satishd commented on code in PR #14034: URL: https://github.com/apache/kafka/pull/14034#discussion_r1461535963
########## storage/src/main/java/org/apache/kafka/storage/internals/log/LocalLog.java: ########## @@ -0,0 +1,1115 @@ +/* + * 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.kafka.storage.internals.log; + +import org.apache.kafka.common.KafkaException; +import org.apache.kafka.common.TopicPartition; +import org.apache.kafka.common.errors.KafkaStorageException; +import org.apache.kafka.common.errors.OffsetOutOfRangeException; +import org.apache.kafka.common.message.FetchResponseData; +import org.apache.kafka.common.record.FileLogInputStream; +import org.apache.kafka.common.record.FileRecords; +import org.apache.kafka.common.record.MemoryRecords; +import org.apache.kafka.common.record.RecordVersion; +import org.apache.kafka.common.utils.LogContext; +import org.apache.kafka.common.utils.Time; +import org.apache.kafka.common.utils.Utils; +import org.apache.kafka.server.util.Scheduler; +import org.slf4j.Logger; + +import java.io.File; +import java.io.IOException; +import java.nio.file.Files; +import java.util.ArrayList; +import java.util.Arrays; +import java.util.Collection; +import java.util.Collections; +import java.util.Comparator; +import java.util.Iterator; +import java.util.List; +import java.util.Optional; +import java.util.OptionalLong; +import java.util.Set; +import java.util.concurrent.atomic.AtomicLong; +import java.util.function.Consumer; +import java.util.function.Function; +import java.util.function.Supplier; +import java.util.regex.Pattern; +import java.util.stream.Collectors; + +/** + * An append-only log for storing messages locally. The log is a sequence of LogSegments, each with a base offset. + * New log segments are created according to a configurable policy that controls the size in bytes or time interval + * for a given segment. + * + * NOTE: this class is not thread-safe. + */ +public class LocalLog { + + /** + * A file that is scheduled to be deleted + */ + public static final String DELETED_FILE_SUFFIX = LogFileUtils.DELETED_FILE_SUFFIX; + + /** + * A temporary file that is being used for log cleaning + */ + public static final String CLEANED_FILE_SUFFIX = ".cleaned"; + + /** + * A temporary file used when swapping files into the log + */ + public static final String SWAP_FILE_SUFFIX = ".swap"; + + /** + * A directory that is scheduled to be deleted + */ + public static final String DELETE_DIR_SUFFIX = "-delete"; + + /** + * A directory that is used for future partition + */ + public static final String FUTURE_DIR_SUFFIX = "-future"; + public static final String STRAY_DIR_SUFFIX = "-stray"; + + public static final Pattern DELETE_DIR_PATTERN = Pattern.compile("^(\\S+)-(\\S+)\\.(\\S+)" + DELETE_DIR_SUFFIX); + public static final Pattern FUTURE_DIR_PATTERN = Pattern.compile("^(\\S+)-(\\S+)\\.(\\S+)" + FUTURE_DIR_SUFFIX); + public static final Pattern STRAY_DIR_PATTERN = Pattern.compile("^(\\S+)-(\\S+)\\.(\\S+)" + STRAY_DIR_SUFFIX); + + public static final long UNKNOWN_OFFSET = -1L; + + private final Logger logger; + + private final LogSegments segments; + private final Scheduler scheduler; + private final Time time; + private final TopicPartition topicPartition; + private final LogDirFailureChannel logDirFailureChannel; + + // Last time the log was flushed + private final AtomicLong lastFlushedTime; + + private volatile File dir; + private volatile LogConfig config; + private volatile long recoveryPoint; + private volatile LogOffsetMetadata nextOffsetMetadata; + + // Cache value of parent directory to avoid allocations in hot paths like ReplicaManager.checkpointHighWatermarks + private volatile String parentDir; + // The memory mapped buffer for index files of this log will be closed with either delete() or closeHandlers() + // After memory mapped buffer is closed, no disk IO operation should be performed for this log. + private volatile boolean isMemoryMappedBufferClosed = false; + + /** + * Creates a new LocalLog instance. + * + * @param dir The directory in which log segments are created. + * @param config The log configuration settings + * @param segments The non-empty log segments recovered from disk + * @param recoveryPoint The offset at which to begin the next recovery i.e. the first offset which has not been flushed to disk + * @param nextOffsetMetadata The offset where the next message could be appended + * @param scheduler The thread pool scheduler used for background actions + * @param time The time instance used for checking the clock + * @param topicPartition The topic partition associated with this log + * @param logDirFailureChannel The LogDirFailureChannel instance to asynchronously handle Log dir failure + */ + public LocalLog(File dir, + LogConfig config, + LogSegments segments, + long recoveryPoint, + LogOffsetMetadata nextOffsetMetadata, + Scheduler scheduler, + Time