opendaylight/md-sal/sal-akka-segmented-journal/src/main/java/org/opendaylight/controller/akka/segjournal/SegmentedJournalActor.java

   1 /*
   2  * Copyright (c) 2019 Pantheon Technologies, s.r.o. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8 package org.opendaylight.controller.akka.segjournal;
   9
  10 import static com.google.common.base.Verify.verify;
  11 import static com.google.common.base.Verify.verifyNotNull;
  12 import static java.util.Objects.requireNonNull;
  13
  14 import akka.actor.AbstractActor;
  15 import akka.actor.Props;
  16 import akka.persistence.AtomicWrite;
  17 import akka.persistence.PersistentRepr;
  18 import com.codahale.metrics.Histogram;
  19 import com.codahale.metrics.Meter;
  20 import com.codahale.metrics.SlidingTimeWindowReservoir;
  21 import com.codahale.metrics.Timer;
  22 import com.google.common.base.MoreObjects;
  23 import io.atomix.storage.StorageLevel;
  24 import io.atomix.storage.journal.Indexed;
  25 import io.atomix.storage.journal.SegmentedJournal;
  26 import io.atomix.storage.journal.SegmentedJournalReader;
  27 import io.atomix.storage.journal.SegmentedJournalWriter;
  28 import io.atomix.utils.serializer.Namespace;
  29 import java.io.File;
  30 import java.io.Serializable;
  31 import java.util.ArrayList;
  32 import java.util.List;
  33 import java.util.Optional;
  34 import java.util.concurrent.TimeUnit;
  35 import java.util.function.Consumer;
  36 import org.opendaylight.controller.akka.segjournal.DataJournalEntry.FromPersistence;
  37 import org.opendaylight.controller.akka.segjournal.DataJournalEntry.ToPersistence;
  38 import org.slf4j.Logger;
  39 import org.slf4j.LoggerFactory;
  40 import scala.collection.Iterator;
  41 import scala.collection.SeqLike;
  42 import scala.concurrent.Future;
  43 import scala.concurrent.Promise;
  44
  45 /**
  46  * This actor handles a single PersistentActor's journal. The journal is split into two {@link SegmentedJournal}s:
  47  * <ul>
  48  *     <li>A memory-mapped data journal, containing actual data entries</li>
  49  *     <li>A simple file journal, containing sequence numbers of last deleted entry</li>
  50  * </ul>
  51  *
  52  * <p>
  53  * This is a conscious design decision to minimize the amount of data that is being stored in the data journal while
  54  * speeding up normal operations. Since the SegmentedJournal is an append-only linear log and Akka requires the ability
  55  * to delete persistence entries, we need ability to mark a subset of a SegmentedJournal as deleted. While we could
  56  * treat such delete requests as normal events, this leads to a mismatch between SegmentedJournal indices (as exposed by
  57  * {@link Indexed}) and Akka sequence numbers -- requiring us to potentially perform costly deserialization to find the
  58  * index corresponding to a particular sequence number, or maintain moderately-complex logic and data structures to
  59  * perform that mapping in sub-linear time complexity.
  60  *
  61  * <p>
  62  * Split-file approach allows us to treat sequence numbers and indices as equivalent, without maintaining any explicit
  63  * mapping information. The only additional information we need to maintain is the last deleted sequence number.
