SaketaChalamchala commented on code in PR #8477: URL: https://github.com/apache/ozone/pull/8477#discussion_r2110660871
########## hadoop-ozone/ozone-manager/src/main/java/org/apache/hadoop/ozone/om/OMDBCheckPointServletInodeBasedXfer.java: ########## @@ -0,0 +1,207 @@ +/* + * 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.hadoop.ozone.om; + +import static org.apache.hadoop.hdds.utils.Archiver.includeFile; +import static org.apache.hadoop.hdds.utils.Archiver.tar; +import static org.apache.hadoop.ozone.om.OMConfigKeys.OZONE_OM_RATIS_SNAPSHOT_MAX_TOTAL_SST_SIZE_DEFAULT; +import static org.apache.hadoop.ozone.om.OMConfigKeys.OZONE_OM_RATIS_SNAPSHOT_MAX_TOTAL_SST_SIZE_KEY; + +import java.io.File; +import java.io.IOException; +import java.io.OutputStream; +import java.nio.file.Files; +import java.nio.file.Path; +import java.nio.file.Paths; +import java.util.HashMap; +import java.util.HashSet; +import java.util.Map; +import java.util.Set; +import java.util.concurrent.atomic.AtomicLong; +import java.util.stream.Collectors; +import java.util.stream.Stream; +import javax.servlet.http.HttpServletRequest; +import org.apache.commons.compress.archivers.ArchiveOutputStream; +import org.apache.commons.compress.archivers.tar.TarArchiveEntry; +import org.apache.hadoop.hdds.conf.OzoneConfiguration; +import org.apache.hadoop.hdds.utils.db.DBCheckpoint; +import org.apache.hadoop.hdds.utils.db.RDBStore; +import org.apache.hadoop.ozone.OzoneConsts; +import org.apache.hadoop.ozone.om.helpers.SnapshotInfo; +import org.apache.hadoop.ozone.om.snapshot.OmSnapshotUtils; +import org.apache.hadoop.util.Time; +import org.apache.ozone.rocksdiff.RocksDBCheckpointDiffer; + +/** + * Specialized OMDBCheckpointServlet implementation that transfers Ozone Manager + * database checkpoints using inode-based deduplication. + * <p> + * This servlet constructs checkpoint archives by examining file inodes, + * ensuring that files with the same inode (i.e., hardlinks or duplicates) + * are only transferred once. It maintains mappings from inode IDs to file + * paths, manages hardlink information, and enforces snapshot and SST file + * size constraints as needed. + * <p> + * This approach optimizes checkpoint streaming by reducing redundant data + * transfer, especially in environments where RocksDB and snapshotting result + * in multiple hardlinks to the same physical data. + */ +public class OMDBCheckPointServletInodeBasedXfer extends OMDBCheckpointServlet { + + @Override + public void writeDbDataToStream(DBCheckpoint checkpoint, HttpServletRequest request, OutputStream destination, + Set<String> sstFilesToExclude, Path tmpdir) throws IOException, InterruptedException { + + // Key is the InodeID and path is the first encountered file path with this inodeID + // This will be later used to while writing to the tar. + Map<String, Path> copyFiles = new HashMap<>(); + Map<String, Set<Path>> hardlinkFiles = new HashMap<>(); + + OzoneManager om = (OzoneManager) getServletContext().getAttribute(OzoneConsts.OM_CONTEXT_ATTRIBUTE); + OMMetadataManager omMetadataManager = om.getMetadataManager(); + RDBStore rdbStore = (RDBStore) omMetadataManager.getStore(); + boolean includeSnapshotData = includeSnapshotData(request); + + long maxTotalSstSize = getConf().getLong(OZONE_OM_RATIS_SNAPSHOT_MAX_TOTAL_SST_SIZE_KEY, + OZONE_OM_RATIS_SNAPSHOT_MAX_TOTAL_SST_SIZE_DEFAULT); + // Tarball limits are not implemented for processes that don't + // include snapshots. Currently, this is just for recon. + if (!includeSnapshotData) { + maxTotalSstSize = Long.MAX_VALUE; + } + + try (ArchiveOutputStream<TarArchiveEntry> archiveOutputStream = tar(destination)) { + Set<Path> snapshotDbPaths = new HashSet<>(); + if (includeSnapshotData) { + RocksDBCheckpointDiffer differ = getDbStore().getRocksDBCheckpointDiffer(); + Path sstBackupDir = new File(differ.getSSTBackupDir()).toPath(); + Path compactionLogDir = new File(differ.getCompactionLogDir()).toPath(); + SnapshotChainManager snapshotChainManager = new SnapshotChainManager(omMetadataManager); + for (SnapshotChainInfo snapInfo : snapshotChainManager.getGlobalSnapshotChain().values()) { + String snapshotDir = OmSnapshotManager.getSnapshotPath(getConf(), + SnapshotInfo.getCheckpointDirName(snapInfo.getSnapshotId())); + Path path = Paths.get(snapshotDir); + snapshotDbPaths.add(path); + } + snapshotDbPaths.add(sstBackupDir); + snapshotDbPaths.add(compactionLogDir); + } + + boolean shouldContinue = true; + for (Path snapshotDbPath : snapshotDbPaths) { + if (!shouldContinue) { + break; + } + shouldContinue = getFilesForArchive(copyFiles, hardlinkFiles, + sstFilesToExclude, snapshotDbPath, maxTotalSstSize); + } + + if (shouldContinue) { + shouldContinue = getFilesForArchive(copyFiles, hardlinkFiles, + sstFilesToExclude, rdbStore.getDbLocation().toPath(), maxTotalSstSize); + } + + writeFilesToArchive(copyFiles, hardlinkFiles, archiveOutputStream, + shouldContinue, checkpoint.getCheckpointLocation()); + + } catch (Exception e) { + LOG.error("got exception writing to archive " + e); + throw e; + } + } + + private OzoneConfiguration getConf() { + return ((OzoneManager) getServletContext() + .getAttribute(OzoneConsts.OM_CONTEXT_ATTRIBUTE)) + .getConfiguration(); + } + + private void writeFilesToArchive(Map<String, Path> copyFiles, Map<String, Set<Path>> hardlinkFiles, + ArchiveOutputStream<TarArchiveEntry> archiveOutputStream, boolean completed, Path checkpointLocation) + throws IOException { + Map<String, Path> filteredCopyFiles = completed ? copyFiles : + copyFiles.entrySet().stream().filter(e -> e.getValue().getFileName().toString().toLowerCase().endsWith(".sst")) + .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue)); + + Path metaDirPath = getMetaDirPath(checkpointLocation); + long bytesWritten = 0L; + int filesWritten = 0; + long lastLoggedTime = Time.monotonicNow(); + + // Go through each of the files to be copied and add to archive. + for (Map.Entry<String, Path> entry : filteredCopyFiles.entrySet()) { + Path path = entry.getValue(); + // Confirm the data is in the right place. + if (!path.toString().startsWith(metaDirPath.toString())) { + throw new IOException("tarball file not in metadata dir: " + + path + ": " + metaDirPath); + } + + File file = path.toFile(); + if (!file.isDirectory()) { + filesWritten++; + } + LOG.info("Writing file = {} for inode {}", file.getAbsolutePath(), entry.getKey()); + bytesWritten += includeFile(file, entry.getKey(), archiveOutputStream); + // Log progress every 30 seconds + if (Time.monotonicNow() - lastLoggedTime >= 30000) { + LOG.info("Transferred {} KB, #files {} to checkpoint tarball stream...", + bytesWritten / (1024), filesWritten); + lastLoggedTime = Time.monotonicNow(); + } + } + + /* + if (completed) { + // TODO: + // 1. take an OM db checkpoint , + // 2. hold a snapshotCache lock, + // 3. copy remaining files + // 4. create hardlink file + } + */ + } + + boolean getFilesForArchive(Map<String, Path> copyFiles, Map<String, Set<Path>> hardlinkFiles, + Set<String> sstFilesToExclude, Path dbDir, long maxTotalSstSize) throws IOException { + AtomicLong copySize = new AtomicLong(maxTotalSstSize); + try (Stream<Path> files = Files.list(dbDir)) { + Iterable<Path> iterable = files::iterator; + for (Path dbFile : iterable) { + if (Files.isDirectory(dbFile)) { + getFilesForArchive(copyFiles, hardlinkFiles, sstFilesToExclude, dbFile, maxTotalSstSize); + } else { + String fileId = OmSnapshotUtils.getInodeAndMtime(dbFile); + if (!sstFilesToExclude.contains(fileId)) { + if (!copyFiles.containsKey(fileId)) { + long fileSize = Files.size(dbFile); + if (copySize.get() - fileSize <= 0) { + return false; + } + copySize.addAndGet(-fileSize); + copyFiles.put(fileId, dbFile); + } + } + hardlinkFiles.getOrDefault(fileId, new HashSet<>()).add(dbFile); Review Comment: ```suggestion if (!sstFilesToExclude.contains(fileId) && !copyFiles.containsKey(fileId)) { long fileSize = Files.size(dbFile); if (copySize.get() - fileSize <= 0) { return false; } copySize.addAndGet(-fileSize); copyFiles.put(fileId, dbFile); } else { Path srcPath = sstFilesToExclude.get(fileId); if (srcPath == null) { copyFiles.get(fileId); } hardlinkFiles.computeIfAbsent(srcPath, k -> new HashSet<>()).add(dbFile); } ``` -- This is an automated message from the Apache Git Service. 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