time, + TopicPartition topicPartition, + LogDirFailureChannel logDirFailureChannel) { + this.dir = dir; + this.config = config; + this.segments = segments; + this.recoveryPoint = recoveryPoint; + this.scheduler = scheduler; + this.nextOffsetMetadata = nextOffsetMetadata; + this.time = time; + this.topicPartition = topicPartition; + this.logDirFailureChannel = logDirFailureChannel; + + parentDir = dir.getParent(); + lastFlushedTime = new AtomicLong(time.milliseconds()); + String logPrefix = "[LocalLog partition=" + topicPartition + ", dir=" + dir + "] "; + logger = new LogContext(logPrefix).logger(LocalLog.class); + } + + public Logger logger() { + return logger; + } + + public LogConfig config() { + return config; + } + + public LogSegments segments() { + return segments; + } + + public Scheduler scheduler() { + return scheduler; + } + + public LogOffsetMetadata nextOffsetMetadata() { + return nextOffsetMetadata; + } + + public TopicPartition topicPartition() { + return topicPartition; + } + + public LogDirFailureChannel logDirFailureChannel() { + return logDirFailureChannel; + } + + public long recoveryPoint() { + return recoveryPoint; + } + + public Time time() { + return time; + } + + /** + * The time this log is last known to have been fully flushed to disk + */ + public long lastFlushTime() { + return lastFlushedTime.get(); + } + + /** + * The offset metadata of the next message that will be appended to the log + */ + public LogOffsetMetadata logEndOffsetMetadata() { + return nextOffsetMetadata; + } + + /** + * The offset of the next message that will be appended to the log + */ + public long logEndOffset() { + return nextOffsetMetadata.messageOffset; + } + + public File dir() { + return dir; + } + + public String name() { + return dir.getName(); + } + + public String parentDir() { + return parentDir; + } + + public File parentDirFile() { + return new File(parentDir); + } + + public boolean isFuture() { + return dir.getName().endsWith(LocalLog.FUTURE_DIR_SUFFIX); + } + + /** + * Rename the directory of the local-log to the given name. + * + * @param name the new dir name + * @throws KafkaStorageException if rename fails + */ + public boolean renameDir(String name) { + return maybeHandleIOException( + () -> "Error while renaming dir for " + topicPartition + " in log dir " + dir.getParent(), + () -> { + File renamedDir = new File(dir.getParent(), name); + Utils.atomicMoveWithFallback(dir.toPath(), renamedDir.toPath()); + if (!renamedDir.equals(dir)) { + dir = renamedDir; + parentDir = renamedDir.getParent(); + segments.updateParentDir(renamedDir); + return true; + } else { + return false; + } + }); + } + + /** + * Update the existing configuration to the new provided configuration. + * + * @param newConfig the new configuration to be updated to + */ + public void updateConfig(LogConfig newConfig) { + LogConfig oldConfig = config; + config = newConfig; + RecordVersion oldRecordVersion = oldConfig.recordVersion(); + RecordVersion newRecordVersion = newConfig.recordVersion(); + if (newRecordVersion.precedes(oldRecordVersion)) + logger.warn("Record format version has been downgraded from {} to {}.", oldRecordVersion, newRecordVersion); + } + + public void checkIfMemoryMappedBufferClosed() { + if (isMemoryMappedBufferClosed) + throw new KafkaStorageException("The memory mapped buffer for log of " + topicPartition + " is already closed"); + } + + public void updateRecoveryPoint(long newRecoveryPoint) { + recoveryPoint = newRecoveryPoint; + } + + /** + * Update recoveryPoint to provided offset and mark the log as flushed, if the offset is greater + * than the existing recoveryPoint. + * + * @param offset the offset to be updated + */ + public void markFlushed(long offset) { + checkIfMemoryMappedBufferClosed(); + if (offset > recoveryPoint) { + updateRecoveryPoint(offset); + lastFlushedTime.set(time.milliseconds()); + } + } + + /** + * The number of messages appended to the log since the last flush + */ + public long unflushedMessages() { + return logEndOffset() - recoveryPoint; + } + + /** + * Flush local log segments for all offsets up to offset-1. + * Note: It does not update the recovery point. + * + * @param offset The offset to flush up to (non-inclusive) + */ + public void flush(long offset) throws IOException { + long currentRecoveryPoint = recoveryPoint; + if (currentRecoveryPoint <= offset) { + Collection<LogSegment> segmentsToFlush = segments.values(currentRecoveryPoint, offset); + for (LogSegment segment : segmentsToFlush) { + segment.flush(); + } + // If there are any new segments, we need to flush the parent directory for crash consistency. + if (segmentsToFlush.stream().anyMatch(x -> x.baseOffset() >= currentRecoveryPoint)) { + // The directory might be renamed concurrently for topic deletion, which may cause NoSuchFileException here. + // Since the directory is to be deleted anyways, we just swallow NoSuchFileException