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 static com.google.common.base.Preconditions.checkArgument; import com.google.common.annotations.VisibleForTesting; import com.google.common.collect.Lists; import com.google.protobuf.ByteString; import io.netty.buffer.ByteBuf; import io.netty.buffer.ByteBufAllocator; import io.netty.util.concurrent.DefaultThreadFactory; import java.io.IOException; import java.util.Collections; import java.util.List; import java.util.PrimitiveIterator.OfLong; import java.util.concurrent.CopyOnWriteArrayList; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import java.util.concurrent.ScheduledExecutorService; import java.util.concurrent.TimeUnit; import java.util.concurrent.atomic.AtomicBoolean; import java.util.concurrent.locks.ReentrantLock; import java.util.concurrent.locks.StampedLock; import org.apache.bookkeeper.bookie.Bookie; import org.apache.bookkeeper.bookie.Bookie.NoEntryException; import org.apache.bookkeeper.bookie.BookieException; import org.apache.bookkeeper.bookie.BookieException.OperationRejectedException; import org.apache.bookkeeper.bookie.CheckpointSource; import org.apache.bookkeeper.bookie.CheckpointSource.Checkpoint; import org.apache.bookkeeper.bookie.Checkpointer; import org.apache.bookkeeper.bookie.CompactableLedgerStorage; import org.apache.bookkeeper.bookie.EntryLocation; import org.apache.bookkeeper.bookie.EntryLogger; import org.apache.bookkeeper.bookie.GarbageCollectionStatus; import org.apache.bookkeeper.bookie.GarbageCollectorThread; import org.apache.bookkeeper.bookie.LastAddConfirmedUpdateNotification; import org.apache.bookkeeper.bookie.LedgerCache; import org.apache.bookkeeper.bookie.LedgerDirsManager; import org.apache.bookkeeper.bookie.LedgerEntryPage; import org.apache.bookkeeper.bookie.StateManager; import org.apache.bookkeeper.bookie.storage.ldb.DbLedgerStorageDataFormats.LedgerData; import org.apache.bookkeeper.bookie.storage.ldb.KeyValueStorage.Batch; import org.apache.bookkeeper.common.util.Watcher; import org.apache.bookkeeper.conf.ServerConfiguration; import org.apache.bookkeeper.meta.LedgerManager; import org.apache.bookkeeper.proto.BookieProtocol; import org.apache.bookkeeper.stats.OpStatsLogger; import org.apache.bookkeeper.stats.StatsLogger; import org.apache.bookkeeper.util.MathUtils; import org.apache.bookkeeper.util.collections.ConcurrentLongHashMap; import org.apache.commons.lang.mutable.MutableLong; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * Single directory implementation of LedgerStorage that uses RocksDB to keep the indexes for entries stored in * EntryLogs. * * <p>This is meant only to be used from {@link DbLedgerStorage}. */ public class SingleDirectoryDbLedgerStorage implements CompactableLedgerStorage { private final EntryLogger entryLogger; private final LedgerMetadataIndex ledgerIndex; private final EntryLocationIndex entryLocationIndex; private final ConcurrentLongHashMap<TransientLedgerInfo> transientLedgerInfoCache; private final GarbageCollectorThread gcThread; // Write cache where all new entries are inserted into protected volatile WriteCache writeCache; // Write cache that is used to swap with writeCache during flushes protected volatile WriteCache writeCacheBeingFlushed; // Cache where we insert entries for speculative reading private final ReadCache readCache; private final StampedLock writeCacheRotationLock = new StampedLock(); protected final ReentrantLock flushMutex = new ReentrantLock(); protected final AtomicBoolean hasFlushBeenTriggered = new AtomicBoolean(false); private final AtomicBoolean isFlushOngoing = new AtomicBoolean(false); private final ExecutorService executor = Executors .newSingleThreadExecutor(new DefaultThreadFactory("db-storage")); // Executor used to for db index cleanup private final ScheduledExecutorService cleanupExecutor = Executors .newSingleThreadScheduledExecutor(new DefaultThreadFactory("db-storage-cleanup")); private