kamalcph commented on code in PR #13837: URL: https://github.com/apache/kafka/pull/13837#discussion_r1261560074
########## storage/src/test/java/org/apache/kafka/server/log/remote/storage/LocalTieredStorage.java: ########## @@ -0,0 +1,564 @@ +/* + * 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.server.log.remote.storage; + +import org.apache.kafka.common.TopicIdPartition; +import org.apache.kafka.common.Uuid; +import org.apache.kafka.common.errors.InvalidConfigurationException; +import org.apache.kafka.server.log.remote.storage.LocalTieredStorageListener.LocalTieredStorageListeners; +import org.apache.kafka.common.utils.LogContext; +import org.apache.kafka.test.TestUtils; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.io.ByteArrayInputStream; +import java.io.File; +import java.io.FileNotFoundException; +import java.io.FileOutputStream; +import java.io.IOException; +import java.io.InputStream; +import java.nio.ByteBuffer; +import java.nio.channels.FileChannel; +import java.nio.file.Files; +import java.nio.file.NoSuchFileException; +import java.util.Arrays; +import java.util.Map; +import java.util.Objects; +import java.util.Optional; +import java.util.concurrent.Callable; +import java.util.concurrent.atomic.AtomicInteger; + +import static java.lang.String.format; +import static java.nio.file.Files.newInputStream; +import static java.nio.file.StandardOpenOption.READ; +import static org.apache.kafka.server.log.remote.storage.LocalTieredStorageEvent.EventType; +import static org.apache.kafka.server.log.remote.storage.LocalTieredStorageEvent.EventType.DELETE_PARTITION; +import static org.apache.kafka.server.log.remote.storage.LocalTieredStorageEvent.EventType.DELETE_SEGMENT; +import static org.apache.kafka.server.log.remote.storage.LocalTieredStorageEvent.EventType.FETCH_LEADER_EPOCH_CHECKPOINT; +import static org.apache.kafka.server.log.remote.storage.LocalTieredStorageEvent.EventType.FETCH_OFFSET_INDEX; +import static org.apache.kafka.server.log.remote.storage.LocalTieredStorageEvent.EventType.FETCH_PRODUCER_SNAPSHOT; +import static org.apache.kafka.server.log.remote.storage.LocalTieredStorageEvent.EventType.FETCH_SEGMENT; +import static org.apache.kafka.server.log.remote.storage.LocalTieredStorageEvent.EventType.FETCH_TIME_INDEX; +import static org.apache.kafka.server.log.remote.storage.LocalTieredStorageEvent.EventType.FETCH_TRANSACTION_INDEX; +import static org.apache.kafka.server.log.remote.storage.LocalTieredStorageEvent.EventType.OFFLOAD_SEGMENT; +import static org.apache.kafka.server.log.remote.storage.RemoteLogSegmentFileset.RemoteLogSegmentFileType.LEADER_EPOCH_CHECKPOINT; +import static org.apache.kafka.server.log.remote.storage.RemoteLogSegmentFileset.RemoteLogSegmentFileType.OFFSET_INDEX; +import static org.apache.kafka.server.log.remote.storage.RemoteLogSegmentFileset.RemoteLogSegmentFileType.PRODUCER_SNAPSHOT; +import static org.apache.kafka.server.log.remote.storage.RemoteLogSegmentFileset.RemoteLogSegmentFileType.SEGMENT; +import static org.apache.kafka.server.log.remote.storage.RemoteLogSegmentFileset.RemoteLogSegmentFileType.TIME_INDEX; +import static org.apache.kafka.server.log.remote.storage.RemoteLogSegmentFileset.RemoteLogSegmentFileType.TRANSACTION_INDEX; +import static org.apache.kafka.server.log.remote.storage.RemoteLogSegmentFileset.openFileset; +import static org.apache.kafka.server.log.remote.storage.RemoteTopicPartitionDirectory.openExistingTopicPartitionDirectory; +import static org.apache.kafka.server.log.remote.storage.RemoteTopicPartitionDirectory.openTopicPartitionDirectory; + +/** + * An implementation of {@link RemoteStorageManager} which relies on the local file system to store + * offloaded log segments and associated data. + * <p> + * Due to the consistency semantic of POSIX-compliant file systems, this remote storage provides strong + * read-after-write consistency and a segment's data can be accessed once the copy to the storage succeeded. + * </p> + * <p> + * In order to guarantee isolation, independence, reproducibility and consistency of unit and integration + * tests, the scope of a storage implemented by this class, and identified via the storage ID provided to + * the constructor, should be limited to a test or well-defined self-contained use-case. + * </p> + * <p> + * The