and let it go. + Utils.flushDirIfExists(dir.toPath()); + } + } + } + + /** + * Updates end offset of the log, and also updates the recoveryPoint. + * + * @param endOffset the new end offset of the log + */ + public void updateLogEndOffset(long endOffset) { + nextOffsetMetadata = new LogOffsetMetadata(endOffset, segments.activeSegment().baseOffset(), segments.activeSegment().size()); + if (recoveryPoint > endOffset) { + updateRecoveryPoint(endOffset); + } + } + + /** + * Close file handlers used by log but don't write to disk. + * This is called if the log directory is offline. + */ + public void closeHandlers() { + segments.closeHandlers(); + isMemoryMappedBufferClosed = true; + } + + /** + * Closes the segments of the log. + */ + public void close() { + maybeHandleIOException( + () -> "Error while renaming dir for " + topicPartition + " in dir " + dir.getParent(), + (StorageAction<Void, IOException>) () -> { + checkIfMemoryMappedBufferClosed(); + segments.close(); + return null; + }); + } + + /** + * Completely delete this log directory with no delay. + */ + public void deleteEmptyDir() { + maybeHandleIOException( + () -> "Error while deleting dir for " + topicPartition + " in dir " + dir.getParent(), + (StorageAction<Void, IOException>) () -> { + if (segments.nonEmpty()) { + throw new IllegalStateException("Can not delete directory when " + segments.numberOfSegments() + " segments are still present"); + } + if (!isMemoryMappedBufferClosed) { + throw new IllegalStateException("Can not delete directory when memory mapped buffer for log of " + topicPartition + " is still open."); + } + Utils.delete(dir); + return null; + }); + } + + /** + * Completely delete all segments with no delay. + * + * @return the deleted segments + */ + public Collection<LogSegment> deleteAllSegments() { + return maybeHandleIOException( + () -> "Error while deleting all segments for " + topicPartition + " in dir " + dir.getParent(), + () -> { + Collection<LogSegment> allSegments = segments.values(); + List<LogSegment> deletableSegments = new ArrayList<>(allSegments); + removeAndDeleteSegments(allSegments, false, new LogDeletion(this.logger)); + isMemoryMappedBufferClosed = true; + return deletableSegments; + }); + } + + /** + * This method deletes the given log segments by doing the following for each of them: + * - It removes the segment from the segment map so that it will no longer be used for reads. + * - It renames the index and log files by appending .deleted to the respective file name + * - It can either schedule an asynchronous delete operation to occur in the future or perform the deletion synchronously + * <p> + * Asynchronous deletion allows reads to happen concurrently without synchronization and without the possibility of + * physically deleting a file while it is being read. + * <p> + * This method does not convert IOException to KafkaStorageException, the immediate caller + * is expected to catch and handle IOException. + * + * @param segmentsToDelete The log segments to schedule for deletion + * @param asyncDelete Whether the segment files should be deleted asynchronously + * @param reason The reason for the segment deletion + */ + public void removeAndDeleteSegments(Collection<LogSegment> segmentsToDelete, + boolean asyncDelete, + SegmentDeletionReason reason) throws IOException { + if (!segmentsToDelete.isEmpty()) { + // Most callers hold an iterator into the `segments` collection and `removeAndDeleteSegment` mutates it by + // removing the deleted segment, we should force materialization of the iterator here, so that results of the + // iteration remain valid and deterministic. We should also pass only the materialized view of the + // iterator to the logic that actually deletes the segments. + List<LogSegment> toDelete = new ArrayList<>(segmentsToDelete); + reason.logReason(toDelete); + for (LogSegment segment : toDelete) { + segments.remove(segment.baseOffset()); + } + deleteSegmentFiles(toDelete, asyncDelete, dir, topicPartition, config, scheduler, logDirFailureChannel, logger); + } + } + + /** + * This method deletes the given segment and creates a new segment with the given new base offset. It ensures an + * active segment exists in the log at all times during this process. + * <p> + * Asynchronous deletion allows reads to happen concurrently without synchronization and without the possibility of + * physically deleting a file while it is being read. + * <p> + * This method does not convert IOException to KafkaStorageException, the immediate caller + * is expected to catch and handle IOException. + * + * @param newOffset The base offset of the new segment + * @param segmentToDelete The old active segment to schedule for deletion + * @param asyncDelete Whether the segment files should be deleted asynchronously + * @param reason The reason for the segment deletion + */ + public LogSegment createAndDeleteSegment(long