final CopyOnWriteArrayList<LedgerDeletionListener> ledgerDeletionListeners = Lists .newCopyOnWriteArrayList(); private final CheckpointSource checkpointSource; private Checkpoint lastCheckpoint = Checkpoint.MIN; private final long writeCacheMaxSize; private final long readCacheMaxSize; private final int readAheadCacheBatchSize; private final long maxThrottleTimeNanos; private final DbLedgerStorageStats dbLedgerStorageStats; static final String READ_AHEAD_CACHE_BATCH_SIZE = "dbStorage_readAheadCacheBatchSize"; private static final int DEFAULT_READ_AHEAD_CACHE_BATCH_SIZE = 100; private static final long DEFAULT_MAX_THROTTLE_TIME_MILLIS = TimeUnit.SECONDS.toMillis(10); public SingleDirectoryDbLedgerStorage(ServerConfiguration conf, LedgerManager ledgerManager, LedgerDirsManager ledgerDirsManager, LedgerDirsManager indexDirsManager, StateManager stateManager, CheckpointSource checkpointSource, Checkpointer checkpointer, StatsLogger statsLogger, ByteBufAllocator allocator, ScheduledExecutorService gcExecutor, long writeCacheSize, long readCacheSize) throws IOException { checkArgument(ledgerDirsManager.getAllLedgerDirs().size() == 1, "Db implementation only allows for one storage dir"); String baseDir = ledgerDirsManager.getAllLedgerDirs().get(0).toString(); log.info("Creating single directory db ledger storage on {}", baseDir); this.writeCacheMaxSize = writeCacheSize; this.writeCache = new WriteCache(allocator, writeCacheMaxSize / 2); this.writeCacheBeingFlushed = new WriteCache(allocator, writeCacheMaxSize / 2); this.checkpointSource = checkpointSource; readCacheMaxSize = readCacheSize; readAheadCacheBatchSize = conf.getInt(READ_AHEAD_CACHE_BATCH_SIZE, DEFAULT_READ_AHEAD_CACHE_BATCH_SIZE); long maxThrottleTimeMillis = conf.getLong(DbLedgerStorage.MAX_THROTTLE_TIME_MILLIS, DEFAULT_MAX_THROTTLE_TIME_MILLIS); maxThrottleTimeNanos = TimeUnit.MILLISECONDS.toNanos(maxThrottleTimeMillis); readCache = new ReadCache(allocator, readCacheMaxSize); ledgerIndex = new LedgerMetadataIndex(conf, KeyValueStorageRocksDB.factory, baseDir, statsLogger); entryLocationIndex = new EntryLocationIndex(conf, KeyValueStorageRocksDB.factory, baseDir, statsLogger); transientLedgerInfoCache = new ConcurrentLongHashMap<>(16 * 1024, Runtime.getRuntime().availableProcessors() * 2); cleanupExecutor.scheduleAtFixedRate(this::cleanupStaleTransientLedgerInfo, TransientLedgerInfo.LEDGER_INFO_CACHING_TIME_MINUTES, TransientLedgerInfo.LEDGER_INFO_CACHING_TIME_MINUTES, TimeUnit.MINUTES); entryLogger = new EntryLogger(conf, ledgerDirsManager, null, statsLogger, allocator); gcThread = new GarbageCollectorThread(conf, ledgerManager, this, statsLogger); dbLedgerStorageStats = new DbLedgerStorageStats(statsLogger, () -> writeCache.size() + writeCacheBeingFlushed.size(), () -> writeCache.count() + writeCacheBeingFlushed.count(), () -> readCache.size(), () -> readCache.count()); } @Override public void initialize(ServerConfiguration conf, LedgerManager ledgerManager, LedgerDirsManager ledgerDirsManager, LedgerDirsManager indexDirsManager, StateManager stateManager, CheckpointSource checkpointSource, Checkpointer checkpointer, StatsLogger statsLogger, ByteBufAllocator allocator) throws IOException { /// Initialized in constructor } /** * Evict all the ledger info object that were not used recently. */ private void cleanupStaleTransientLedgerInfo() { transientLedgerInfoCache.removeIf((ledgerId, ledgerInfo) -> { boolean isStale = ledgerInfo.isStale(); if (isStale) { ledgerInfo.close(); } return isStale; }); } @Override public void start() { gcThread.start(); } @Override public void forceGC() { gcThread.enableForceGC(); } @Override public boolean isInForceGC() { return gcThread.isInForceGC(); } @Override public void shutdown() throws InterruptedException { try { flush(); gcThread.shutdown(); entryLogger.shutdown(); cleanupExecutor.shutdown(); cleanupExecutor.awaitTermination(1, TimeUnit.SECONDS); ledgerIndex.close(); entryLocationIndex.close(); writeCache.close(); writeCacheBeingFlushed.close(); readCache.close(); executor.shutdown(); } catch (IOException e) { log.error("Error closing db storage", e); } } @Override public boolean ledgerExists(long ledgerId) throws IOException { try { LedgerData ledgerData = ledgerIndex.get(ledgerId); if (log.isDebugEnabled()) { log.debug("Ledger exists. ledger: {} : {}", ledgerId, ledgerData.getExists()); } return ledgerData.getExists(); } catch (Bookie.NoLedgerException nle) { // ledger does not exist return false; } } @Override public boolean isFenced(long ledgerId) throws IOException { if (log.isDebugEnabled()) { log.debug("isFenced. ledger: {}", ledgerId); } return ledgerIndex.get(ledgerId).getFenced(); } @Override public boolean setFenced(long ledgerId) throws IOException { if (log.isDebugEnabled()) { log.debug("Set fenced. ledger: {}", ledgerId); } boolean changed = ledgerIndex.setFenced(ledgerId); if (changed) { // notify all the watchers if a ledger is fenced TransientLedgerInfo ledgerInfo = transientLedgerInfoCache.get(ledgerId); if (null != ledgerInfo) { ledgerInfo.notifyWatchers(Long.MAX_VALUE); } } return changed; } @Override public void setMasterKey(long ledgerId, byte[] masterKey) throws IOException { if (log.isDebugEnabled()) { log.debug("Set master key. ledger: {}", ledgerId); } ledgerIndex.setMasterKey(ledgerId, masterKey); } @Override public byte[] readMasterKey(long ledgerId) throws IOException, BookieException { if (log.isDebugEnabled()) { log.debug("Read master key. ledger: {}", ledgerId); } return ledgerIndex.get(ledgerId).getMasterKey().toByteArray(); } @Override public long addEntry(ByteBuf entry) throws IOException, BookieException { long startTime = MathUtils.nowInNano(); long ledgerId = entry.getLong(entry.readerIndex()); long entryId = entry.getLong(entry.readerIndex() + 8); long lac = entry.getLong(entry.readerIndex() + 16); if (log.isDebugEnabled()) { log.debug("Add entry. {}@{}, lac = {}", ledgerId, entryId, lac); } // First we try to do an optimistic locking to get access to the current write cache. // This is based on the fact that the write cache is only being rotated (swapped) every 1 minute. During the // rest of the time, we can have multiple thread using the optimistic lock here without interfering. long stamp = writeCacheRotationLock.tryOptimisticRead(); boolean inserted = false; inserted = writeCache.put(ledgerId, entryId, entry); if (!writeCacheRotationLock.validate(stamp)) { // The write cache was rotated while we were inserting. We need to acquire the proper read lock and repeat // the operation because we might have inserted in a write cache that was already being flushed and cleared, // without being sure about this last entry being flushed or not. stamp = writeCacheRotationLock.readLock(); try { inserted = writeCache.put(ledgerId, entryId, entry); } finally { writeCacheRotationLock.unlockRead(stamp); } } if (!inserted) { triggerFlushAndAddEntry(ledgerId, entryId, entry); } // after successfully insert the entry, update LAC and notify the watchers updateCachedLacIfNeeded(ledgerId, lac); recordSuccessfulEvent(dbLedgerStorageStats.getAddEntryStats(), startTime); return entryId; } private void triggerFlushAndAddEntry(long ledgerId, long entryId, ByteBuf entry) throws IOException, BookieException { // Write cache is full, we need to trigger a flush so that it gets rotated // If the flush has already been triggered or flush has already switched the // cache, we don't need to trigger another flush if (!isFlushOngoing.get() && hasFlushBeenTriggered.compareAndSet(false, true)) { // Trigger an early flush in background log.info("Write cache is full, triggering flush"); executor.execute(() -> { try { flush(); } catch (IOException e) { log.error("Error during flush", e); } }); } dbLedgerStorageStats.getThrottledWriteRequests().inc(); long absoluteTimeoutNanos = System.nanoTime() + maxThrottleTimeNanos; while (System.nanoTime() < absoluteTimeoutNanos) { long stamp = writeCacheRotationLock.readLock(); try { if (writeCache.put(ledgerId, entryId, entry)) { // We succeeded in putting the entry in write cache in the return; } } finally { writeCacheRotationLock.unlockRead(stamp); } // Wait some time and try again try { Thread.sleep(1); } catch (InterruptedException e) { Thread.currentThread().interrupt(); throw new IOException("Interrupted when adding entry " + ledgerId + "@" + entryId); } } // Timeout expired and we weren't able to insert in write cache dbLedgerStorageStats.getRejectedWriteRequests().inc(); throw new OperationRejectedException(); } @Override public ByteBuf getEntry(long ledgerId, long entryId) throws IOException { long startTime = MathUtils.nowInNano(); if (log.isDebugEnabled()) { log.debug("Get Entry: {}@{}", ledgerId, entryId); } if (entryId == BookieProtocol.LAST_ADD_CONFIRMED) { return getLastEntry(ledgerId); } // We need to try to read from both write caches, since recent entries could be found in either of the two. The // write caches are already thread safe on their own, here we just need to make sure we get references to both // of them. Using an optimistic lock since the read lock is always free, unless we're swapping the caches. long stamp = writeCacheRotationLock.tryOptimisticRead(); WriteCache localWriteCache = writeCache; WriteCache localWriteCacheBeingFlushed = writeCacheBeingFlushed; if (!writeCacheRotationLock.validate(stamp)) { // Fallback to regular read lock approach stamp = writeCacheRotationLock.readLock(); try { localWriteCache = writeCache; localWriteCacheBeingFlushed = writeCacheBeingFlushed; } finally { writeCacheRotationLock.unlockRead(stamp); } } // First try to read from the write cache of recent entries ByteBuf entry = localWriteCache.get(ledgerId, entryId); if (entry != null) { recordSuccessfulEvent(dbLedgerStorageStats.getReadCacheHitStats(), startTime); recordSuccessfulEvent(dbLedgerStorageStats.getReadEntryStats(), startTime); return entry; } // If there's a flush going on, the entry might be in the flush buffer entry = localWriteCacheBeingFlushed.get(ledgerId, entryId); if (entry != null) { recordSuccessfulEvent(dbLedgerStorageStats.getReadCacheHitStats(), startTime); recordSuccessfulEvent(dbLedgerStorageStats.getReadEntryStats(), startTime); return entry; } // Try reading from read-ahead cache entry = readCache.get(ledgerId, entryId); if (entry != null) { recordSuccessfulEvent(dbLedgerStorageStats.getReadCacheHitStats(), startTime); recordSuccessfulEvent(dbLedgerStorageStats.getReadEntryStats(), startTime); return entry; } // Read from main storage long entryLocation; try { entryLocation = entryLocationIndex.getLocation(ledgerId, entryId); if (entryLocation == 0) { throw new NoEntryException(ledgerId, entryId); } entry = entryLogger.readEntry(ledgerId, entryId, entryLocation); } catch (NoEntryException e) { recordFailedEvent(dbLedgerStorageStats.getReadEntryStats(), startTime); throw e; } readCache.put(ledgerId, entryId, entry); // Try to read more entries long nextEntryLocation = entryLocation + 4 /* size header */ + entry.readableBytes(); fillReadAheadCache(ledgerId, entryId + 1, nextEntryLocation); recordSuccessfulEvent(dbLedgerStorageStats.getReadCacheMissStats(), startTime); recordSuccessfulEvent(dbLedgerStorageStats.getReadEntryStats(), startTime); return entry; } private void fillReadAheadCache(long orginalLedgerId, long firstEntryId, long firstEntryLocation) { try { long firstEntryLogId = (firstEntryLocation >> 32); long currentEntryLogId = firstEntryLogId; long currentEntryLocation = firstEntryLocation; int count = 0; long size = 0; while (count < readAheadCacheBatchSize && currentEntryLogId == firstEntryLogId) { ByteBuf entry = entryLogger.internalReadEntry(orginalLedgerId, -1, currentEntryLocation); try { long currentEntryLedgerId = entry.getLong(0); long currentEntryId = entry.getLong(8); if (currentEntryLedgerId != orginalLedgerId) { // Found