local tiered storage keeps a simple structure of directories mimicking that of Apache Kafka. + * <p> + * The name of each of the files under the scope of a log segment (the log file, its indexes, etc.) + * follows the structure UuidBase64-FileType. + * <p> + * Given the root directory of the storage, segments and associated files are organized as represented below. + * </p> + * <code> + * / storage-directory / LWgrMmVrT0a__7a4SasuPA-0-topic / bCqX9U--S-6U8XUM9II25Q-segment + * . . bCqX9U--S-6U8XUM9II25Q-offset_index + * . . bCqX9U--S-6U8XUM9II25Q-time_index + * . . h956soEzTzi9a-NOQ-DvKA-segment + * . . h956soEzTzi9a-NOQ-DvKA-offset_index + * . . h956soEzTzi9a-NOQ-DvKA-segment + * . + * / LWgrMmVrT0a__7a4SasuPA-1-topic / o8CQPT86QQmbFmi3xRmiHA-segment + * . . o8CQPT86QQmbFmi3xRmiHA-offset_index + * . . o8CQPT86QQmbFmi3xRmiHA-time_index + * . + * / DRagLm_PS9Wl8fz1X43zVg-3-btopic / jvj3vhliTGeU90sIosmp_g-segment + * . . jvj3vhliTGeU90sIosmp_g-offset_index + * . . jvj3vhliTGeU90sIosmp_g-time_index + * </code> + */ +public final class LocalTieredStorage implements RemoteStorageManager { + + public static final String STORAGE_CONFIG_PREFIX = "remote.log.storage.local."; + + /** + * The root directory of this storage. + */ + public static final String STORAGE_DIR_PROP = "dir"; + + /** + * Delete all files and directories from this storage on close, substantially removing it + * entirely from the file system. + */ + public static final String DELETE_ON_CLOSE_PROP = "delete.on.close"; + + /** + * The implementation of the transfer of the data of the canonical segment and index files to + * this storage. The only reason the "transferer" abstraction exists is to be able to simulate + * file copy errors and exercise the associated failure modes. + */ + public static final String TRANSFERER_CLASS_PROP = "transferer"; + + /** + * Whether the deleteLogSegment() implemented by this storage should actually delete data or behave + * as a no-operation. This allows to simulate non-strongly consistent storage systems which do not + * guarantee visibility of a successful delete for subsequent read or list operations. + */ + public static final String ENABLE_DELETE_API_PROP = "delete.enable"; + + /** + * The ID of the broker which owns this instance of {@link LocalTieredStorage}. + */ + public static final String BROKER_ID = "broker.id"; + + private static final String ROOT_STORAGES_DIR_NAME = "kafka-tiered-storage"; + + private volatile File storageDirectory; + private volatile boolean deleteOnClose = false; + private volatile boolean deleteEnabled = true; + private volatile Transferer transferer = new Transferer() { + @Override + public void transfer(File from, File to) throws IOException { + if (from.exists()) { + Files.copy(from.toPath(), to.toPath()); + } + } + + @Override + public void transfer(ByteBuffer from, File to) throws IOException { + if (from != null && from.hasRemaining()) { + try (FileOutputStream fileOutputStream = new FileOutputStream(to, false); + FileChannel channel = fileOutputStream.getChannel()) { + channel.write(from); + } + } + } + }; + + private volatile int brokerId = -1; + + private volatile Logger logger = LoggerFactory.getLogger(LocalTieredStorage.class); + + /** + * Used to explicit a chronological ordering of the events generated by the local tiered storage + * which this instance gives access to. + */ + // TODO: Makes this timestamp only dependent on the assigned broker, not the class instance. + private final AtomicInteger eventTimestamp = new AtomicInteger(-1); + + /** + * Used to notify users of this storage of internal updates - new topic-partition recorded (upon directory + * creation) and segment file written (upon segment file write(2)). + */ + private final LocalTieredStorageListeners storageListeners = new LocalTieredStorageListeners(); + + private final LocalTieredStorageHistory history = new LocalTieredStorageHistory(); + + public LocalTieredStorage() { + history.listenTo(this); + } + + /** + * Walks through this storage and notify the traverser of every topic-partition, segment and record discovered. + * <p> + * - The order of traversal of the topic-partition is not specified. + * - The order of traversal of the segments within a topic-partition is in ascending order + * of the modified