newOffset, + LogSegment segmentToDelete, + boolean asyncDelete, + SegmentDeletionReason reason) throws IOException { + if (newOffset == segmentToDelete.baseOffset()) { + segmentToDelete.changeFileSuffixes("", LogFileUtils.DELETED_FILE_SUFFIX); + } + + LogSegment newSegment = LogSegment.open(dir, + newOffset, + config, + time, + false, + config.initFileSize(), + config.preallocate, + ""); + segments.add(newSegment); + + reason.logReason(Collections.singletonList(segmentToDelete)); + if (newOffset != segmentToDelete.baseOffset()) { + segments.remove(segmentToDelete.baseOffset()); + } + + deleteSegmentFiles(Collections.singletonList(segmentToDelete), asyncDelete, dir, topicPartition, config, scheduler, logDirFailureChannel, logger); + + return newSegment; + } + + /** + * Given a message offset, find its corresponding offset metadata in the log. + * If the message offset is out of range, throw an OffsetOutOfRangeException + */ + public LogOffsetMetadata convertToOffsetMetadataOrThrow(long offset) { + FetchDataInfo fetchDataInfo = read(offset, 1, false, nextOffsetMetadata, false); + return fetchDataInfo.fetchOffsetMetadata; + } + + + /** + * Read messages from the log. + * + * @param startOffset The offset to begin reading at + * @param maxLength The maximum number of bytes to read + * @param minOneMessage If this is true, the first message will be returned even if it exceeds `maxLength` (if one exists) + * @param maxOffsetMetadata The metadata of the maximum offset to be fetched + * @param includeAbortedTxns If true, aborted transactions are included + * @return The fetch data information including fetch starting offset metadata and messages read. + * @throws OffsetOutOfRangeException If startOffset is beyond the log end offset + */ + public FetchDataInfo read(long startOffset, + int maxLength, + boolean minOneMessage, + LogOffsetMetadata maxOffsetMetadata, + boolean includeAbortedTxns) { + return maybeHandleIOException( + () -> "Exception while reading for " + topicPartition + " in dir " + dir.getParent(), + () -> { + logger.trace("Reading maximum {} bytes at offset {} from log with total length {} bytes", maxLength, startOffset, segments.sizeInBytes()); + + LogOffsetMetadata endOffsetMetadata = nextOffsetMetadata; + long endOffset = endOffsetMetadata.messageOffset; + Optional<LogSegment> segmentOpt = segments.floorSegment(startOffset); + + // return error on attempt to read beyond the log end offset + if (startOffset > endOffset || !segmentOpt.isPresent()) + throw new OffsetOutOfRangeException("Received request for offset " + startOffset + " for partition " + topicPartition + ", but we only have log segments upto " + endOffset + "."); + + if (startOffset == maxOffsetMetadata.messageOffset) + return emptyFetchDataInfo(maxOffsetMetadata, includeAbortedTxns); + else if (startOffset > maxOffsetMetadata.messageOffset) + return emptyFetchDataInfo(convertToOffsetMetadataOrThrow(startOffset), includeAbortedTxns); + else { + // Do the read on the segment with a base offset less than the target offset + // but if that segment doesn't contain any messages with an offset greater than that + // continue to read from successive segments until we get some messages or we reach the end of the log + FetchDataInfo fetchDataInfo = null; + while (fetchDataInfo == null && segmentOpt.isPresent()) { + LogSegment segment = segmentOpt.get(); + long baseOffset = segment.baseOffset(); + + int maxPosition = + // Use the max offset position if it is on this segment; otherwise, the segment size is the limit. + maxOffsetMetadata.segmentBaseOffset == segment.baseOffset() ? maxOffsetMetadata.relativePositionInSegment : segment.size(); + + fetchDataInfo = segment.read(startOffset, maxLength, maxPosition, minOneMessage); + if (fetchDataInfo != null) { + if (includeAbortedTxns) + fetchDataInfo = addAbortedTransactions(startOffset, segment, fetchDataInfo); + } else segmentOpt = segments.higherSegment(baseOffset); + } + + if (fetchDataInfo != null) return fetchDataInfo; + else { + // okay we are beyond the end of the last segment with no data fetched although the start offset is in range, + // this can happen when all messages with offset larger than start offsets have been deleted. + // In this case, we will return the empty set with log end offset metadata + return new FetchDataInfo(nextOffsetMetadata, MemoryRecords.EMPTY); + } + } + }); + } + + public void append(long lastOffset, long largestTimestamp, long shallowOffsetOfMaxTimestamp, MemoryRecords records) throws IOException { + segments.activeSegment().append(lastOffset, largestTimestamp, shallowOffsetOfMaxTimestamp, records); + updateLogEndOffset(lastOffset + 1); + } + + FetchDataInfo addAbortedTransactions(long startOffset, LogSegment segment, FetchDataInfo fetchInfo) throws IOException { + int fetchSize = fetchInfo.records.sizeInBytes(); + OffsetPosition startOffsetPosition + = new