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.cassandra.config.*;
import org.apache.cassandra.io.FSError;
import org.apache.cassandra.io.FSWriteError;
import org.apache.cassandra.io.util.FileUtils;
import org.apache.cassandra.io.sstable.*;
import org.apache.cassandra.service.StorageService;
import org.apache.cassandra.utils.ByteBufferUtil;
import org.apache.cassandra.utils.Pair;
/**
* Encapsulate handling of paths to the data files.
*
* Since v2.1, the directory layout is the following:
* /<path_to_data_dir>/ks/cf1-cfId/ks-cf1-ka-1-Data.db
* /cf2-cfId/ks-cf2-ka-1-Data.db
* ...
*
* cfId is an hex encoded CFID.
*
* For backward compatibility, Directories uses older directory layout if exists.
*
* In addition, more that one 'root' data directory can be specified so that
* <path_to_data_dir> potentially represents multiple locations.
* Note that in the case of multiple locations, the manifest for the leveled
* compaction is only in one of the location.
*
* Snapshots (resp. backups) are always created along the sstables thare are
* snapshoted (resp. backuped) but inside a subdirectory named 'snapshots'
* (resp. backups) (and snapshots are furter inside a subdirectory of the name
* of the snapshot).
*
* This class abstracts all those details from the rest of the code.
*/
public class Directories
{
private static final Logger logger = LoggerFactory.getLogger(Directories.class);
public static final String BACKUPS_SUBDIR = "backups";
public static final String SNAPSHOT_SUBDIR = "snapshots";
public static final String SECONDARY_INDEX_NAME_SEPARATOR = ".";
public static final DataDirectory[] dataDirectories;
static
{
String[] locations = DatabaseDescriptor.getAllDataFileLocations();
dataDirectories = new DataDirectory[locations.length];
for (int i = 0; i < locations.length; ++i)
dataDirectories[i] = new DataDirectory(new File(locations[i]));
}
/**
* Checks whether Cassandra has RWX permissions to the specified directory. Logs an error with
* the details if it does not.
*
* @param dir File object of the directory.
* @param dataDir String representation of the directory's location
* @return status representing Cassandra's RWX permissions to the supplied folder location.
*/
public static boolean verifyFullPermissions(File dir, String dataDir)
{
if (!dir.isDirectory())
{
logger.error("Not a directory {}", dataDir);
return false;
}
else if (!FileAction.hasPrivilege(dir, FileAction.X))
{
logger.error("Doesn't have execute permissions for {} directory", dataDir);
return false;
}
else if (!FileAction.hasPrivilege(dir, FileAction.R))
{
logger.error("Doesn't have read permissions for {} directory", dataDir);
return false;
}
else if (dir.exists() && !FileAction.hasPrivilege(dir, FileAction.W))
{
logger.error("Doesn't have write permissions for {} directory", dataDir);
return false;
}
return true;
}
public enum FileAction
{
X, W, XW, R, XR, RW, XRW;
private FileAction()
{
}
public static boolean hasPrivilege(File file, FileAction action)
{
boolean privilege = false;
switch (action) {
case X:
privilege = file.canExecute();
break;
case W:
privilege = file.canWrite();
break;
case XW:
privilege = file.canExecute() && file.canWrite();
break;
case R:
privilege = file.canRead();
break;
case XR:
privilege = file.canExecute() && file.canRead();
break;
case RW:
privilege = file.canRead() && file.canWrite();
break;
case XRW:
privilege = file.canExecute() && file.canRead() && file.canWrite();
break;
}
return privilege;
}
}
private final CFMetaData metadata;
private final File[] dataPaths;
/**
* Create Directories of given ColumnFamily.
* SSTable directories are created under data_directories defined in cassandra.yaml if not exist at this time.
