steveloughran commented on a change in pull request #1208: HADOOP-16423. S3Guard fsck: Check metadata consistency between S3 and metadatastore (log) URL: https://github.com/apache/hadoop/pull/1208#discussion_r316661259
########## File path: hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/s3guard/S3GuardFsck.java ########## @@ -0,0 +1,395 @@ +/* + * 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 + * <p> + * http://www.apache.org/licenses/LICENSE-2.0 + * <p> + * 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.hadoop.fs.s3a.s3guard; + +import org.apache.hadoop.fs.FileStatus; +import org.apache.hadoop.fs.Path; +import org.apache.hadoop.fs.s3a.S3AFileStatus; +import org.apache.hadoop.fs.s3a.S3AFileSystem; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.io.IOException; +import java.security.InvalidParameterException; +import java.util.ArrayDeque; +import java.util.ArrayList; +import java.util.Arrays; +import java.util.HashSet; +import java.util.List; +import java.util.Queue; +import java.util.Set; + +import static java.util.stream.Collectors.toList; +import static java.util.stream.Collectors.toSet; + +/** + * Main class for the FSCK factored out from S3GuardTool + * The implementation uses fixed DynamoDBMetadataStore as the backing store + * for metadata. + * + * Functions: + * <ul> + * <li>Checking metadata consistency between S3 and metadatastore</li> + * </ul> + */ +public class S3GuardFsck { + private static final Logger LOG = LoggerFactory.getLogger(S3GuardFsck.class); + public static final String ROOT_PATH_STRING = "/"; + + private S3AFileSystem rawFS; + private DynamoDBMetadataStore metadataStore; + + /** + * Creates an S3GuardFsck. + * @param fs the filesystem to compare to + * @param ms metadatastore the metadatastore to compare with (dynamo) + */ + S3GuardFsck(S3AFileSystem fs, MetadataStore ms) + throws InvalidParameterException { + this.rawFS = fs; + + if (ms == null) { + throw new InvalidParameterException("S3AFileSystem should be guarded by" + + " a " + DynamoDBMetadataStore.class.getCanonicalName()); + } + this.metadataStore = (DynamoDBMetadataStore) ms; + + if (rawFS.hasMetadataStore()) { + throw new InvalidParameterException("Raw fs should not have a " + + "metadatastore."); + } + } + + /** + * Compares S3 to MS. + * Iterative breadth first walk on the S3 structure from a given root. + * Creates a list of pairs (metadata in S3 and in the MetadataStore) where + * the consistency or any rule is violated. + * Uses {@link S3GuardFsckViolationHandler} to handle violations. + * The violations are listed in Enums: {@link Violation} + * + * @param p the root path to start the traversal + * @throws IOException + * @return + */ + public List<ComparePair> compareS3RootToMs(Path p) throws IOException { + final Path rootPath = rawFS.qualify(p); + final S3AFileStatus root = + (S3AFileStatus) rawFS.getFileStatus(rootPath); + final List<ComparePair> comparePairs = new ArrayList<>(); + final Queue<S3AFileStatus> queue = new ArrayDeque<>(); + queue.add(root); + + while (!queue.isEmpty()) { + // pop front node from the queue + final S3AFileStatus currentDir = queue.poll(); + + // Get a listing of that dir from s3 and add just the files. + // (Each directory will be added as a root.) + // Files should be casted to S3AFileStatus instead of plain FileStatus + // to get the VersionID and Etag. + final Path currentDirPath = currentDir.getPath(); + + final FileStatus[] s3DirListing = rawFS.listStatus(currentDirPath); + final List<S3AFileStatus> children = + Arrays.asList(s3DirListing).stream() + .filter(status -> !status.isDirectory()) + .map(S3AFileStatus.class::cast).collect(toList()); + + // Compare the directory contents if the listing is authoritative + final DirListingMetadata msDirListing = + metadataStore.listChildren(currentDirPath); + if (msDirListing != null && msDirListing.isAuthoritative()) { + final ComparePair cP = + compareAuthDirListing(s3DirListing, msDirListing); + if (cP.containsViolation()) { + comparePairs.add(cP); + } + } + + // Compare directory and contents, but not the listing + final List<ComparePair> compareResult = + compareS3DirToMs(currentDir, children).stream() + .filter(comparePair -> comparePair.containsViolation()) + .collect(toList()); + comparePairs.addAll(compareResult); + + // Add each dir to queue + children.stream().filter(pm -> pm.isDirectory()) + .forEach(pm -> queue.add(pm)); + } + + // Create a handler and handle each violated pairs + S3GuardFsckViolationHandler handler = + new S3GuardFsckViolationHandler(rawFS, metadataStore); + comparePairs.forEach(handler::handle); + + return comparePairs; + } + + private ComparePair compareAuthDirListing(FileStatus[] s3DirListing, + DirListingMetadata msDirListing) { + ComparePair cP = new ComparePair(s3DirListing, msDirListing); + + if (!msDirListing.isAuthoritative()) { + return cP; + } + + if (s3DirListing.length != msDirListing.numEntries()) { + cP.violations.add(Violation.AUTHORITATIVE_DIRECTORY_CONTENT_MISMATCH); + } else { + final Set<Path> msPaths = msDirListing.getListing().stream() + .map(pm -> pm.getFileStatus().getPath()).collect(toSet()); + final Set<Path> s3Paths = Arrays.stream(s3DirListing) + .map(pm -> pm.getPath()).collect(toSet()); + if (!s3Paths.equals(msPaths)) { + cP.violations.add(Violation.AUTHORITATIVE_DIRECTORY_CONTENT_MISMATCH); + } + } + + return cP; + } + + protected List<ComparePair> compareS3DirToMs(S3AFileStatus s3CurrentDir, + List<S3AFileStatus> children) throws IOException { + final Path path = s3CurrentDir.getPath(); + final PathMetadata pathMetadata = metadataStore.get(path); + List<ComparePair> violationComparePairs = new ArrayList<>(); + + final ComparePair rootComparePair = + compareFileStatusToPathMetadata(s3CurrentDir, pathMetadata); + if (rootComparePair.containsViolation()) { + violationComparePairs.add(rootComparePair); + } + + children.forEach(s3ChildMeta -> { + try { + final PathMetadata msChildMeta = + metadataStore.get(s3ChildMeta.getPath()); + final ComparePair comparePair = + compareFileStatusToPathMetadata(s3ChildMeta, msChildMeta); + if (comparePair.containsViolation()) { + violationComparePairs.add(comparePair); + } + } catch (Exception e) { + e.printStackTrace(); + } + }); + + return violationComparePairs; + } + + protected ComparePair compareFileStatusToPathMetadata( + S3AFileStatus s3FileStatus, + PathMetadata msPathMetadata) throws IOException { + final Path path = s3FileStatus.getPath(); + System.out.println("== Path: " + path); + ComparePair comparePair = new ComparePair(s3FileStatus, msPathMetadata); + + if (!path.equals(path(ROOT_PATH_STRING))) { + final Path parentPath = path.getParent(); + final PathMetadata parentPm = metadataStore.get(parentPath); + + if (parentPm == null) { + comparePair.violations.add(Violation.NO_PARENT_ENTRY); + } else { + if (!parentPm.getFileStatus().isDirectory()) { + comparePair.violations.add(Violation.PARENT_IS_A_FILE); + } + if (parentPm.isDeleted()) { + comparePair.violations.add(Violation.PARENT_TOMBSTONED); + } + } + } else { + LOG.info("Entry is in the root, so there's no parent"); Review comment: Typo ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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