OffsetPosition(fetchInfo.fetchOffsetMetadata.messageOffset, fetchInfo.fetchOffsetMetadata.relativePositionInSegment); + long upperBoundOffset = segment.fetchUpperBoundOffset(startOffsetPosition, fetchSize) + .orElse(segments.higherSegment(segment.baseOffset()) + .map(LogSegment::baseOffset).orElse(logEndOffset())); + + List<FetchResponseData.AbortedTransaction> abortedTransactions = new ArrayList<>(); + + Consumer<List<AbortedTxn>> accumulator = abortedTxns -> abortedTransactions.addAll(abortedTxns.stream() + .map(AbortedTxn::asAbortedTransaction).collect(Collectors.toList())); + + collectAbortedTransactions(startOffset, upperBoundOffset, segment, accumulator); + + return new FetchDataInfo(fetchInfo.fetchOffsetMetadata, + fetchInfo.records, + fetchInfo.firstEntryIncomplete, + Optional.of(abortedTransactions)); + } + + void collectAbortedTransactions(long startOffset, + long upperBoundOffset, + LogSegment startingSegment, + Consumer<List<AbortedTxn>> accumulator) throws IOException { + Iterator<LogSegment> higherSegments = segments.higherSegments(startingSegment.baseOffset()).iterator(); + Optional<LogSegment> segmentEntryOpt = Optional.of(startingSegment); + while (segmentEntryOpt.isPresent()) { + LogSegment segment = segmentEntryOpt.get(); + TxnIndexSearchResult searchResult = segment.collectAbortedTxns(startOffset, upperBoundOffset); + accumulator.accept(searchResult.abortedTransactions); + if (searchResult.isComplete) return; + segmentEntryOpt = nextItem(higherSegments); + } + } + + public List<AbortedTxn> collectAbortedTransactions(long logStartOffset, + long baseOffset, + long upperBoundOffset) throws IOException { + Optional<LogSegment> segmentEntry = segments.floorSegment(baseOffset); + List<AbortedTxn> allAbortedTxns = new ArrayList<>(); + + if (segmentEntry.isPresent()) + collectAbortedTransactions(logStartOffset, upperBoundOffset, segmentEntry.get(), allAbortedTxns::addAll); + + return allAbortedTxns; + } + + public LogSegment roll() { + return roll(OptionalLong.empty()); + } + + /** + * Roll the log over to a new active segment starting with the current logEndOffset. + * This will trim the index to the exact size of the number of entries it currently contains. + * + * @param expectedNextOffset The expected next offset after the segment is rolled + * @return The newly rolled segment + */ + public LogSegment roll(OptionalLong expectedNextOffset) { + return maybeHandleIOException( + () -> "Error while rolling log segment for " + topicPartition + " in dir " + dir.getParent(), + () -> { + long start = time.hiResClockMs(); + checkIfMemoryMappedBufferClosed(); + long newOffset = Math.max(expectedNextOffset.orElse(0L), logEndOffset()); + File logFile = LogFileUtils.logFile(dir, newOffset, ""); + LogSegment activeSegment = segments.activeSegment(); + if (segments.contains(newOffset)) { + // segment with the same base offset already exists and loaded + if (activeSegment.baseOffset() == newOffset && activeSegment.size() == 0) { + // We have seen this happen (see KAFKA-6388) after shouldRoll() returns true for an + // active segment of size zero because of one of the indexes is "full" (due to _maxEntries == 0). + logger.warn("Trying to roll a new log segment with start offset {} =max(provided offset = {}, LEO = {}) while it already exists and is active with size 0. Size of time index: {}, size of offset index: {}.", + newOffset, expectedNextOffset, logEndOffset(), activeSegment.timeIndex().entries(), activeSegment.offsetIndex().entries()); + LogSegment newSegment = createAndDeleteSegment(newOffset, activeSegment, true, new LogRoll(this.logger)); + updateLogEndOffset(nextOffsetMetadata.messageOffset); + logger.info("Rolled new log segment at offset {} in {} ms.", newOffset, time.hiResClockMs() - start); + return newSegment; + } else { + throw new KafkaException("Trying to roll a new log segment for topic partition " + + topicPartition + " with start offset " + newOffset + " + =max(provided offset = " + + expectedNextOffset + ", LEO = " + logEndOffset() + " while it already exists. Existing segment is " + + segments.get(newOffset) + "."); + } + } else if (!segments.isEmpty() && newOffset < activeSegment.baseOffset()) { + throw new KafkaException("Trying to roll a new log segment for topic partition " + topicPartition + + " with start offset " + newOffset + " =max(provided offset = " + expectedNextOffset + + ", LEO = " + logEndOffset() + ") lower than start offset of the active segment " + activeSegment); + } else { + File offsetIdxFile = LogFileUtils.offsetIndexFile(dir, newOffset); + File timeIdxFile = LogFileUtils.timeIndexFile(dir, newOffset); + File txnIdxFile = LogFileUtils.transactionIndexFile(dir, newOffset); + + for (File file : Arrays.asList(logFile, offsetIdxFile, timeIdxFile, txnIdxFile)) { + if (file.exists()) { + logger.warn("Newly rolled segment file {} already exists; deleting it