Java tutorial
/** * * 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.bookkeeper.bookie.storage.ldb; import com.google.common.collect.Sets; import io.netty.buffer.ByteBuf; import java.io.IOException; import java.nio.file.FileSystems; import java.nio.file.Files; import java.nio.file.Path; import java.text.SimpleDateFormat; import java.util.Date; import java.util.Set; import java.util.concurrent.TimeUnit; import org.apache.bookkeeper.bookie.Bookie; import org.apache.bookkeeper.bookie.EntryLogger; import org.apache.bookkeeper.bookie.EntryLogger.EntryLogScanner; import org.apache.bookkeeper.bookie.LedgerDirsManager; import org.apache.bookkeeper.bookie.storage.ldb.KeyValueStorageFactory.DbConfigType; import org.apache.bookkeeper.conf.ServerConfiguration; import org.apache.bookkeeper.stats.NullStatsLogger; import org.apache.bookkeeper.util.DiskChecker; import org.apache.commons.lang.time.DurationFormatUtils; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * Scan all entries in the entry log and rebuild the ledgerStorageIndex. */ public class LocationsIndexRebuildOp { private final ServerConfiguration conf; public LocationsIndexRebuildOp(ServerConfiguration conf) { this.conf = conf; } public void initiate() throws IOException { LOG.info("Starting index rebuilding"); // Move locations index to a backup directory String basePath = Bookie.getCurrentDirectory(conf.getLedgerDirs()[0]).toString(); Path currentPath = FileSystems.getDefault().getPath(basePath, "locations"); String timestamp = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSZ").format(new Date()); Path backupPath = FileSystems.getDefault().getPath(basePath, "locations.BACKUP-" + timestamp); Files.move(currentPath, backupPath); LOG.info("Created locations index backup at {}", backupPath); long startTime = System.nanoTime(); EntryLogger entryLogger = new EntryLogger(conf, new LedgerDirsManager(conf, conf.getLedgerDirs(), new DiskChecker(conf.getDiskUsageThreshold(), conf.getDiskUsageWarnThreshold()))); Set<Long> entryLogs = entryLogger.getEntryLogsSet(); String locationsDbPath = FileSystems.getDefault().getPath(basePath, "locations").toFile().toString(); Set<Long> activeLedgers = getActiveLedgers(conf, KeyValueStorageRocksDB.factory, basePath); LOG.info("Found {} active ledgers in ledger manager", activeLedgers.size()); KeyValueStorage newIndex = KeyValueStorageRocksDB.factory.newKeyValueStorage(locationsDbPath, DbConfigType.Huge, conf); int totalEntryLogs = entryLogs.size(); int completedEntryLogs = 0; LOG.info("Scanning {} entry logs", totalEntryLogs); for (long entryLogId : entryLogs) { entryLogger.scanEntryLog(entryLogId, new EntryLogScanner() { @Override public void process(long ledgerId, long offset, ByteBuf entry) throws IOException { long entryId = entry.getLong(8); // Actual location indexed is pointing past the entry size long location = (entryLogId << 32L) | (offset + 4); if (LOG.isDebugEnabled()) { LOG.debug("Rebuilding {}:{} at location {} / {}", ledgerId, entryId, location >> 32, location & (Integer.MAX_VALUE - 1)); } // Update the ledger index page LongPairWrapper key = LongPairWrapper.get(ledgerId, entryId); LongWrapper value = LongWrapper.get(location); newIndex.put(key.array, value.array); } @Override public boolean accept(long ledgerId) { return activeLedgers.contains(ledgerId); } }); ++completedEntryLogs; LOG.info("Completed scanning of log {}.log -- {} / {}", Long.toHexString(entryLogId), completedEntryLogs, totalEntryLogs); } newIndex.sync(); newIndex.close(); LOG.info("Rebuilding index is done. Total time: {}", DurationFormatUtils .formatDurationHMS(TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - startTime))); } private Set<Long> getActiveLedgers(ServerConfiguration conf, KeyValueStorageFactory storageFactory, String basePath) throws IOException { LedgerMetadataIndex ledgers = new LedgerMetadataIndex(conf, storageFactory, basePath, NullStatsLogger.INSTANCE); Set<Long> activeLedgers = Sets.newHashSet(); for (Long ledger : ledgers.getActiveLedgersInRange(0, Long.MAX_VALUE)) { activeLedgers.add(ledger); } ledgers.close(); return activeLedgers; } private static final Logger LOG = LoggerFactory.getLogger(LocationsIndexRebuildOp.class); }