  64  *
  65  * @author Robert Varga
  66  */
  67 final class SegmentedJournalActor extends AbstractActor {
  68     abstract static class AsyncMessage<T> {
  69         final Promise<T> promise = Promise.apply();
  70     }
  71
  72     private static final class ReadHighestSequenceNr extends AsyncMessage<Long> {
  73         private final long fromSequenceNr;
  74
  75         ReadHighestSequenceNr(final long fromSequenceNr) {
  76             this.fromSequenceNr = fromSequenceNr;
  77         }
  78
  79         @Override
  80         public String toString() {
  81             return MoreObjects.toStringHelper(this).add("fromSequenceNr", fromSequenceNr).toString();
  82         }
  83     }
  84
  85     private static final class ReplayMessages extends AsyncMessage<Void> {
  86         private final long fromSequenceNr;
  87         private final long toSequenceNr;
  88         private final long max;
  89         private final Consumer<PersistentRepr> replayCallback;
  90
  91         ReplayMessages(final long fromSequenceNr,
  92                 final long toSequenceNr, final long max, final Consumer<PersistentRepr> replayCallback) {
  93             this.fromSequenceNr = fromSequenceNr;
  94             this.toSequenceNr = toSequenceNr;
  95             this.max = max;
  96             this.replayCallback = requireNonNull(replayCallback);
  97         }
  98
  99         @Override
 100         public String toString() {
 101             return MoreObjects.toStringHelper(this).add("fromSequenceNr", fromSequenceNr)
 102                     .add("toSequenceNr", toSequenceNr).add("max", max).toString();
 103         }
 104     }
 105
 106     static final class WriteMessages {
 107         private final List<AtomicWrite> requests = new ArrayList<>();
 108         private final List<Promise<Optional<Exception>>> results = new ArrayList<>();
 109
 110         Future<Optional<Exception>> add(final AtomicWrite write) {
 111             final Promise<Optional<Exception>> promise = Promise.apply();
 112             requests.add(write);
 113             results.add(promise);
 114             return promise.future();
 115         }
 116
 117         @Override
 118         public String toString() {
 119             return MoreObjects.toStringHelper(this).add("requests", requests).toString();
 120         }
 121     }
 122
 123     private static final class DeleteMessagesTo extends AsyncMessage<Void> {
 124         final long toSequenceNr;
 125
 126         DeleteMessagesTo(final long toSequenceNr) {
 127             this.toSequenceNr = toSequenceNr;
 128         }
 129
 130         @Override
 131         public String toString() {
 132             return MoreObjects.toStringHelper(this).add("toSequenceNr", toSequenceNr).toString();
 133         }
 134     }
 135
 136     private static final Logger LOG = LoggerFactory.getLogger(SegmentedJournalActor.class);
 137     private static final Namespace DELETE_NAMESPACE = Namespace.builder().register(Long.class).build();
 138     private static final int DELETE_SEGMENT_SIZE = 64 * 1024;
 139
 140     // Tracks the time it took us to write a batch of messages
 141     private final Timer batchWriteTime = new Timer();
 142     // Tracks the number of individual messages written
 143     private final Meter messageWriteCount = new Meter();
 144     // Tracks the size distribution of messages for last 5 minutes
 145     private final Histogram messageSize = new Histogram(new SlidingTimeWindowReservoir(5, TimeUnit.MINUTES));
 146
 147     private final String persistenceId;
 148     private final StorageLevel storage;
 149     private final int maxSegmentSize;
 150     private final int maxEntrySize;
 151     private final File directory;
 152
 153     private SegmentedJournal<DataJournalEntry> dataJournal;
 154     private SegmentedJournal<Long> deleteJournal;
 155     private long lastDelete;
 156
 157     // Tracks largest message size we have observed either during recovery or during write
 158     private int largestObservedSize;
 159
 160     SegmentedJournalActor(final String persistenceId, final File directory, final StorageLevel storage,
 161             final int maxEntrySize, final int maxSegmentSize) {
 162         this.persistenceId = requireNonNull(persistenceId);
 163         this.directory = requireNonNull(directory);
 164         this.storage = requireNonNull(storage);
 165         this.maxEntrySize = maxEntrySize;
 166         this.maxSegmentSize = maxSegmentSize;
 167     }
 168
 169     static Props props(final String persistenceId, final File directory, final StorageLevel storage,
 170             final int maxEntrySize, final int maxSegmentSize) {