first", file.getAbsolutePath()); + Files.delete(file.toPath()); + } + } + + Optional<LogSegment> logSegmentOption = segments.lastSegment(); + if (logSegmentOption.isPresent()) logSegmentOption.get().onBecomeInactiveSegment(); + } + + LogSegment newSegment = LogSegment.open(dir, + newOffset, + config, + time, + false, + config.initFileSize(), + config.preallocate, + ""); + segments.add(newSegment); + + // We need to update the segment base offset and append position data of the metadata when log rolls. + // The next offset should not change. + updateLogEndOffset(nextOffsetMetadata.messageOffset); + + logger.info("Rolled new log segment at offset {} in {} ms.", newOffset, time.hiResClockMs() - start); + + return newSegment; + }); + } + + /** + * Delete all data in the local log and start at the new offset. + * + * @param newOffset The new offset to start the log with + * @return the list of segments that were scheduled for deletion + */ + public Collection<LogSegment> truncateFullyAndStartAt(long newOffset) { + return maybeHandleIOException( + () -> "Error while truncating the entire log for " + topicPartition + " in dir " + dir.getParent(), + () -> { + logger.debug("Truncate and start at offset {}", newOffset); + checkIfMemoryMappedBufferClosed(); + List<LogSegment> segmentsToDelete = new ArrayList<>(segments.values()); + + if (!segmentsToDelete.isEmpty()) { + removeAndDeleteSegments(segmentsToDelete.subList(0, segmentsToDelete.size() - 1), true, new LogTruncation(this.logger)); + // Use createAndDeleteSegment() to create new segment first and then delete the old last segment to prevent missing + // active segment during the deletion process + createAndDeleteSegment(newOffset, segmentsToDelete.get(segmentsToDelete.size() - 1), true, new LogTruncation(this.logger)); + } + + updateLogEndOffset(newOffset); + + return segmentsToDelete; + }); + } + + /** + * Truncate this log so that it ends with the greatest offset < targetOffset. + * + * @param targetOffset The offset to truncate to, an upper bound on all offsets in the log after truncation is complete. + * @return the list of segments that were scheduled for deletion + */ + public Collection<LogSegment> truncateTo(long targetOffset) throws IOException { + Collection<LogSegment> deletableSegments = segments.filter(segment -> segment.baseOffset() > targetOffset); + removeAndDeleteSegments(deletableSegments, true, new LogTruncation(this.logger)); + segments.activeSegment().truncateTo(targetOffset); + updateLogEndOffset(targetOffset); + return deletableSegments; + } + + private <T> T maybeHandleIOException(Supplier<String> errorMsgSupplier, + StorageAction<T, IOException> func) { + return maybeHandleIOException(logDirFailureChannel, parentDir, errorMsgSupplier, func); + } + + /** + * Wraps the value of iterator.next() in an Optional instance. + * + * @param iterator given iterator to iterate over + * @return if a next element exists, Optional#empty otherwise. + * @param <T> the type of object held within the iterator + */ + public static <T> Optional<T> nextItem(Iterator<T> iterator) { + return iterator.hasNext() ? Optional.of(iterator.next()) : Optional.empty(); + } + + /** + * Return a directory name to rename the log directory to for async deletion. + * The name will be in the following format: "topic-partitionId.uniqueId-delete". + * If the topic name is too long, it will be truncated to prevent the total name + * from exceeding 255 characters. + */ + public static String logDeleteDirName(TopicPartition topicPartition) { + return logDirNameWithSuffixCappedLength(topicPartition, DELETE_DIR_SUFFIX); + } + + /** + * Return a new directory name in the following format: "${topic}-${partitionId}.${uniqueId}${suffix}". + * If the topic name is too long, it will be truncated to prevent the total name + * from exceeding 255 characters. + */ + static String logDirNameWithSuffixCappedLength(TopicPartition topicPartition, String suffix) { + String uniqueId = java.util.UUID.randomUUID().toString().replaceAll("-", ""); + String fullSuffix = "-" + topicPartition.partition() + "." + uniqueId + suffix; + int prefixLength = Math.min(topicPartition.topic().length(), 255 - fullSuffix.length()); + return topicPartition.topic().substring(0, prefixLength) + fullSuffix; + } + + /** + * Return a directory name to rename the log directory to for stray partition deletion. + * The name will be in the following format: "topic-partitionId.uniqueId-stray". + * If the topic name is too long, it will be truncated to prevent the total name + * from exceeding 255 characters. + */ + public static String logStrayDirName(TopicPartition topicPartition) { + return logDirNameWithSuffixCappedLength(topicPartition, STRAY_DIR_SUFFIX); + } + + /** + * Return a future directory name for the given topic partition. The name will be in the following + * format: topic-partition.uniqueId-future where topic, partition and uniqueId are variables. + */ + public static String