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*
* Licensed to the Apache Software Foundation (ASF) under one
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* 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
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* under the License.
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package org.apache.cassandra.db.lifecycle;
import java.io.File;
import java.nio.file.Path;
import java.util.*;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.stream.Collectors;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.collect.Iterables;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.cassandra.db.compaction.OperationType;
import org.apache.cassandra.db.lifecycle.LogRecord.Type;
import org.apache.cassandra.io.sstable.SSTable;
import org.apache.cassandra.io.sstable.format.big.BigFormat;
import org.apache.cassandra.utils.Throwables;
import static org.apache.cassandra.utils.Throwables.merge;
/**
* A transaction log file. We store transaction records into a log file, which is
* copied into multiple identical replicas on different disks, @see LogFileReplica.
*
* This class supports the transactional logic of LogTransaction and the removing
* of unfinished leftovers when a transaction is completed, or aborted, or when
* we clean up on start-up.
*
* @see LogTransaction
*/
final class LogFile implements AutoCloseable
{
private static final Logger logger = LoggerFactory.getLogger(LogFile.class);
static String EXT = ".log";
static char SEP = '_';
// cc_txn_opname_id.log (where cc is one of the sstable versions defined in BigVersion)
static Pattern FILE_REGEX = Pattern.compile(String.format("^(.{2})_txn_(.*)_(.*)%s$", EXT));
// A set of physical files on disk, each file is an identical replica
private final LogReplicaSet replicas = new LogReplicaSet();
// The transaction records, this set must be ORDER PRESERVING
private final LinkedHashSet<LogRecord> records = new LinkedHashSet<>();
// The type of the transaction
private final OperationType type;
// The unique id of the transaction
private final UUID id;
static LogFile make(File logReplica)
{
return make(logReplica.getName(), Collections.singletonList(logReplica));
}
static LogFile make(String fileName, List<File> logReplicas)
{
Matcher matcher = LogFile.FILE_REGEX.matcher(fileName);
boolean matched = matcher.matches();
assert matched && matcher.groupCount() == 3;
// For now we don't need this but it is there in case we need to change
// file format later on, the version is the sstable version as defined in BigFormat
//String version = matcher.group(1);
OperationType operationType = OperationType.fromFileName(matcher.group(2));
UUID id = UUID.fromString(matcher.group(3));
return new LogFile(operationType, id, logReplicas);
}
Throwable syncDirectory(Throwable accumulate)
{
return replicas.syncDirectory(accumulate);
}
OperationType type()
{
return type;
}
UUID id()
{
return id;
}
Throwable removeUnfinishedLeftovers(Throwable accumulate)
{
try
{
// we sync the parent directories before content deletion to ensure
// any previously deleted files (see SSTableTider) are not
// incorrectly picked up by record.getExistingFiles() in
// deleteRecordFiles(), see CASSANDRA-12261
Throwables.maybeFail(syncDirectory(accumulate));
deleteFilesForRecordsOfType(committed() ? Type.REMOVE : Type.ADD);
// we sync the parent directories between contents and log deletion
// to ensure there is a happens before edge between them
Throwables.maybeFail(syncDirectory(accumulate));
accumulate = replicas.delete(accumulate);
}
catch (Throwable t)
{
accumulate = merge(accumulate, t);
}
return accumulate;
}
static boolean isLogFile(File file)
{
return LogFile.FILE_REGEX.matcher(file.getName()).matches();
}
LogFile(OperationType type, UUID id, List<File> replicas)
{
this(type, id);
this.replicas.addReplicas(replicas);
}
LogFile(OperationType type, UUID id)
{
this.type = type;
this.id = id;
}
boolean verify()
{
records.clear();
if (!replicas.readRecords(records))
{
logger.error("Failed to read records for transaction log {}", this);
return false;
}
records.forEach(LogFile::verifyRecord);
Optional<LogRecord> firstInvalid = records.stream().filter(LogRecord::isInvalidOrPartial).findFirst();
if (!firstInvalid.isPresent())
return true;
LogRecord failedOn = firstInvalid.get();
if (getLastRecord() != failedOn)
{
setErrorInReplicas(failedOn);
return false;
}
records.stream().filter((r) -> r != failedOn).forEach(LogFile::verifyRecordWithCorruptedLastRecord);
if (records.stream()
.filter((r) -> r != failedOn)
.filter(LogRecord::isInvalid)
.map(this::setErrorInReplicas)
.findFirst().isPresent())
{
setErrorInReplicas(failedOn);
return false;
}
// if only the last record is corrupt and all other records have matching files on disk, @see verifyRecord,
// then we simply exited whilst serializing the last record and we carry on
logger.warn("Last record of transaction {} is corrupt or incomplete [{}], " +
"but all previous records match state on disk; continuing",
id, failedOn.error());
return true;
}
LogRecord setErrorInReplicas(LogRecord record)
{
replicas.setErrorInReplicas(record);
return record;
}
static void verifyRecord(LogRecord record)
{
if (record.checksum != record.computeChecksum())
{
record.setError(String.format("Invalid checksum for sstable [%s]: [%d] should have been [%d]",
record.fileName(),
record.checksum,
record.computeChecksum()));
return;
}
if (record.type != Type.REMOVE)
return;
// Paranoid sanity checks: we create another record by looking at the files as they are
// on disk right now and make sure the information still matches. We don't want to delete
// files by mistake if the user has copied them from backup and forgot to remove a txn log
// file that obsoleted the very same files. So we check the latest update time and make sure
// it matches. Because we delete files from oldest to newest, the latest update time should
// always match.