an entry belonging to a different ledger, stopping read-ahead return; } // Insert entry in read cache readCache.put(orginalLedgerId, currentEntryId, entry); count++; size += entry.readableBytes(); currentEntryLocation += 4 + entry.readableBytes(); currentEntryLogId = currentEntryLocation >> 32; } finally { entry.release(); } } dbLedgerStorageStats.getReadAheadBatchCountStats().registerSuccessfulValue(count); dbLedgerStorageStats.getReadAheadBatchSizeStats().registerSuccessfulValue(size); } catch (Exception e) { if (log.isDebugEnabled()) { log.debug("Exception during read ahead for ledger: {}: e", orginalLedgerId, e); } } } public ByteBuf getLastEntry(long ledgerId) throws IOException { long startTime = MathUtils.nowInNano(); long stamp = writeCacheRotationLock.readLock(); try { // First try to read from the write cache of recent entries ByteBuf entry = writeCache.getLastEntry(ledgerId); if (entry != null) { if (log.isDebugEnabled()) { long foundLedgerId = entry.readLong(); // ledgedId long entryId = entry.readLong(); entry.resetReaderIndex(); if (log.isDebugEnabled()) { log.debug("Found last entry for ledger {} in write cache: {}@{}", ledgerId, foundLedgerId, entryId); } } recordSuccessfulEvent(dbLedgerStorageStats.getReadCacheHitStats(), startTime); recordSuccessfulEvent(dbLedgerStorageStats.getReadEntryStats(), startTime); return entry; } // If there's a flush going on, the entry might be in the flush buffer entry = writeCacheBeingFlushed.getLastEntry(ledgerId); if (entry != null) { if (log.isDebugEnabled()) { entry.readLong(); // ledgedId long entryId = entry.readLong(); entry.resetReaderIndex(); if (log.isDebugEnabled()) { log.debug("Found last entry for ledger {} in write cache being flushed: {}", ledgerId, entryId); } } recordSuccessfulEvent(dbLedgerStorageStats.getReadCacheHitStats(), startTime); recordSuccessfulEvent(dbLedgerStorageStats.getReadEntryStats(), startTime); return entry; } } finally { writeCacheRotationLock.unlockRead(stamp); } // Search the last entry in storage long lastEntryId = entryLocationIndex.getLastEntryInLedger(ledgerId); if (log.isDebugEnabled()) { log.debug("Found last entry for ledger {} in db: {}", ledgerId, lastEntryId); } long entryLocation = entryLocationIndex.getLocation(ledgerId, lastEntryId); ByteBuf content = entryLogger.readEntry(ledgerId, lastEntryId, entryLocation); recordSuccessfulEvent(dbLedgerStorageStats.getReadCacheMissStats(), startTime); recordSuccessfulEvent(dbLedgerStorageStats.getReadEntryStats(), startTime); return content; } @VisibleForTesting boolean isFlushRequired() { long stamp = writeCacheRotationLock.readLock(); try { return !writeCache.isEmpty(); } finally { writeCacheRotationLock.unlockRead(stamp); } } @Override public void checkpoint(Checkpoint checkpoint) throws IOException { Checkpoint thisCheckpoint = checkpointSource.newCheckpoint(); if (lastCheckpoint.compareTo(checkpoint) > 0) { return; } long startTime = MathUtils.nowInNano(); // Only a single flush operation can happen at a time flushMutex.lock(); try { // Swap the write cache so that writes can continue to happen while the flush is // ongoing swapWriteCache(); long sizeToFlush = writeCacheBeingFlushed.size(); if (log.isDebugEnabled()) { log.debug("Flushing entries. count: {} -- size {} Mb", writeCacheBeingFlushed.count(), sizeToFlush / 1024.0 / 1024); } // Write all the pending entries into the entry logger and collect the offset // position for each entry Batch batch = entryLocationIndex.newBatch(); writeCacheBeingFlushed.forEach((ledgerId, entryId, entry) -> { try { long location = entryLogger.addEntry(ledgerId, entry, true); entryLocationIndex.addLocation(batch, ledgerId, entryId, location); } catch (IOException e) { throw new RuntimeException(e); } }); entryLogger.flush(); long batchFlushStarTime = System.nanoTime(); batch.flush(); batch.close(); if (log.isDebugEnabled()) { log.debug("DB batch flushed time : {} s", MathUtils.elapsedNanos(batchFlushStarTime) / (double) TimeUnit.SECONDS.toNanos(1)); } ledgerIndex.flush(); cleanupExecutor.execute(() -> { // There can only be one single cleanup task running because the cleanupExecutor // is single-threaded try { if (log.isDebugEnabled()) { log.debug("Removing deleted ledgers from db indexes"); } entryLocationIndex.removeOffsetFromDeletedLedgers(); ledgerIndex.removeDeletedLedgers(); } catch (Throwable t) { log.warn("Failed to cleanup db indexes", t); } }); lastCheckpoint = thisCheckpoint; // Discard all the entry from the write cache, since they're now persisted writeCacheBeingFlushed.clear(); double flushTimeSeconds = MathUtils.elapsedNanos(startTime) / (double) TimeUnit.SECONDS.toNanos(1); double flushThroughput = sizeToFlush / 1024.0 / 1024.0 / flushTimeSeconds; if (log.isDebugEnabled()) { log.debug("Flushing done time {} s -- Written {} MB/s", flushTimeSeconds, flushThroughput); } recordSuccessfulEvent(dbLedgerStorageStats.getFlushStats(), startTime); dbLedgerStorageStats.getFlushSizeStats().registerSuccessfulValue(sizeToFlush); } catch (IOException e) { // Leave IOExecption as it is throw e; } catch (RuntimeException e) { // Wrap unchecked exceptions throw new IOException(e); } finally { try { isFlushOngoing.set(false); } finally { flushMutex.unlock(); } } } /** * Swap the current write cache with the replacement cache. */ private void swapWriteCache() { long stamp = writeCacheRotationLock.writeLock(); try { // First, swap the current write-cache map with an empty one so that writes will // go on unaffected. Only a single flush is happening at the same time WriteCache tmp = writeCacheBeingFlushed; writeCacheBeingFlushed = writeCache; writeCache = tmp; // since the cache is switched, we can allow flush to be triggered hasFlushBeenTriggered.set(false); } finally { try { isFlushOngoing.set(true); } finally { writeCacheRotationLock.unlockWrite(stamp); } } } @Override public void flush() throws IOException { Checkpoint cp = checkpointSource.newCheckpoint(); checkpoint(cp); checkpointSource.checkpointComplete(cp, true); } @Override public void deleteLedger(long ledgerId) throws IOException { if (log.isDebugEnabled()) { log.debug("Deleting ledger {}", ledgerId); } // Delete entries from this ledger that are still in the write cache long stamp = writeCacheRotationLock.readLock(); try { writeCache.deleteLedger(ledgerId); } finally { writeCacheRotationLock.unlockRead(stamp); } entryLocationIndex.delete(ledgerId); ledgerIndex.delete(ledgerId); for (int i = 0, size = ledgerDeletionListeners.size(); i < size; i++) { LedgerDeletionListener listener = ledgerDeletionListeners.get(i); listener.ledgerDeleted(ledgerId); } TransientLedgerInfo tli = transientLedgerInfoCache.remove(ledgerId); if (tli != null) { tli.close(); } } @Override public Iterable<Long> getActiveLedgersInRange(long firstLedgerId, long lastLedgerId) throws IOException { return ledgerIndex.getActiveLedgersInRange(firstLedgerId, lastLedgerId); } @Override public void updateEntriesLocations(Iterable<EntryLocation> locations) throws IOException { // Trigger a flush to have all the entries being compacted in the db storage flush(); entryLocationIndex.updateLocations(locations); } @Override public EntryLogger getEntryLogger() { return entryLogger; } @Override public long getLastAddConfirmed(long ledgerId) throws IOException { TransientLedgerInfo ledgerInfo = transientLedgerInfoCache.get(ledgerId); long lac = null != ledgerInfo ? ledgerInfo.getLastAddConfirmed() : TransientLedgerInfo.NOT_ASSIGNED_LAC; if (lac == TransientLedgerInfo.NOT_ASSIGNED_LAC) { ByteBuf bb = getEntry(ledgerId, BookieProtocol.LAST_ADD_CONFIRMED); try { bb.skipBytes(2 * Long.BYTES); // skip ledger id and entry id lac = bb.readLong(); lac = getOrAddLedgerInfo(ledgerId).setLastAddConfirmed(lac); } finally { bb.release(); } } return lac; } @Override public boolean waitForLastAddConfirmedUpdate(long ledgerId, long