logFutureDirName(TopicPartition topicPartition) { + return logDirNameWithSuffix(topicPartition, FUTURE_DIR_SUFFIX); + } + + static String logDirNameWithSuffix(TopicPartition topicPartition, String suffix) { + String uniqueId = java.util.UUID.randomUUID().toString().replaceAll("-", ""); + return logDirName(topicPartition) + "." + uniqueId + suffix; + } + + /** + * Return a directory name for the given topic partition. The name will be in the following + * format: topic-partition where topic, partition are variables. + */ + public static String logDirName(TopicPartition topicPartition) { + return topicPartition.topic() + "-" + topicPartition.partition(); + } + + /** + * Parse the topic and partition out of the directory name of a log + */ + public static TopicPartition parseTopicPartitionName(File dir) { + if (dir == null) throw new KafkaException("dir should not be null"); + + Function<File, KafkaException> exceptionFn + = file -> new KafkaException("Found directory " + dir.getAbsolutePath() + ", '" + dir.getName() + + "' is not in the form of topic-partition or topic-partition.uniqueId-delete (if marked for deletion).\n" + + "Kafka's log directories (and children) should only contain Kafka topic data."); + + String dirName = dir.getName(); + if (dirName == null || dirName.isEmpty() || !dirName.contains("-")) + throw exceptionFn.apply(dir); + + if (dirName.endsWith(DELETE_DIR_SUFFIX) && !DELETE_DIR_PATTERN.matcher(dirName).matches() || + dirName.endsWith(FUTURE_DIR_SUFFIX) && !FUTURE_DIR_PATTERN.matcher(dirName).matches() || + dirName.endsWith(STRAY_DIR_SUFFIX) && !STRAY_DIR_PATTERN.matcher(dirName).matches()) + throw exceptionFn.apply(dir); + + String name = dirName.endsWith(DELETE_DIR_SUFFIX) || dirName.endsWith(FUTURE_DIR_SUFFIX) || dirName.endsWith(STRAY_DIR_SUFFIX) + ? dirName.substring(0, dirName.lastIndexOf('.')) : dirName; + + int index = name.lastIndexOf('-'); + String topic = name.substring(0, index); + String partitionString = name.substring(index + 1); + + if (topic.isEmpty() || partitionString.isEmpty()) throw exceptionFn.apply(dir); + + try { + int partition = Integer.parseInt(partitionString); + return new TopicPartition(topic, partition); + } catch (NumberFormatException ex) { + throw exceptionFn.apply(dir); + } + } + + public static boolean isIndexFile(File file) { + String fileName = file.getName(); + return fileName.endsWith(LogFileUtils.INDEX_FILE_SUFFIX) + || fileName.endsWith(LogFileUtils.TIME_INDEX_FILE_SUFFIX) + || fileName.endsWith(LogFileUtils.TXN_INDEX_FILE_SUFFIX); + } + + public static boolean isLogFile(File file) { + return file.getPath().endsWith(LogFileUtils.LOG_FILE_SUFFIX); + } + + FetchDataInfo emptyFetchDataInfo(LogOffsetMetadata fetchOffsetMetadata, boolean includeAbortedTxns) { + Optional<List<FetchResponseData.AbortedTransaction>> abortedTransactions + = includeAbortedTxns ? Optional.of(Collections.emptyList()) : Optional.empty(); + + return new FetchDataInfo(fetchOffsetMetadata, MemoryRecords.EMPTY, false, abortedTransactions); + } + + public static LogSegment createNewCleanedSegment(File dir, LogConfig logConfig, long baseOffset) throws IOException { + LogSegment.deleteIfExists(dir, baseOffset, CLEANED_FILE_SUFFIX); + return LogSegment.open(dir, + baseOffset, + logConfig, + Time.SYSTEM, + false, + logConfig.initFileSize(), + logConfig.preallocate, + CLEANED_FILE_SUFFIX); + } + + /** + * Perform physical deletion of the index and log files for the given segment. + * Prior to the deletion, the index and log files are renamed by appending .deleted to the + * respective file name. Allows these files to be optionally deleted asynchronously. + * <p> + * This method assumes that the file exists. It does not need to convert IOException + * (thrown from changeFileSuffixes) to KafkaStorageException because it is either called before + * all logs are loaded or the caller will catch and handle IOException. + * + * @param segmentsToDelete The segments to be deleted + * @param asyncDelete If true, the deletion of the segments is done asynchronously + * @param dir The directory in which the log will reside + * @param topicPartition The topic + * @param config The log configuration settings + * @param scheduler The thread pool scheduler used for background actions + * @param logDirFailureChannel The LogDirFailureChannel to asynchronously handle log dir failure + * @param logger The logger to log messages + * @throws IOException if the file can't be renamed and still exists + */ + public static void deleteSegmentFiles(Collection<LogSegment> segmentsToDelete, + boolean asyncDelete, + File dir, + TopicPartition topicPartition, + LogConfig config, + Scheduler scheduler, + LogDirFailureChannel logDirFailureChannel, + Logger logger) throws IOException { + for (LogSegment segment : segmentsToDelete) { + if (!segment.hasSuffix(LogFileUtils.DELETED_FILE_SUFFIX)) + segment.changeFileSuffixes("", LogFileUtils.DELETED_FILE_SUFFIX); + } + + Runnable