timestamp of the segment file. + * - The order of traversal of records within a segment corresponds to the insertion + * order of these records in the original segment from which the segment in this storage + * was transferred from. + * <p> + * This method is NOT an atomic operation w.r.t the local tiered storage. This storage may change while + * being traversed topic-partitions, segments and records are communicated to the traverser. There is + * no guarantee updates to the storage which happens during traversal will be communicated to the traverser. + * Especially, in case of concurrent read and write/delete to a topic-partition, a segment or a record, + * the behaviour depends on the underlying file system. + * + * @param traverser User-specified object to which this storage communicates the topic-partitions, + * segments and records as they are discovered. + */ + public void traverse(final LocalTieredStorageTraverser traverser) { + Objects.requireNonNull(traverser); + + final File[] files = storageDirectory.listFiles(); + if (files == null) { + // files can be null if the directory is empty. + return; + } + + Arrays.stream(files) + .filter(File::isDirectory) + .forEach(dir -> + openExistingTopicPartitionDirectory(dir.getName(), storageDirectory).traverse(traverser)); + } + + public void addListener(final LocalTieredStorageListener listener) { + this.storageListeners.add(listener); + } + + @Override + public void configure(Map<String, ?> configs) { + if (storageDirectory != null) { + throw new InvalidConfigurationException(format("This instance of local remote storage" + + "is already configured. The existing storage directory is %s. Ensure the method " + + "configure() is only called once.", storageDirectory.getAbsolutePath())); + } + + final String storageDir = (String) configs.get(STORAGE_DIR_PROP); + final String shouldDeleteOnClose = (String) configs.get(DELETE_ON_CLOSE_PROP); + final String transfererClass = (String) configs.get(TRANSFERER_CLASS_PROP); + final String isDeleteEnabled = (String) configs.get(ENABLE_DELETE_API_PROP); + final Integer brokerIdInt = (Integer) configs.get(BROKER_ID); + + if (brokerIdInt == null) { + throw new InvalidConfigurationException( + "Broker ID is required to configure the LocalTieredStorage manager."); + } + + brokerId = brokerIdInt; + logger = new LogContext(format("[LocalTieredStorage Id=%d] ", brokerId)).logger(this.getClass()); + + if (shouldDeleteOnClose != null) { + deleteOnClose = Boolean.parseBoolean(shouldDeleteOnClose); + } + + if (isDeleteEnabled != null) { + deleteEnabled = Boolean.parseBoolean(isDeleteEnabled); + } + + if (transfererClass != null) { + try { + transferer = (Transferer) getClass().getClassLoader().loadClass(transfererClass).newInstance(); + + } catch (InstantiationException | IllegalAccessException | ClassNotFoundException | ClassCastException e) { + throw new RuntimeException(format("Cannot create transferer from class '%s'", transfererClass), e); + } + } + + + if (storageDir == null) { + storageDirectory = TestUtils.tempDirectory(ROOT_STORAGES_DIR_NAME + "-"); + + logger.debug("No storage directory specified, created temporary directory: {}", + storageDirectory.getAbsolutePath()); + + } else { + storageDirectory = new File(storageDir + "/" + ROOT_STORAGES_DIR_NAME); + // NOTE: Provide the relative storage directory path to view the files in the same directory when running tests. + // storageDirectory = new File(new File("."), ROOT_STORAGES_DIR_NAME + "/" + storageDir); + final boolean existed = storageDirectory.exists(); + + if (!existed) { + logger.info("Creating directory: [{}]", storageDirectory.getAbsolutePath()); + storageDirectory.mkdirs(); + + } else { + logger.warn("Remote storage with ID [{}] already exists on the file system. Any data already " + + "in the remote storage will not be deleted and may result in an inconsistent state and/or " + + "provide stale data.", storageDir); + } + } + + logger.info("Created local tiered storage manager [{}]:[{}]", brokerId, storageDirectory.getName()); + } + + @Override + public void copyLogSegmentData(final RemoteLogSegmentMetadata metadata, final LogSegmentData data) + throws RemoteStorageException { + Callable<Void> callable = () -> { + final RemoteLogSegmentId id = metadata.remoteLogSegmentId(); + final