mimaison commented on code in PR #17587:
URL: https://github.com/apache/kafka/pull/17587#discussion_r1818656010
##########
storage/src/main/java/org/apache/kafka/storage/internals/log/LocalLog.java:
##########
@@ -29,25 +35,768 @@
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.Set;
+import java.util.UUID;
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.function.Consumer;
import java.util.function.Supplier;
+import java.util.regex.Pattern;
import java.util.stream.Collectors;
+import static java.util.Collections.singletonList;
import static org.apache.kafka.common.utils.Utils.require;
import static
org.apache.kafka.storage.internals.log.LogFileUtils.CLEANED_FILE_SUFFIX;
import static
org.apache.kafka.storage.internals.log.LogFileUtils.DELETED_FILE_SUFFIX;
+import static
org.apache.kafka.storage.internals.log.LogFileUtils.DELETE_DIR_SUFFIX;
+import static
org.apache.kafka.storage.internals.log.LogFileUtils.FUTURE_DIR_SUFFIX;
+import static
org.apache.kafka.storage.internals.log.LogFileUtils.STRAY_DIR_SUFFIX;
import static
org.apache.kafka.storage.internals.log.LogFileUtils.SWAP_FILE_SUFFIX;
import static org.apache.kafka.storage.internals.log.LogFileUtils.isLogFile;
+/**
+ * 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, and it relies on the thread safety
provided by the Log class.
+ */
public class LocalLog {
private static final Logger LOG = LoggerFactory.getLogger(LocalLog.class);
+ public static final Pattern DELETE_DIR_PATTERN =
Pattern.compile("^(\\S+)-(\\S+)\\.(\\S+)" + LogFileUtils.DELETE_DIR_SUFFIX);
+ public static final Pattern FUTURE_DIR_PATTERN =
Pattern.compile("^(\\S+)-(\\S+)\\.(\\S+)" + LogFileUtils.FUTURE_DIR_SUFFIX);
+ public static final Pattern STRAY_DIR_PATTERN =
Pattern.compile("^(\\S+)-(\\S+)\\.(\\S+)" + LogFileUtils.STRAY_DIR_SUFFIX);
+ public static final long UNKNOWN_OFFSET = -1L;
+
+ // Last time the log was flushed
+ private final AtomicLong lastFlushedTime;
+ private final String logIdent;
+ private final LogSegments segments;
+ private final Scheduler scheduler;
+ private final Time time;
+ private final TopicPartition topicPartition;
+ private final LogDirFailureChannel logDirFailureChannel;
+ private final Logger logger;
+
+ private volatile LogOffsetMetadata nextOffsetMetadata;
+ // 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;
+ // Cache value of parent directory to avoid allocations in hot paths like
ReplicaManager.checkpointHighWatermarks
+ private volatile String parentDir;
+ private volatile LogConfig config;
+ private volatile long recoveryPoint;
+ private File dir;
+
+ /**
+ * @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.nextOffsetMetadata = nextOffsetMetadata;
+ this.scheduler = scheduler;
+ this.time = time;
+ this.topicPartition = topicPartition;
+ this.logDirFailureChannel = logDirFailureChannel;
+ this.logIdent = "[LocalLog partition=" + topicPartition + ", dir=" +
dir + "] ";
+ this.logger = new LogContext(logIdent).logger(LocalLog.class);
+ // Last time the log was flushed
+ this.lastFlushedTime = new AtomicLong(time.milliseconds());
+ this.parentDir = dir.getParent();
+ }
+
+ public File dir() {
+ return dir;
+ }
+
+ 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;
+ }
+
+ 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(LogFileUtils.FUTURE_DIR_SUFFIX);
+ }
+
+ private <T> T maybeHandleIOException(Supplier<String> errorMsgSupplier,
StorageAction<T, IOException> function) {
+ return maybeHandleIOException(logDirFailureChannel, parentDir,
errorMsgSupplier, function);
+ }
+
+ /**
+ * Rename the directory of the log
+ * @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 " +
oldRecordVersion + " to " + 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.
+ * 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 logSegment : segmentsToFlush) {
+ logSegment.flush();
+ }
+ // If there are any new segments, we need to flush the parent
directory for crash consistency.
