swamirishi commented on code in PR #8477: URL: https://github.com/apache/ozone/pull/8477#discussion_r2132226323
########## hadoop-ozone/ozone-manager/src/main/java/org/apache/hadoop/ozone/om/OMDBCheckpointServletInodeBasedXfer.java: ########## @@ -0,0 +1,365 @@ +/* + * 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.*; +import static org.apache.hadoop.ozone.OzoneConsts.*; +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 static org.apache.hadoop.ozone.om.snapshot.OmSnapshotUtils.DATA_PREFIX; +import static org.apache.hadoop.ozone.om.snapshot.OmSnapshotUtils.DATA_SUFFIX; + +import java.io.File; +import java.io.IOException; +import java.io.OutputStream; +import java.nio.charset.StandardCharsets; +import java.nio.file.Files; +import java.nio.file.Path; +import java.nio.file.Paths; +import java.time.Duration; +import java.time.Instant; +import java.util.ArrayList; +import java.util.Collection; +import java.util.HashMap; +import java.util.HashSet; +import java.util.Iterator; +import java.util.LinkedHashSet; +import java.util.List; +import java.util.Map; +import java.util.Set; +import java.util.concurrent.atomic.AtomicLong; +import java.util.stream.Stream; +import javax.servlet.ServletException; +import javax.servlet.http.HttpServletRequest; +import javax.servlet.http.HttpServletResponse; +import org.apache.commons.compress.archivers.ArchiveOutputStream; +import org.apache.commons.compress.archivers.tar.TarArchiveEntry; +import org.apache.commons.io.FileUtils; +import org.apache.commons.io.IOCase; +import org.apache.commons.io.file.PathFilter; +import org.apache.commons.io.filefilter.SuffixFileFilter; +import org.apache.hadoop.hdds.conf.OzoneConfiguration; +import org.apache.hadoop.hdds.recon.ReconConfig; +import org.apache.hadoop.hdds.utils.DBCheckpointServlet; +import org.apache.hadoop.hdds.utils.db.DBCheckpoint; +import org.apache.hadoop.ozone.OzoneConsts; +import org.apache.hadoop.ozone.lock.BootstrapStateHandler; +import org.apache.hadoop.ozone.om.helpers.SnapshotInfo; +import org.apache.hadoop.ozone.om.snapshot.OmSnapshotUtils; +import org.apache.hadoop.security.UserGroupInformation; +import org.apache.ozone.rocksdiff.RocksDBCheckpointDiffer; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** + * 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 DBCheckpointServlet { + + protected static final Logger LOG = + LoggerFactory.getLogger(OMDBCheckpointServletInodeBasedXfer.class); + private static final long serialVersionUID = 1L; + private static final PathFilter SST_FILE_FILTER = + new SuffixFileFilter(ROCKSDB_SST_SUFFIX, IOCase.INSENSITIVE); + + @Override + public void init() throws ServletException { + OzoneManager om = (OzoneManager) getServletContext() + .getAttribute(OzoneConsts.OM_CONTEXT_ATTRIBUTE); + + if (om == null) { + LOG.error("Unable to initialize OMDBCheckpointServlet. OM is null"); + return; + } + + OzoneConfiguration conf = getConf(); + // Only Ozone Admins and Recon are allowed + Collection<String> allowedUsers = + new LinkedHashSet<>(om.getOmAdminUsernames()); + Collection<String> allowedGroups = om.getOmAdminGroups(); + ReconConfig reconConfig = conf.getObject(ReconConfig.class); + String reconPrincipal = reconConfig.getKerberosPrincipal(); + if (!reconPrincipal.isEmpty()) { + UserGroupInformation ugi = + UserGroupInformation.createRemoteUser(reconPrincipal); + allowedUsers.add(ugi.getShortUserName()); + } + + initialize(om.getMetadataManager().getStore(), + om.getMetrics().getDBCheckpointMetrics(), + om.getAclsEnabled(), + allowedUsers, + allowedGroups, + om.isSpnegoEnabled()); + } + + + protected static Path getMetaDirPath(Path checkpointLocation) { + // This check is done to take care of findbugs else below getParent() + // should not be null. + Path locationParent = checkpointLocation.getParent(); + if (null == locationParent) { + throw new RuntimeException( + "checkpoint location's immediate parent is null."); + } + Path parent = locationParent.getParent(); + if (null == parent) { + throw new RuntimeException( + "checkpoint location's path is invalid and could not be verified."); + } + return parent; + } + + // Returns value of http request parameter. + protected static boolean includeSnapshotData(HttpServletRequest request) { + String includeParam = + request.getParameter(OZONE_DB_CHECKPOINT_INCLUDE_SNAPSHOT_DATA); + return Boolean.parseBoolean(includeParam); + } + + @Override + protected void processMetadataSnapshotRequest(HttpServletRequest request, HttpServletResponse response, + boolean isFormData, DBCheckpoint checkpoint, boolean flush) { + List<String> excludedSstList = new ArrayList<>(); + String[] sstParam = isFormData ? + parseFormDataParameters(request) : request.getParameterValues( + OZONE_DB_CHECKPOINT_REQUEST_TO_EXCLUDE_SST); + Set<String> receivedSstFiles = fetchSstFilesReceived(sstParam); + Path tmpdir = null; + try (BootstrapStateHandler.Lock lock = getBootstrapStateLock().lock()) { + tmpdir = Files.createTempDirectory(getBootstrapTempData().toPath(), + "bootstrap-data-"); + String tarName = "om.data-" + System.currentTimeMillis() + ".tar"; + response.setContentType("application/x-tar"); + response.setHeader("Content-Disposition", "attachment; filename=\"" + tarName + "\""); + Instant start = Instant.now(); + writeDbDataToStream(request, response.getOutputStream(), receivedSstFiles, tmpdir); + Instant end = Instant.now(); + long duration = Duration.between(start, end).toMillis(); + LOG.info("Time taken to write the checkpoint to response output " + + "stream: {} milliseconds", duration); + logSstFileList(excludedSstList, + "Excluded {} SST files from the latest checkpoint{}: {}", 5); + } catch (Exception e){ + LOG.error( + "Unable to process metadata snapshot request. ", e); + response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR); + } finally { + try { + if (tmpdir != null) { + FileUtils.deleteDirectory(tmpdir.toFile()); + } + } catch (IOException e) { + LOG.error("unable to delete: " + tmpdir); + } + } + super.processMetadataSnapshotRequest(request, response, isFormData, checkpoint, flush); + } + + + public void writeDbDataToStream(HttpServletRequest request, OutputStream destination, + Set<String> sstFilesToExclude, Path tmpdir) throws IOException, InterruptedException { + DBCheckpoint checkpoint = null; + // Key is the InodeID and the first encountered file path with this inodeID + Map<String, Path> copyFiles = new HashMap<>(); + OzoneManager om = (OzoneManager) getServletContext().getAttribute(OzoneConsts.OM_CONTEXT_ATTRIBUTE); + OMMetadataManager omMetadataManager = om.getMetadataManager(); + boolean includeSnapshotData = includeSnapshotData(request); + AtomicLong maxTotalSstSize = new AtomicLong(getConf().getLong(OZONE_OM_RATIS_SNAPSHOT_MAX_TOTAL_SST_SIZE_KEY, + OZONE_OM_RATIS_SNAPSHOT_MAX_TOTAL_SST_SIZE_DEFAULT)); + + if (!includeSnapshotData) { + maxTotalSstSize.set(Long.MAX_VALUE); + } + + boolean shouldContinue = true; + + Set<Path> allPathsToVisit = new HashSet<>(); + try (ArchiveOutputStream<TarArchiveEntry> archiveOutputStream = tar(destination)) { + if (includeSnapshotData) { + Set<Path> snapshotDbPaths = collectSnapshotPaths(omMetadataManager); + // Process each snapshot db path and write it to archive + for (Path snapshotDbPath : snapshotDbPaths) { + if (!shouldContinue) { + break; + } + shouldContinue = writeDBToArchive(copyFiles, sstFilesToExclude, snapshotDbPath, + maxTotalSstSize, archiveOutputStream, tmpdir); + } + + RocksDBCheckpointDiffer differ = getDbStore().getRocksDBCheckpointDiffer(); + Path sstBackupDir = new File(differ.getSSTBackupDir()).toPath(); + Path compactionLogDir = new File(differ.getCompactionLogDir()).toPath(); + + if (shouldContinue) { + shouldContinue = writeDBToArchive(copyFiles, sstFilesToExclude, sstBackupDir, + maxTotalSstSize, archiveOutputStream, tmpdir); + } + + if (shouldContinue) { + shouldContinue = writeDBToArchive(copyFiles, sstFilesToExclude, compactionLogDir, + maxTotalSstSize, archiveOutputStream, tmpdir); + } + // Add paths of snapshot databases, SST backups, and compaction logs to visit list + allPathsToVisit.addAll(snapshotDbPaths); + allPathsToVisit.add(sstBackupDir); + allPathsToVisit.add(compactionLogDir); + } + + if (shouldContinue) { + // we finished transferring files from snapshot DB's by now and + // this is the last step where we transfer the active om.db contents + checkpoint = getCheckpoint(tmpdir,true); + // unlimited files as we want the Active DB contents to be transferred in a single batch + maxTotalSstSize.set(Long.MAX_VALUE); + Path checkpointDir = checkpoint.getCheckpointLocation(); + writeDBToArchive(copyFiles, sstFilesToExclude, checkpointDir, + maxTotalSstSize, archiveOutputStream, tmpdir); + allPathsToVisit.add(checkpointDir); + generateAndWriteHardlinkFile(checkpointDir, allPathsToVisit, archiveOutputStream); + } + + } catch (Exception e) { + LOG.error("got exception writing to archive " + e); + throw e; + } finally { + cleanupCheckpoint(checkpoint); + } + } + + private static void cleanupCheckpoint(DBCheckpoint checkpoint) { + if (checkpoint != null) { + try { + checkpoint.cleanupCheckpoint(); + } catch (IOException e) { + LOG.error("Error trying to clean checkpoint at {} .", + checkpoint.getCheckpointLocation().toString()); + } + } + } + + /** + * Generates a file containing hardlink information and writes it to the archive. + * + * @param checkpointDir Directory containing the checkpoint + * @param allPathsToVisit Set of all paths to visit for hardlink information + * @param archiveOutputStream Archive output stream + * @throws IOException if an I/O error occurs + */ + private static void generateAndWriteHardlinkFile(Path checkpointDir, Set<Path> allPathsToVisit, + ArchiveOutputStream<TarArchiveEntry> archiveOutputStream) throws IOException { + Path data = Files.createTempFile(DATA_PREFIX, DATA_SUFFIX); + Path metaDirPath = getMetaDirPath(checkpointDir); + int truncateLength = metaDirPath.toString().length() + 1; Review Comment: This relative path wont work for snapshots. You are supposed to get the location relative om data directory. So an sst file corresponding to AOS om.db would become om.db/1.sst . An sst file corresponding to snapshot db should become db.checkpoints/om.db-<snapshotId>/1.sst -- 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]