*
* @param metadata metadata of ColumnFamily
*/
public Directories(CFMetaData metadata)
{
this.metadata = metadata;
if (StorageService.instance.isClientMode())
{
dataPaths = null;
return;
}
String cfId = ByteBufferUtil.bytesToHex(ByteBufferUtil.bytes(metadata.cfId));
int idx = metadata.cfName.indexOf(SECONDARY_INDEX_NAME_SEPARATOR);
// secondary indicies go in the same directory as the base cf
String directoryName = idx > 0 ? metadata.cfName.substring(0, idx) + "-" + cfId : metadata.cfName + "-" + cfId;
this.dataPaths = new File[dataDirectories.length];
// If upgraded from version less than 2.1, use existing directories
for (int i = 0; i < dataDirectories.length; ++i)
{
// check if old SSTable directory exists
dataPaths[i] = new File(dataDirectories[i].location,
join(metadata.ksName,
idx > 0 ? metadata.cfName.substring(0, idx) : metadata.cfName));
}
boolean olderDirectoryExists = Iterables.any(Arrays.asList(dataPaths), new Predicate<File>()
{
public boolean apply(File file)
{
return file.exists();
}
});
if (!olderDirectoryExists)
{
// use 2.1-style path names
for (int i = 0; i < dataDirectories.length; ++i)
dataPaths[i] = new File(dataDirectories[i].location, join(metadata.ksName, directoryName));
}
for (File dir : dataPaths)
{
try
{
FileUtils.createDirectory(dir);
}
catch (FSError e)
{
// don't just let the default exception handler do this, we need the create loop to continue
logger.error("Failed to create {} directory", dir);
FileUtils.handleFSError(e);
}
}
}
/**
* Returns SSTable location which is inside given data directory.
*
* @param dataDirectory
* @return SSTable location
*/
public File getLocationForDisk(DataDirectory dataDirectory)
{
if (dataDirectory != null)
for (File dir : dataPaths)
if (dir.getAbsolutePath().startsWith(dataDirectory.location.getAbsolutePath()))
return dir;
return null;
}
public Descriptor find(String filename)
{
for (File dir : dataPaths)
{
if (new File(dir, filename).exists())
return Descriptor.fromFilename(dir, filename).left;
}
return null;
}
/**
* Basically the same as calling {@link #getWriteableLocationAsFile(long)} with an unknown size ({@code -1L}),
* which may return any non-blacklisted directory - even a data directory that has no usable space.
* Do not use this method in production code.
*
* @throws IOError if all directories are blacklisted.
*/
public File getDirectoryForNewSSTables()
{
return getWriteableLocationAsFile(-1L);
}
/**
* Returns a non-blacklisted data directory that _currently_ has {@code writeSize} bytes as usable space.
*
* @throws IOError if all directories are blacklisted.
*/
public File getWriteableLocationAsFile(long writeSize)
{
return getLocationForDisk(getWriteableLocation(writeSize));
}
/**
* Returns a non-blacklisted data directory that _currently_ has {@code writeSize} bytes as usable space.
*
* @throws IOError if all directories are blacklisted.
*/
public DataDirectory getWriteableLocation(long writeSize)
{
List<DataDirectoryCandidate> candidates = new ArrayList<>();
long totalAvailable = 0L;
// pick directories with enough space and so that resulting sstable dirs aren't blacklisted for writes.