record.status.onDiskRecord = record.withExistingFiles();
if (record.updateTime != record.status.onDiskRecord.updateTime && record.status.onDiskRecord.updateTime > 0)
{
record.setError(String.format("Unexpected files detected for sstable [%s]: " +
"last update time [%tT] should have been [%tT]",
record.fileName(),
record.status.onDiskRecord.updateTime,
record.updateTime));
}
}
static void verifyRecordWithCorruptedLastRecord(LogRecord record)
{
if (record.type == Type.REMOVE && record.status.onDiskRecord.numFiles < record.numFiles)
{ // if we found a corruption in the last record, then we continue only
// if the number of files matches exactly for all previous records.
record.setError(String.format("Incomplete fileset detected for sstable [%s]: " +
"number of files [%d] should have been [%d].",
record.fileName(),
record.status.onDiskRecord.numFiles,
record.numFiles));
}
}
void commit()
{
assert !completed() : "Already completed!";
addRecord(LogRecord.makeCommit(System.currentTimeMillis()));
}
void abort()
{
assert !completed() : "Already completed!";
addRecord(LogRecord.makeAbort(System.currentTimeMillis()));
}
private boolean isLastRecordValidWithType(Type type)
{
LogRecord lastRecord = getLastRecord();
return lastRecord != null &&
lastRecord.type == type &&
lastRecord.isValid();
}
boolean committed()
{
return isLastRecordValidWithType(Type.COMMIT);
}
boolean aborted()
{
return isLastRecordValidWithType(Type.ABORT);
}
boolean completed()
{
return committed() || aborted();
}
void add(Type type, SSTable table)
{
if (!addRecord(makeRecord(type, table)))
throw new IllegalStateException();
}
private LogRecord makeRecord(Type type, SSTable table)
{
assert type == Type.ADD || type == Type.REMOVE;
File directory = table.descriptor.directory;
String fileName = StringUtils.join(directory, File.separator, getFileName());
replicas.maybeCreateReplica(directory, fileName, records);
return LogRecord.make(type, table);
}
private boolean addRecord(LogRecord record)
{
if (records.contains(record))
return false;
replicas.append(record);
return records.add(record);
}
void remove(Type type, SSTable table)
{
LogRecord record = makeRecord(type, table);
assert records.contains(record) : String.format("[%s] is not tracked by %s", record, id);
deleteRecordFiles(record);
records.remove(record);
}
boolean contains(Type type, SSTable table)
{
return records.contains(makeRecord(type, table));
}
void deleteFilesForRecordsOfType(Type type)
{
records.stream()
.filter(type::matches)
.forEach(LogFile::deleteRecordFiles);
records.clear();
}
private static void deleteRecordFiles(LogRecord record)
{
List<File> files = record.getExistingFiles();
// we sort the files in ascending update time order so that the last update time
// stays the same even if we only partially delete files, see comment in isInvalid()
files.sort((f1, f2) -> Long.compare(f1.lastModified(), f2.lastModified()));
files.forEach(LogTransaction::delete);
}
/**
* Extract from the files passed in all those that are of the given type.
*
* Scan all records and select those that are of the given type, valid, and
* located in the same folder. For each such record extract from the files passed in
* those that belong to this record.
*
* @return a map linking each mapped record to its files, where the files where passed in as parameters.
*/
Map<LogRecord, Set<File>> getFilesOfType(Path folder, NavigableSet<File> files, Type type)
{
Map<LogRecord, Set<File>> ret = new HashMap<>();
records.stream()
.filter(type::matches)
.filter(LogRecord::isValid)
.filter(r -> r.isInFolder(folder))
.forEach((r) -> ret.put(r, getRecordFiles(files, r)));
return ret;
}
LogRecord getLastRecord()
{
return Iterables.getLast(records, null);
}
private static Set<File> getRecordFiles(NavigableSet<File> files, LogRecord record)
{
String fileName = record.fileName();
return files.stream().filter(f -> f.getName().startsWith(fileName)).collect(Collectors.toSet());
}
boolean exists()
{
return replicas.exists();
}
public void close()
{
replicas.close();
}
@Override
public String toString()
{
return toString(false);
}
public String toString(boolean showContents)
{
StringBuilder str = new StringBuilder();
str.append('[');
str.append(getFileName());
str.append(" in ");
str.append(replicas.getDirectories());
str.append(']');
if (showContents)
{
str.append(System.lineSeparator());
str.append("Files and contents follow:");
str.append(System.lineSeparator());
replicas.printContentsWithAnyErrors(str);
}
return str.toString();
}
@VisibleForTesting
List<File> getFiles()
{
return replicas.getFiles();
}
@VisibleForTesting
List<String> getFilePaths()
{
return replicas.getFilePaths();
}
private String getFileName()
{
return StringUtils.join(BigFormat.latestVersion,
LogFile.SEP,
"txn",
LogFile.SEP,
type.fileName,
LogFile.SEP,
id.toString(),
LogFile.EXT);
}
}