satishd commented on code in PR #14034: URL: https://github.com/apache/kafka/pull/14034#discussion_r1461532356
########## 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); + } + + Set<Long> newSegmentBaseOffsets = sortedNewSegments.stream().map(LogSegment::baseOffset) + .collect(Collectors.toSet()); + + // delete the old files + List<LogSegment> deletedNotReplaced = new ArrayList<>(); + for (LogSegment seg : sortedOldSegments) { + // remove the index entry + if (seg.baseOffset() != sortedNewSegments.get(0).baseOffset()) + existingSegments.remove(seg.baseOffset()); + deleteSegmentFiles( + Collections.singletonList(seg), + true, + dir, + topicPartition, + config, + scheduler, + logDirFailureChannel, + logger); + if (!newSegmentBaseOffsets.contains(seg.baseOffset())) { + deletedNotReplaced.add(seg); + } + } + + // okay we are safe now, remove the swap suffix + for (LogSegment segment : sortedNewSegments) { + segment.changeFileSuffixes(SWAP_FILE_SUFFIX, ""); + } + Utils.flushDir(dir.toPath()); + + return deletedNotReplaced; + } + + /** + * Split a segment into one or more segments such that there is no offset overflow in any of them. The + * resulting segments will contain the exact same messages that are present in the input segment. On successful + * completion of this method, the input segment will be deleted and will be replaced by the resulting new segments. + * See replaceSegments for recovery logic, in case the broker dies in the middle of this operation. + * <p> + * Note that this method assumes we have already determined that the segment passed in contains records that cause + * offset overflow. + * <p> + * The split logic overloads the use of .clean files that LogCleaner typically uses to make the process of replacing + * the input segment with multiple new segments atomic and recoverable in the event of a crash. See replaceSegments + * and completeSwapOperations for the implementation to make this operation recoverable on crashes.</p> + * + * @param segment Segment to split + * @param existingSegments The existing segments of 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 + * @return List of new segments that replace the input segment + */ + public static SplitSegmentResult splitOverflowedSegment(LogSegment segment, + LogSegments existingSegments, + File dir, + TopicPartition topicPartition, + LogConfig config, + Scheduler scheduler, + LogDirFailureChannel logDirFailureChannel, + Logger logger) throws IOException { Review Comment: Yes, it was intentional. Earlier, `logPrefix` was passed so that the respective method callers could check the respective log statements in `LocalLog` logger logs by filtering with the passed log-prefixes. So, I thought it is better to print these logs with the respective loggers instead of sending their prefixes. If the caller method uses a different logger then it would have been hard for users to shuffle between their logs and `LocalLog` class logs. With the new change, they will get all the related logs in their respective logger logs. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: jira-unsubscr...@kafka.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