boolean tooBig = false;
for (DataDirectory dataDir : dataDirectories)
{
if (BlacklistedDirectories.isUnwritable(getLocationForDisk(dataDir)))
{
logger.debug("removing blacklisted candidate {}", dataDir.location);
continue;
}
DataDirectoryCandidate candidate = new DataDirectoryCandidate(dataDir);
// exclude directory if its total writeSize does not fit to data directory
if (candidate.availableSpace < writeSize)
{
logger.debug("removing candidate {}, usable={}, requested={}", candidate.dataDirectory.location, candidate.availableSpace, writeSize);
tooBig = true;
continue;
}
candidates.add(candidate);
totalAvailable += candidate.availableSpace;
}
if (candidates.isEmpty())
if (tooBig)
return null;
else
throw new IOError(new IOException("All configured data directories have been blacklisted as unwritable for erroring out"));
// shortcut for single data directory systems
if (candidates.size() == 1)
return candidates.get(0).dataDirectory;
sortWriteableCandidates(candidates, totalAvailable);
return pickWriteableDirectory(candidates);
}
// separated for unit testing
static DataDirectory pickWriteableDirectory(List<DataDirectoryCandidate> candidates)
{
// weighted random
double rnd = ThreadLocalRandom.current().nextDouble();
for (DataDirectoryCandidate candidate : candidates)
{
rnd -= candidate.perc;
if (rnd <= 0)
return candidate.dataDirectory;
}
// last resort
return candidates.get(0).dataDirectory;
}
// separated for unit testing
static void sortWriteableCandidates(List<DataDirectoryCandidate> candidates, long totalAvailable)
{
// calculate free-space-percentage
for (DataDirectoryCandidate candidate : candidates)
candidate.calcFreePerc(totalAvailable);
// sort directories by perc
Collections.sort(candidates);
}
public boolean hasAvailableDiskSpace(long estimatedSSTables, long expectedTotalWriteSize)
{
long writeSize = expectedTotalWriteSize / estimatedSSTables;
long totalAvailable = 0L;
for (DataDirectory dataDir : dataDirectories)
{
if (BlacklistedDirectories.isUnwritable(getLocationForDisk(dataDir)))
continue;
DataDirectoryCandidate candidate = new DataDirectoryCandidate(dataDir);
// exclude directory if its total writeSize does not fit to data directory
if (candidate.availableSpace < writeSize)
continue;
totalAvailable += candidate.availableSpace;
}
return totalAvailable > expectedTotalWriteSize;
}
public static File getSnapshotDirectory(Descriptor desc, String snapshotName)
{
return getOrCreate(desc.directory, SNAPSHOT_SUBDIR, snapshotName);
}
public File getSnapshotManifestFile(String snapshotName)
{
return new File(getDirectoryForNewSSTables(), join(SNAPSHOT_SUBDIR, snapshotName, "manifest.json"));
}
public static File getBackupsDirectory(Descriptor desc)
{
return getOrCreate(desc.directory, BACKUPS_SUBDIR);
}
public SSTableLister sstableLister()
{
return new SSTableLister();
}
public static class DataDirectory
{
public final File location;
public DataDirectory(File location)
{
this.location = location;
}
public long getAvailableSpace()
{
return location.getUsableSpace();
}
}
static final class DataDirectoryCandidate implements Comparable<DataDirectoryCandidate>
{
final DataDirectory dataDirectory;
final long availableSpace;
double perc;
public DataDirectoryCandidate(DataDirectory dataDirectory)
{
this.dataDirectory = dataDirectory;
this.availableSpace = dataDirectory.getAvailableSpace();
}
void calcFreePerc(long totalAvailableSpace)
{
double w = availableSpace;
w /= totalAvailableSpace;
perc = w;
}
public int compareTo(DataDirectoryCandidate o)
{
if (this == o)
return 0;
int r = Double.compare(perc, o.perc);
if (r != 0)
return -r;
// last resort
return System.identityHashCode(this) - System.identityHashCode(o);
}
}
public class SSTableLister
{
private boolean skipTemporary;
private boolean includeBackups;
private boolean onlyBackups;
private int nbFiles;
private final Map<Descriptor, Set<Component>> components = new HashMap<>();
private boolean filtered;
private String snapshotName;
public SSTableLister skipTemporary(boolean b)
{
if (filtered)
throw new IllegalStateException("list() has already been called");
skipTemporary = b;
return this;
}
public SSTableLister includeBackups(boolean b)
{
if (filtered)
throw new IllegalStateException("list() has already been called");
includeBackups = b;
return this;
}
public SSTableLister onlyBackups(boolean b)
{
if (filtered)
throw new IllegalStateException("list() has already been called");
onlyBackups = b;
includeBackups = b;
return this;
}
public SSTableLister snapshots(String sn)