LocalTieredStorageEvent.Builder eventBuilder = newEventBuilder(OFFLOAD_SEGMENT, id); + RemoteLogSegmentFileset fileset = null; + + try { + fileset = openFileset(storageDirectory, id); + + logger.info("Offloading log segment for {} from offset={}", id.topicIdPartition(), data.logSegment()); + + fileset.copy(transferer, data); + + storageListeners.onStorageEvent(eventBuilder.withFileset(fileset).build()); + + } catch (final Exception e) { + // + // Keep the storage in a consistent state, i.e. a segment stored should always have with its + // associated offset and time indexes stored as well. Here, delete any file which was copied + // before the exception was hit. The exception is re-thrown as no remediation is expected in + // the current scope. + // + if (fileset != null) { + fileset.delete(); + } + + storageListeners.onStorageEvent(eventBuilder.withException(e).build()); + throw e; + } + + return null; + }; + + wrap(callable); + } + + @Override + public InputStream fetchLogSegment(final RemoteLogSegmentMetadata metadata, + final int startPos) throws RemoteStorageException { + return fetchLogSegment(metadata, startPos, Integer.MAX_VALUE); + } + + @Override + public InputStream fetchLogSegment(final RemoteLogSegmentMetadata metadata, + final int startPos, + final int endPos) throws RemoteStorageException { + checkArgument(startPos >= 0, "Start position must be positive", startPos); + checkArgument(endPos >= startPos, + "End position cannot be less than startPosition", startPos, endPos); + + return wrap(() -> { + + final LocalTieredStorageEvent.Builder eventBuilder = newEventBuilder(FETCH_SEGMENT, metadata); + eventBuilder.withStartPosition(startPos).withEndPosition(endPos); + + try { + final RemoteLogSegmentFileset fileset = openFileset(storageDirectory, metadata.remoteLogSegmentId()); + + final InputStream inputStream = newInputStream(fileset.getFile(SEGMENT).toPath(), READ); + inputStream.skip(startPos); + + // endPosition is ignored at this stage. A wrapper around the file input stream can implement + // the upper bound on the stream. + + storageListeners.onStorageEvent(eventBuilder.withFileset(fileset).build()); + + return inputStream; + + } catch (final Exception e) { + storageListeners.onStorageEvent(eventBuilder.withException(e).build()); + throw e; + } + }); + } + + @Override + public InputStream fetchIndex(RemoteLogSegmentMetadata metadata, IndexType indexType) throws RemoteStorageException { + EventType eventType = getEventTypeForFetch(indexType); + RemoteLogSegmentFileset.RemoteLogSegmentFileType fileType = getLogSegmentFileType(indexType); + return wrap(() -> { + final LocalTieredStorageEvent.Builder eventBuilder = newEventBuilder(eventType, metadata); + + try { + final RemoteLogSegmentFileset fileset = openFileset(storageDirectory, metadata.remoteLogSegmentId()); + + File file = fileset.getFile(fileType); + final InputStream inputStream = (fileType.isOptional() && !file.exists()) ? + new ByteArrayInputStream(new byte[0]) : newInputStream(file.toPath(), READ); + + storageListeners.onStorageEvent(eventBuilder.withFileset(fileset).build()); + + return inputStream; + + } catch (final Exception e) { + storageListeners.onStorageEvent(eventBuilder.withException(e).build()); + throw e; + } + }); + } + + @Override + public void deleteLogSegmentData(final RemoteLogSegmentMetadata metadata) throws RemoteStorageException { + wrap(() -> { + final LocalTieredStorageEvent.Builder eventBuilder = newEventBuilder(DELETE_SEGMENT, metadata); + + if (deleteEnabled) { + try { + final RemoteLogSegmentFileset fileset = openFileset( + storageDirectory, metadata.remoteLogSegmentId()); + + if (!fileset.delete()) { + throw new RemoteStorageException("Failed to delete remote log segment with id:" + + metadata.remoteLogSegmentId()); + } + + storageListeners.onStorageEvent(eventBuilder.withFileset(fileset).build()); + + } catch (final Exception e) { + storageListeners.onStorageEvent(eventBuilder.withException(e).build()); + throw e; + } + } + return null; + }); + } + + // New API to be added in RemoteStorageManager + // @Override Review Comment: Filed: https://issues.apache.org/jira/browse/KAFKA-15166 to track it. -- This is an automated message from the Apache Git Service. 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