deleteSegments = () -> { + logger.info("Deleting segment files {}", Utils.join(segmentsToDelete, ", ")); + String parentDir = dir.getParent(); + maybeHandleIOException(logDirFailureChannel, parentDir, + () -> "Error while deleting segments for " + topicPartition + " in dir " + parentDir, + () -> { + for (LogSegment segment : segmentsToDelete) { + segment.deleteIfExists(); + } + return null; + }); + }; + + if (asyncDelete) { + scheduler.scheduleOnce("delete-file", deleteSegments, config.fileDeleteDelayMs); + } else { + deleteSegments.run(); + } + } + + /** + * Swap one or more new segment in place and delete one or more existing segments in a crash-safe + * manner. The old segments will be asynchronously deleted. + * <p> + * This method does not need to convert IOException to KafkaStorageException because it is either + * called before all logs are loaded or the caller will catch and handle IOException + * <p> + * The sequence of operations is: + * <p> + * - Cleaner creates one or more new segments with suffix .cleaned and invokes replaceSegments() on + * the Log instance. If broker crashes at this point, the clean-and-swap operation is aborted and + * the .cleaned files are deleted on recovery in LogLoader. + * - New segments are renamed .swap. If the broker crashes before all segments were renamed to .swap, the + * clean-and-swap operation is aborted - .cleaned as well as .swap files are deleted on recovery in + * in LogLoader. We detect this situation by maintaining a specific order in which files are renamed + * from .cleaned to .swap. Basically, files are renamed in descending order of offsets. On recovery, + * all .swap files whose offset is greater than the minimum-offset .clean file are deleted. + * - If the broker crashes after all new segments were renamed to .swap, the operation is completed, + * the swap operation is resumed on recovery as described in the next step. + * - Old segment files are renamed to .deleted and asynchronous delete is scheduled. If the broker + * crashes, any .deleted files left behind are deleted on recovery in LogLoader. + * replaceSegments() is then invoked to complete the swap with newSegment recreated from the + * .swap file and oldSegments containing segments which were not renamed before the crash. + * - Swap segment(s) are renamed to replace the existing segments, completing this operation. + * If the broker crashes, any .deleted files which may be left behind are deleted + * on recovery in LogLoader. + * + * @param existingSegments The existing segments of the log + * @param newSegments The new log segment to add to the log + * @param oldSegments The old log segments to delete from the log + * @param dir The directory in which the log will reside + * @param topicPartition The topic + * @param config The log configuration settings + * @param scheduler The thread pool scheduler used for background actions + * @param logDirFailureChannel The LogDirFailureChannel to asynchronously handle log dir failure + * @param logger The logger to log messages + * @param isRecoveredSwapFile true if the new segment was created from a swap file during recovery after a crash + */ + public static List<LogSegment> replaceSegments(LogSegments existingSegments, + List<LogSegment> newSegments, + List<LogSegment> oldSegments, + File dir, + TopicPartition topicPartition, + LogConfig config, + Scheduler scheduler, + LogDirFailureChannel logDirFailureChannel, + Logger logger, + boolean isRecoveredSwapFile) throws IOException { + List<LogSegment> sortedNewSegments = new ArrayList<>(newSegments); + sortedNewSegments.sort(Comparator.comparingLong(LogSegment::baseOffset)); + // Some old segments may have been removed from index and scheduled for async deletion after the caller reads segments + // but before this method is executed. We want to filter out those segments to avoid calling deleteSegmentFiles() + // multiple times for the same segment. + List<LogSegment> sortedOldSegments = oldSegments.stream() + .filter(seg -> existingSegments.contains(seg.baseOffset())) + .sorted(Comparator.comparingLong(LogSegment::baseOffset)) + .collect(Collectors.toList()); + + // need to do this in two phases to be crash safe AND do the delete asynchronously + // if we crash in the middle of this we complete the swap in loadSegments() + List<LogSegment> reversedSegmentsList = new ArrayList<>(sortedNewSegments); + Collections.reverse(reversedSegmentsList); + if (!isRecoveredSwapFile) { + for (LogSegment logSegment : reversedSegmentsList) { + logSegment.changeFileSuffixes(CLEANED_FILE_SUFFIX, SWAP_FILE_SUFFIX); + } + } + for (LogSegment logSegment : reversedSegmentsList) { + existingSegments.add(logSegment); Review Comment: `existingSegments` is not a collection but `LogSegments` class. -- This is an automated message from the Apache Git Service. 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