previousLAC, Watcher<LastAddConfirmedUpdateNotification> watcher) throws IOException { return getOrAddLedgerInfo(ledgerId).waitForLastAddConfirmedUpdate(previousLAC, watcher); } @Override public void cancelWaitForLastAddConfirmedUpdate(long ledgerId, Watcher<LastAddConfirmedUpdateNotification> watcher) throws IOException { getOrAddLedgerInfo(ledgerId).cancelWaitForLastAddConfirmedUpdate(watcher); } @Override public void setExplicitlac(long ledgerId, ByteBuf lac) throws IOException { getOrAddLedgerInfo(ledgerId).setExplicitLac(lac); } @Override public ByteBuf getExplicitLac(long ledgerId) { TransientLedgerInfo ledgerInfo = transientLedgerInfoCache.get(ledgerId); if (null == ledgerInfo) { return null; } else { return ledgerInfo.getExplicitLac(); } } private TransientLedgerInfo getOrAddLedgerInfo(long ledgerId) { TransientLedgerInfo tli = transientLedgerInfoCache.get(ledgerId); if (tli != null) { return tli; } else { TransientLedgerInfo newTli = new TransientLedgerInfo(ledgerId, ledgerIndex); tli = transientLedgerInfoCache.putIfAbsent(ledgerId, newTli); if (tli != null) { newTli.close(); return tli; } else { return newTli; } } } private void updateCachedLacIfNeeded(long ledgerId, long lac) { TransientLedgerInfo tli = transientLedgerInfoCache.get(ledgerId); if (tli != null) { tli.setLastAddConfirmed(lac); } } @Override public void flushEntriesLocationsIndex() throws IOException { // No-op. Location index is already flushed in updateEntriesLocations() call } /** * Add an already existing ledger to the index. * * <p>This method is only used as a tool to help the migration from InterleaveLedgerStorage to DbLedgerStorage * * @param ledgerId * the ledger id * @param pages * Iterator over index pages from Indexed * @return the number of */ public long addLedgerToIndex(long ledgerId, boolean isFenced, byte[] masterKey, LedgerCache.PageEntriesIterable pages) throws Exception { LedgerData ledgerData = LedgerData.newBuilder().setExists(true).setFenced(isFenced) .setMasterKey(ByteString.copyFrom(masterKey)).build(); ledgerIndex.set(ledgerId, ledgerData); MutableLong numberOfEntries = new MutableLong(); // Iterate over all the entries pages Batch batch = entryLocationIndex.newBatch(); for (LedgerCache.PageEntries page : pages) { try (LedgerEntryPage lep = page.getLEP()) { lep.getEntries((entryId, location) -> { entryLocationIndex.addLocation(batch, ledgerId, entryId, location); numberOfEntries.increment(); return true; }); } } batch.flush(); batch.close(); return numberOfEntries.longValue(); } @Override public void registerLedgerDeletionListener(LedgerDeletionListener listener) { ledgerDeletionListeners.add(listener); } public EntryLocationIndex getEntryLocationIndex() { return entryLocationIndex; } private void recordSuccessfulEvent(OpStatsLogger logger, long startTimeNanos) { logger.registerSuccessfulEvent(MathUtils.elapsedNanos(startTimeNanos), TimeUnit.NANOSECONDS); } private void recordFailedEvent(OpStatsLogger logger, long startTimeNanos) { logger.registerFailedEvent(MathUtils.elapsedNanos(startTimeNanos), TimeUnit.NANOSECONDS); } long getWriteCacheSize() { return writeCache.size() + writeCacheBeingFlushed.size(); } long getWriteCacheCount() { return writeCache.count() + writeCacheBeingFlushed.count(); } long getReadCacheSize() { return readCache.size(); } long getReadCacheCount() { return readCache.count(); } @Override public List<GarbageCollectionStatus> getGarbageCollectionStatus() { return Collections.singletonList(gcThread.getGarbageCollectionStatus()); } /** * Interface which process ledger logger. */ public interface LedgerLoggerProcessor { void process(long entryId, long entryLogId, long position); } private static final Logger log = LoggerFactory.getLogger(DbLedgerStorage.class); @Override public OfLong getListOfEntriesOfLedger(long ledgerId) throws IOException { throw new UnsupportedOperationException( "getListOfEntriesOfLedger method is currently unsupported for SingleDirectoryDbLedgerStorage"); } }