 171         return Props.create(SegmentedJournalActor.class, requireNonNull(persistenceId), directory, storage,
 172             maxEntrySize, maxSegmentSize);
 173     }
 174
 175     @Override
 176     public Receive createReceive() {
 177         return receiveBuilder()
 178                 .match(DeleteMessagesTo.class, this::handleDeleteMessagesTo)
 179                 .match(ReadHighestSequenceNr.class, this::handleReadHighestSequenceNr)
 180                 .match(ReplayMessages.class, this::handleReplayMessages)
 181                 .match(WriteMessages.class, this::handleWriteMessages)
 182                 .matchAny(this::handleUnknown)
 183                 .build();
 184     }
 185
 186     @Override
 187     public void preStart() throws Exception {
 188         LOG.debug("{}: actor starting", persistenceId);
 189         super.preStart();
 190     }
 191
 192     @Override
 193     public void postStop() throws Exception {
 194         LOG.debug("{}: actor stopping", persistenceId);
 195         if (dataJournal != null) {
 196             dataJournal.close();
 197             LOG.debug("{}: data journal closed", persistenceId);
 198             dataJournal = null;
 199         }
 200         if (deleteJournal != null) {
 201             deleteJournal.close();
 202             LOG.debug("{}: delete journal closed", persistenceId);
 203             deleteJournal = null;
 204         }
 205         LOG.debug("{}: actor stopped", persistenceId);
 206         super.postStop();
 207     }
 208
 209     static AsyncMessage<Void> deleteMessagesTo(final long toSequenceNr) {
 210         return new DeleteMessagesTo(toSequenceNr);
 211     }
 212
 213     static AsyncMessage<Long> readHighestSequenceNr(final long fromSequenceNr) {
 214         return new ReadHighestSequenceNr(fromSequenceNr);
 215     }
 216
 217     static AsyncMessage<Void> replayMessages(final long fromSequenceNr, final long toSequenceNr, final long max,
 218             final Consumer<PersistentRepr> replayCallback) {
 219         return new ReplayMessages(fromSequenceNr, toSequenceNr, max, replayCallback);
 220     }
 221
 222     private void handleDeleteMessagesTo(final DeleteMessagesTo message) {
 223         ensureOpen();
 224
 225         LOG.debug("{}: delete messages {}", persistenceId, message);
 226         final long to = Long.min(dataJournal.writer().getLastIndex(), message.toSequenceNr);
 227         LOG.debug("{}: adjusted delete to {}", persistenceId, to);
 228
 229         if (lastDelete < to) {
 230             LOG.debug("{}: deleting entries up to {}", persistenceId, to);
 231
 232             lastDelete = to;
 233             final SegmentedJournalWriter<Long> deleteWriter = deleteJournal.writer();
 234             final Indexed<Long> entry = deleteWriter.append(lastDelete);
 235             deleteWriter.commit(entry.index());
 236             dataJournal.writer().commit(lastDelete);
 237
 238             LOG.debug("{}: compaction started", persistenceId);
 239             dataJournal.compact(lastDelete);
 240             deleteJournal.compact(entry.index());
 241             LOG.debug("{}: compaction finished", persistenceId);
 242         } else {
 243             LOG.debug("{}: entries up to {} already deleted", persistenceId, lastDelete);
 244         }
 245
 246         message.promise.success(null);
 247     }
 248
 249     @SuppressWarnings("checkstyle:illegalCatch")
 250     private void handleReadHighestSequenceNr(final ReadHighestSequenceNr message) {
 251         LOG.debug("{}: looking for highest sequence on {}", persistenceId, message);
 252         final Long sequence;
 253         if (directory.isDirectory()) {
 254             ensureOpen();
 255             sequence = dataJournal.writer().getLastIndex();
 256         } else {
 257             sequence = 0L;
 258         }
 259
 260         LOG.debug("{}: highest sequence is {}", message, sequence);
 261         message.promise.success(sequence);
 262     }
 263
 264     @SuppressWarnings("checkstyle:illegalCatch")
 265     private void handleReplayMessages(final ReplayMessages message) {
 266         LOG.debug("{}: replaying messages {}", persistenceId, message);
 267         ensureOpen();
 268
 269         final long from = Long.max(lastDelete + 1, message.fromSequenceNr);
 270         LOG.debug("{}: adjusted fromSequenceNr to {}", persistenceId, from);
 271
 272         try (SegmentedJournalReader<DataJournalEntry> reader = dataJournal.openReader(from)) {
 273             int count = 0;
 274             while (reader.hasNext() && count < message.max) {
 275                 final Indexed<DataJournalEntry> next = reader.next();
 276                 if (next.index() > message.toSequenceNr) {
 277                     break;
 278                 }