{
if (filtered)
throw new IllegalStateException("list() has already been called");
snapshotName = sn;
return this;
}
public Map<Descriptor, Set<Component>> list()
{
filter();
return ImmutableMap.copyOf(components);
}
public List<File> listFiles()
{
filter();
List<File> l = new ArrayList<>(nbFiles);
for (Map.Entry<Descriptor, Set<Component>> entry : components.entrySet())
{
for (Component c : entry.getValue())
{
l.add(new File(entry.getKey().filenameFor(c)));
}
}
return l;
}
private void filter()
{
if (filtered)
return;
for (File location : dataPaths)
{
if (BlacklistedDirectories.isUnreadable(location))
continue;
if (snapshotName != null)
{
new File(location, join(SNAPSHOT_SUBDIR, snapshotName)).listFiles(getFilter());
continue;
}
if (!onlyBackups)
location.listFiles(getFilter());
if (includeBackups)
new File(location, BACKUPS_SUBDIR).listFiles(getFilter());
}
filtered = true;
}
private FileFilter getFilter()
{
// Note: the prefix needs to include cfname + separator to distinguish between a cfs and it's secondary indexes
final String sstablePrefix = getSSTablePrefix();
return new FileFilter()
{
// This function always return false since accepts adds to the components map
public boolean accept(File file)
{
// we are only interested in the SSTable files that belong to the specific ColumnFamily
if (file.isDirectory() || !file.getName().startsWith(sstablePrefix))
return false;
Pair<Descriptor, Component> pair = SSTable.tryComponentFromFilename(file.getParentFile(), file.getName());
if (pair == null)
return false;
if (skipTemporary && pair.left.type.isTemporary)
return false;
Set<Component> previous = components.get(pair.left);
if (previous == null)
{
previous = new HashSet<>();
components.put(pair.left, previous);
}
previous.add(pair.right);
nbFiles++;
return false;
}
};
}
}
/**
*
* @return Return a map of all snapshots to space being used
* The pair for a snapshot has size on disk and true size.
*/
public Map<String, Pair<Long, Long>> getSnapshotDetails()
{
final Map<String, Pair<Long, Long>> snapshotSpaceMap = new HashMap<>();
for (final File dir : dataPaths)
{
final File snapshotDir = new File(dir,SNAPSHOT_SUBDIR);
if (snapshotDir.exists() && snapshotDir.isDirectory())
{
final File[] snapshots = snapshotDir.listFiles();
if (snapshots != null)
{
for (final File snapshot : snapshots)
{
if (snapshot.isDirectory())
{
final long sizeOnDisk = FileUtils.folderSize(snapshot);
final long trueSize = getTrueAllocatedSizeIn(snapshot);
Pair<Long,Long> spaceUsed = snapshotSpaceMap.get(snapshot.getName());
if (spaceUsed == null)
spaceUsed = Pair.create(sizeOnDisk,trueSize);
else
spaceUsed = Pair.create(spaceUsed.left + sizeOnDisk, spaceUsed.right + trueSize);
snapshotSpaceMap.put(snapshot.getName(), spaceUsed);
}
}
}
}
}
return snapshotSpaceMap;
}
public boolean snapshotExists(String snapshotName)
{
for (File dir : dataPaths)
{
File snapshotDir = new File(dir, join(SNAPSHOT_SUBDIR, snapshotName));
if (snapshotDir.exists())
return true;
}
return false;
}
public static void clearSnapshot(String snapshotName, List<File> snapshotDirectories)
{
// If snapshotName is empty or null, we will delete the entire snapshot directory
String tag = snapshotName == null ? "" : snapshotName;
for (File dir : snapshotDirectories)
{
File snapshotDir = new File(dir, join(SNAPSHOT_SUBDIR, tag));
if (snapshotDir.exists())
{
if (logger.isDebugEnabled())
logger.debug("Removing snapshot directory {}", snapshotDir);
FileUtils.deleteRecursive(snapshotDir);
}
}
}
// The snapshot must exist
public long snapshotCreationTime(String snapshotName)
{
for (File dir : dataPaths)
{
File snapshotDir = new File(dir, join(SNAPSHOT_SUBDIR, snapshotName));
if (snapshotDir.exists())
return snapshotDir.lastModified();
}
throw new RuntimeException("Snapshot " + snapshotName + " doesn't exist");
}
public long trueSnapshotsSize()
{
long result = 0L;
for (File dir : dataPaths)
result += getTrueAllocatedSizeIn(new File(dir, join(SNAPSHOT_SUBDIR)));
return result;
}
private String getSSTablePrefix()
{
return metadata.ksName + Component.separator + metadata.cfName + Component.separator;
}
public long getTrueAllocatedSizeIn(File input)
{
if (!input.isDirectory())
return 0;
TrueFilesSizeVisitor visitor = new TrueFilesSizeVisitor();
try
{
Files.walkFileTree(input.toPath(), visitor);
}
catch (IOException e)
{
logger.error("Could not calculate the size of {}. {}", input, e);
}
return visitor.getAllocatedSize();
}
// Recursively finds all the sub directories in the KS directory.