+ if (segmentsToFlush.stream().anyMatch(s -> s.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());
+ }
+ }
+ }
+
+ /**
+ * 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;
+ }
+
+ /**
+ * Update end offset of the log, and update 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(),
+ () -> {
+ 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(),
+ () -> {
+ if (!segments.isEmpty()) {
+ 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 List<LogSegment> deleteAllSegments() {
+ return maybeHandleIOException(
+ () -> "Error while deleting all segments for $topicPartition in
dir ${dir.getParent}",
+ () -> {
+ List<LogSegment> deletableSegments = new
ArrayList<>(segments.values());
+ removeAndDeleteSegments(segments.values(), false, new
LogDeletion(logger));
+ isMemoryMappedBufferClosed = true;
+ return deletableSegments;
+ }
+ );
+ }
+
+ /**
+ * This method deletes the given log segments by doing the following for
each of them:
+ * <ul>
+ * <li>It removes the segment from the segment map so that it will no
longer be used for reads.
+ * <li>It renames the index and log files by appending .deleted to the
respective file name
+ * <li>It can either schedule an asynchronous delete operation to occur
in the future or perform the deletion synchronously
+ * </ul>
+ * Asynchronous deletion allows reads to happen concurrently without
synchronization and without the possibility of
+ * physically deleting a file while it is being read.
+ * 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);
+ toDelete.forEach(segment -> segments.remove(segment.baseOffset()));
+ deleteSegmentFiles(toDelete, asyncDelete, dir, topicPartition,
config, scheduler, logDirFailureChannel, logIdent);
+ }
+ }
+
+ /**
+ * 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.
+ * <br/>
+ * Asynchronous deletion allows reads to happen concurrently without
synchronization and without the possibility of
+ * physically deleting a file while it is being read.
+ * <br/>
+ * 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,
+ config.initFileSize(),
+ config.preallocate);
+ segments.add(newSegment);
+
+ reason.logReason(singletonList(segmentToDelete));
+ if (newOffset != segmentToDelete.baseOffset()) {
+ segments.remove(segmentToDelete.baseOffset());
+ }
+ deleteSegmentFiles(singletonList(segmentToDelete), asyncDelete, dir,
topicPartition, config, scheduler, logDirFailureChannel, logIdent);
+ 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)
throws IOException {
+ 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
+ * @throws OffsetOutOfRangeException If startOffset is beyond the log end
offset
+ * @return The fetch data information including fetch starting offset
metadata and messages read.
+ */
+ public FetchDataInfo read(long startOffset,
+ int maxLength,
+ boolean minOneMessage,
+ LogOffsetMetadata maxOffsetMetadata,
+ boolean includeAbortedTxns) throws IOException {
+ return maybeHandleIOException(
+ () -> "Exception while reading from " + topicPartition + " in
dir " + dir.getParent(),
+ () -> {
+ logger.trace("Reading maximum $maxLength bytes at offset "
+ startOffset + " from log with " +
+ "total length " + segments.sizeInBytes() + "
bytes");
+
+ 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.isEmpty()) {
+ 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();
+
+ // 1. If `maxOffsetMetadata#segmentBaseOffset <
segment#baseOffset`, then return maxPosition as empty.
+ // 2. Use the max-offset position if it is on this
segment; otherwise, the segment size is the limit.
+ // 3. When maxOffsetMetadata is
message-offset-only, then we don't know the relativePositionInSegment so
+ // return maxPosition as empty to avoid reading
beyond the max-offset
+ Optional<Long> maxPositionOpt;
+ if (segment.baseOffset() <
maxOffsetMetadata.segmentBaseOffset)
+ maxPositionOpt = Optional.of((long)
segment.size());
+ else if (segment.baseOffset() ==
maxOffsetMetadata.segmentBaseOffset && !maxOffsetMetadata.messageOffsetOnly())
+ maxPositionOpt = Optional.of((long)
maxOffsetMetadata.relativePositionInSegment);
+ else
+ maxPositionOpt = Optional.empty();
+
+ fetchDataInfo = segment.read(startOffset,
maxLength, maxPositionOpt, 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 -> {
+ for (AbortedTxn abortedTxn : abortedTxns)
+ abortedTransactions.add(abortedTxn.asAbortedTransaction());
+ };
+ collectAbortedTransactions(startOffset, upperBoundOffset, segment,
accumulator);
Review Comment:
I'm uneasy trying to include many refactors with the rewrite. I'd rather
make changes like this in a follow up PR.
--
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: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