 279
 280                 LOG.trace("{}: replay {}", persistenceId, next);
 281                 updateLargestSize(next.size());
 282                 final DataJournalEntry entry = next.entry();
 283                 verify(entry instanceof FromPersistence, "Unexpected entry %s", entry);
 284
 285                 final PersistentRepr repr = ((FromPersistence) entry).toRepr(persistenceId, next.index());
 286                 LOG.debug("{}: replaying {}", persistenceId, repr);
 287                 message.replayCallback.accept(repr);
 288                 count++;
 289             }
 290             LOG.debug("{}: successfully replayed {} entries", persistenceId, count);
 291         } catch (Exception e) {
 292             LOG.warn("{}: failed to replay messages for {}", persistenceId, message, e);
 293             message.promise.failure(e);
 294         } finally {
 295             message.promise.success(null);
 296         }
 297     }
 298
 299     @SuppressWarnings("checkstyle:illegalCatch")
 300     private void handleWriteMessages(final WriteMessages message) {
 301         ensureOpen();
 302
 303         final SegmentedJournalWriter<DataJournalEntry> writer = dataJournal.writer();
 304         final long startTicks = System.nanoTime();
 305         final int count = message.requests.size();
 306         final long start = writer.getLastIndex();
 307
 308         for (int i = 0; i < count; ++i) {
 309             final long mark = writer.getLastIndex();
 310             try {
 311                 writeRequest(writer, message.requests.get(i));
 312             } catch (Exception e) {
 313                 LOG.warn("{}: failed to write out request", persistenceId, e);
 314                 message.results.get(i).success(Optional.of(e));
 315                 writer.truncate(mark);
 316                 continue;
 317             }
 318
 319             message.results.get(i).success(Optional.empty());
 320         }
 321         writer.flush();
 322         batchWriteTime.update(System.nanoTime() - startTicks, TimeUnit.NANOSECONDS);
 323         messageWriteCount.mark(writer.getLastIndex() - start);
 324     }
 325
 326     private void writeRequest(final SegmentedJournalWriter<DataJournalEntry> writer, final AtomicWrite request) {
 327         // Cast is needed for Eclipse because of https://bugs.eclipse.org/bugs/show_bug.cgi?id=468276
 328         final Iterator<PersistentRepr> it = ((SeqLike<PersistentRepr, ?>) request.payload()).iterator();
 329         while (it.hasNext()) {
 330             final PersistentRepr repr = it.next();
 331             final Object payload = repr.payload();
 332             if (!(payload instanceof Serializable)) {
 333                 throw new UnsupportedOperationException("Non-serializable payload encountered " + payload.getClass());
 334             }
 335
 336             final int size = writer.append(new ToPersistence(repr)).size();
 337             messageSize.update(size);
 338             updateLargestSize(size);
 339         }
 340     }
 341
 342     private void handleUnknown(final Object message) {
 343         LOG.error("{}: Received unknown message {}", persistenceId, message);
 344     }
 345
 346     private void updateLargestSize(final int size) {
 347         if (size > largestObservedSize) {
 348             largestObservedSize = size;
 349         }
 350     }
 351
 352     private void ensureOpen() {
 353         if (dataJournal != null) {
 354             verifyNotNull(deleteJournal);
 355             return;
 356         }
 357
 358         deleteJournal = SegmentedJournal.<Long>builder().withDirectory(directory).withName("delete")
 359                 .withNamespace(DELETE_NAMESPACE).withMaxSegmentSize(DELETE_SEGMENT_SIZE).build();
 360         final Indexed<Long> lastEntry = deleteJournal.writer().getLastEntry();
 361         lastDelete = lastEntry == null ? 0 : lastEntry.index();
 362
 363         dataJournal = SegmentedJournal.<DataJournalEntry>builder()
 364                 .withStorageLevel(storage).withDirectory(directory).withName("data")
 365                 .withNamespace(Namespace.builder()
 366                     .register(new DataJournalEntrySerializer(context().system()),
 367                         FromPersistence.class, ToPersistence.class)
 368                     .build())
 369                 .withMaxEntrySize(maxEntrySize).withMaxSegmentSize(maxSegmentSize)
 370                 .build();
 371         final SegmentedJournalWriter<DataJournalEntry> writer = dataJournal.writer();
 372         writer.commit(lastDelete);
 373         LOG.debug("{}: journal open with last index {}, deleted to {}", persistenceId, writer.getLastIndex(),
 374             lastDelete);
 375     }
 376 }