public static List<File> getKSChildDirectories(String ksName)
{
List<File> result = new ArrayList<>();
for (DataDirectory dataDirectory : dataDirectories)
{
File ksDir = new File(dataDirectory.location, ksName);
File[] cfDirs = ksDir.listFiles();
if (cfDirs == null)
continue;
for (File cfDir : cfDirs)
{
if (cfDir.isDirectory())
result.add(cfDir);
}
}
return result;
}
public List<File> getCFDirectories()
{
List<File> result = new ArrayList<>();
for (File dataDirectory : dataPaths)
{
if (dataDirectory.isDirectory())
result.add(dataDirectory);
}
return result;
}
private static File getOrCreate(File base, String... subdirs)
{
File dir = subdirs == null || subdirs.length == 0 ? base : new File(base, join(subdirs));
if (dir.exists())
{
if (!dir.isDirectory())
throw new AssertionError(String.format("Invalid directory path %s: path exists but is not a directory", dir));
}
else if (!dir.mkdirs() && !(dir.exists() && dir.isDirectory()))
{
throw new FSWriteError(new IOException("Unable to create directory " + dir), dir);
}
return dir;
}
private static String join(String... s)
{
return StringUtils.join(s, File.separator);
}
@VisibleForTesting
static void overrideDataDirectoriesForTest(String loc)
{
for (int i = 0; i < dataDirectories.length; ++i)
dataDirectories[i] = new DataDirectory(new File(loc));
}
@VisibleForTesting
static void resetDataDirectoriesAfterTest()
{
String[] locations = DatabaseDescriptor.getAllDataFileLocations();
for (int i = 0; i < locations.length; ++i)
dataDirectories[i] = new DataDirectory(new File(locations[i]));
}
private class TrueFilesSizeVisitor extends SimpleFileVisitor<Path>
{
private final AtomicLong size = new AtomicLong(0);
private final Set<String> visited = newHashSet(); //count each file only once
private final Set<String> alive;
private final String prefix = getSSTablePrefix();
public TrueFilesSizeVisitor()
{
super();
Builder<String> builder = ImmutableSet.builder();
for (File file: sstableLister().listFiles())
builder.add(file.getName());
alive = builder.build();
}
private boolean isAcceptable(Path file)
{
String fileName = file.toFile().getName();
return fileName.startsWith(prefix)
&& !visited.contains(fileName)
&& !alive.contains(fileName);
}
@Override
public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException
{
if (isAcceptable(file))
{
size.addAndGet(attrs.size());
visited.add(file.toFile().getName());
}
return FileVisitResult.CONTINUE;
}
@Override
public FileVisitResult visitFileFailed(Path file, IOException exc) throws IOException
{
return FileVisitResult.CONTINUE;
}
public long getAllocatedSize()
{
return size.get();
}
}
}