rdblue commented on code in PR #5669: URL: https://github.com/apache/iceberg/pull/5669#discussion_r990827767
########## core/src/main/java/org/apache/iceberg/ReachableFileCleanup.java: ########## @@ -0,0 +1,152 @@ +/* + * 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.iceberg; + +import java.io.IOException; +import java.util.Set; +import java.util.concurrent.ConcurrentHashMap; +import java.util.concurrent.ExecutorService; +import java.util.function.Consumer; +import java.util.stream.Collectors; +import org.apache.iceberg.exceptions.RuntimeIOException; +import org.apache.iceberg.io.CloseableIterable; +import org.apache.iceberg.io.FileIO; +import org.apache.iceberg.relocated.com.google.common.collect.Sets; +import org.apache.iceberg.util.Tasks; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** + * File cleanup strategy for snapshot expiration which determines, via an in-memory reference set, + * metadata and data files that are not reachable given the previous and current table states. + */ +class ReachableFileCleanup extends FileCleanupStrategy { + + private static final Logger LOG = LoggerFactory.getLogger(ReachableFileCleanup.class); + + ReachableFileCleanup( + FileIO fileIO, + ExecutorService deleteExecutorService, + ExecutorService planExecutorService, + Consumer<String> deleteFunc) { + super(fileIO, deleteExecutorService, planExecutorService, deleteFunc); + } + + @Override + public void cleanFiles(TableMetadata beforeExpiration, TableMetadata afterExpiration) { + Set<String> manifestListsToDelete = Sets.newHashSet(); + + Set<Snapshot> snapshotsBeforeExpiration = Sets.newHashSet(beforeExpiration.snapshots()); + Set<Snapshot> snapshotsAfterExpiration = Sets.newHashSet(afterExpiration.snapshots()); + Set<Snapshot> expiredSnapshots = Sets.newHashSet(); + for (Snapshot snapshot : snapshotsBeforeExpiration) { + if (!snapshotsAfterExpiration.contains(snapshot)) { + expiredSnapshots.add(snapshot); + if (snapshot.manifestListLocation() != null) { + manifestListsToDelete.add(snapshot.manifestListLocation()); + } + } + } + + Set<ManifestFile> candidateManifestFilesForDeletion = readManifests(expiredSnapshots); + Set<ManifestFile> manifestFilesAfterExpiration = readManifests(snapshotsAfterExpiration); + + Set<ManifestFile> manifestsToDelete = Sets.newHashSet(candidateManifestFilesForDeletion); + for (ManifestFile candidateManifestFile : candidateManifestFilesForDeletion) { + if (manifestFilesAfterExpiration.contains(candidateManifestFile)) { + manifestsToDelete.remove(candidateManifestFile); + } + } + + Set<String> dataFilesToDelete = + findFilesToDelete(manifestsToDelete, manifestFilesAfterExpiration); + deleteFiles(dataFilesToDelete, "Data"); + + Set<String> manifestPathsToDelete = + manifestsToDelete.stream().map(ManifestFile::path).collect(Collectors.toSet()); + + deleteFiles(manifestPathsToDelete, "manifest"); + deleteFiles(manifestListsToDelete, "manifest list"); + } + + private Set<ManifestFile> readManifests(Set<Snapshot> snapshots) { + Set<ManifestFile> manifestFiles = Sets.newHashSet(); + for (Snapshot snapshot : snapshots) { + try (CloseableIterable<ManifestFile> manifestFilesForSnapshot = readManifestFiles(snapshot)) { + for (ManifestFile manifestFile : manifestFilesForSnapshot) { + manifestFiles.add(manifestFile.copy()); + } + } catch (IOException e) { + throw new RuntimeIOException( + e, "Failed to close manifest list: %s", snapshot.manifestListLocation()); + } + } + + return manifestFiles; + } + + // Helper to compute files to delete + private Set<String> findFilesToDelete( + Set<ManifestFile> manifestFilesToDelete, Set<ManifestFile> currentManifestFiles) { + Set<String> filesToDelete = ConcurrentHashMap.newKeySet(); + Tasks.foreach(manifestFilesToDelete) + .retry(3) + .suppressFailureWhenFinished() + .executeWith(planExecutorService) + .onFailure( + (item, exc) -> + LOG.warn("Failed to get deleted files: this may cause orphaned data files", exc)) + .run( + manifest -> { + // the manifest has deletes, scan it to find files to delete + try (CloseableIterable<String> paths = ManifestFiles.readPaths(manifest, fileIO)) { + paths.forEach(filesToDelete::add); + } catch (IOException e) { + throw new RuntimeIOException(e, "Failed to read manifest file: %s", manifest); + } + }); + + if (filesToDelete.isEmpty()) { + return filesToDelete; + } + + Tasks.foreach(currentManifestFiles) + .retry(3) + .suppressFailureWhenFinished() Review Comment: If this fails, there could be a data file that was referenced by a deleted manifest that is still in `filesToDelete` because the manifest that still references it was not read. That means this can't suppress failures and needs to throw the final failure, if there was one. That way, if this can't read existing manifests, no data file cleanup will be done. The caller can still clean up the known manifests that are no longer referenced, but not data files. -- 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] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
